Title says it all. I’ve been battling overheating issues with my cobra since I’ve owned it and I’m at a loss at this point. Basically after I replaced water pump(preventative maintance), new sve radiator(old one shit out), thermostat, and cap the car ran fine for two weeks or so. No overheating etc. the car then lost heat ( no overheating, just not heat) so I just went about by my business for another few weeks and while sitting at a light I saw the temp crack a bit over halfway as if it was going to start overheating. Finished my drive to work with no issue. After work drove the car for 15 min at operating temp until the car started to push coolant out of the cap and overheat. Let the car cool down and filled it up with water and basically did this a few times. Drove as far as I could until the car started to get hot and shut it off and repeated. On about the 3rd or 4th go the car didn’t overheat and I was able to finish the last 10-15 miles of my drive at operating temp. I did notice the temps creep up once I made it home. The car does not get hot at idle but only after I drive it for 5 minutes or so it pushes coolant out of the cap. I have tried completely bypassing the heater core. Fan is working, I’ve pulled the radiator out and it’s clean with nothIng affecting flow through there. The upper hose on the radiator is definitely a touch warmer than the lower. The thermostat really only fits one way so I don’t believe it’s backwards. Oil on the dipstick looks fine. Could the expansion tank just be bad and causing my issue. Another thing I notice is after I fill the resivour over about a night it’s near empty if not empty. But the hose running into it from below always has coolant in it up to the resivour almost. I know the oil cooler leaks and I have a rebuild kit for that. The issue seems like a headgasket problem but the car doesn’t smoke any, runs fine, and I can’t see oil mixing with coolant on the dipstick. Could a stretched belt be causing the water pump to be “slipping” per say and not push enough coolant through the engine to cause an overheating issue while driving? I know a leak down test would be a sure fire way to tell if it is a headgasket but I need to be able to get my car to my work to do so, so until that happens that really isn’t much of an option.
Another overheating thread
- Thread starter Braydon kahl
- Start date
it sounds like you need to read and follow the burping procedure, filling through the degas tank is NOT the proper way to do it. It usually took me 3-4 cycles to burp my car completely - you fill it through the crossover tube, NOT the degas tank. Yes, it's kind of a pain in the ass.
I would finish the burping procedure first. If you still have issues consider replacing the degas tank since you've replace the lid. If it's still an issue Id be looking at head gaskets (they have a tester that will check coolant for combustion gasses)
its cold enough out right now I doubt the fan is the issue but you'd want to make sure the high speed is working and its not just stuck on low.
I would finish the burping procedure first. If you still have issues consider replacing the degas tank since you've replace the lid. If it's still an issue Id be looking at head gaskets (they have a tester that will check coolant for combustion gasses)
its cold enough out right now I doubt the fan is the issue but you'd want to make sure the high speed is working and its not just stuck on low.
I have burped the system through the crossover port multiple times. I’ve done it before and it was never a huge issue to get aid out of the system. But maybe I have a huge airpocket still that I haven’t got out. I’ll try a new expansion tank and re-burp the system. And yes the leakdown test is what I was referring to test for cylinder leakage. But testing for combustion gases in the cooling system would work as well.
Are you running the stock reservoir or an aftermarket aluminum unit?
Stock
Did you follow the burping procedure? Car running with the crossover plug out and that's where you should be filling from.
Replace the cap as well. Mine was bad and over time I lost a bit of coolant from vaporization.
Sent from my SM-G950U using the svtperformance.com mobile app
Replace the cap as well. Mine was bad and over time I lost a bit of coolant from vaporization.
Sent from my SM-G950U using the svtperformance.com mobile app
Yes, I’ve burped the system through the crossover pipe. I’ve had to burp the system before and never really had an issue doing that properly. So I wouldn’t think the issue would be there but it is a possibility. I have tried burping the car multiple times with my current issue and couldn’t get anything to change.
Def gotta have heat on full blast too. I like to squeeze the upper and lower radiator hoses as well.
I'd get a new cap, follow the burp procedure linked here and see what happens.
And I'd get an aero force or something. Had no idea how worthless tha factory gauge was until I got one.
Sent from my SM-G950U using the svtperformance.com mobile app
This. I'd be curious to know what the actual temps are. Plus, I've been told before that once the engine overheats to get a new reservoir. Supposedly the plastic warps and never seals again. I've been running an aluminum tank for years.
It's really odd that you randomly lost heat though. Either an air bubble or lack of flow would cause that I'd think.
A slight update, I’ve used a combustion gas tester to check for a possible HG issue. The car passed and I was unable to get the fluid to change color other than when I sucked up some coolant. Tested from the crossover plug and expansion tank. Another note is I have no coolant flow through the crossover plug. Just steadily smokes out the plug and spits out some coolant. The smoke is just a strong coolant smell. I started with this because some of my coworkers (technicians themselves) all were leaning towards headgasket failure. At this point I’m about to remove everything from the cooling system and see if anything is clogged and not allowing flow.
I would do a compression check.
I have had head issues 3/4 times on my. Each caused this issue.
Burping these is easy.
Heater will flow coolant at all times and can leak and cause this.
Feel carpet on passenger floor
Or have you noticed windows fog on inside.
I have had head issues 3/4 times on my. Each caused this issue.
Burping these is easy.
Heater will flow coolant at all times and can leak and cause this.
Feel carpet on passenger floor
Or have you noticed windows fog on inside.
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