2000 Jeep Wrangler Cooling System

Tiny
MCOH1030
  • MEMBER
  • 2000 JEEP WRANGLER
  • 6 CYL
  • 4WD
  • MANUAL
  • 10,000 MILES
Don't faint!

I LOVE MY JEEP!

That said, it's killing me.

It's been running hot. So I changed out the radiator, water pump, thermostat and radiator cap. I flushed the heater core and there aren't any leaks.

I can smell antifreeze and I'm unable to get hot air out of the vents when the heater is turned on. I'm not loosing coolant, I've pressure tested the cooling system, I've "burped" or "bleed" the air out of the system as well. I've also back filled the radiator core. And it's still running hot. Temps are 220 to 265.

I brought it to a shop and they did a block test with the blue liquid. They said that when they did the test the liquid turned green which means I've got a broken head gasket or cyclinder head.

Could I be missing something? Could the build up of exhaust gas cause there to be a vapor lock prevent the coolant from flowing into the ehater core?

Repair estimate to replace head gasket $ 1,250.00. Is that reasonable. Can a novice tackel this job on his own?
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Wednesday, July 21st, 2010 AT 6:31 PM

5 Replies

Tiny
CJ MEDEVAC
  • EXPERT
See my profile....I do not know your rig well (much at all) I do share your LOVE AFFAIR, I have owned 7 Jeeps....6 CJ 5s and a '46 Willys (My Avatar)....all except "WILLY" have been my primary drivers since 1981..... I now have a '77 CJ 5 and the '46 Willys. I have done and may can share some of my Mechanical/ Etc. Modifications with you...ask me later.

On to your problem...I am guessing you have a conventional belt driven fan.

I want you to return here and tell me your results...regardless if they are embarrassing!

I want you to tell me if your radiator is getting hot? (stupid question huh?)

How quick is it getting hot?

The hoses to your heater core are they hot?

At this end...at that end...hot, how far up the hose(s)???

I know this probably won't affect the heater core (?) But you did not mention your FAN CLUTCH...is it freewheeling too much and needs replacement?

How about a freewheeling Water Pump IMPELLER? This can be tested by removing a BIG HOSE on the pump and sticking a "hooked" clothes-hanger wire in the casting and seeing if it loose or moves with pulley movement.

Last but not least.....I saw this ONE TIME (ONLY) It is EZily OVERLOOKED by many (EVEN SEVERAL "EXPERTS")...it would definitly make the heater core inoperable and cause you to OVERHEAT...it would do this within the 1st 5-10 minutes of driving.........I did not catch it either....the engine machinist did, by accident....It was not my vehicle...but I look for this "WILD" problem, everytime now!

IS YOUR SERPENTINE BELT (SOMEHOW) MIS--ROUTED AND TURNING YOUR WATER-PUMP BACKWARDS?

IF IT IS...THROW THE BLAME ON YOUR BUDDY WHEN YOU ANSWER BACK.

RESPOND

The Medic


http://www.2carpros.com/forum/automotive_pictures/411289_100_0327_1.jpg

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Friday, July 23rd, 2010 AT 10:00 PM
Tiny
MCOH1030
  • MEMBER
Your reply is dead on!

I love reading about all your Jeeps. Man, you really do love them too.

Since this problem developed, I've been tinkering with the idea of getting a "new car." Anyway, I can't! Just love the Jeep too much and don't care if it kills me. I'd rather die fighting for something I believe in, that actually means something, than live a lie.

Anyway, I would really love to see photos of all the Jeeps. Looks like Willy is a special member of the family. I'd say, he's probably the "bravest" of the bunch, no? Is he a veteran?

OK, so I'm still jerking around with my "running hot" problem and here are some of the up to date details and answers to your questions;

1) In the morning, when I start the jeep, with the heat turned on, it gets up to operating temp. 190 and stays there forever. It never goes about norm temp, at idle.

2) The heater hoses do not seem full. However, this morning, Saturday, I plan to pull off the heater hoses one by one, with the engine running to see if theres a flow coming out of each hose.

3) When I start driving the Jeep, after about 5 minutes of local driving, at speeds no greater than 45 mph, the temp gauge reads slightly over 210. Then when I push the speed up to 55 for an extended period, say 5 to 10 minutes, the temp goes up to 220 to 230 and sometimes higher.

4) I have a pressure release radiator cap, it's brand new. When I stop, I open the red latch and of course, theres pressure which can be heard releasing into the overflow tank as I slowly lift the red latch on the cap. Basically, the radiator pressure is releasing into the overflow tank in the form of bubbles.

5) I have a 180 thermostat, also brand new in the vehicle, it's the fail-safe type and I find it hard to believe (as some have suggested) that it's wasn't good right out of the box.

6) I did several test since my first post, I did a cooling system pressure test and a block test. The reason I did these test is because I brought the Jeep into a mechanic who took the Jeep into the back of his shop and tried to diagnose my problem. He came out of the shop about 15 minutes later and said "you have a blown head gasket." "Idid a block test and it showed that you have exhaust gas in your coolant."

He didn't offer to show me the test or the results. And indicated that the cost to repair would be $ 1,250.00. So, being the untrsting SOB that I am, I decided to preform the same test myself and verify the results. Well, naturally, the tests were both negative. No exhaust gas in the coolant, I ran the test 5 spearate times, and the system is holding pressure.

7) The idea that you suggested that the water pump may be broken, sounds very viable. Exactly how do I check it. Drop the lower radiator hose from the water pump opening and try and turn the pump using a coat wire? If it free spins, then it's broken, right?

8) Serpentine belt is routed correctly. I'm certain of it. Have the diagram which is pasted on the Factory original radiator which I still have. However, I'll look again and again, because maybe just maybe something wacky is going on. Let me ask you this, assuming the Serpentine belt were on backwards, what would happe? Would the pump still pump? Would the flow to the heater hoses be reversed?
What would happen to the water pump assuming it could work backwards? Would it have a much shorted life span?

9) I have a new fan clutch which I would love to install, but I can't get the Fan Clutch Nut off. It needs a set of special wrenchs which my local auto parts store doesn't carry. Do you know of any way to remove the nut without using those wrenches?
My fan clutch doesn't free wheel and seems normal. But I'd still like to replace it.

Thanks,

Will wait to hear back,

Mike
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Saturday, July 24th, 2010 AT 7:00 AM
Tiny
CJ MEDEVAC
  • EXPERT
I am going to investigate your fan clutch nuts/bolts very soon. Will get back soon.

Here's another no brainer. Didn't even think about this at the time.

1). Check your lower radiator hose, insure it is not old and SQUISHY. The water pump will suck it flat as it gets hot, thus reducing water flow from your radiator.

2). Used to, your lower radiator hose had a spring inside of it. Nowadays sometimes and sometimes not. Even a new hose can suck flat. I would check at whatever auto parts place you go to that there is a spring inside the hose.

3). In my CJ 5 the thermostat is a 56 mm, I have found that a Subura 56 mm thermostat will fit into the housing. The Subura thermostat (I believe is from the 80's, they only had 2 or 3 styles in the Subaru's and you should be able to find the right one that I am talking about EZily.) Has a much larger opening then the traditional thermostat when it is in the open position. Thus allowing more water to flow thru and this could help you! (If your thermostat is the same size and type as a CJ.)

Your impeller is somewhat like a squirrel cage fan---blows one way only. Will disturb the air in the immediate area, if turned backwards. But essentially creates no productive flow.

The test for the impeller is basically (keeps from pulling the pump--right off the bat!), Hook a blade with the wire hanger (thru the lower hose opening. Insure you caught the impeller, and with the belt off. See if the pulley shaft will do 360s while you hold the impeller still. IF IT DOES TURN and the IMPELLER DOES NOT. Something is wrong. Pull the pump off the engine and test with your hands

Just sent you a pm about my "Nelsomatic" Jeep Modification Pic--thru Walmart Photo, if you are interested.

The Medic
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Saturday, July 24th, 2010 AT 11:01 AM
Tiny
CJ MEDEVAC
  • EXPERT
SORRY! You sorta got lost, in my Hectic Life.

You get the Clutch on!

If not, describe your "BOLT" plight---What kind of fasteners did they use? Whats wrong with them? Still might be able to EXPLAIN them out!

The Medic
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Friday, September 17th, 2010 AT 11:53 PM
Tiny
CJ MEDEVAC
  • EXPERT
This is probably really too late, I believe the wrenches you need, are much like those needed on a Ford Explorer.

Can you check other stores (sure you have by now)

Sometimes you cannot rent them, and you have to bite the bullet and buy them. Surely available on line?

Sometimes you can get a small time shop, one of the fellers stop by and break it loose for you, and tighten it up when you're done.

I really hope this is repaired and it was EZ, I've been dealing with my Dad, Cancer is sorta at a standstill, but he can barely get around, weak from Chemo and other Medical crap they are doing.

The Medic
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Monday, October 25th, 2010 AT 9:43 PM

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