Service Issue w/ Local Dealer...

[pshep138]

Hello fellow F8x owners! I'm hoping to get some insight here as I'm having an issue with my M4 at my local dealer, and I've never been in this situation before. This is going to be a lengthy thread as this has been going on for over two weeks.

Some background on me - this is my second M car, my last being an E46 M3. I work for a dealership selling European and exotic cars, and I've been around cars of that caliber for most of my adult life. I'm intimately familiar with the automotive industry, both in service and sales.

In April 2023, I bought a 2020 M4 Competition with 19k miles from a dealer out of state. Car has factory warranty to February of 2024, and the dealer threw in a year of CPO warranty to carry me to February 2025. I've put roughly 3k miles on the car since I've had it, through a mix of daily driving as well as some more enthusiastic drives with friends. The car has been absolutely flawless since I've owned it. No weird idles, no strange noises, no check engine lights... nothing.

The car came due for service in June 2023, so I booked it in to my local BMW dealer and dropped it off as soon as they could get it in, which ended up being 14 July. I dropped it off at 08:30 and they confirmed it was due for the year 3 service, which includes an oil service, cabin air filter, engine air filter, and spark plugs. They told me everything was in stock, and the car would be done the same day. The service advisor at the store happens to be a buddy of mine who started there a couple of months ago, but he's been a service advisor at other stores for the better part of a decade.

I get a call later that day that they got the car done, got it put back together, and it threw a misfire on cylinder 6. They're going to pull the new plug out of cylinder 6 and replace it with another new one, but my car should still be done by the end of the day.

I get a call a couple of hours later that they replaced the cylinder 6 spark plug, and now the car is throwing a misfire on cylinder 1. They're now going to replace THAT spark plug again, as well as all six ignition coils under warranty, just to be safe. They have the ignition coils in stock, but the car won't be done today, so I can pick it up Saturday, 15 July. Okay, no problem.

I get a call Saturday morning, cylinder 1 spark plug has been replaced, as well as all six coils, and the car is still throwing cylinder 1 misfire. They're now going to replace the fuel injector for cylinder 1. They have to order it, but it should be there Monday, car will be done Monday or Tuesday. They gave me a loaner, so at this point, I'm just going with the flow. Car is under warranty and I'm assuming it'll be taken care of.

To keep the story somewhat brief, the car has continued to throw a variety of codes since they did the service. It's thrown misfire codes on several cylinders, as well as A/F mixture too rich codes on cylinders 2 and 3. The car drives completely normally until it enters boost, and then it throws codes and develops a rough idle.

In the last 18 days, the dealer has replaced the following -

• All six spark plugs (most twice)
• All six ignition coils
• All six fuel injectors (one twice because it failed testing new out of the box)
• Turbo inlet pipe to the front turbo (the seal was found to be leaking when they smoke tested the intake system)
• BOTH fuel pumps

They've done leak down and compression tests on every cylinder and it showed 2% valve leak and compression was normal across the board. They've scoped every cylinder to check for debris that could've entered the cylinder when the plugs were done and found nothing. They scoped the intake system to make sure the intercooler wasn't leaking coolant into the intake air. Their master techs have looked over the car and found nothing, and all of their shop management staff has looked over the car and data logs and found nothing. They've even gone so far as to review video of the tech servicing the car to see if something was done incorrectly, and found nothing. BMW North America is now involved, and the dealer has run all of their test plans, and the car continues to throw error lights with seemingly no explanation.

The latest update today (2 August) is that BMW North America now wants them to pull the valve cover off to inspect the valvetrain, and a rep from BMW NA now has to come to the dealer and look over everything, and he'll either be there "late this week or into next week" which will put me beyond the three week mark of my car being in their shop. The dealer has put over $14,000 in parts (warranty FTW I guess) into the car with no improvement and no answer. My buddy seems to think it's a DME issue, but BMW won't authorize a DME replacement under warranty until this rep comes and looks at my car.

Has ANYONE had a similar issue with an S55 powered car? I just can't wrap my head around how I dropped off a perfectly running 22k mile car for a routine service, and it's turned in to this. Is there something very obvious that everyone at the dealership is missing?

Related, what sort of compensation (if any?) should I expect from the dealer at this point? I work at a Bentley store that also sells used exotics, and we've comp'd many, many hours of labor and parts when we've had similar issues, and we've even gone so far as to cover car payments when a car is in the shop for an extended period of time. I did ask the dealer if I could get an M Performance exhaust at cost with free install while the car is there as a kind of olive branch, and they told me not only will they not sell it to me at cost, they won't match getBMWparts or any other online price, and it would be full MSRP if I wanted it. Loooool

[pshep138]

Since I've gotten zero replies, I figure I'd offer an update -

The rep from BMW North America inspected my car today. They plugged some proprietary tool that BMW NA has into the wiring harness of my car, and they can basically use a tablet to test the entire electrical system of the car. They got what they're calling a "slow response" from the DME with regard to the ignition system, so they're now replacing the DME.

As far as a cause, the BMW rep said they've seen this happen "a handful of times" when spark plugs are replaced - essentially when the spark plugs get too worn, the car can experience what they called "electrical blow-by" that the DME tries to make up for, and when you replace the plugs and fix this problem, the DME swinging back the other way to make up the difference can actually cause it to short. They inspected my old plugs and confirmed that this appeared to be the case. For what it's worth, the plugs are supposed to be done at 3 years or 30k miles, and I'm at 3 years and 22k miles. He said replacing plugs more often than even what the factory maintenance calls for can prevent the issue.

DME will be here later this week, and we'll see if I get my car back or not.

[N1rve]

Originally Posted by pshep138

Since I've gotten zero replies, I figure I'd offer an update -

The rep from BMW North America inspected my car today. They plugged some proprietary tool that BMW NA has into the wiring harness of my car, and they can basically use a tablet to test the entire electrical system of the car. They got what they're calling a "slow response" from the DME with regard to the ignition system, so they're now replacing the DME.

As far as a cause, the BMW rep said they've seen this happen "a handful of times" when spark plugs are replaced - essentially when the spark plugs get too worn, the car can experience what they called "electrical blow-by" that the DME tries to make up for, and when you replace the plugs and fix this problem, the DME swinging back the other way to make up the difference can actually cause it to short. They inspected my old plugs and confirmed that this appeared to be the case. For what it's worth, the plugs are supposed to be done at 3 years or 30k miles, and I'm at 3 years and 22k miles. He said replacing plugs more often than even what the factory maintenance calls for can prevent the issue.

DME will be here later this week, and we'll see if I get my car back or not.

I think you're the only one I've read that has ever had this issue lol.

[mapster37]

Never heard of this issue, especially not 2 different cylinders...

[pshep138]

Bump - DME didn't fix it. Since that didn't fix it, they thought maybe it was a wiring issue with the part of the harness going to the fuel injectors, so they replaced that today and it didn't do anything.

Now timing is being mentioned. They're replacing the crankshaft position sensor, and if that doesn't fix it, they're ripping into the timing system.

[pshep138]

Originally Posted by N1rve

I think you're the only one I've read that has ever had this issue lol.

Lucky me I guess.

[pshep138]

Will I ever see it again?

[WordOnRoad]

This is a nightmare, sorry to hear it OP.

When I worked at BMW, we handed out car payments like Oprah in cases like this. You've got a solid case and your advisor should be advocating for you as well.

[pshep138]

Originally Posted by ArnoldRobson

I love the color.

Me too. I looked at several others before landing on San Marino Blue, and now I can't imagine having anything else (non-Individual, that is). It gets so many compliments.

Originally Posted by WordOnRoad

This is a nightmare, sorry to hear it OP.

When I worked at BMW, we handed out car payments like Oprah in cases like this. You've got a solid case and your advisor should be advocating for you as well.

Yep, we do the same at the store I work at, though we've only had to do it once (knock on wood).

BMW NA is sending me $1,000, and I have another payment due next week, so I'm seeing if they'll send me another $1,000 since there's seemingly no remedy on the horizon.

[pshep138]

Bump again - engine timing was perfect today when inspected, so they've ruled that out. They've now submitted to BMW to see what they recommend. We're all out of ideas at this point.

[alex2364]

Originally Posted by pshep138

Bump again - engine timing was perfect today when inspected, so they've ruled that out. They've now submitted to BMW to see what they recommend. We're all out of ideas at this point.

Probably not what you want to hear, but replace the whole engine?

[pshep138]

Originally Posted by alex2364

Probably not what you want to hear, but replace the whole engine?

The engine, mechanically speaking, is perfect. They've scoped the cylinders to inspect for damage and found nothing, and leakdown and compression test were totally normal.

It's some weird electrical gremlin somewhere.

[pshep138]

Went to see it yesterday. BMW NA basically has them replacing MAF sensors and O2 sensors to rule everything out. They also said they'll be checking the flywheel, since apparently the flywheel being out of balance can cause the crankshaft to spin erratically and throw timing off.

The phrase "engine replacement" is now being openly discussed.

[Hxngs]

Oh man what a nightmare

[pshep138]

Originally Posted by Hxngs

Oh man what a nightmare

I'm not stoked, to say the very least. If they end up replacing the engine I might just sell the car.

Sucks because it took me longer to find the car and buy the car than I've owned it.

[FrozenGT]

My 2020 M4 Comp has 18900 miles and get babies and serviced at the same BMW dealer near my home.

I’ve heard of people beating the crap out of their cars and never have any issue so hopefully this is a one time fluke.

[DeezBluBallz]

Originally Posted by pshep138

I'm not stoked, to say the very least. If they end up replacing the engine I might just sell the car.

Sucks because it took me longer to find the car and buy the car than I've owned it.

Any updates?

[pshep138]

Originally Posted by DeezBluBallz

Any updates?

Yes. After a few more fruitless weeks, we finally have some progress.

Last week, the dealer determined it to be an issue with the valvetrain. BMW had them pull the intake manifold and put liquid on the intake valves, pressurize the cylinders, and look for bubbles. They found bubbles on the intake valves in cylinders 1 and 6 - two of the cylinders that have been misfiring persistently. Inspecting the intake valves revealed what BMW determined to be an excess of carbon buildup. The dealer said I'm not driving my car hard enough, I guess?

Rather than carbon clean the valves, they elected to replace the cylinder head under warranty ($18k for the part). There isn't a new S55 cylinder head anywhere in the US, so they requested it from Germany. Turns out, there isn't one in Germany, either.

Since they can't find a cylinder head by itself, and seemingly don't want to rebuild/reuse mine, they're replacing the entire engine. The engine arrived at the dealer this morning. So, we'll see how that goes.

My Service Advisor told me between parts and labor, total bill is going to be about $86,000. Biggest ticket this dealer has ever had on a single car.

[G35POPPEDMYCHERRY]

i mean 86k is a bullshit price lmfao. most f8x were cheaper than that brand new.


also, they should have pulled the head immediately after the leak down. this shows the utter incompetency of bmw service. why the fuck would you replace the head without looking for damage more down end...

anways, so sorry this happened to you man. i cringe every time I put my car into service.

[G35POPPEDMYCHERRY]

also, plugs worn at 3 years 22k. that is total utter bullshit.

[pshep138]

9 week update - new motor arrived at the dealership and is going in.

Car will be in break-in mode when I get it back. Now I get to try and put 1,000 break-in miles on it before the snow gets here, just in time to put it away for 3 - 4 months for winter.

[pshep138]

Originally Posted by G35POPPEDMYCHERRY

i mean 86k is a bullshit price lmfao. most f8x were cheaper than that brand new.


also, they should have pulled the head immediately after the leak down. this shows the utter incompetency of bmw service. why the fuck would you replace the head without looking for damage more down end...

anways, so sorry this happened to you man. i cringe every time I put my car into service.

As far as the $86k, I believe it. All of the parts pricing I've been quoted is at full dealer MSRP, so it's been insanely expensive. The new S55 by itself was $35k. DME computer was something like $3,500, they've put two sets of injectors in at $1,500 each time, both fuel pumps, turbo inlet pipes, a couple of sets of ignition coils, plus whatever they've tried that I'm forgetting... plus god knows how many hours of labor.

The parts total alone before the new S55 was over $30k.