Was this really a good idea? (BMW 335i)

I just wanted to share my new project.  It’s a 2007 BMW 335i with 173,000 miles.  I saw it sitting behind one of the used car lots I do work for.  When I asked about it they said they just took it in on trade that morning and they didn’t know anything about it and wouldn’t feel good about selling it on the lot, but I could have it for what they had in it.  $1500.  How  could I say no?  It did have a CEL for a misfire in cylinder 3.  I looked underneath and it has unknown coilovers.  Under the hood it has dual cone filters, a throttle body spacer and I found a jb plus tuner plugged into the harness.  I drove it and under higher boost it went into limp mode, but if restarted it cleared.It needs paint on the hood and roof, but the body is straight.  The rockers are plasti dipped as are the wheels and window trim.   I think with some elbow grease and a little work it has a lot of potential.

it Idles rough on start up, but clears up after it warms up. As long as you stay out of higher boost it drives fine. The injector on cylinder three has a little play in it and I think this is why it’s getting the misfire under boost.  I found a cheap fix on an N54 forum that may help.  It involves stacking two decoupler rings and Teflon tape on the injector.  Hopefully it will be that easy.  I also have new spark plugs on the way.

Nice! Any interior pics? Are you bringing it to the Challenge?

The N54  is like a new  2jz for turners. I have fallen to a rabbit hole one youtube watching big single turbo videos. Nasty motor.

Nice pick up! Good luck with the codes and such.

Good score. I'll be interested to see where this goes. N54 BMWs are cool.

Might wanna media blast the intake ports/ valves on that DI. Common problem.

In reply to 2GRX7 :

A previous owner plasti dipped most of the wood trim and some is peeling.  Besides that it’s really nice.  I’d love to bring it to the challenge if I can get the misfire issue resolved under budget.

OMG $1500 is a fantastic price even with the autotragic.  Ignition coils are known to E36 M3 the bed, and they are sensitive to spark plugs as well.  Try a double parts swap, trade #3 plug with #2 and #3 coil with #1. If misfire stays on #3, it’s the injector.

also, I’ve read that the rough idle is typical on cold-start with E50 and up tune, so maybe refuel with E0 and see if it goes away.

Damn that's a great find! Is there a way you can remove the tune then reset everything? 

Then from there troubleshoot the misfire? 

As I'm sure you know, the N54 is known for its fair share of issues  (HPFP, injectors, wastegate rattle, charge pipe failure, etc). But $1500 is still an absolute steal for that car! Looking forward to seeing what you can do with a little effort. Watching with interest.

Yeah my only frame of reference on E92 335i pricing is a friend of mine bought a red on black 335is a couple years back with 86k miles and a blown up n54 and paid $7k if I remember right. Hers has has been super reliable as far as I know after the engine got rebuilt and put back in. Only major issue was a fuel system gremlin that took a couple months to track down last year. 

For 1500, I don't see how you could lose on this. Excellent score!

We can tell you rmpiracly that the trans will not hold more than 500hp in 1-3.  A buddy’s single turbo had to have the tune limited to avoid eating so many trans.  It was really rowdy at 500whp, btw Meth is a hell of a drug.

I decided to pull the cylinder 3 fuel injector today and try the cheap fix I found on the N54tech forum for a loose injector.  When I pulled the injector I found that whoever installed it didn’t even put a de-coupler element on it which is probably why it was loose.  I put a new rubber seal on the tip and put some Teflon tape in for some extra seal.  I took it for a spin and no miss-fires in three pretty solid pulls.  Hopefully that works.

No de-coupler

With new de-coupler, Teflon tape and new seal.

Gotta love cheap fixes! 

Gastropod class has a new front runner!

packrat said:

it Idles rough on start up, but clears up after it warms up.

It has a vacuum leak.

These engines are kinda weird.  The throttle body only really comes into play for the first 60 seconds or so on a cold start.  After that, it runs at WOT and controls everything with intake valve lift.  So if you have a vacuum leak, usually a broken PCV system hose, it only has a vacuum leak during that first 60 seconds.  After that, it runs fine, because no vacuum means no vacuum leak.  Probably would run like E36 M3 under boost though.

In reply to Knurled. :

Im sure you are right.  I have had a code come up for vacuum leak, but wasn’t really worried about that because of the cylinder 3 misfire and assuming that was the main problem.  It ran it hard yesterday afternoon after I worked on the fuel injector and it ran great.  Yesterday evening I went out in it and the first hard pull it went into limp mode which cleared once I restarted it.  Pretty sure it’s a vacuum leak.  Now to find where it is.  Thank you for the advice.

In reply to Knurled. :

That's the N55 you're thinking of.  This one has the N54, which doesn't have valvetronic.  It is DI though.  

I haven't messed around with a 335i before, but OP, get yourself a cheap laptop, a K/DCAN cable and download the ediabas software (look at bimmergeeks.com) so you can code injectors and modules.  The E90s are tricky to work on if you don't have a computer and the right software.  

In reply to rothwem :

I will check into that.  Right now I’m just using a cheap code reader for simple diagnostic.  I’ve read that there are quite a few parts that have to be coded after replacement before they will work properly.  I’m definitely not use to that.  Thank you.

Since you've already made it to an N54 forum I'm sure you know these things, but definitely check the valve cover gasket and oil filter housing gasket for leaks, and the intake ports/valves for sludge. It might need a good walnut blast depending on how well it was maintained. Your vacuum leak could very likely be from the PCV system. On the plastic valve cover motors (N52, N54, N55) the factory PCV system isn't very robust and tends to fail. 

All that said, that's a FANTASTIC score. If nothing else, fix the vacuum leak, clean it up a little, and you could probably sell it for upwards of 7k without much trouble.

In reply to rothwem :

Doh!   Nice catch.

I changed all the plugs but one yesterday.  I’ve never had this, but the cylinder five plug got harder to turn the farther out it came.  Almost like it was stripping on the way out.  I didn’t want to force it, so for now I’m going to leave it.    It would be a bummer to get it out and not be able to get it back in.  It seems to run smoother with the new plugs.  I ran it pretty hard and it seems fine.  We’ll see.  I will definitely need to replace the valve cover gasket at some point.  There was a little oil in almost every spark plug hole. 

Did you put any lube on the #5 plug? It seems like some pb blaster or other penetrating lube put on it while it was partway out would then have time to soak in after you tightened it back up. Should help it come out later.

In reply to dculberson :

I’m going to try that.  With the oil leaking from the valve cover you would think there would be enough lube ;)