EPC | Hide Cylinder | Misfires

[Innocznt]

One day I put my car in park and was idling while dropping off my sisters friends and the EPC light came on and started shaking a lot. I turned it off and back on and it went away. Seems like while idle, it’s a problem but when I’m driving, it drives completely fine with no issues.

When I got home, scanned it for codes and had a Cyl4 misfire and Hide Cylinder code. I then bought spark plugs and got my cousin to put them in.

I was still getting the codes after changing the plug so I went and bought a coil pack at an auto store and put it on cyl 4 hoping that would fix the issue and nothing.

Not sure why I’m getting misfires still after changing all 4 plugs but I’m lost. I’ve been looking into this issue and it’s been a thing but people have different issues and I’m not sure how to find out what mine is and how to fix it.

It also seems like if I keep the car running while the EPC light is on, more misfires occur. I attached a picture when I scanned it the other day and had more than one misfire. Again, car drives completely fine when I restart it and don’t idle.

2016 GTI — 113,000 km.

 

[MK7GTIJACOB]

One day I put my car in park and was idling while dropping off my sisters friends and the EPC light came on and started shaking a lot. I turned it off and back on and it went away. Seems like while idle, it’s a problem but when I’m driving, it drives completely fine with no issues.

When I got home, scanned it for codes and had a Cyl4 misfire and Hide Cylinder code. I then bought spark plugs and got my cousin to put them in.

I was still getting the codes after changing the plug so I went and bought a coil pack at an auto store and put it on cyl 4 hoping that would fix the issue and nothing.

Not sure why I’m getting misfires still after changing all 4 plugs but I’m lost. I’ve been looking into this issue and it’s been a thing but people have different issues and I’m not sure how to find out what mine is and how to fix it.

It also seems like if I keep the car running while the EPC light is on, more misfires occur. I attached a picture when I scanned it the other day and had more than one misfire. Again, car drives completely fine when I restart it and don’t idle.

2016 GTI — 113,000 km.

Have you ever done a carbon cleaning?

 

[yakboyslim]

Leaky injectors is another possibility (though it looks like the problem is spread across multiple cylinders).

Do you have anyway to log? Like simostools or accessport?

 

[scrllock]

how did your plugs look? if they were oily, consider replacing the PCV. if they smelled like fuel, probably a leaking injector. likely need to take the manifold off and inspect the valves/injectors.

 

[Innocznt]

how did your plugs look? if they were oily, consider replacing the PCV. if they smelled like fuel, probably a leaking injector. likely need to take the manifold off and inspect the valves/injectors.

Did a compression test at a shop and cylinder 4 had 60 psi. They say likely a valve spring, fixable he said. I’m hoping not too much damage, things have gotten worse and I basically have to restart the car every time I’m stopped until I’m moving and things are fine.

Waiting for a quote to see how much it’ll likely be.

 

[skwalter2]

Something similar has been happening to my Mk7.5 GTI S (~52k miles) over the past 18 months, or so. I'll be driving, the EPC code pops, car vibrates, and I pull over. After a few minutes, I'll start my car again and go about my day. However, sometimes the code will pop again and it will be accompanied by the check engine light. My car is still under warranty and is currently at the dealership for the 3rd time (in the past 18 or so months). It could even be the 4th, but no less than 3. Anyways, they've replaced cylinder #2, part of the engine wiring harness, the entire engine wiring harness, and this time they'll be replacing both cylinder #2 and the wiring harness. To this point they've not given me much in terms of why it keeps happening, and I'm not knowledgeable enough myself to figure it out. After each of the aforementioned repairs, my car's run well for a while, but it always returns. Any thoughts?

This doesn't help with the issue that started this thread, but I just want you to know I'm here in solidarity.

 

[hans611]

Wow this is getting more common, I have seen this 3 times before, but they where all 2015 model year GTIs... first time I see this happen on a 2016.....

The last guy this happened to got charged about $2500 for parts and labor by a CA shop....

 

[YamR1rider]

Something similar has been happening to my Mk7.5 GTI S (~52k miles) over the past 18 months, or so. I'll be driving, the EPC code pops, car vibrates, and I pull over. After a few minutes, I'll start my car again and go about my day. However, sometimes the code will pop again and it will be accompanied by the check engine light. My car is still under warranty and is currently at the dealership for the 3rd time (in the past 18 or so months). It could even be the 4th, but no less than 3. Anyways, they've replaced cylinder #2, part of the engine wiring harness, the entire engine wiring harness, and this time they'll be replacing both cylinder #2 and the wiring harness. To this point they've not given me much in terms of why it keeps happening, and I'm not knowledgeable enough myself to figure it out. After each of the aforementioned repairs, my car's run well for a while, but it always returns. Any thoughts?

This doesn't help with the issue that started this thread, but I just want you to know I'm here in solidarity.

I recently went through this with my daughter's 145k mile 2015 Tsi 18Tsi. I changed spark plugs coil packs, carbon cleaned and put in new injectors (which made the car run really nicely), but we still ended up with the random misfiring and EPC light/shuddering/loss of power. Turn off, turn on and all was fine (till the next time). Typically happened every 2-3 weeks, usually when the car was lukewarm and at steady suburban speeds. Codes in my case were always 'cylinder pressure too high' (any given cylinder), followed by the 'hide cylinder' which would trip the EPC.

Did a bit of researching around and turns out that (specific to those codes only), it seemed that it was a known problem on some 2015-2016 VWs and A3/S3 Audis and eventually, there was a little known software fix put out for it. I also heard that flashing the car with a tune might fix it, so that's what I did (APR) and lo and behold, the problem is now long gone.

Not saying that's your issue though as I've not really heard of it really affecting the 2 liter cars so much (and codes getting thrown may be different from those two specific ones in which case it could be something else entirely). But might just be worth checking if there may be some sort of software fix out there (from the other threads out there, it seems that dealers didn't really know, so they needed some prompting).

 

[Diggs24]

cylinder pressure too high is caused by pre-ignition knock. They probably just turned the gain up on the knock sensors.

 

[YamR1rider]

Makes sense. This was one of the threads I found out there on the issue , at least one person had the problem solved by replacing the knock sensor, others a tune or software fix....and many others getting the royal runaround. Interesting that in nearly all cases it always happened when car was lukewarm and typically at light throttle. One of the Audi TSBs (I think I came across others too when I was researching it): https://static.nhtsa.gov/odi/tsbs/2015/MC-10128395-9999.pdf

 

[Diggs24]

It can also be cause by excessive noise in the motor. Built motor guys run into this code a lot due to the piston slap from their forged pistons.

 

[Innocznt]

It can also be cause by excessive noise in the motor. Built motor guys run into this code a lot due to the piston slap from their forged pistons.

Shop quoted me for valve springs and camshaft stuff, then double checked when I dropped the car off and did a leak test.

Wasn't valve springs.

Now he's saying something about piston rings or some shit. Compression is leaking near where some oil shit is, I didn't hear much other than "not good news" and "we need your car for a week". He said he'd have to remove my engine and transmission to replace what he needs to. Is it worth doing this? I have a pretty stupid fucking loan for this car and have NO idea what to do.

 

[Innocznt]

how did your plugs look? if they were oily, consider replacing the PCV. if they smelled like fuel, probably a leaking injector. likely need to take the manifold off and inspect the valves/injectors.

Plugs were fine. No fuel, no oil. Injectors aren't an issue and carbon cleaning isn't an issue either. I'm being waiting on a quote to get my piston rings replaced, or think about if it's even fucking worth it to have a car at this point.

 

[phoffman183]

I had the same misfire issues with my 2016 GTI. Cylinder 4 misfire kept coming up and I found oil on plug 4. performed a compression test and cylinders 1-3 had 180 psi and 4 had 90 psi. Pulled the engine this past weekend and found pieces of the #4 piston and rings in the oil pan. Looks like it’s time for a rebuild.

Car just rolled 75k.

 

[Innocznt]

I had the same misfire issues with my 2016 GTI. Cylinder 4 misfire kept coming up and I found oil on plug 4. performed a compression test and cylinders 1-3 had 180 psi and 4 had 90 psi. Pulled the engine this past weekend and found pieces of the #4 piston and rings in the oil pan. Looks like it’s time for a rebuild.

Car just rolled 75k.View attachment 281863

Took mine to VW and they said Cylinder 4 has 0 compression. Cars all apart, cams are out and the cam sprockets are leaking oil. Won't know for sure until the morning and hopefully the number is in my favor.

Sorry about your car though I'll probably rebuild unless they give me a number that's doable.