If your car sound like it has an exhaust leak, check your heads

flyn high again

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I had what I and several other people thought was an exhaust leak on the passenger side of my motor. My Cobra was ticking for a week. I had a gasket ordered to try to quiet down the leak. Turns out the problem was blow by on my #2 cylinder. The threads were failing and exhaust was getting past the spark plug. Could have been from a loose plug or just from too few threads in the head.

I was on my way home from being tuned by RWTD. I was almost home before traffic lessened enough to get on the car. Punched it and heard a loud BANG! The car was suddenly running on 7 cylinders and I wasn't sure what had happened. I coasted to the next stop sign and listened. The idle was smooth and there were no rattles or bad noises coming from the motor. I decided to limp the last mile home on the 7 cylinders. Whatever damage there was was already there and it didn't seem that driving it was hurting it more.

In my garage, I noticed the ticking was gone. Hmmm. I shut the car down and pulled off the passenger side coil cover. Sure enough, one of my coil packs was in 3 pieces and the plug was lying in the bottom of the tube. Luckily the plug was intact and nothing bad got into the cylinder. My problem was that I had blown the spark plug out of the head.

I called Shelby Guy who has had experience with this problem. He came over today and put a threaded insert into the head. Basically this involves reaming out the spark plug hole to a larger size, tapping it and then inserting a "Timesert" threaded insert to repair the head. The end result is that the head is fixed and that cylinder will probably hold the spark plug better than any other. Lightning guys insert Timeserts into all 8 cylinders as a preventive measure against spark plug blow out. Shelby Guy repaired one of his own cylinders and it has held through two years of road course racing so this should be a permanent repair.

The car is running great again and the ticking is gone. Big thanks to Shelby Guy for the Timesert install.

Anybody who has an exhaust ticking that is most noticeable in their passenger side wheel wells, check your spark plugs for tightness. You may be able to benefit from my misfortune and catch yours in time.
 

SlowSVT

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Perhaps you should have titled the thread:

"If your 03 sound like it has an exhaust leak, check your heads"
 

04CobraMatt

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I had the samething happen to my 2000 Mustang GT, it ticked louder and louder for at least 2 weeks until a spark plug blew out... worst part is i had it looked at by a Ford garage twice, first time they said it was injector noise which it was obviously not, second time they said it was something in the bottem end...

I check mine every 5000miles now.
 

flyn high again

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SlowSVT said:
Perhaps you should have titled the thread:

"If your 03 sound like it has an exhaust leak, check your heads"

I misspelled "sounds", too. That's what I get for posting late at night...

Maybe one of the mods could change the thread title to : "If your Mustang sounds like it has an exhaust leak, check your heads". ;-)
 

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