Misfire - Check Engine

[Rambl3r]

Need some advice on an issue I'm having.

A week ago, the check engine light came on while cruising at a steady 70ish mph. I took it to the dealership last Friday and the service advisor said it was a misfire so per Ford's recommendation, they replaced a spark plug and cleared the code. When picking it up, the advisor said it's a common issue with 16-17 MYs and that Ford hadn't issued a fix so there is a chance the check engine light might come back on. Sure enough, the next day cruising again at 70ish mph it comes back on! The car now feels a little sluggish and not sure if just in my head but the start up isnt as loud and crisp.

My car has had the PP2 since July with no issues. Could the issue be tune related? Should I reload the tune? Or is this more likely related to the intake Manifold runner control that I've been reading about? I'm taking the car back to the dealership this week but not sure if I should try something with the tune before doing so.

Thanks in advance!

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[ScottsGT]

I think I read here that this is also related to a cracked intake manifold? Please don't quote me, research it.

 

[Rambl3r]

I think I read here that this is also related to a cracked intake manifold? Please don't quote me, research it.

Thanks. Yeah, I found a couple threads with owners with a similar issue that ended up being a broken control rod/shaft but none of them mentioned if they were tuned or not.

 

[usgiorgi]

Thanks. Yeah, I found a couple threads with owners with a similar issue that ended up being a broken control rod/shaft but none of them mentioned if they were tuned or not.

I had a tune on mine when it happened, but it definitely happens to stock cars too. It was the intake manifold runner control valve that broke. The dealer hooked up my car to a computer and took it for a drive. They saw that one of the valves wasn't shutting in the manifold. They replaced the whole thing and found that it was cracked. All under warranty, but I did remove the tune first.

If they really want to blame mods like the air intake, they can since it's all related to the air system. They have to technically prove that the mod did the damage, but who wants to go to court...

If they do say that it's not covered for some stupid reason, fight them, but it'd also be a good time to get the GT350 manifold.

 

[Rambl3r]

I had a tune on mine when it happened, but it definitely happens to stock cars too. It was the intake manifold runner control valve that broke. The dealer hooked up my car to a computer and took it for a drive. They saw that one of the valves wasn't shutting in the manifold. They replaced the whole thing and found that it was cracked. All under warranty, but I did remove the tune first.

If they really want to blame mods like the air intake, they can since it's all related to the air system. They have to technically prove that the mod did the damage, but who wants to go to court...

If they do say that it's not covered for some stupid reason, fight them, but it'd also be a good time to get the GT350 manifold.

Thanks! Fortunately, its the Ford Performance tune and installed by this same dealership.

 

[usgiorgi]

Thanks! Fortunately, its the Ford Performance tune and installed by this same dealership.

At that point start bugging them. If your misfires and bucking sensation only happens under light throttle, it's definitely not spark plugs.

 

[Rambl3r]

At that point start bugging them. If your misfires and bucking sensation only happens under light throttle, it's definitely not spark plugs.

Thanks, again. Yeah, that's the plan. Just wondering if I should try reloading the tune on my own since I have the file on my laptop. But the more I read, the more it sounds like a intake manifold problem.

 

[usgiorgi]

Thanks, again. Yeah, that's the plan. Just wondering if I should try reloading the tune on my own since I have the file on my laptop. But the more I read, the more it sounds like a intake manifold problem.

No, I'd just bring it in and have them fix it. Ask them to check runner control valves as you've seen online posts about the same issue.

 

[Rambl3r]

No, I'd just bring it in and have them fix it. Ask them to check runner control valves as you've seen online posts about the same issue.

Thanks, I appreciate the advice. I'll report back once I take it in to the dealership

 

[rlclemmons]

My car has been to the dealer 4 times for P0308 misfire code. Still no resolution, anyone know what the procedure is for escalation on these sorts of things?

 

[jasonstang]

Make sure your intake manifold is not cracked.
Seems to be related to misfire.

 

[mikeD4V]

My car has been to the dealer 4 times for P0308 misfire code. Still no resolution, anyone know what the procedure is for escalation on these sorts of things?

Honestly, take it to another dealer and quit wasting your time. It's their discretion on how to handle your warranty claim. I also chased my tail on a misfire for several months with one dealer. The first time they actually threw parts at it but from there on they just erased the code and told me to come pick it up. Ended up taking it to another dealer who replaced the pcm (injector driver failed) and gave it back to me within a week. These misfires are unfortunately pretty common and from what I've seen it's either the manifold (cracked or imrc) or the pcm. Good luck.

 

[ITSMEPAUL]

My car has been to the dealer 4 times for P0308 misfire code. Still no resolution, anyone know what the procedure is for escalation on these sorts of things?

Holy smokes... I'd be pissed. Had the same code and it ended up being a broken control rod shaft and also the intake manifold. Car only took 1 full day to repair and give back to me on warranty..

The dealer I went to said that if they discovered a tune on or previously on. They would have kindly rejected the warranty

 

[Rambl3r]

Make sure your intake manifold is not cracked.
Seems to be related to misfire.

Yeah, thats what it sounds like. I told my advisor that I personally think the manifold is cracked or broken and he said they cant replace it without diagnosing it. I'm giving them one more chance to diagnose and fix. Otherwise, I got a recommendation from a member on here for a different dealership that replaced his.

 

[Rambl3r]

Just want to update my thread in case anyone has the same issue. The dealership finally replaced my intake manifold even though they said there was no visible damage. The car has been running strong for a week with no check engine lights Thanks to all who chimed in!

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