Overheating

You should have the thermostat replaced. If the coolant is not restricted, it may be processing too fast and not cooling down. Have you checked for a bad head gasket? This truck has all the signs and they had problems with them. Here is a guide to help you confirm the issue:

https://www.2carpros.com/articles/head-gasket-blown-test

and

https://www.2carpros.com/articles/replace-thermostat

Please run down these guides and report back.

Cheers

Note: the car would still overheat with the thermostat so I thought by removing it, it would cool better. That was before I had the fan clutch replaced. I will try again with the thermostat.

How do I know if the head gasket is blown? The car runs fine. No white stuff on the oil cap, no white smoke, clean coolant and the system held its pressure when tested.

It only overheats when still. Note: the temperature goes down when the heater is turned on.

Thanks,

JC

Yes, you can still have a blown head gasket even with no signs but overheating.

Yes, you were right. I did the chemical test and has blown head gaskets.
I am going nuts! Going to cost me $1,500.00

JC

This car overheats while climbing a hill, on freeway, while driving around town no problem. I did the head gaskets last November while this problem just started. It is a v6 with AC,automatic transmission, the radiator is approximately two years old. Since the heating problem I have put a new thermostat, a new fan clutch, new rad cap. I did a block check plus took it to a radiator shop and they did a block check and found nothing, in fact they are scratching there heads? I have worked in the auto industry (for Chevrolet) and have asked everyone. I hope you can give me some ideas as this is my daughters vehicle and a want my wheels back. This seems to have me stumped! Thanks for your time.

I have come across these cars with radiator problems, being residue casting sand blocking the cores, you still appear to have reasonable flow, but the blockage is enough to cause problems. I would still get the radiator removed and flow tested, start here.

This is a problem with inefficient cooling and the most likely cause is a partially clogged radiator. 2 years is a long time for sludged build-up, especially if no coolant had been used or they had been mixed with different brands.

Thanks for your information. I installed a new radiator as you suggested went on a road trip same hill same heating problem, boil all the water out. No problem around town as I stated. Any other ideas? Thanks for you time.

You have done almost everything except the water pump. Have it checked to see if the impellers are worn.

i replaced the water pump along with the head gaskets in November.

My vehicle overheats at slower speeds, especially when the A/C is on. I can get the temperature gauge to go back to normal at higher speeds or by, when at a stop light, putting it in neutral and revving the engine. Also, A/C not as cool as it should be, may be unrelated. I live in the DFW area and the ambient temperature here outside is in the high nineties.

When did this overheating started? Was any repairs done prior to this ocurring?

Have you checked the radiator cooling fins for external clogging ?

Have you rechecked for an ongoing head problem? do not discount this just because the heads have been done earlier.

As I stated I did the head gaskets in November 2011 had no problem until jun 2012 when car overheated on a grade. Since then I have done a thermostat,fan clutch, and radiator. The water pump was replaced with the head gaskets in November. I drove this same grade a few days ago and this vehicle overheated again, at that time I stopped and did a block check with the correct equipment and it did not show a head gasket problem. As I said no problem around town town with only on grade.

What was the average engine rpm when climbing the grade and what was the driving time?

Not sure about the grade, but it last for about a mile. Someone suggested the transmission converter was heating the fluid while on a grade. Since the fluid runs through radiator I added a ext cooler an deleted the one in the radiator. Well the vehicle still overheated on the hill. The rpm was probably in the 4,000 rpm range.

I have had to put Freon in my car a couple of times now for the air to work and the last time I did this it worked great for one day and the next day it was hot again. My brother is a mechanic and told me that I had a big leak in one of my hoses and that it needed to be checked to see which one it might be. I took it to get checked and they put more Freon in it about two weeks ago and it is still working. But now when I go up any hills while driving down the road my temperature hands goes up and it starts running hot. Please let me know what could be causing this?

Check the coolant temperature sensor. Also, if the AC condenser fan is coming on to include the coolant level.

Transmission fluid would not be sufficient to heat the coolant until it overheats as the cooling system should be able to take care of that.

What you have is inefficient cooling due to excessive strain on the engine and the only way you are going to resolve this is to get a bigger capacity radiator.

Overheats after about an hour on the road. We have replaced radiator, fan clutch, thermostat, water pump and had it pressure checked. Pressure check did not indicate a problem. What is it?

Heater core may be clogged, flush cooling system. Also, ensure temperature gauge is accurate and not sending false overheating signal.

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!

The block check is to check for hydrocarbons, meaning if it is present you have a combustion leakage coming from the head/gasket and block.

Do a pressure test on the cooling system.

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.

Hi Scott,

If coolant is depleting, then you need to check for leakages. A pressure test would verify where the leaking is coming from.

When coolant level is low, overheating would occur.
A stuck thermostat would also cause overheating.
Did you check the clutch fan?

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

To test the thermostat, it has to be removed. Hang it with a piece of thread in a beaker of water and put the water to boil. If it opens fully, then it is good.

When leaks are not visible, a pressure test would have to be performed to locate the source.

To test the clutch fan, it is mechanical and not controlled by the A/C on or off. Only the condenser fan (if equipped) is affected.

When engine is stopped, turn the fan blades with your hand. There should be some resistance whne the fan is being turned. If it freewheels too easily, the clutch fan siscus fluids have leaked out and dried up. Replenishment is required.

Check if the fan is pulling in air strongly and ensure the radiator shroud is not damaged.

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

If everything is working correctly with no coolant losses, then the radiator would have to be checked for clogging.

If there are any leakages, the recovery tank should be depleting.

The gurgling noise indicates the radiator cap might be bad.

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

Check to see if cooling fans are operating.

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

You are correct in everything you are saying. You can also hard wire the fans to the battery to confirm that the fans work, another possibility I am sure you know is, the thermostat, and the engine coolant temperature sensor.

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.