PDA

View Full Version : Still Over-Heating

ar0ck
10-09-2006, 02:37 PM
And now its 10x's worse when I drive on the Highway even with the heat blasting it does absolutely nothing! Could it still be bubles? Could my sensor have failed? Could uncoated headers really generate that much heat? It defenitly gets worse to under moderate excelleration. Its pretty bad. A few times Ive watched the guage go up and pulled over right before it toped out. The anti-freeze is still clean and it wasn't bubbeling. Usually I can hear that. Just one thing I thought was the fans weren't comming on, but my car should still technically cool on the highway. I don't know whats going on. Im going to check the thermostat this weekend to see if its stuck or something. Any suggestions?

Im stumped :scratch:

Could it also be tune related? I feel that somethings wrong with my tune due to some other issues Im having that are possibly fuel related. And I need some more things to justify sending the computer out again, maybe this time to PCM4Less, or seeing him in Philly in a few weeks.
Tsar
10-09-2006, 02:42 PM
well if you got some spare time, then drain your coolant (rad. and block) then refill it and purge it properly this time.

are you 100% sure your water pump is working? cuz that would be my second guess, plus my old car used to do the same yours does, and it ended up being ****** water pump. i guess checking the t-stats doesnt hurt either.
ar0ck
10-09-2006, 02:46 PM
well if you got some spare time, then drain your coolant (rad. and block) then refill it and purge it properly this time.

are you 100% sure your water pump is working? cuz that would be my second guess, plus my old car used to do the same yours does, and it ended up being ****** water pump. i guess checking the t-stats doesnt hurt either.

Pretty sure the water pump is working. The thing thats odd, is I'll pull over if I see it get too hot, I'll turn off the car, and let the water pump run (which I can hear clearly) for a few seconds, and usually within a minute the temps are back to normal.
Pampered-Z
10-09-2006, 04:01 PM
Are the hoses new? Could a hose be collapsing when it gets hot?

Maybe pull the thermostat, could be not opening all the way?

Not sure on the LT1s, Some cars you can put the thermostat in upside down which will cause it not to open all the wayas well?


Could the blade on the pump be loose and just not moving the coolant?

How about double checking the wiring on the water pump, make sure it's not running backwards? As the engine warms up the hose from the back of the heads that goes into the rad. about 1.5 " below cap should be flowing water back into the rad. ( I think only once the thermostat opens. ).
V
10-09-2006, 05:01 PM
the one thing that doesnt seem right to me, is that he says once its shut off, the temp go all the way back to normal in like just a minute. Usually if a car overheats, it takes a short time to cool down. IMO, i'd run a mechanical temp gauge, JUST to rule out a gauge/wiring issue. If the problem still shows, then move on from there.
IROCdan330
10-09-2006, 06:01 PM
do LT1s have the air damn on the bottom?

i know in a thirdgen if the air damn is gone, these issues occur...

also, i would maybe say get an infrared thermometer (a cheapy) and check different points on the rad...youll be able to tell if its doing its job...thermostat would be another thing to check...
Tsar
10-09-2006, 07:23 PM
do LT1s have the air damn on the bottom?

yes they do, i doubt alex took it off but i guess its worth a check.

and no you cant put the tstat backwards, its pretty impossible in that little space. you would actually have to try and cram it in there for it to go the wrong way.

um...overheating problems are usually easy to solve, i dunno. i got my old tstat that i pulled from my car when i switched to 180, if you want that thing to try it out. :shrug:
ar0ck
10-09-2006, 07:34 PM
I will defenitly try a mechanical guage. Im also going to go over all the lines to make sure they haven't crushed. I run an Meizer Electric Water pump, never had any problems with it as far as cooling before I took it off the car when I did the heads/cam so the wiring harness is exactly how i left it (in working order) I'll try another thermostat though, that could also be a problem that its not working properly. I curently have a BeCool 180*
camaro2you
10-09-2006, 08:30 PM
sounds like an issue with the rad, i would try giving the system a good flushing
bad64chevelle
10-09-2006, 08:53 PM
I think checking out a faulty sensor/gauge/wiring would be a legit thing especially since you say it cools down fast, or like pampered said that a hose is collapsing. When I got the Chevelle on the road it would overheat like it was nobodys business really fast, and it was a rebuilt radiator, but as soon as I went to the Be Cool those problems stopped. Start narrowing it down and replace the small stuff for added insurance.
WildBillyT
10-09-2006, 09:29 PM
and no you cant put the tstat backwards, its pretty impossible in that little space. you would actually have to try and cram it in there for it to go the wrong way.


For what it's worth, I have heard of parts counter guys giving an incorrect non-LT1 specific thermo to people before...
NJLT1SS
10-19-2006, 08:26 AM
I would try purging it again. Maybe this time jack up the front of the car a little, just to make sure all of the air bubbles/pockets are out. I would also take a trip to the dealer and get a new temp sending unit. It doesnt cost much, and its easy to replace. Did you check the coolant crossover tube that connects at the back of cylinder heads? They have been known to clog on cars over time, and could cause some air not to purge out of the system.
ar0ck
10-19-2006, 04:46 PM
Well as far as the thermostat goes its defenitly the right one, because they are different then the average thermostat. Its possible that its stuck half way though so I will never know unless i crack that open again and test it in hot water.

As for the coolent cross over, I cleaned that out by using an air compressor and blowing air through untill enough crap got through.

Another idea that I had was, is it possible for uncoated headers to generate enough heat to throw off the coolent temp sensor in the head? I replaced that one sensor on the drivers side head when I finished everything up, but it is right between the first 2 primary tubes. Just another idea, I have been montoring my fluids and the color is still very clean, no leaks, no over-flowing. Everything seems normal on the surface.

It still does it to me, its very bad on the highway but around town, it keeps a normal temp, and if it does rise it goes back down rather quickly.
NJLT1SS
10-19-2006, 04:58 PM
Hmmm, the symptom you are experiencing seems to point to an air pocket. Also, dont rule out that the new temp sensor could also be faulty. I have had new GM parts bad right out of the box. Do you still have the old one to maybe swap and compare? I still think jacking the car up a few inches, and craking the bleeder screws will help, as it can be a pain to get some of the air pockets out. I wouldnt worry about the uncoated headers throwing it off, the cast iron exhaust manifolds Im sure get wayyyy hotter.
1984camaroz28
10-19-2006, 08:30 PM
Another idea that I had was, is it possible for uncoated headers to generate enough heat to throw off the coolent temp sensor in the head? I replaced that one sensor on the drivers side head when I finished everything up, but it is right between the first 2 primary tubes. Just another idea, I have been montoring my fluids and the color is still very clean, no leaks, no over-flowing. Everything seems normal on the surface.



nope i ran uncloated headers on my lt1 without any problems. Are both cooling fans coming on?
Savage_Messiah
10-20-2006, 12:50 AM
you DID check to see if something is blocking the radiator (liek a plastic bag or something) right?
ar0ck
10-23-2006, 07:21 PM
lol well the radiator was out of the car for a month & a half, and this over heating started right as I drove it out.
ar0ck
11-03-2006, 03:31 PM
Replaced the 180* thermostat with Tsar's stocker, and it fixed the problem. By just looking at the thermostat, it looks stuck partially open. Sending it back on Monday for a replacement! Car runs cold as ice now !
Firebird67dude
11-03-2006, 04:16 PM
you DID check to see if something is blocking the radiator (liek a plastic bag or something) right?

Wow u think i would let a car be driven around with a bag by the radiator? jeez.

I told you Alex it was the thermostat.
Tru2Chevy
11-03-2006, 06:01 PM
Heh....glad to hear that it's all fixed :)

- Justin
Tsar
11-03-2006, 06:46 PM
Replaced the 180* thermostat with Tsar's stocker, and it fixed the problem. By just looking at the thermostat, it looks stuck partially open. Sending it back on Monday for a replacement! Car runs cold as ice now !
:w00t: me ftw!