Overheating

Hi! Mine is an XE, 5 speed, 4WD, 3.3L V6 with 120,000 miles.

I am chasing an overheating problem that will not go away. In addition to the overheat, I have noticed the odor of coolant after driving for a while but cannot find a leak.

A little over a year ago I began having problems with the engine temperature spiking whenever I had to sit in traffic after being at normal operating temperature. However, I could get the temperature back to normal once I started moving again. I took it to the dealer who replaced the water pump, and the problem went away. (Feburary 2006)

In July I was sitting in traffic and suddenly had the exact same problem again. Again, I could get it back down once I started moving. Had the cooling system flushed, and the problem went away (July 2006).

In November, in traffic again, the problem returned. Again, it went away at speed. Finally decided to start looking into it more on my own, and found the coolant was low. Added coolant, and the problem immediately stopped. (Nov 2006).

I should mention that the faint coolant odor was present even during the times it wasn't overheating.

Last week it started again. Adding more coolant did not immediately fix the problem. Also, I could not get the temperature back down by driving. Another difference is that this time the temperature gauge did not spike to the top. Instead it rose to about 3/4 and held there, slowly increasing at higher RPMs. I was able to get it to a local shop, and here is where we are:
a.) The coolant level was low, so that was remedied. They then diagnosed the problem as a worn out upper hose after finding seepage near the connection. On the way home, the engine again started to run hot after about 15 minutes of normal driving, but did not spike.
B.) They tested it again, and found it was running steadily at about 217 instead of 185. Replaced the thermostat. Again, 15 minutes into driving, it ran hot.
At this point we weren't sure what to do. They administered a block test (I believe checking pH of the coolant), but it had been changed/added enough that there may not have been enough evidence for a conclusive test.
C.) Today, replaced the lower hoses as we'd read that sometimes the collapse at higher speeds if they're weak. Mechanic tested, and she still gets hot.
D.) Replaced the fan clutch. Again, no effect.
They also visually watched the radiator flow, and do now *think* there is a blockage.
E.) The radiator cap was also replaced today.

Additional information:
- In the morning I can drive it most of the way to work (or the shop) without any overheating at all, as long as I stay under 55, which correlates to about 200 RPM in fifth. I do this with the heat on high for the most part. On the way home from the shop, I cannot control the heat as well, but the gauge does not spike as long as I am under 2500.
- The coolant odor was still present as of this morning, before the lower hoses and cap were replaced. I am assuming this is still present with the overheating issue.

Any help you can provide is greatly appreciated. We are already down to one car, and this is the good one! (Ugh)

Thanks!

Took the radiator out and had it "officially" checked. That was it!

Can you tell me, was your heater blowing cool air when you were idling at a stop light?

My 2001 Xterra is doing the same things you were describing.

Mine just started to doing the same thing. Any ideas?

Six cylinder two wheel drive automatic 75,000 miles.

Overheating after twenty minutes of driving. I added water and 50/50 coolant both to radiator. Still same thing happens. I not sure if I need to flush all and replace with real anti freeze or the water pump. There is no check engine light that comes on.

I did read some other article on your site about hoses. I have the bad smell as well coming from the motor area also. So, I guess that means a leak some where.

I just do not want to replace water pump if that is not the problem.

The top radiator hose did have small leak last year. I trimmed off an inch or so and put it back on.

Thanks,

Scott

Yes, mine started blowing cold air at traffic lights. I found a leak on some line near where the hood hinges on the drivers side. The leak was right on the hose fitting. Rather than spend the money to replace it. I just wrapped it with thread tape. Then a layer of "Mighty Putty" then wrapped tight with electrical tape. That held for a year or so. I just sold the Xterra in November 2009 and it was still working fine. If you need some more detail take a picture of your engine compartment and upload it. I will circle where I made the patch.

I do not see any visible leaks anywhere. The A/C line along the fire wall drips from condensation pretty heavy.

Not sure how to check the clutch fan. Unless it is by turning on A/C button on and off to see if it comes on.

I guess the thermostate might be an option as well. How do I know if it is stuck?

Thanks,

Scott

I will be darned. I will look closer at that connection. Thanks a million!

Rob O

Last night I replaced thermostate and upper hose. I drove to work today and it over heated again. I did check the fan. It will not spin freely, maybe a half turn.

The radiator shroud is factory and sealed good. I do have a very small leak in a short (L shaped) bypass hose that is very difficult to get to on top, middle of the motor. There is some corrosion and damp. No heavy leak or drip where I see it. I sprayed brake cleaner on all hose connection areas to see if I can see any leaks. No drips anywhere.

I guess I will take to do a pressure test. I am not losing any water day by day. I pulled the pressure cap of a little bit ago. It made a gurgle sound. I added very little water and filled overflow tank to limit also.

When I drive home tonight from work, I will see if any of that helps.

What do you think I should do next?

Thanks again,
Scott

My car keeps overheating. I took it to the mechanic and they checked for leaks and they checked the thermostat. They even did a complete flush to check of all the possible problems. The leaks were fixed the thermostat was fixed but the car continues to overheat. It overheats when it is not moving but when it is moving it is fine. Could it need a tune up or is it another problem? And can you recommend a mechanic in the Miami, Florida area? Thanks

Hi. I also have an Xterra but I had this a couple years ago on my father's Camry. At that time the mechanic checked the fuse box (which seemed fine from above). Turned out it was all corroded on the underside. He cleaned it up and changed a few fuses, worked like a charm (not the most permanent solution but has not happened since). I hope your problem is that simple.

Otherwise, I have had some issues with coolant leaks, ask your mechanic to check to see what temperature the coolant is measuring up at? They have little gauges that test for quality.

The Xterra on earlier models has always had plenty reported issues for heating. May be look into installing a mini-radiator/cooler?

Cheers!

My vehicle runs great otherwise, but it overheats when running but not driving. When driving and forcing air it will return to normal quickly, and noticed today that when parked even idling at about 2,500 RPM's it will cool, but not in traffic, or at lights, etc, it heats up quick and returns just as quickly. To check fan clutch (which is my first instinct) can I simply watch/listen for it to come on to know if it is working properly? Thermostat problems would just stay hot correct?And radiator problems would just stay hot correct? Just had major maintenance done. So would like to troubleshoot here as much as possible before spending on parts. Thank you in advance for your input!

David

My vehicle overheats or gets close to overheating by normal driving. I turn on the A/C it will get hot within minutes. Had the thermostat replaced and still nothing.