IHateStangs

My 11 GT is misfiring, I replaced the plug and it's still missing, I am worried about the dealer because I have the "cammed" tune by Jon Lund, and I can return to stock and take it back but I have soooo many mods, they would find some way motto honor it....anyone heard of this

shoeys08dkcandygt

Ouch. That sucks buddy. What other mods do u have? But for what I've read on here and how I interpret the bulletin Ford sent out saying if the #8 is determined to be blown and there is evidence of a aftermarket tune, present or in the past(bc Ford is reading the ecu's and will know if the car has been tuned) the warranty on the powertrain is voided and up to the customer to pay for repairs.
Good luck buddy. hate to hear about this. Makes me worry about my tuned 5.0 but I know if it goes boom the repairs are on me.

lawrencecar1

swap the coil plug and see if misfire moves ?

moosestang

There are only three things that cause a cylinder to misfire. Hopefully it is not a loss of compression.

slickman

Check the coil pack, swap one over from a good cyl.

pinn

https://mustangforums.com/forum/5-0l...n-failure.html

TSB for this issue is in the first post.

daredevil95

After trying a coil swap, see if you could squeeze in a compression gauge in there and do a compression test. The #8 compression test will answer all questions....wish you luck!

I attached a thread of a guy that had a low compression problem on cylinder #8, Ford wouldn't warranty the engine due to the tune, the guy ended up selling the car

http://www.svtperformance.com/forums...ion-8-cyl.html

Derf00

Worst thing to do is remove the tune, they will potentially void the engine warranty without question due to evidence of tune tampering and not being able to confirm if that was really the cause. "We don't know therefore we will assume" attitude.

If you leave the tune in let them diagnose the problem. You may still have a voided warranty but in the event it could be something else, at least you still have a chance they won't void it if it's not the tunes fault.

IHateStangs

It is low compression in #8, every spark plug I put in comes out with oil...any fixes to this?

Entaille

I am pretty sure you are hosed and a large repair bill is in your future. I am interested in hearing what all has to be done to remedy this though.