LS1 Overheating
 

01 Z28

Here's my story for you guys and hopefully i'll get a few ideas out of it

Yesterday my car over heated (that needle was in the reddd), under normal driving circumstances. Last summer I had the same problem, it over heated alot... added some coolant and it went away, I also did a flush in October and it never gave me a problem all winter.

Back to today, within the past few months I've seen very slight leaks from the sides of the radiator (the plastic part), like I said... very slight.

There was no heat coming from the vents, bone cold...

I replaced the thermostat/housing and added Dexcool and let it idle.. needle went dancing at 210 and started to climb so I shut it off. Thermostat didn't look visibly damaged when I popped it out

Water pump was replaced 2.5 years ago after it blew up on me on the parkway my first day driving it home

All the hoses look fine, no cracks or anything.

I dont see coolant on the ground when I leave it parked over night.

As i've just done this thermostat, could I of let air in the system and it just needs to pass through? Or could I still have a problem? Why did it overheat in the first place?

you just replaced the thermostat? most likely air pockets. I would let it cool all the way and check the level and top it off again.

Doesn't explain why it over heated in the first place

Top of the radiator and let it run a bit and level out. Rule out an air pocket by pulling the heater hose forward an inch or so to bleed it.

With you having no heat, I'd start looking at the t-stat and radiator if the problem continues.



How's the coolant look?

I just replaced the t-stat, coolant looked good (replaced it anyways), and I think the radiator will be next on the list of things to do

radiator could be clogged up. dexcool gets kind of sludgey

why couldn't a bad thermostat cause it to overheat in the first place? Just because it looks good doesn't mean it is?

Are the fans coming on and are the fins blocked on the radiator ?

sounds like a clogged radiator to me, could even be heater core too. if all of that is original.

take the rad out and flush it with a hose see if any garbage comes out

I'd pressure test it and ensure the fans are operating properly. You can put the thermostat in a pot of boiling water to ensure it opens completely.

check the new thermostat too before dropping a new one in. all products can come faulty right out of the box.

Fans would be irrelevant at highway speeds with cold weather, I drove my Jeep without a fan for months in the winter and it worked fine, wheeling... different story...

I'm gonna replace the radiator next..

If the plastic tanks are leaking on the sides of the radiator then it's ****ed anyway.

just a thought but are you sure the car is legitimently over heating? cause i had an issue a ways back on diffrent car . i thought it was overheating and it drove me bonkers. turned out my coolant tempature sensor was dirty and therefore making the gauge spike hot but the car wasnt actually over heating..... just something to put out there.

That coolant was boiling like a mofo, absolutely over heating.

And yeah, might as well replace the radiator with the plastic tanks taking a crap.

yeah, you absolutely have to fix the radiator first. otherwise you are guessing at everything else. rad leaks = pressure problems, air pockets, low coolant issues

It honestly sounds like it was just low on coolant being that you had no heat and since you see a leak, it obviously needs repair. The fact that it continued to climb could be air pockets or a fan issue. You didn't really specify if the car was idling when it was climbing or if the fans were operating so its guessing at this point. Like the guys said, replace the leaking rad first then check for proper operation.

Unless your air damn is ripped off ....

Replace the radiator, make sure there are no air pockets. If you still have no heat, undo the heater hoses at the pump and flush with a hose. Dexcool sometimes has a habit of clogging heater cores...

Coolant levels were good, I check that on the regular. Car over heated while driving the first time, and over heated idling the second time after replacing t-stat.

Is the tank cracked?

Have you topped it off since you replaced it ?

Ok, is there a strong difference in temp between the upper and lower hose? Be careful grabbing it, coolant gets fuggin hot! If one is hot and the other significantly colder, you could try removing the tstat to see if it changes. If you don't see any dexcool mud, chances are the water pump isn't circulating coolant. Just be certain you've burped all of the air out of the system before you go chasing these ideas. Also, have you verified proper fan operation when its idling? These are suggestions based on the info at hand.

When I did my flush In october I didn't use dexcool, and there wasn't a significant difference in hose temps. Fans are not what made the car overheat, I'm positive on that.

I agree but you could be fighting several problems here. How hot are the hoses? What about the heater hoses?

If you take the thermostat out, run it , and it doesn't overheat again, I'd say your building head pressure. Your rad is also rotted.

Long story short, replaced the radiator.. fixed the over heating problem and I got heat back. I would say my radiator was clogged...

thanks for the help guys