Cobra overheating

[rtvickers]

My 04 Cobra has been having overheating issues for about 2 months now. I am at the end of my rope with this thing. Ive thrown 2 T stats at it and I have a new high dollar one on the way. Ive put in a new radiator fan and a new fan relay. I believe Im dealing with air bubbles in the system. I have burped the system so many times the crossover tube plug is on its last leg. I have a new crossover tube and plug on its way. I can sit there for hours burping the system and keep getting air bubbles. And there are so many different ways to burp it. Ive even used a Radkitplusa. Ive done a pressure test on the system and couldnt find any leaks. Heres my latest burping issue.

Yesterday: Removed the crossover tube plug and inserted funnel. Filled with coolant until funnel was about 1/4 full. Squeezed the upper hoses atleast five times. Started it and let run for 5 min. Shut off and made sure I kept the coolant in the funnel as it filled the system. Let cool for 10 min. Cracked open the radiator cap. The level in the funnel went down as the level in the expansion tank went up to the full line. Tighten cap and removed funnel and put the plug back in. I drove the car for about 30 min. Let cool down and drove it for about an hour with about 30 min of that was sitting in traffic on my way to the eastside. Temp never went over normal. Drove it to work this morning on 275 and it took about 10 min to overheat. The coolant in the tank was cold. Removed the crossover tube plug and added 1 1/2 gallon of coolant. Thats all I had with me. Temp went down and I drove it the rest of the way to work and never overheated.


Today: I did that same burping method about 6 times today. And got air bubble everytime. But it did seem to have less air the more I did it.

Could this system really have that many air bubbles? The other day I burped it for about 3 hours.

So I ask... Who is the expert and can guarantee me that they can get all the air out of this system and how much do you charge if I supply the coolant?

Thanks
Tommy

[may93]

Do a compression test and also pressurize the coolant system to check for leaks. Those air bubbles might be caused by such a leak!

[blown96cobra]

Pm 700hp04mystic. He has fixed several with this same problem.

[rtvickers]

Do a compression test and also pressurize the coolant system to check for leaks. Those air bubbles might be caused by such a leak!

I have done a pressure test. It held the pressure and I couldnt find any leaks. The pressure in the system did not drop.

[bobtsgt]

well if your pressure tester didn't leak down then you don't have a leak. One way to test your thermostat is to put it in a pot of hot water and slowly raise the temp and watch the vavle pop open. If it does then you know its working right. does sound like you have a bad air pocket in there somewhere but the degas bottle should help with that.The only thing I can suggest is to start fresh. Drain it out completely. Refilling from the plug on the crossover only.

Also have you checked all your car basics? As in clogged radiator/condensor fins, possible blockage of the radiator, weak hoses restricting the system,ect.. If the radiator internially has some light blockage then that could be where your seeing the pockets of air come from. As the blockage breaks down its allowing the air to push threw the tube into the system.

[zippy94]

I would pull some spark plugs to see any water signs. Are you sure your high speed on fan is working?I agree start fresh and make sure your mixture is right. Winter is a few months away

[SCHMUCKINGHAM]

Is the carpet wet anywhere?

[rtvickers]

well if your pressure tester didn't leak down then you don't have a leak. One way to test your thermostat is to put it in a pot of hot water and slowly raise the temp and watch the vavle pop open. If it does then you know its working right. does sound like you have a bad air pocket in there somewhere but the degas bottle should help with that.The only thing I can suggest is to start fresh. Drain it out completely. Refilling from the plug on the crossover only.

Also have you checked all your car basics? As in clogged radiator/condensor fins, possible blockage of the radiator, weak hoses restricting the system,ect.. If the radiator internially has some light blockage then that could be where your seeing the pockets of air come from. As the blockage breaks down its allowing the air to push threw the tube into the system.

Ive tested the Tstat like 10 times. It opened everytime. But Im gonna make sure I have a good one so I bought one from Lethal.

Ive checked for obstruction around the radiator. Nothing.

Thanks

[rtvickers]

Is the carpet wet anywhere?

Nope carpets not wet, heater core seems good.

[rtvickers]

After all the burping I did yesterday, I drove it to work this morning. I only live 1 mile from work. Got to work and let it sit and warm up. It got up to normal temp and start to spit out the radiator cap. It happened like every 15 seconds or so. Then it would stop and do it again. I think its running hot cause its spitting out the coolant through the cap. The cap holds pressure under normal driving. If I drive it for awhile and it dont overheat I will crack open the cap to see if its holding pressure, and it does. I dont know...


Thanks to everyone who has offer advice. It really does help.

[bobtsgt]

sounds like there is still a blockage somewhere. possibly inside the radiator. Is the fan constantly running once it heats up?

[rtvickers]

sounds like there is still a blockage somewhere. possibly inside the radiator. Is the fan constantly running once it heats up?

No the fan is running fine from what I can tell. Untill it overheats. Im not sure about the high speed fan. But doesnt it only kick on when you use the a/c. I will test the fan when I put the new tstat and crossover tube in. Would a flush and fill get out any blockages in the radiator and the coolant system?

[bobtsgt]

It wouldn't hurt. They have radiator flushes you can add while you flush the system that should help clear out the corrosion inside.

[rtvickers]

Ok here's an update. After work I burped it for about 30 min and drove home. Let it sit for about an hour. Burped it for about ten min. Drove from Newport to eastgate and no issues. Open hood and had no spillage. Ill go check it this evening and update.

[Black Horse]

Hopefully you just had a bunch of air pockets. If it keeps coming back you might want to check your cylinder compression to make sure you don't have a leaking head gasket.

[rtvickers]

Update from lastnight. I topped off the plug and tank before leave eastgate lastnight. Drove to carwash in Southgate. No issues. Did some more burping there. Drove home and no issues. I havent been out to look at the car yet. Im getting a sinus infection and I feel like crap. After I get the new tstat and crossover tube, I think Im gonna take it to Ford and have them do a flush and fill. Unless someone on here can do it and guarantee no air in the system. If it helps I have access to a Radikitplusa. But no air compressor. Ill supply the coolant. Let me know.

Thanks

[may93]

Hopefully that fixes your problem. If not the next thing I would look into is the head gaskets. What you describen sounds like the typical head gasket thats blown. It pressurizes the coolant system pushing the coolant out and therefore causes the car to overheat. At idle it may not show up but under load it will do so..Especially seeing as your car is supercharged.

[2Fast4You]

Have you replaced the radiator cap, this is a common over looked issue. I have had this same issue in the past and it is a cheap fix.

[rtvickers]

Well... I think I figured it out. I think I have a blown head gasket. I did a combustion gas test on it today. The instruction say if the fluid in the tube turns yellow, there is a leak. It turned yellow. So I guess Im gonna have to rip this thing apart. This may take awhile. Thanks for everyones help.