Overheating issue

[Vengenz666]

Hey guys,

So here's the specs. 1997 12 valve with 234k miles.

Last year around summer time (in Phoenix) I was having cooling problems. Temp would start to climb whilst stopped, ac would go to crap etc. Once I turned off the ac and started moving again the temp would drop back to normal range.

I replaced the entire cooling system, hoses, radiator, tstat, fan clutch and water pump. All seemed well throughout the summer and winter.

Today, my wife was in the drive thru, ambient temp was 106* and she had the a/c on. Well i guess she didnt notice but the temp climbed and the truck shut down on its own. I met up with her, opened the hood, turned off the a/c and started the truck. Started just fine, cooled down and drove it home. Any ideas on what I couldve missed parts wise? Clogged intercooler maybe?

Hooked a scan tool up and got P0645 - A/C clutch relay circuit, P1388 - Auto shutdown relay circuit, P1492 - Ambient battery temp sensor input voltage high.

I know all the parts I already replaced could be bad again. Only thing I could test was the fan clutch, which is working.

Thanks in advance, Rob

 

[Vengenz666]

Little update. Just sat in the driveway and let it idle for an hour. 30 min in park and 30 min in drive. It runs about 1/4 on the gauge whilst in park and goes up to half in drive. If I pop the hood it'll drop right back down. Tested the fan clutch with cardboard. Shredded it. Coolant is nice and clean (red CAT coolant). No leaks. A/C blowing 60*. Outside air temp reported at 105*.

 

[Matt42]

For what it may be worth, others have been reporting issues having to do with either airflow around the battery temperature sensors, or the sensors themselves. Can I find those posts? No.

 

[GAmes]

If you opted for the cheap auto parts house fan clutch you wasted your money. None of them I tried would ever fully engage the fan and provide enough air flow. If the fan clutch is fully engaged it sounds like a jet engine under the hood. I went through several of them. The extra money for a new OEM is money well spent. Having nothing to do with cooling, but is a potential killer of your alternator, a battery temp sensor can be had at AutoZone. The specs for checking the one you have are in the factory service manual. I was in Phoenix about 5 days ago. Outside temp was 107, A/C was 40, the engine fan was howling every time the coolant temp gauge got to 190.

 

[crabman]

2nd it on only using OEM fan clutch.
Many members have used non OEM ones and reported engine overheating problems while using them.