HHR 2.2L LT Overheating issue - Please help??
11-03-2017, 08:46 PM
#82
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Join Date: 01-23-2009
Location: Fredericksburg,VA
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That would not cause boilover.
But I have absolutely no idea how the existence of a t-stat could cause anything like that. There must be something else going on.
I guess it would be worth checking for exhaust gas in the coolant. You can get a kit at your local bigbox parts store.
But I have absolutely no idea how the existence of a t-stat could cause anything like that. There must be something else going on.
I guess it would be worth checking for exhaust gas in the coolant. You can get a kit at your local bigbox parts store.
11-03-2017, 09:29 PM
#84
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Post #32, chemical block test was performed, and a second time in post #49. One idea that was not checked, is the timing chain. I am still curious how this could cause overheating. If it were so badly timed, wouldn't it set a code?
I find that when I am told the "why", the lesson sticks with me.
I can't help but think that the likely cause is air getting into the system. That would explain why it didn't overheat for a day or so after successfully burping the system. But OP said that the system held 15 lbs for 20 minutes in a test. OP also said he replaced the filler cap.
This is very perplexing.
I find that when I am told the "why", the lesson sticks with me.
I can't help but think that the likely cause is air getting into the system. That would explain why it didn't overheat for a day or so after successfully burping the system. But OP said that the system held 15 lbs for 20 minutes in a test. OP also said he replaced the filler cap.
This is very perplexing.
11-03-2017, 10:19 PM
#85
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It "should" set a code. But anything that causes boiling would too.
If the valve timing is off the spark will be off, causing too much heat in the combustion chamber. and that kind of thing.
Maybe the radiator is partially plugged and the t-stat just restricts it enough more?
If the valve timing is off the spark will be off, causing too much heat in the combustion chamber. and that kind of thing.
Maybe the radiator is partially plugged and the t-stat just restricts it enough more?
11-03-2017, 10:46 PM
#86
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Location: California
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Regarding the Dexcool, I initially filed the system with Dexcool only after it started overheating I added other brands of 50/50 then eventually water to keep the system topped up since it kept spitting out the coolant that was in there. Once I figure out what the overheating issue is I'll drain and refill with Dexcool but until then it seems to be a waste of money.
I don't think we ever got any history on the vehicle. What happened in the month or so before it started overheating? Why did you put the DexCool in? Was there any work done to it, or a collision?
Did you ever take care of those MAF sensor codes? If the codes appeared about the same time as the overheat, there may be some sort of link. Doubtful, but shouldn't be so quick to dismiss the thought.
11-04-2017, 07:46 AM
#87
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Join Date: 09-23-2009
Location: Hurst Texas
Posts: 467
In post #60, Donbrew explains the function of the cooling system. He is correct in all respects except there was no mention of the head gasket role in regulating the "FLOW" of the coolant. If the head gasket is corroded where the head and block seal off the water passages then the water flow will be too great when the T Stat opens.
I had this very same issue with a small block Chevy one time after I flushed the block and radiator with too much water pressure and got flakes of head gasket coming out of the system. After doing everything mentioned here I finally pulled the heads to discover what I had done. In this case the radiator would swell up from being over pressurized when the T stat opened and closed. New head gaskets resolved the issue and this whole post reminds me of this. The original holes were about the size of a 1/4 " drill bit, but mine were eaten away to the size of a nickel. This would explain the difficulty the T stat is having trying to regulate the water flow with such high volume.
What do you think?
I had this very same issue with a small block Chevy one time after I flushed the block and radiator with too much water pressure and got flakes of head gasket coming out of the system. After doing everything mentioned here I finally pulled the heads to discover what I had done. In this case the radiator would swell up from being over pressurized when the T stat opened and closed. New head gaskets resolved the issue and this whole post reminds me of this. The original holes were about the size of a 1/4 " drill bit, but mine were eaten away to the size of a nickel. This would explain the difficulty the T stat is having trying to regulate the water flow with such high volume.
What do you think?
11-04-2017, 08:45 AM
#88
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Join Date: 12-06-2009
Location: Alabama
Posts: 11,111
In post #60, Donbrew explains the function of the cooling system. He is correct in all respects except there was no mention of the head gasket role in regulating the "FLOW" of the coolant. If the head gasket is corroded where the head and block seal off the water passages then the water flow will be too great when the T Stat opens.
I had this very same issue with a small block Chevy one time after I flushed the block and radiator with too much water pressure and got flakes of head gasket coming out of the system. After doing everything mentioned here I finally pulled the heads to discover what I had done. In this case the radiator would swell up from being over pressurized when the T stat opened and closed. New head gaskets resolved the issue and this whole post reminds me of this. The original holes were about the size of a 1/4 " drill bit, but mine were eaten away to the size of a nickel. This would explain the difficulty the T stat is having trying to regulate the water flow with such high volume.
What do you think?
I had this very same issue with a small block Chevy one time after I flushed the block and radiator with too much water pressure and got flakes of head gasket coming out of the system. After doing everything mentioned here I finally pulled the heads to discover what I had done. In this case the radiator would swell up from being over pressurized when the T stat opened and closed. New head gaskets resolved the issue and this whole post reminds me of this. The original holes were about the size of a 1/4 " drill bit, but mine were eaten away to the size of a nickel. This would explain the difficulty the T stat is having trying to regulate the water flow with such high volume.
What do you think?
quote: "In this case the radiator would swell up from being over pressurized"
Not sure I understand this. Was your radiator pressure cap not venting the excess pressure ?
Anyhow. Don't think your SB Chevy issue was the same as the OP's problem. I think he has a circulation/flow problem. Either a weak water pump or some kind of obstruction in the cooling system(my guess would be radiator)
Fwiw. Years back, my Dodge truck was having minor overheating issues. Replaced the T-stat. Nope. Water pump. Nope again. Fan clutch. Nope.
Finally took some external temp readings. Sides and top of the radiator were
hot. Middle and lower radiator cold. Plugged up radiator. Put in a new one and no more problems.
Last edited by firemangeorge; 11-04-2017 at 07:15 PM.
11-04-2017, 09:25 AM
#89
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Join Date: 09-23-2009
Location: Hurst Texas
Posts: 467
I my case yes the radiator would swell and crack after about two weeks of this. I installed two new radiators in that blazer before we realized what was happening. The T Stat would open and let too much volume hit the radiator too fast before the cap would relieve the extra pressure. It all happened so fast that the system couild not compensate for it.
It was just a suggestion to check because this was almost the same trouble I had....this was after the power flush I did that started the whole problem, new head gaskets fixed the problem without any further parts replaced. Lesson learned not to over do it on the flush with older engines that might have corrosion problems internally.
It was just a suggestion to check because this was almost the same trouble I had....this was after the power flush I did that started the whole problem, new head gaskets fixed the problem without any further parts replaced. Lesson learned not to over do it on the flush with older engines that might have corrosion problems internally.
11-04-2017, 11:14 AM
#90
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Join Date: 01-23-2009
Location: Fredericksburg,VA
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I had something like that go on in a VW Rabbit.
They had plastic radiator ends, and a crossflow design. If the coolant ever overheats the internal dividers/baffles in the plastic would break because of the swelling. That would cause a flow problem, the fluid would bypass the cooling tubes, and more overheating. Pressure test told me nothing.
The problem is that you can't actually see the crack when cold so, every junkyard rad I put in had the same problem. Ended up having to buy a brand new one.
They had plastic radiator ends, and a crossflow design. If the coolant ever overheats the internal dividers/baffles in the plastic would break because of the swelling. That would cause a flow problem, the fluid would bypass the cooling tubes, and more overheating. Pressure test told me nothing.
The problem is that you can't actually see the crack when cold so, every junkyard rad I put in had the same problem. Ended up having to buy a brand new one.