Engine start up issues - N54

[Drawn05]

I have been searching for a similar issue on these forums but havent come across anything the same. I have had my N54 135i for only 1.5 months and I have been noticing that on cold starts, when it idles between 900rpm and 700rpm it is a bit on the rough side. I am not too concerned with that but rather when the engine starts warm, it will hit 1500rpm and a slight clunking noise can be heard then revs plummet down to 600/700rpm.

It seems to run fine, no cels or any other issues, but I am not sure if it is fine or not?

I will try and get a video later and run the BT tool on it but has anyone had a issue that sounds like this? There is no long crank just a clunk when it hits 1500rpm.

Edit: it does this intermittently, sometimes it will start perfectly with no weird noise and other times it clunks really loudly.

[mcmn]

Does it happen only in gear, or out of gear too? Is the car MT or AT?

Paul

[Drawn05]

Originally Posted by mcmn

Does it happen only in gear, or out of gear too? Is the car MT or AT?

Paul

Only happens in park in startup - its an auto.

[mcmn]

If it only happens in Park - and not in another gear, its gotta be trans related?

Is the car still under warranty? You'd wanna get that checked out.

Paul

[Drawn05]

I still have about 7 months warranty left so I will take it to a dealership. As I said, its intermittent so hopefully they wont do the "well we couldnt hear anything" spiel.

[Zuzu]

Originally Posted by Drawn05

I still have about 7 months warranty left so I will take it to a dealership. As I said, its intermittent so hopefully they wont do the "well we couldnt hear anything" spiel.

Doesn't matter what they say.. As long as the fault is reported and investigated during the warranty period you are covered..

[RaihaX]

Mine dissapeared after changing my vanos solenoid.

[Drawn05]

Originally Posted by RaihaX

Mine dissapeared after changing my vanos solenoid.

So you had a clunking noise on warm starts too? Was your engine performing ok apart from that?

[RaihaX]

Originally Posted by Drawn05

So you had a clunking noise on warm starts too? Was your engine performing ok apart from that?

Hmm I wouldn't call it a clunking noise but on a cold start as the rev goes down every now and then I will hear this sort of like a knock sound.

Change my solenoid and now is gone.

I did pull a solenoid code though (2A87 - Exhaust Solenoid) every now and then while cruising.

[Superdaws]

Originally Posted by Zuzu

Doesn't matter what they say.. As long as the fault is reported and investigated during the warranty period you are covered..

^ just make sure its logged as to why you brought it in and your good.

[MikeVictor]

Just a thought, but it's not the exhaust flap closing is it? It'll be open on start up and can make a noticeable noise when it shuts.

[Drawn05]

No, its definitely coming from engine bay. I am going to take it the dealers and get their opinion. Does procede have a complete bypass or will I need to remove it before going to dealers?

[Stuart@BMRAutowerkes]

Originally Posted by Drawn05

No, its definitely coming from engine bay. I am going to take it the dealers and get their opinion. Does procede have a complete bypass or will I need to remove it before going to dealers?

It has a bypass 'valet mode' which works fine on most service items eg oil change, brake pad change...

but if they are investigating things in the engine bay for peace of mind I'd remove it altogether. Happy to do it for you if you want to drop by.

[Drawn05]

Originally Posted by bmroxm5

It has a bypass 'valet mode' which works fine on most service items eg oil change, brake pad change...

but if they are investigating things in the engine bay for peace of mind I'd remove it altogether. Happy to do it for you if you want to drop by.

That would be great. Maybe you could have a listen to the noise it makes and see what you think. When is good for you?

[Tallest]

any more on this? I got the same issue - engine bay under somewhere a clunking noise. it's as I start up the car (cold) and as I shift into R sometimes (also on start up - i back out of driveway). But in warm car it doesnt happen. I have 325i N52, I'm not sure it has a flap of any kind.

[JB4-335]

I get the same noise Steve. Not everytime but most. Never really worried me to be honest although I would like to know what it is.

[Drawn05]

I dont get it anymore - I think it was just because of infrequant use as the previous owner had it sitting in the garage for 3-4 months before I got it. Or maybe its still there and I am used to it?

I have a worse noise at the moment - coin stuck in the drivers sub-woofer (I think?) thats shifting around in there!! Its terrible and I cant get it out.

[RaihaX]

Originally Posted by Drawn05

I have a worse noise at the moment - coin stuck in the drivers sub-woofer (I think?) thats shifting around in there!! Its terrible and I cant get it out.

Welcome to my nightmare, I have ripped apart every single dash board finding this thing and I think mine is in there too

[Drawn05]

Originally Posted by RaihaX

Welcome to my nightmare, I have ripped apart every single dash board finding this thing and I think mine is in there too

Its seems to be a bit of a design flaw as they have these large openings at floor level that go straight into the sub-woofer. I have been meaning to take it to the dealers and let them sort it out.