[Kryptek49]

Hi, I'm chasing a Vanos issue in my newly purchased N54 335i (59 plate). The code I'm getting (2A98) relates to the intake side. So far I've changed oil, filter, oil filter cap with cage, vanos check valves, and finally vanos solenoids. I've also swapped camshaft sensors, but the code has always stayed on the intake side.

The car did have a new head gasket & timing chain kit fitted in April-21 (before I bought it), fitted by a BMW specialist.

I noted when I took the valve cover off that the Vanos gears on the end of the camshafts are aftermarket. I've spoken to the garage who carried out all the work, they remembered the car and said yes, they used aftermarket Vanos gears as part of the timing kit, but they use these alot and have never had any issues or failures.

The garage reckons that an oil passageway in the head might be clogged, and need blowing out. I believe the oil passageway for the Vanos feeds directly into the camshaft ledge, so I would need to remove the camshaft to access this?

The 2A98 code came on suddenly, and appears immediately after turning the car on (or once the revs have settled to idle). The car drives fine (despite being in limp mode), and there's no weird noises, just a very rough idle. The sudden appearance makes me think it's not the camshaft bearing ledges, as this would have been a more gradual failure. The code reappears immediately after clearing, and doesn't disappear after the car heats up.

Any thoughts on this? I'm thinking I've got no option now but to pull the camshaft out and take a look. Possibly just chuck an OEM Vanos gear in to make sure that's not the issue, but they are about £400 from BMW, so I don't want to replace unless they are actually the fault.

[Kryptek49]

Bump - any ideas?

[Tyc0]

Never heard of aftermarket cam gears…but this sounds like cam ledge issues, do some research and see if this sounds right. If you are an earlier build date it's very possible, had the problem myself on an 08.

[Dave92N54]

Originally Posted by Tyc0

Never heard of aftermarket cam gears…but this sounds like cam ledge issues, do some research and see if this sounds right. If you are an earlier build date it's very possible, had the problem myself on an 08.

It appears that ECS lists Dorman intake/exhaust cam gears and a Vaico exhaust cam gear.

OP I'm guessing they're Dorman?

[Kryptek49]

Originally Posted by Tyc0

Never heard of aftermarket cam gears…but this sounds like cam ledge issues, do some research and see if this sounds right. If you are an earlier build date it's very possible, had the problem myself on an 08.

Me neither, but the garage said the previous owner didn't want to pay full price for BMW so they fitted the aftermarket ones instead.

The car is an 09, but I'm based in the UK so I don't think we got any revised cam parts on the later model cars.

I've ordered a timing kit, so I'm going to pull the camshaft out either way and inspect the ledges. I've ordered a used OEM vanos gear too, and will chuck that in for good measure while the cam is out.


Cam ledge is the obvious issue, but it just doesn't make sense that it would be a sudden failure?

[Kryptek49]

Originally Posted by Dave92N54

It appears that ECS lists Dorman intake/exhaust cam gears and a Vaico exhaust cam gear.

OP I'm guessing they're Dorman?

No idea on the brand, I couldn't see anything clearly stamped on it, but I wasn't really paying that much attention as I was just replacing the valve cover, not digging in to the Vanos at that point.

I'm based in the UK though, so probably not parts from ECS. I can't find any aftermarket Vanos units available through reputable websites in the UK, only via Autodoc which is imported from Germany.

[Tyc0]

I wouldn't call it a sudden failure, but it has to start failing at some point right

[Alkapwn]

My money would be on ledges. Unfortunately they keep getting more expensive parts wise for some reason. Maybe they stopped making them?

[Kryptek49]

All sorted now: the timing had slipped...

I took the valve cover off on Saturday, lined the cams up and the locking tool fit nicely.

Went to put the crank locking tool in, but it wouldn't go in.

I took the cam locking tools off, and had to rotate the engine again until the crank pin finally went in.

Went back to put the cam locking tool on, and both cams were out! Both still slightly pointed to the left...

I assume the exhaust vanos has slightly more movement than the intake vanos, hence why I was only getting in an intake camshaft error.

I've retimed it now and everything is running perfectly now.

Obviously the big worry is why did it slip? I wasn't pushing it that hard when the error came up, it was the second day I'd owned the car and I was taking my Dad for a test drive, so a few full throttle applications, but nothing crazy? Car dyno'd at 350hp, so again nothing crazy there.

It did have a timing kit fitted back in April this year, maybe it was just fitted incorrectly? I would have thought that the code would appeared much sooner though. If the timing has slipped, then it might be an issue with the crank bolt?

[Dave92N54]

Try to do some searching, I can't remember what I did to come across it but came across a thread almost exactly like this. Someone fitted new cam gears, rode fine for a bit and then bam timing was off just a tad.

[Kryptek49]

Interesting - I hadn't thought that aftermarket cam gears could somehow relate to timing going out - I'll do a bit of googling to see if I can come up with anything. I've got a set of OEM vanos gears that I purchased second hand, but I reused the aftermarket ones as they appeared to be in very good condition when removing them. They are a fairly simple design to be honest, so I can't quite wrap my head around how I could lose timing due to the gears.

[Mustafa.e92]

I mean the car just had the timing chain done could be installer error on something? I'd go over everything related to the timing system and double check torque ect

[Alkapwn]

Originally Posted by Kryptek49

All sorted now: the timing had slipped...

I took the valve cover off on Saturday, lined the cams up and the locking tool fit nicely.

Went to put the crank locking tool in, but it wouldn't go in.

I took the cam locking tools off, and had to rotate the engine again until the crank pin finally went in.

Went back to put the cam locking tool on, and both cams were out! Both still slightly pointed to the left...

I assume the exhaust vanos has slightly more movement than the intake vanos, hence why I was only getting in an intake camshaft error.

I've retimed it now and everything is running perfectly now.

Obviously the big worry is why did it slip? I wasn't pushing it that hard when the error came up, it was the second day I'd owned the car and I was taking my Dad for a test drive, so a few full throttle applications, but nothing crazy? Car dyno'd at 350hp, so again nothing crazy there.

It did have a timing kit fitted back in April this year, maybe it was just fitted incorrectly? I would have thought that the code would appeared much sooner though. If the timing has slipped, then it might be an issue with the crank bolt?

Do you know if they replaced the friction discs on the crank hub? If they didn't, or if it wasn't torqued correctly, that can cause this issue. This is one of my largest concerns with this platform, so I intend to do the timing soon and throw on an aftermarket crank hub with splines to try to reduce the likely hood of this occurring. I'm also going FBO though.

As mentioned, it could just be that the timing was not set correctly when the service was performed, however if you have been using the vehicle regularly since, this would seem unlikely, as its been many months, for the issue to just now be ocurring.

[Kryptek49]

Well... Timing slipped again and engine is now written off. The crank bolt came loose - not sure if garage that replaced it didn't torque it properly, or maybe reused the stretch bolt. Either way, it's new engine time.

[Dave92N54]

Ouch. That's rough man. Sad to hear.

[Kryptek49]

Thanks, I'm going to make the most of a bad situation by fitting new turbos and downpipes while the engine is out.

Reason for failure is a reused crank bolt - now I've taken it out it's clearly the original, and not a 6 month old part. Takes the p*ss a garage can charge £500 for a timing kit (just for the parts), and not replace a stretch bolt that is torqued 100NM + 360 degrees.