jgarmo
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- Joined
- Apr 26, 2018
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- Location
- Detroit, MI
- Vehicle(s)
- 2017 Mustang GT
- Thread starter
- #1
Hey everyone! New to the forums, and fairly new to mustangs. I purchased my 2017 Mustang GT from a wholesale dealership in Miami, FL in July 2018. I had the car inspected before purchasing, and I drove it all the way home to Detroit, MI, and everything was perfect. The car was modified, but all I knew about or all that was obvious, was a PMAS CAI, and MBRP Catback exhaust.
Well, one day, I'm cruising down the freeway, and I put my foot to the floor while in too high of a gear. After a split second, of course, I noticed, and downshifted. As soon as I downshifted, my CEL came on and was flashing. So of course I figured, okay probably a misfire, no big deal right? Wrong. I get my codes read, and it was a Cylinder 8 misfire. I went ahead and pulled the plug in Cylinder 8, and found oil on the plug. I replaced the plug, and the car was still misfiring. I swapped the coils with a different cylinder to see if that would move the misfire; it didn't. I pulled the fuel rail and checked the injectors, Cyl 8 injector had oil on it as well. I swapped the injectors, and the misfire still did not move to a different cylinder. So at this point, I ruled out all of the small ticket items. One other thing to note... after changing the plug initially, I had the car running, and removed the oil cap to find a white vapor emitting from the motor, and turned the car off of course.
Now, at this point, I went to my local mustang friends, and grabbed a stock intake, and stock exhaust so I could swap em and bring my car to the local dealership. I put the stock airbox on the car, and my car would not start. So I sat there like FUCK MY LIFE THIS CAR IS TUNED. So of course I had absolutely no idea the car was tuned previously. I have no way, at least no way that I know of to flash the stock PCM, since I do not know who the owner was, or how they tuned it, I'm basically screwed.
Anyway...
After getting under the car to get the MBRP exhaust off... I noticed that the previous owner had modified the stock headers to cut the cats out. He had flanges welded to the stock headers, and had it hook up to the MBRP catback which he also modified. So after learning this, I was pissed as hell, and had to go get OEM headers. Anyway, I end up swapping the headers out, I left the PMAS CAI, and threw the stock exhaust on the car, and took it to the dealer. The Dealership was pretty cool about it, as they did NOT void my warranty. They replaced my headgasket, and my intake manifold to see if that would fix the issue; it did not. They did a compression test as well, and the compression was good; they did not give me the compression numbers.. They called me and said they can't figure out the issue, and would need to do an engine teardown in which I'd need to provide 2500$ as a deposit for them to do the teardown, to see IF they would warranty it.So I was like okay fuck that I can't afford it right now. So I took my car home, and it's been sitting ever since.
I cannot figure out if the issue has to do with the rings or if its got something to do with my valves.
The car is still misfiring, and has been sitting in my garage the last 6 months probably.
Curious to see what anyone's opinion might be on this issue.
EDIT: I was perusing the forums, and found that other people had this valve cover issue I had as well. My valve cover, driver side is/was definitely leaking, as I did have an oil leak as well where it was coming out down my headers on the driver side. I never knew about tightening those bolts. I may try that out, and see where I'm at after that.
I appreciate it in advance! Any questions just ask. I may have missed some stuff.
Here is a pic of my 17 GT. After buying the car, I did the Cervini Cowl Hood, and GT350 front bumper, and fenders; I did not buy it that way.
Well, one day, I'm cruising down the freeway, and I put my foot to the floor while in too high of a gear. After a split second, of course, I noticed, and downshifted. As soon as I downshifted, my CEL came on and was flashing. So of course I figured, okay probably a misfire, no big deal right? Wrong. I get my codes read, and it was a Cylinder 8 misfire. I went ahead and pulled the plug in Cylinder 8, and found oil on the plug. I replaced the plug, and the car was still misfiring. I swapped the coils with a different cylinder to see if that would move the misfire; it didn't. I pulled the fuel rail and checked the injectors, Cyl 8 injector had oil on it as well. I swapped the injectors, and the misfire still did not move to a different cylinder. So at this point, I ruled out all of the small ticket items. One other thing to note... after changing the plug initially, I had the car running, and removed the oil cap to find a white vapor emitting from the motor, and turned the car off of course.
Now, at this point, I went to my local mustang friends, and grabbed a stock intake, and stock exhaust so I could swap em and bring my car to the local dealership. I put the stock airbox on the car, and my car would not start. So I sat there like FUCK MY LIFE THIS CAR IS TUNED. So of course I had absolutely no idea the car was tuned previously. I have no way, at least no way that I know of to flash the stock PCM, since I do not know who the owner was, or how they tuned it, I'm basically screwed.
Anyway...
After getting under the car to get the MBRP exhaust off... I noticed that the previous owner had modified the stock headers to cut the cats out. He had flanges welded to the stock headers, and had it hook up to the MBRP catback which he also modified. So after learning this, I was pissed as hell, and had to go get OEM headers. Anyway, I end up swapping the headers out, I left the PMAS CAI, and threw the stock exhaust on the car, and took it to the dealer. The Dealership was pretty cool about it, as they did NOT void my warranty. They replaced my headgasket, and my intake manifold to see if that would fix the issue; it did not. They did a compression test as well, and the compression was good; they did not give me the compression numbers.. They called me and said they can't figure out the issue, and would need to do an engine teardown in which I'd need to provide 2500$ as a deposit for them to do the teardown, to see IF they would warranty it.So I was like okay fuck that I can't afford it right now. So I took my car home, and it's been sitting ever since.
I cannot figure out if the issue has to do with the rings or if its got something to do with my valves.
The car is still misfiring, and has been sitting in my garage the last 6 months probably.
Curious to see what anyone's opinion might be on this issue.
EDIT: I was perusing the forums, and found that other people had this valve cover issue I had as well. My valve cover, driver side is/was definitely leaking, as I did have an oil leak as well where it was coming out down my headers on the driver side. I never knew about tightening those bolts. I may try that out, and see where I'm at after that.
I appreciate it in advance! Any questions just ask. I may have missed some stuff.
Here is a pic of my 17 GT. After buying the car, I did the Cervini Cowl Hood, and GT350 front bumper, and fenders; I did not buy it that way.
![](http://<blockquote class="imgur-embed-pub" lang="en" data-id="a/CYzhC9i"><a href="//imgur.com/a/CYzhC9i"></a></blockquote><script async src="//s.imgur.com/min/embed.js" charset="utf-8"></script>)
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