2000 Isuzu Amigo coolant leak

Tiny
JAC26
  • 2000 ISUZU AMIGO

Engine Cooling problem
2000 Isuzu Amigo 6 cyl Two Wheel Drive Automatic 90,000 miles

my car was leaking coolant in October last year so I took it to pep boys, they did a cooling system evaluation, and told me it was a cracked radiator, which cost $400. After a few days, the leak started up again and hasn't stopped since. I took it back in January this year, but they couldn't find the source of the leak. Now it's March and I took it back again, and they still couldn't find the source of the leak. So they pressure tested it, found nothing. Then they put dye in it, and told me to bring it back next week.

If the same leak is still happening today, doesn't that mean the radiator was not the source of the leak? Did they lie about the cracked radiator?

Could it be the intake gasket or head gasket?

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Friday, March 19th, 2010 AT 4:19 PM

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Tiny
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Doesn't automatically mean they lied. If they did intentionally, what did they expect to happen when it didn't solve the leak?

A crack / leak in the radiator is pretty easy to see. The fact that it doesn't appear to be leaking again suggests there COULD have been a second leak. How did you know you had the original leak? Was it leaving a puddle, or was the coolant level going down? If it left a puddle, is it doing that again now?

Caradiodoc

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Friday, March 19th, 2010 AT 6:42 PM
Tiny
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Yes it has been leaving puddles since before I got the new radiator in October. In the beginning they were inconsistent, maybe every couple days, but in the past month they've been very consistent, one every day. I had put a piece of cardboard under the car and saw that the fluid was green. I took it in this week because I checked the coolant level and it was almost empty, plus there were still leak spots on the ground every day. When I was there yesterday he showed me some green spots in a place that was hard to see. He was saying that they couldn't find the source of the leak and if it's the hose or gasket, they'd have to do a $300 service which includes lifting the top part of the engine up as well as many little pieces, to get to those parts. But they're not even sure that's where the leak is. So they decided to try the pressure test and the dye test first. I'm supposed to drive it around for a few days before I take it back. If they can't find the leak, it's not overheating, I don't smell anything different, and I don't notice anything out of the ordinary, what could it possibly be?

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Friday, March 19th, 2010 AT 7:14 PM
Tiny
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I would suggest going back tomorrow if possible. By waiting a few days, coolant will have a chance to leak out and spread all over, so the dye will be spread around too. That will make it nearly impossible to tell where it is coming from.

Some of these leaks can be really hard to find. It is possible for a leak to be forced into sealing up by doing a pressure test. That would correspond to your system not leaking while driving, but it would leak when the engine cools down. Those types of leaks can be especially hard to find. This might be a good time to consider visiting the dealer because they will be familiar with common problems.

A $300.00 estimate suggests they want to remove the cylinder head to check the head gasket for signs of leakage. Leaking head gaskets are fairly common, but I would like to be sure before going through that much work. One more clue to look for is a white, crusty-looking residue. That is sure sign of leaking coolant and usually only develops at the source of the leak and where the coolant runs down. The residue will not appear higher than the leaking spot.

Caradiodoc

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Friday, March 19th, 2010 AT 10:15 PM
Tiny
JAC26
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The guy specifically told me on Thursday to "drive it around for a few days" and "bring it back one day next week." Am I getting bad service from these guys?

I called the dealer and he said the same thing about the dye. He told me that they'd do a $45 pressure test and that will absolutely lead to the source of the leak. If pep boys didn't find anything from their pressure test, and you're saying that it's possible for the leak to seal up when pressure tested, then how does the dealer know that their pressure test will definitely lead to the leak? I must be missing something cause things aren't adding up.

I know that the leak could be one of many things so I'm taking your advice and going to the dealer. Seems they'd be my best bet. Thanks for the advice and info.

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Saturday, March 20th, 2010 AT 5:14 PM
Tiny
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Sorry for the confusion. Sometimes too much information is not a good thing.

The first guys probably determined the leak is very small / slow and it will take a few days for enough dye to show up so they can find it. My comment about not waiting too long is more appropriate for a larger leak. Given too much time, the leaked-out dye will spread all over making it impossible to trace it back to the source.

Imagine if you had water in your basement. If it was a real tiny leak that only happened after a heavy rain, you might not see the leaking water unless it rained for a few days. That would be the same as driving your car for a few days. My recommendation referred more to a larger leak. If you found a foot of water in your basement after every rainstorm, you wouldn't wait until the next day to look for the leak; you would head down there as soon as the rain started.

I hope that part makes sense. I would go with the mechanic's recommendation because they can actually see how big the leak is. They probably know it will take a while for the dye to show up.

As for the dealer, things always get lost in translation between the mechanics, service advisors, and you. Mechanics talk in technical terms the service advisors often don't understand. Service advisors try to interpret that into something both of you understand. They are good at translating your complaint or request to the mechanic, but they are terrible at diagnostics. That's why they sometimes will say they never heard of your problem before when really, it's one the mechanics see over and over. No deliberate disception was intended, but that's the impression customers are often left with. Just remember that mechanics have good car skills and poor people skills. Service advisors have good people skills and very little car skills.

As for the pressure test, the service advisor you spoke with has confidence in his mechanics that they can find the leak. In some cases there are places where they repeatedly find leaks on almost every car so they know right where to look. That's one of the advantages of going to the dealer. Because they are so familiar with your model, they often find the problem faster than the independent mechanics who have to be experts on many more brands and models. Had you spoken directly with the mechanic, he would likely have expressed a little less confidence in his ability to find the leak quickly. There's always the chance it will allude him.

99 percent of the time pressurized coolant will push out through the leak and should be fairly easy to see. It doesn't matter if the system is pressurized with a hand pump / tester or if it's due to the coolant expanding as the engine warms up. There's always that one percent of the time where pressure on a rubber seal could cause it to be forced to expand and seal better, or warmed up engine parts could expand and temporarily block a leak. That's what I was referring to about pressure causing a leak to seal. It doesn't happen often, but often enough that most mechanics will test for a leak a second time when the engine cools down if they don't find it when the engine is hot.

Another example is in order. I have a tire on my sad van that will go flat if it is only pumped up half way. It leaks when it has low pressure. If it is pumped up all the way, it doesn't leak. The higher pressure makes the tire seal to the wheel better and there is no leak.

As far as "things not adding up", you're actually getting the same service, just approached in different ways by different mechanics, and explained in different ways by different people. From what you've shared so far, I don't think anyone is trying to mislead you. Too much information from too many sources is similar to getting different advice from different doctors for the same ailment. Both treatment plans might work but could involve different tests.

Caradiodoc

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Saturday, March 20th, 2010 AT 10:48 PM
Tiny
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Ah, yes, it all makes sense. Thanks for the clarification. I guess the only thing that concerns me that I can't do anything about anymore is the replacement radiator I bought. That should have fixed the leak so it is possible that that wasn't the problem and the only way I could have been sure is if I had asked for the old radiator so I could see the crack they were talking about. That's what the dealer told me I should do. Always ask for the old parts. Oh well, lesson learned.

So, having to assume that the radiator was actually cracked and that this is a second leak, the dealer is probably the best way to go right now, considering these leaks can be hard to find. I'm still going to go back to Pepboys tomorrow to see what they tell me after they check the dye. Then I'm going to the dealer on Tuesday to get the pressure test (do pressure tests normally cost $45 by the way? Pepboys didn't charge me I think because of the radiator warranty). So this way I have 2 opinions. Just hope it's not the water pump or head gasket, the most expensive to fix, right. Thanks so much for the info and advice!

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Sunday, March 21st, 2010 AT 4:36 PM
Tiny
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The test itself simply involves attaching a hand pump to the radiator neck and pumping the system up to around 15 psi, then watching the pressure gauge and watching for leaks. The 45 bucks is for their time to search for the leak and for the mechanic to work up an estimate for repairs. He will do that with the help of the guys in the parts department.

It sounds like they expect to spend around a half hour. 90 bucks per hour is on the lower end of what most dealerships have to charge to cover all their expenses.

Caradiodoc

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Sunday, March 21st, 2010 AT 8:02 PM
Tiny
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I decided not to go to the dealer for the pressure test because pep boys told me today that the leak is coming from the timing cover and that it is most likely because I need to replace my water pump and timing belt. They actually suggested a water pump package in October because of mileage, so I guess that makes sense. Even though there's a plastic cover blocking access to the pump, he made is sound like the it couldn't be anything else. I stopped by the dealer to get an estimate (which would be the same price pepboys would charge) except the dealer mentioned a tensioner that would be included in the price. Pepboys didn't mention the tensioner and they didn't put it on the rundown they gave me. Is the tensioner something that should normally be replaced if the water pump and timing belt are being replaced?

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Monday, March 22nd, 2010 AT 5:56 PM
Tiny
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Both of them are probably basing their recommendations on past experience. It sounds like they suspect the water pump of leaking and its pulley is one of them that the timing belt goes around. That's the way my Caravans are designed.

The timing belt cover is just a plastic shield that keeps fingers and dirt away from the belt. The water pump is a real common source of a leak. When the timing belt goes around it, it's real cheap insurance to replace the belt right away. The work of removing it and replacing it is already being done. To install the new one only involves perhaps an extra half hour labor and the cost of the belt. If it has to be replaced later, it can be a three to four hour job.

They're right about there not being much else in there that can cause a leak. I can think of some things, but 99 percent chance it's the water pump. As for the tensioner, there are a few different styles and they have to be inspected. Some have a real strong spring in a cylinder. The spring can break or get weak. They have to be removed and squeezed in a vise to retract them to install the belt. They will be able to tell if it's weak when they do that. If the problem was the timing belt, they would look for signs the tensioner wasn't holding enough tension on the belt. The dealer most likely wanted to replace it for insurance. It's less expensive in the long run to do a little extra than to go back and make remedial repairs later.

Some tensioners are just a pulley on a spring-loaded lever. The bearings in the pulley will have to be inspected, but if that style needs to be replaced, they are relatively inexpensive.

Caradiodoc

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Monday, March 22nd, 2010 AT 8:32 PM
Tiny
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I found out that the tensioner was included in the estimate pepboys gave me (it was under "timing belt component kit"), and they also have a "Thermostat, " "Coolant Exchange, " "Rad Flush, " in the $1080 itemized estimate. The dealer only included the water pump, timing belt, tensioner and fluid drain and fill in their $950 estimate. Are all those extra things pepboys includes part of the "insurance" or "remedial repairs" you were talking about? Should I have all that done to prevent any more problems in the future?

By the way, "Rad flush" means radiator flush, right?

Is a coolant exchange and a chemical flush the same thing? A drain and fill is a different service than a flush, right?

Pepboys also recommended a serpentine belt but I had that replaced at 52,000 miles and I've been told that a serpentine belt pretty much lasts forever. So I wouldn't need one right?

Sorry for all the questions but I want to make sure I'm not spending all this extra money for nothing. I'm on a very tight budget right now so this is a big deal for me and I want to make sure I know exactly what I'm getting. You've helped me out soo much so far. Thanks so much.

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Tuesday, March 23rd, 2010 AT 6:14 PM
Tiny
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OH, one more thing. Pepboys included an $80 1 year extended warranty on top of the 90 warranty. Is this really necessary? Would I really have any problems with the whole new water pump system?

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Tuesday, March 23rd, 2010 AT 6:17 PM
Tiny
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Sometimes too much information just adds to the confusion. Let me clarify what I mean by "remedial repairs". Suppose the main problem was the timing belt. On some engines this is a very common failure item due to nothing more than regular wear. Typically no other parts are required to complete the repair besides the new belt. On other engines it is very rare to have a timing belt failure so when one does fail, the mechanic is going to look extra close for the cause. A weak tensioner or a pulley with worn bearings could cause the belt to track off-center and get chewed up. If the cause of the failure can be found, those are the parts that will be replaced. If no definite cause can be found, logic would dictate the belt just wore out, but the smart mechanic who knows this isn't common will be skeptical. He will likely want to replace additional parts that appear to be ok as "insurance" against the same thing happening to the new belt. He has to weigh the risk of a repeat failure, in which case he has to do the job over for free, and his reputation, against his desire to save you some money which will make him look better. In many cases it's a judgement call as to how much risk he is willing to take.

The same is true for you. You want to spend as little as possible, but not at the risk of the new parts failing again. In most cases, the mechanic is in the best position to decide what is in the best interest of each person because they understand how all the parts in an engine are related and affect each other, and he knows the common problems with various models and how to avoid them. This is one place where many do-it-yourselfers get into trouble. They can replace parts, but they don't understand how other things in the car affect their repairs.

The mechanic could do the most perfect job of replacing the belt, but if the new one has a problem, he will have to start over and perform some "remedial" repairs. This could be replacing a tensioner he didn't replace the first time, or a worn pulley, or some other cause he didn't see. Any attempt to save you some money just bit him and is costing him time and money in not being able to move on to the next job. Less experienced mechanics such as those who are fresh out of school, tend to go overboard and err on the side of caution and replace too much. As a former instructor, I was constantly sharing information on common problems when I saw those cars in the shop, but it is unrealistic for the kids to remember all that stuff. Unfortunately, the way most of us remember the mistakes is to make them. That doesn't mean they're bad mechanics; they just haven't developed the sense of what's good enough and what isn't good enough. That's where experience comes in. Anyone can be trained to be a parts replacer. A good mechanic has learned WHICH parts to replace and why.

To change gears now, your car needs the water pump. The timing belt is just a maintenance item that makes good sense because the job of replacing it is done already. To go back and replace it in a year or two will cost just as much money and time as replacing the water pump, so in effect, you're getting two expensive repairs done at once. The tensioner, in this case, is the "insurance" that the new belt will last a long time. Some customers would argue the belt and tensioner are not needed and they are being ripped off. It is true they aren't NEEDED, but there is hardly an attempt to rip them off. This is one of the misconceptions that give this, or my other specialty, tv repair, a bad name. These are also usually the people who would complain the loudest if the timing belt failed in a few months. This is what I mean about the mechanic being in the best position to recommend which parts should be replaced.

To prevent replacing unnecessary parts, it is YOUR job to inform them of parts and services that were done recently. If the belt, for example, was replaced a few months ago, there would be no need to replace it now, but your mechanic wouldn't know that unless you told him. That's one benefit of going to a dealer. They keep records of previous service work done to your car. Many independent shops do too for their regular customers, but at the dealer, it pops up on their computers automatically. At least that's how it worked at the Chrysler dealership I worked at and at the Pontiac dealer down the road.

You're right about "rad flush". That is radiator flush. When the water pump is removed, the coolant is going to "fall out", hopefully into a drain pan. At the very least, they will just pour it back into the radiator when the new pump is installed. Antifreeze is mostly alcohol, and it will always be antifreeze, but it is usually recommended it be replaced every two years for two reasons. First of all, combustion gases, (a fancy term for exhaust gas), has a tendency to sneak into the cooling system. This is normal, but it causes acids to form in the coolant. The cooling system includes parts made from cast iron, aluminum, copper, brass, tin, and lead. Any two different metals and an acid form a battery, but instead of producing usable electricity, it causes "galvanic action", more commonly known as corrosion. Antifreeze includes additives for water pump lubricant and acid neutralizers. These additives wear out in about two years. The coolant is replaced to get the acids out and the additives in. Some shops off a service now to recycle and reuse your old antifreeze. The system neutralizes the acid and the mechanic adds a can of additives. I never got involved with that so I don't know what the advantages are.

Reusing your old antifreeze is ok if it was replaced recently. The next step up is to use new antifreeze. At least there will be mostly new additives in it and most of the acid will be gone. The better alternative, as long as they're going to go through the trouble, is to flush the cooling system. That involves forcing water through all the passages in both directions to dislodge rust, scale, and sand. When the system is just drained and refilled, there are many places for coolant to hide and not drain out. That includes the bottom of the radiator, passages in the engine, and the heater core inside the car. Flushing the system can be done anytime. It does not have to be done as part of the water pump replacement, but if you plan on having it done soon, it would be silly to have them use new antifreeze now. They don't like to see people be penny wise and dollar foolish, so consider making an appointment with them to have the flush done at a later time.

I think I would draw the line at replacing the thermostat. They have such a low failure rate, and a new one is just as likely to cause problems as an old one. They are also easy to replace later if needed. There is a risk the new gasket could leak or the housing could crack. This won't save a lot of bucks, but unless they know the thermostat is a common problem on this engine, it's best to just leave it alone.

"Coolant exchange" could be the same as a "drain and refill", but is more likely to involve refilling with new antifreeze. You can ask ahead of time or wait to see if about two gallons of antifreeze are listed on the itemized bill. A chemical flush involves adding a strong cleaner to dislodge material that could plug tubes on the radiator or heater core, then it is washed out later. This too might be overkill along with the serpentine belt. You're right about them not breaking very often. The nice thing is if the belt were to break, you can still drive the vehicle for quite a while. The battery will run down in about an hour, and you won't have power steering, but since the water pump is driven by the timing belt, the engine won't overheat.

As for the extended warranty, it's really an insurance policy. If a problem occurs related to their work or the new parts, it will likely show up in the first 90 days. What I would rather know is if they will cover additional problems caused by a failure of the new parts. A lot of smaller engines are of the "interference" design. That means the moving pistons and the moving valves occupy the same space, just not at the same time. The job of the timing belt is to keep those moving parts in the right relationship. When the belt breaks, or even jumps a few teeth, the pistons will hit the valves and bend them. Replacing bent valves involves major engine disassembly. It would be nice to know if they will take care of those repairs if the damage was caused by the work they did with the water pump / timing belt. If the additional repairs would not be covered under either warranty, I think I would skip the extra expense. If the additional repairs would only be covered with the extended warranty, it might be worth it. Be aware though that some shops make it very hard to prove damage was caused by their work and not other causes. Sometimes they're right too. It's not always easy to tell.

Caradiodoc

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Wednesday, March 24th, 2010 AT 6:31 AM
Tiny
JAC26
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Wow, thanks so much for all that.

You should first know that the last time I had service done at the Isuzu dealer was in April 2008 in California (they replaced my transmission under warranty then) and I just realized on that invoice that they also recommended the following:

"Timing belt, Tensioner, & Waterpump Assy $860"
"& Fuel Filter $76"
"& Fuel Induction services $199.95"
"TX & Carbon Flush &145.95"

I vaguely remember him telling me that these were not immediately needed but would eventually need to get done. I guess I should have done all the research I'm doing now about these things, back then. Guess I'm paying the price now. Could you tell me anything about the fuel filter, fuel induction services, and tx & carbon flush? Not sure what all those are but I keep track of everything that's been done to my car since I got it in 2001 and I'm pretty sure I haven't had any of these services (I have had "fuel system cleaner" and "15,000 mile engine treatment" in the past 2 years though).

So the remedial repairs make sense. One thing could eventually lead to another so better to be safe than sorry in the future. What I'm thinking now though is that Pepboys is recommending all these extra things because they can't actually see if I need them yet. He can only see the leak coming from the timing cover because he can't actually get to the water pump, timing belt, tensioner, thermostat, gasket, etc. Until he starts the actual waterpump work, right? So besides the obvious components. The waterpump, timing belt, & tensioner. Pepboys and the Isuzu dealer can't really tell me what should be replaced/repaired until they actually get in there, right? The dealer's $45 pressure test wouldn't tell them exactly what I needed. Only that the water pump needs replacing.

So lets say I go with the dealer instead (since they only recommended what you seem to be recommending. Only the waterpump, belt, & tensioner).I'm actually in Colorado for the time being, so this dealer hasn't actually looked at my car at all yet. They are just going off of what Pepboys told me. That the leak is coming from the timing cover and that obviously means I need a new waterpump. As they are replacing the waterpump, would they inspect all the other parts and let me know, while they're in there, if something else should be replaced or repaired for insurance? Or are you pretty sure that all I'm going to need done is the waterpump, timing belt and tensioner?

The itemized estimate from pepboys does include 2 of "Prestone All Makes & Models" for $25.98, so I'm assuming that's 2 gallons of antifreeze.

I've had a.

"Radiator drain and fill" in 2007
"Coolant drain and fill" in 2008
"Remove and replace Radiator" in October 2009, which included 2 gallons of Proline Antifreeze.

The last "super cooling system service, flush cooling sytem, refill with anti-freeze" that I have recorded was 6 years ago. There is the possibility that I did not record an invoice from another flush, but assuming it's been 6 years since my last flush, I should have them do the flush now, right (it should be every 40,000 miles)? And you're saying that if I don't do the flush now, they should NOT add new antifreeze, right? Just to reuse what's in there now and add what I've lost from the daily leaks?

From everything you've told me so far though, and based on what services I've had done in the past, it seems that I should only need the waterpump, timing belt, tensioner, and coolant flush. And I'd need to find out from pepboys and the dealer about what the warranty includes. I can tell pepboys that I don't want the extras they recommended. Thermostat, serpentine belt, etc, but I still haven't decided whether it would make a difference having the work done there or at the Isuzu dealer. Would you go to one place over the other for whatever reason?

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Wednesday, March 24th, 2010 AT 3:46 PM
Tiny
JAC26
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Oh, and while they're in there, are they able to check the head gasket? That's a really expensive repair right? How long do head gaskets normally last?

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Wednesday, March 24th, 2010 AT 7:47 PM
Tiny
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Head gaskets are rather expensive. On a V-6 engine, there are two of them. My '88 Grand Caravan has 378,000 miles on the original head gaskets. That's not normal. Some engines commonly develop corroded head gaskets at 15 - 20,000 miles. That isn't common either. The best thing you can do to prevent corroded head gaskets is to change the antifreeze every two years to get the acids out. By the way, I haven't changed my antifreeze in the last, .... Uhm, ... Opps, at least eight years ago.

Do as I say, not as I do.

IF you have trouble with the new timing belt, and IF it jumps enough teeth or breaks, and IF your engine is the interference design, it will bend the valves as I mentioned earlier. To replace the bent valves requires removal of the cylinder heads. You would automatically get new head gaskets when the engine is reassembled.

The edge of each head gasket can be seen on all four sides of each head, but the timing belt cover might hide them on that one side. It is possible you have a leaking head gasket instead of the water pump, but there's no way to tell until the covers are removed. Those covers have to come of anyhow to replace the head gaskets. The good news is corroded / leaking head gaskets USUALLY leak coolant into the engine where it is burned and exits the tail pipe as white smoke. It was fairly common on older Ford Escort engines to leak coolant out the front, but most engines leak internally.

Caradiodoc

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Wednesday, March 24th, 2010 AT 10:33 PM

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