I have a 88 GT conv. and it keeps melting the speedometer cable when i sit idle for 20 min or so. i have put 3 defferent cables on and all have melted. I have even rapped the last 2 in heat resistant tape. any ideas?

 

where are they melting? have you tried header wrap to keep the header heat contained?

 

It is melting under the car next to the collector or pre-cats not sure what they are? It has the factory exhaust on it so I am wondering if the collectors or pre-cats are clogged up and getting to hot. But if so how would i tell?

 

That would prolly be the BEST solution but MAN wat a PITA that would be. I would see iff I could wrap it in that tape again and try to find a flexible steel hose or tubeing to slide it through. Hell after that wrap some header wrap around that tube just for safe keeping. Just my idea is all!

 

A kevlar sleeve around the cable should help (header wrap works great) should be able to help isolate the heat but if it's the front cats then you may have high EGT's and that's a sign of a serious tune problem. I'd suggest getting a IR gun and checking the external temps of the first cats (I'm assuming you do not have LT headers) or better yet hooking a pyrometer and guage to the primaries and checking your EGT. This could be a sign of a clogged cat or a tune problem or any number of things.

Please don't just wrap the cable and be done with it. You need to find out why the temps are so high down there. Also anything you can do to add space between the exhaust and the cable is a good thing.

Can you take a pic of the affected area (make sure to include bright shots of the header pipes and collector and cats and the cable melting area)? We can be more helpful if we can see the problem.

 

I talk to a preformance exhaust guy and he said he would replace the hole exhaust system and put some fake cats in the place of the old ones. ( the state I live in does not test exhuast gases on anything later than 95 but they do look for your cats under the car somtimes) could this be a salution to it all? What other kind of tuning problem could it be?

 

If you're running lean your EGT's can climb dramatically. Also boost, nitrous, timing, cooling fan function and EGR function can all affect underhood and exhaust temps. Getting rid of the cats will probably help drop the heat shield temps significantly but without knowing more about what parts are on the car I can't make too many guesses. Are you running MAF or speed density or do you know?

 

it is all stock no mods and it is speed density