Detonation at WOT and coolant loss... help!!!

[KTD SC]

The past month iv been having alot of problems with detonation and coolant loss. First ill start out with the detonation... The car has been detonating realy badly at WOT, and i can see a dim grey smoke in my rear view mirror come out when i punch the throttle, also if i get on it for long enough the car will start heating up fast. I recently changed the sparkplugs to motorcraft coppers, i cleaned the MAF, and i installed an AFPR and set it to 38 psi. And the timing is set to 10*tds. When i drive the car like a grandma is runs fine, but im not a grandma. Iv tryed everything to try and stop the detonation, but nothing works.

Also about every month or so ill loose a few inches of coolant out of the overflow tank.

All of this sounds like a headgasket to me, but i want to be positive iv tryed everything before i take apart my daily driver... can anyone give me any more suggestions to try and stop this problem?

oh yea, on more thing... When i start the car in the morning and let it run for awhile sometimes the idle will surge. Only sometimes it will surge so bad that the car turns off. Also sometimes when i step on the brakes to stop at a stoplight the car will surge to about 300-400rpms and the battery light will come on and the car will ether shut off, or if im lucky it will start back up on its own.

A similar situation happend to me in my 94 thunderbird sc and cost me nearly 12,000 because the headgasket blowing... iv had my 94 mustang gt for almost 2 years now and i dont want to let it go, but im very close to giving up on ford all tegether.

 

[bill302]

run a pressure test on coolant system should tell you what you need to know. cel light on or have you attempted to retrieve codes.

 

[bill302]

also a compression test of each cylinder might tell you something i would do this first and post results.

 

[BlackVert]

wow, $12,000 for a head gasket? what else did you have to fix?

did the surging start when the detonation started?

as to the detonation, i bet you have a vacuum leak somewhere. the hoses are 12 years old now; it is understandable that one (or more) of them might have gotten brittle and cracked.

did you try spraying carb cleaner at different spots in the intake track while idling to see if the idle changes? that is a pretty easy to track down a leak.