[Rob S.]

Hey guys,

Since a couple of weeks my 335i is making a loud rattle/knocking noice. It seems to get worse every week now. The car also gave a engine fault light (reduced power) 2 times...never did this before. After restarting the car the engine light went off.

Can someone tell me what this is? I think it is the wastegate or turbos going bad but im really not sure.

Thanks.

[CustomColours]

Sounds really odd. Almost like when an engine has spat a spark plug apart from the fact its running on all cylinders. Wait till one of the hardcores come and they mite have an answer.

[Rob S.]

Also good to note; this morning the car started up really bad. Never done this before.
Idle was really rough....first 2000rpm idle, then a little bit of stuttering. When the car warmed up everything was fine.

The noice from the above video also disappears when the car is fully warmed up.

[phil200tdi]

Better to open the bonnet to check these things. Turbos are the other side of the car.

Could be the throttle body struggling to open or close due to oil residue -just guessing really.

Any codes?

[Rob S.]

I'll have too be very honest, i'm really no mechanic at all so opening the bonnet wont help me much. I checked but everything seemed fine too me

I will read codes later this day when i get home from work.

[Rob S.]

I really think it is my hpfp going bad. I always ran a mix of about 45L 102 oct mixed with 15L E85 the last months. Yesterday evening i only filled up with 102 oct and the noice is gone. Can it be that my "old" hpfp cant handle the E85 or something like that?

[BEAR-AvHistory]

Do you have current firmware on the JB4? They have been working on the rattle issue if that is your problem.

[Rob S.]

I have ISO 25 now...uploaded it on august 20. Maybe i'll have to try one of the newer 26 versions to see what happens.

[boostaholic786]

That sound after the revs come down has nothing to do with the turbos....IMPO... It sounds more like a belt type noise in my opinion. You also might have a bad injector, coilpack.. When was the last time you changed the spark plugs?

[Rob S.]

You could be right. Can this also be the reason why my car is starting up rough lately?

I only have the car for about 7000 miles and didnt change the spark plugs in this time. I'll have to check the service books for that.

[bigdaddycane]

Rob, how long have you had the JB4? New?

[Rob S.]

Yes i bought it new and installed it about a week after i got the car.

[bigdaddycane]

What are the codes? You can pull them from the JB4 if you have the USB cable hooked up.

[Rob S.]

I will check for codes as soon as i get home from work. Thanks.

[Mike@N54Tuning.com]

Originally Posted by Rob S.

I have ISO 25 now...uploaded it on august 20. Maybe i'll have to try one of the newer 26 versions to see what happens.

Sounds like a misfire to me. First step is to read the codes once they trigger to go at it that way.

Mike

[Rob S.]

Before i uploaded the new firmware i checked the codes. This is what i got:



I then uploaded the new firmware 26.5. When i started the car i only heard a little bit of WG rattle. I set the WG to 0 instead of 80 and the WG is completely rattle free now. Drove a couple of miles and then checked for codes again;



All seems fine now. I have no idea why the car acted so weird and why it threw all those codes.
The car feels very different now because i set the WG to 0. You have too give much more throttle too build up boost now. Atleast it seems that way.

Btw sorry for the HUGE pictures. I uploaded them with my mobile.

[bigdaddycane]

keep checking for codes to make sure they don't come back.

[Rob S.]

When i drove to work a couple of minutes ago the engine light (reduced power) came on again when cruising on the highway. Guess i'll have too check for codes again as soon as i get home.