Engine is overheating??

[Niklaus]

over the past few days I've noticed that my engine temps have been going quite high especially when sitting in traffic. Friday it was 86 degrees out or something like so, was running my A/C and sitting in some bad traffic. I checked my temp gauge and I only saw it slowly rising. It hit 1 tick past.. then 2.. then 3.. and almost 4. I got freaked out, not sure what can be going on. When cruising down the highway at 45 minimum usually like 70 or so then the gauge reads 1 tick below 210 which I dont think is normal. As soon as I slow down again when I hit more traffic the temps slowly rise. On my longer drive back home today I had experienced the same thing as before but this time it hit 3 ticks max. It was also a lot warmer today, about 91-93 degrees on highway. Whenever I stop or get stuck in traffic and come to a stop, I dont hear the fan clutch engaging like I used to (even in colder weather). Did not hear the fan clutch engage, maybe it did once or twice but it seemed very faint and not so quick like it should be. Instinct tells me that when you hit 2-3 ticks above 210 the fan clutch should be on 100%. I hear the clutch engage on startup and it's on at idle but turns off when I drive to not be heard again..

Replaced thermostat and water pump 3 months ago. Weird. I did not replace the coolant temp sensor though which I should have. Coolant was reused from the thermostat change

No SES or service lights on

I remember seeing a post on trailvoy that the needle should be on 210 at all times unless you do heavy towing and are going uphill and its hot out.That may have been an over exaggeration though

Is it possible fan clutch is dead? or temp sensor could be causing this? I might get a coolant flush if that would even help. Wouldnt a fan clutch throw a code if it wasnt engaging??

I will further test on upcoming Friday meaning run the car idle and see what happens and turn on/off AC to see if temps drop/

Would like a second opinion on this
Thanks

 

[KNBlazer]

Turn your A/C off when hitting stop and go traffic... You're not the only one having this problem, I myself have this issue... Dealer replaced fan clutch, radiator, flashed PCM resulting in no fix when ambient temps are in the 90s and A/C is on....

2004 Ext 4.2

 

[Niklaus]

Turn your A/C off when hitting stop and go traffic... You're not the only one having this problem, I myself have this issue... Dealer replaced fan clutch, radiator, flashed PCM resulting in no fix when ambient temps are in the 90s and A/C is on....

2004 Ext 4.2

That's pretty wild. What do your temps get up to in 90s weather with the AC on then? Wondering if mine would eventually stabilize even if its a few ticks over. I don't want my engine to boil though.

I saw Roadie made a post on Trailvoy about a fuse relay #48 I believe, wondered if that could be a possibility in this case.

 

[BrownHP800]

That is not normal behavior. It was 96 here today. Had A/C on full. Temp gauge never went above 210.

Sure sounds like a bad thermostat to me. Mine did the same thing, replaced it and temp sensor and it is rock steady at 210.

 

[KNBlazer]

That's pretty wild. What do your temps get up to in 90s weather with the AC on then? Wondering if mine would eventually stabilize even if its a few ticks over. I don't want my engine to boil though.

I saw Roadie made a post on Trailvoy about a fuse relay #48 I believe, wondered if that could be a possibility in this case.

Mine normalizes within minutes of turning off A/C, mine just climbs tick after tick....Sometimes I think it might be my CAT...

 

[KNBlazer]

That is not normal behavior. It was 96 here today. Had A/C on full. Temp gauge never went above 210.

Sure sounds like a bad thermostat to me. Mine did the same thing, replaced it and temp sensor and it is rock steady at 210.

There are many others who have had this issue, the TSB fix was applied to my truck, but it didn't fix it... thermostat has been replaced a few times already...I also replaced Temp sensor, all parts have been AcDelco...The fan clutch was a GM and was replaced twice by dealer under extended warranty....

 

[The_Roadie]

Agreed. Bad replacement thermostat if it ever goes below 210 while warmed up and otherwise running well. Could also be a bad fan clutch, harness, relay, or power feed. Best way to diagnose that is with a GM Tech II that can command any fan clutch speed and see what the speed feedback sensor reads. FOr what you pay a dealer to use their Tech II, you can almost pay for a new fan clutch, though. This issue gets shotgunned a lot unless you have a sweetheart deal with a trusted, competent dealer.

Don't ever let it go that hot in traffic though. Could warp your head or boil you over. Turn off the AC and turn ON the heaters if you have to. Personal comfort goes out the window when you're trying to avoid a $2000 head job.

 

[KNBlazer]

I only let it go 2 ticks past 210 before I shut off the A/C....

 

[Matt]

Personal comfort goes out the window when you're trying to avoid a $2000 head job.

So that's how much I have to pay the wife...

 

[Mooseman]

The fact you said you don't hear the fan like you used to sure says fan clutch to me. Easy way to find out would be to start the engine, turn on the A/C, let it get warm a bit and then try to stop the fan while wearing a heavy glove and/or using a rag. If it's easy to stop it, it's dead.

Also check and clean the front of the A/C condenser with a pressure washer. One member had a similar issue where his was full of sand but he does live in the desert.

As far as the temperature being reported, the dash gauge could be off. Only way to really know is to get actual readings from a tool that can read OBD2 data. An ELM327 with an Android phone and the Torque app are cheap and effective.

 

[Sparky]

When in stopped traffic on a hot day with the AC on my temp gauge will climb a few ticks but stop climbing well before it gets near red. Usually 2-3 ticks. AC tends to go warm on me too. If I speed the engine up a couple hundred RPM that usually helps both out as now there is more RPM available to turn the fan. The fan at 600RPM engine idle speed just isn't enough sometimes.

Honestly I wouldn't worry about a couple ticks to the right of 210. That isn't near the red zone at all, and can be expected when sitting in traffic on a hot day like that. 230 is not overheating, and isn't going to risk warping anything. Why would the engine be designed to run only 20 degrees below overheat? Makes no sense.

Obviously if it was getting close to the red zone I'd be really concerned.

 

[The_Roadie]

The fan at 600RPM engine idle speed just isn't enough sometimes.

I drive at low ground speeds, and high engine RPM, in 100 degree deserts sometimes, so I changed my fan clutch table with EFILive to make it come on more aggressively. For non-tuned folks, GM did come out with an updated PCM fix around 2005 for more aggressive fan clutch operation on a cold start when the cabin temp might be very high, where the engine coolant temperature would not force the fan to come on, and AC performance was suffering.

But you're right, none of these helps when the gauge is already over 210 and the RPMs are low. (Actually, the PCM lies a bit about the ECT when the gauge is at 230-240, as well as the way it lies and averages the measurements when it displays 210)

 

[KNBlazer]

Mine keeps climbing a tick at a time ... it doesn't start falling back until either, the A/C is turned off or traffic gets going...

 

[Niklaus]

Thanks all for the input. I will try to stop the fan clutch today and see if turning the AC off lets it sit at normal temps.
Either way it seems like it won't stop climbing after 2-3 ticks which is a problem for me. Seems like I need to spend some cash and effort to get this fixed.

I have a feeling it's the thermostat considering at idle temps in cooler weather the gauge sits on 1 tick below 210 or maybe 1.5 . If the thermostat is sticky it won't be opening as much to allow cooling.
Funky thing is I replaced it not even a whole 3 months ago. Also I should still hear my fan clutch even if the thermostat's bad... right?

 

[Sparky]

What brand thermostat did you use last time?

 

[Niklaus]

What brand thermostat did you use last time?

Honestly don't remember since a local shop put it in for me at the time, I don't think it was a good quality one though which probably explains the issue. I think I will stop by to have em replace it since it's under warranty. I know you are supposed to go with ACDelco but I couldn't find one at the time or even now for that matter. Maybe Duralast from Autozone will be ok

 

[Sparky]

I've used Stant in the past on other cars without issue but they were older and I don't think were as picky.

 

[Niklaus]

Well I took it out for a drive and I'm almost certain it's the fan clutch. It engages but it does not run at full power. I felt the fan clutch and I was able to slow it down by hand. At first there wasn't really any airflow but it did engage somewhat. I didn't hear it in traffic and don't hear it when driving anywhere else anymore. I think I will go with Hayden.132.79$ on RockAuto and it seems like it's a good build quality. I would go with Dorman but I haven't heard too many good things about it.

 

[Sparky]

I read that the Hayden is a rebranded Behr, which is good.

 

[Matt]

We replaced mine at the mid west meet with the Hayden. The reason I went with that one was the lifetime warranty.

 

[Kelly@PCMofNC]

The fan clutches in those are pretty famous for going out, I think that may be your problem unfortunately! Usually with these GM also has an updated flash which brings the fan clutch on sooner. GM can do that for you, or so can we as we have all of their software.

 

[Mooseman]

Definitely get one with a lifetime warranty. You'll need it! Definitely one of the flakiest things to ever come out from GM.

 

[The_Roadie]

I have a feeling it's the thermostat considering at idle temps in cooler weather the gauge sits on 1 tick below 210 or maybe 1.5 .

No matter what's happening with the fan clutch or overheating, the observation above is enough to indict the thermostat and invite it to leave the vehicle. Running too cool wastes fuel and risks damaging the cat. $$

 

[Alexo1us]

Since I’m KISS guy I didn’t see anything done on belts.
I know this dumb ass fan can be problem.
I got a fan code and found my belt and it looked good I found compared to the new Delco, it was about half the thickness replaced it never look back almost same issues.

I have read somewhere, the fans could be wrong. They never lock if working right. so in theory u should be able to stop it.

Now mine runs at 90-92 c on torque and on the dumb meter at 100...
in traffic gone up to 98 with A/C I think i was 2 past on dash.


Ima cheap ass guy ill spend hrs. making sure before I spend a dollar

JMLO I to the real experience here...

 

[KNBlazer]

well, I'm going to clean my condenser, and see if there's any impact on cooling temps... I bought a can of A/C coil detergent, will clean and wait for the next heat wave...

 

[CarbEnvoy]

I need to replace my water pump, and I'm thinking I should replace the fan clutch at the same time as it has been making a ticking sound at idle.

Should I replace the fan clutch with a new electronic version, probably the Hayden model from RockAuto, or should I go with the 2008/09 non-electronic fan clutch? What are the pros and cons of doing that? I have a 2003 Envoy.

 

[The_Roadie]

The mechanical fan clutch should have much higher reliability, but your PCM will throw a code because it's checking for the electronic performance of the original fan clutch. A tune from PCM of NC can suppress this code if you're already thinking about a tune for better performance and less torque strangling from GM.

 

[CarbEnvoy]

I don't plan on getting a PCM tune. I just can't justify that for myself, and it would leave me without the truck for awhile, up here in Northwest BC, Canada. Maybe in the future? I'm not sure how long I will hang on to this truck either. I have about 170,000 kms now, but it seems like every month I'm replacing another $200 to $300 in parts.

Maybe I will just stick with an electronic clutch. They are about $60 more depending on the brands I think.

 

[Mooseman]

Hayden is the recommended brand. Dorman is junk for this particular part. ACDelco/GM/OEM is expensive and is apparently the same supplier to Hayden (Behr)

 

[CarbEnvoy]

Sounds good. Any recommendations for the water pump?

Gates (incl. metal gasket) is $27.70, up to ACDelco for $44.99. The ACDelco pumps say to order new mounting bolts as well.

Funny, the Hayden description says not to replace the fan clutch unless there is a code related to it found using diagnostics. I have never had a code show up for the fan clutch. It just seemed like good preventative maintenance since I need to do the water pump. I haven't had issues, and it seem to function normally. I've noticed that pulling a trailer it will engage right away at low speed.

 

[Texan]

I have not had to replace pump or fan at 134k miles, knock on wood.
The ticking sound may be the pump. The fan clutch will set a code if the
brain (ECM) thinks it is not turning at the correct RPM. If you read some
other recent threads on this subject, you find that the WP bolts can be reused.

 

[Sparky]

My clutch is (finally after 200k miles) started to not engage how it should at times. Could tell because I stopped the fan with my finger when the AC was on, and it didn't start spinning right away either after lifting my finger off it. Still no codes though. I think the tolerance for the code to be thrown must be awful high.

 

[Mooseman]

Of all the posts about failing clutches, I haven't seen one where it threw a code, except maybe when it locked full on.