View Full Version : Please Help Diagnose Problem on 03 cobra

hi ofcr cobra
10-23-2007, 11:28 PM
So here's the story:

Driving friday afternoon my car kicked into limp-home mode (shuttering @ 3000), temp looked good but when I stopped at a light, I watched the temp gauge start climbing. I bailed into a parking lot and shut the car down, I then popped the hood and watched some coolant boil out from the cap. After some bad ass on-spot diagnostics, some friends and I discovered my intercooler relay had gone out. The car also threw 2 codes: Over Temp and Over Boost. After clearing the codes, I replaced the relay and hopped back on the street. About 15 min of driving and one 10min stop later, the car overheated again! I pulled into a gas station and checked the intercooler pump first... running as normal. Checked the codes and now there were 3: Over Temp, Over Boost and P1000 Monitor Checks Not Complete. Not wanting to tempt fate I had the car towed home.

Friday night I burped the system thinking the original overheat trapped some air in the system causing the second overheat. At about midnight I took the stang for a test drive (and to bed my new brakes in)... everything worked fine. Stayed at good temp the whole time and I made a point to get into boost numerous times.

Saturday morn I travelled about 10 miles to Texas World Speedway for a DE weekend. The car sat for about 2 hours during drivers meetings and other run groups, then it was my turn. I completed my first 20 min session with no problems. The car then rested about 1.5 hours until my next session, I made it about 10 min into the session before a fair amount of coolant blew out of the reservoir cap, through the hood heat extractor and onto my windshield! I took it easy for the rest of the lap and made my way into the pits. No limp mode though.

The rest of my Saturday was busy burping the system and trying numorous other things that all failed.

Sunday morn I finally found the root of the problem! My coolant reservoir had a crack in the threading for the cap. I borrowed another tank from a downed cobra and made the last 2 sessions of the weekend (thanks again Edmond!). Here's the scary part... I had serious power loss during those sessions! At the end of each session the car was a little warmer than I would like, but not full out HOT. I first thought the power loss was maybe from heat soaked air, but on my last run of the day I noticed power loss during my warm up lap (before the car was even up to normal operating temp), suggesting intake air temp was not to blame.

Sunday night I checked codes again an the car was still showing the P1000 code. When I looked it up online I found P1000 is a normal code because I have cleared codes recently and it will disappear after enough driving cycles.

Could the P1000 code cause my power loss issues? Does it screw with the timing?

Here's a few more clues...

Some friends working corners during the event said they could smell coolant when I when by (suggesting blown head gasket or maybe crack in the intercooler). Intercooler reservoir seems to be at the same level it always has and since I've had coolant boiling out of the radiator overflow reservoir I havent been able to watch the water level for changes. I figure it may just be coolant burning off since my engine bay was soaked in it after my cracked reservoir sprayed everying down.

I pulled the plugs tonight and all look clean (no rust, no residue, no water).

I havent been driving the car and I dont plan on doing so until i get my new canton reservoir in.

P1000 code is still there.

Powertrain is almost all stock: K&N air filter, C&L maf and inlet pipe... stock TB on. Fluidyne heat exchanger & larger intercooler reservior, stock intercooler, stock pump, stock lines.

If your still with me... any ideas? :scratch:

10-24-2007, 06:22 PM
My car was going in to limp mode almost every session. I have the Fluidyne heat exchanger also & 2.91 pulley, no other cooling mods. My car was not spitting out fluid & did not have any a coolant smell. The car did the same thing with the temperature gauge once, it was in the normal position and the car went into limp mode then the gauge went up. I was even running with the heating on all weekend.

I have not checked the codes yet will do that this weekend. I did not experience power lost until limp mod & after about coupler hundred yards the power came back but the temperature was still high for a few laps.

I guess the probable fix is a radiator, the evenflow head cooling mod, bigger storage tank for heat exchanger, anything else?

Does any body have an oil cooler on their car?

Thanks Gary.

10-24-2007, 11:35 PM
ok... this sounds like a heat soak problem... Now, i know that using a better h/e is good for making power, but, unfortunatly.. it uses water. problem is, the exchanges are made out of alum, which does dissapate heat more, but.. it also soaks in heat just as fast.. now, u mix that with consistant hot laps, and not letting the car get some wind through it (above highway speeds under NO load that is) well.. then i can see how this would cause a problem...

my question is... did u have the a/c on? are u still using the stock thermostat? ever change it? can u hear the fan come on in BOTH speeds? What was the weather like when it went into limp mode the first time? Im curious about this also, since im gonna be doing some driving school at VIR hopefully.

Keep us posted!


10-25-2007, 08:52 AM
thermostat is going or is bad, replace it and try again....

10-25-2007, 02:39 PM
I am going to replace the thermostat, hope it is the problem. Just had the tune changed before the DE event. Now the low speed fan comes on @ 170 & the high speed @ 190, plus I was running the heating on full & the fan was running when I came in @ the end of my session. Not sure what the temperature was in the morning close to 80, ending up close the 90.
I am doing the HMSR on 11/10 will see if the thermostat was the problem, however it will be 10 cooler.
Thanks Gary.

10-30-2007, 07:58 PM
I've been fighting this overheating problem forever. One time it's ok and the next time out here comes the fluids. There doesn't seem to be any common reasoning. I have started looking for a track car so i can keep the Cobra off the track. Please let me know if anyone figures this out.


10-31-2007, 12:55 AM
I have had some of the same problems, but only at the track, and only when it is above 90 degrees and humid. I can always get about 15 minutes out of the car and sometimes the whole 30, but if it is hot the chances are better for overheating. I have changed radiator, heat exchanger, done the head mod, different temp thermostat, long tube headers, and now 2 overflow tanks for the supercharger and the more efficient whipple along with an aluminum overflow tank for the radiator. I will see how it works at Houston in a week or so. I have had cars next to me have no problems with less cooling mods and it frustrates me also. I think every car is different, but we will see.

11-02-2007, 09:44 PM
Such a common problem it seems. I just had Ford put a new motor in cause I lost 7&8 piston. That was 2 months ago and I cant keep from puking. I have done soo much also. Changed the thermo, burped her, had ford change the thermo and burp, changed the overflow cap burp burp burp. On my car..it seems that the head gasket is blown. I dont have cooling in my oil but I do seem to have millions of bubbles in my coolant and an over pressurized cooling system. It seems more after being in boost. So of course overheating is after the coolant loss. I cant even compress my upper hose when the car is on. Good luck-Shane