I'm once again hoping the TBN/CBN team comes through.
I have an '89 Chevy truck that was recently in for some work (previous post "Chevy front end work"). While it was in the shop, I had them flush the radiator and replace the thermostat (the temp gauge would occasional spike and then drop back to normal so I figured the t'stat was sticking now and then).
I got the truck back and the same thing still was happening, only it got worse very quickly. The gauge will now slowly rise and stay pegged (I obviously turn the truck off when this happens). I changed the thermostat and water pump and I still have the problem. I even pulled the thermostat out and I still have the problem. I replaced the engine coolant temperature sensor, temperature sending switch and checked the integrity of the wires to both. I still have the problem.
When the gauge is pegged, the hoses to/from the radiator don't get hard, like they would if I was boiling over and there's minimal pressure at the radiator cap when I pull it off (Coolant tests at 260F boiling point, gauge pegs at 250F.) If I turn the heater on, it's warm, but not blazing. The upper radiator hose isn't hot along it's length (like if the t'stat was closed). Also, if I crimp the upper hose, it doesn't feel like I've stopped any flow.
I'm now puzzled and think it's one of two things. 1. the gauge cluster or 2. that the radiator is plugged.
I'm thinking the radiator is plugged. I would have thought the repair shop would have told me something wasn't right when they flushed the system (I wasn't there to witness the work so I can't say for sure that it was flushed) A plugged radiator would prevent, or reduce the amount of coolant actually being pumped and would lead to the cold upper hose and lukewarm cab heat (I think).
Does this sound plausible? Any surefire way to check for a plugged radiator?. Can I pull the upper hose and see how much volume flows out while it's running with the t'stat out?
The symptons you describe are exactly how our Honda behaved when the radiator was plugged on it. When I pulled it out of the car you could run your finger along the coils and they would just disingrate under your fingers. Found a new one at Autozone for about $175 and haven't had a problem since (about 14 months and 25k miles). While I had it apart I went ahead and did water pump and timing belts. Figure that should be the last timing belts on this car as I now have over 200k on it.
Had an overheating problem with a 52 International truck once. Did all the things you have mentioned plus pulled out my hair and uttered a few unmentionable words.
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Turned out to be a head gasket leak.
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Oh, Egon. I don't even want to think along those lines. I'm still trying to justify to the wife why I just shelled out 2K to do the front end etc. My allowance would dry up for sure, if I just threw that kind of money into a truck with a bad engine.
I don't have any vapor at the tailpipe or coolant in the oil, so I'm hoping that's not it.
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Had an overheating problem with a 52 International truck once. Did all the things you have mentioned plus pulled out my hair and uttered a few unmentionable words.
Turned out to be a head gasket leak.
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Ditto. Went through the same experience with my 87 Chevy.
Dang and double dang! I'm rapidly approaching the "blown head gasket" diagnosis that Egon and others had. I swapped out the radiator and I still have the problem.
I'm going to let it run for a little bit and then drain the oil and check for coolant. I'll also check the coolant for oil. Right now, I don't show any signs of coolant in the exhaust, on the dipstick or under the oil fill cap. I think I'm following down the same road Egon did. I've added some words to my vocabulary and I'm missing some more hair. [img]/forums/images/icons/confused.gif[/img]
Yahooooo!!
After greatly reducing the remaining hairs on my head, I drove the truck (somewhat puckered as I watched the pegged temperature gauge) over to the repair shop that had it last week. It turns out that they noticed the problem and did some investigating. After checking all the usual signs that indicate an engines running hot and coming up empty handed, they finally checked the temperature with an infrared and determined temps were normal and the gauge was bad. They forgot to tell me all this when I picked the truck up.
I'll find an aftermarket gauge and hang it, or see if I can find a gauge cluster for something short of an arm and a leg on ebay.
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