Broken IMRC shaft - P0308, P0300

[17gbgtpp]

My car (17 GT, 18K miles) recently triggered codes P0300 (general misfire) and P0308 (misfire #8), at the same time it developed a stumble only at really light throttle at around 2000 rpm. Google gave up a couple hits that pointed toward a broken intake manifold runner control (IMRC) shaft:
[ame]
There are plenty of comments on the video with people with the same issue, and the common thread is that the dealer couldn't diagnose it.

Long story short, took the car in and after a couple mis-diagnoses, the dealer pulled the manifold and confirmed it was the issue. So, making this thread for a couple reasons:
-if your car has this same set of symptoms, check the intake manifold!
-I haven't found any other threads on this, are other people having this issue? If this happened once it'll happen again, and I think Ford should publish a TSB for it (the tech that wrote up the repair on my car was really surprised there wasn't a TSB since it's hard to diagnose). This might need a revision to the IMRC shaft design if it's breaking at 17K miles.

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[johnny.3sgte]

Mine decided to go out at 31k miles on my 2017, I had to take apart the intake manifold myself and document it with a video to prove to the technician and service writer that it was the manfiold and not the plugs and coils. They replaced it today.

 

[usgiorgi]

Mine went at around 10k in my 2016 gt

 

[69mach1-395]

I see 3 cases here...do all of you drive 'enthusiastically' or have mods for such?

 

[usgiorgi]

I see 3 cases here...do all of you drive 'enthusiastically' or have mods for such?

There's a whole thread about this issue a few pages over. Alot of people have had their IMRCs go bad.

Mine had an intake and a tune at the time but alot of stock people had theirs break as well.

 

[69mach1-395]

Okay...I'll check it out. Didn't mean to imply anything. Just wondering how common an issue it is.
Edit; looked for several pages and did not see...got a link?

 

[17gbgtpp]

I couldn't find any threads on it. My engine is bone stock. It's my commuter and I drive pretty conservatively most of the time.

 

[usgiorgi]

Here's one. Some call it a cracked manifold. I believe it cracks and gets the IMRC valve stuck. That's what happened to mine.
https://www.mustang6g.com/forums/showthread.php?t=85551

 

[17gbgtpp]

Thanks, glad it's not just me at least. They seem to fail at pretty low mileage, I wonder how many repeats are out there? Just thinking that if it's a manufacturing or design defect, it's just as likely to happen again.

 

[2morrow]

I see 3 cases here...do all of you drive 'enthusiastically' or have mods for such?

Add 1 more. Mine is pretty much a track car at this point. I'm thinking my IMRC shaft might be broken as all the vacuum lines are good and the connectors are all looking fine.

 

[Daffy]

My car (17 GT, 18K miles) recently triggered codes P0300 (general misfire) and P0308 (misfire #8), at the same time it developed a stumble only at really light throttle at around 2000 rpm. Google gave up a couple hits that pointed toward a broken intake manifold runner control (IMRC) shaft:
[ame]
There are plenty of comments on the video with people with the same issue, and the common thread is that the dealer couldn't diagnose it.

Long story short, took the car in and after a couple mis-diagnoses, the dealer pulled the manifold and confirmed it was the issue. So, making this thread for a couple reasons:
-if your car has this same set of symptoms, check the intake manifold!
-I haven't found any other threads on this, are other people having this issue? If this happened once it'll happen again, and I think Ford should publish a TSB for it (the tech that wrote up the repair on my car was really surprised there wasn't a TSB since it's hard to diagnose). This might need a revision to the IMRC shaft design if it's breaking at 17K miles.

My 2016 GT mustang broke one at only 15000 km. Repair bill in Australia was just over $2000 - certainly not impressed.

 

[Cobra Jet]

This thread, another M6G member repaired the broken IMRC shaft using JB Weld and it was fully functional again after the repair.
https://www.mustang6g.com/forums/threads/our-first-dtc-p0308.160243/

99% of the time, the IMRC failures are due to the broken shaft. Looking at images of the shaft, the break is occurring because the diameter of the shaft is too small for the torque being applied by constant activation.

 

[shadowx]

I think I'm having the same issue with my 2019 FBO E85 tune has 30k miles. got P0300 first and now disappeared and got P0308. changed spark plugs and replaced ignition coil 7 with 8 but got same 308 code so coils are good.

yesterday got 308, 307 and I think 316. ( sometimes flashing CEL when I push half throttle and it shakes. flashing CEL stops after normal driving.

anyone knows if a dealer would cover it under the warranty since it's tuned? or just fix it in other shop?

 

[Cobra Jet]

Since you have a Tune it's a gray area with Service Centers. Some M6G members have listed they had warranty work completed with a Tune, others have not been so lucky.

You can take it in and see what happens, worst case is they charge you for the work performed. Some won't event touch it if it has a Tune, because they don't know anything about the Tune and it's a liability issue for them.

--

Go to the link a few post above yours here and see the hyperlink for the other M6G member who repaired their IMRC actuating rod. You'll easily be able to tell if that is the same issue on your intake (snapped).

 

[shadowx]

is there like something they can put in the system that they voided my warranty if I brought it in and they saw I got a tune?

thank you

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