[Mikep83]

Maf looks like new. Taken car out a few times today, not had issue this afternoon. Weird

 

[Rupes]

Unfortunately the fact that it's new might be part of the problem, Mike.

You can buy imitation MAFs online for a fraction of the price of a genuine part. The only drawback is that they don't work.

See if you can make friends with someone nearby who could lend you theirs for a few minutes to help you find out if this is the problem.

Alternatively, hook the car up to diagnostic software (like INPA, for example) to see if the signal being generated by the MAF looks plausible.

 

[Timm]

Maf looks like new. Taken car out a few times today, not had issue this afternoon. Weird

Yes, probably new and Chinese!

Typical behaviour, cold starts good - hot starts bad

 

[Mikep83]

Thanks. Will have closer look next week.
Any obvious way to spot a fake?

What if I ignore it, is it bad for car or just a minor inconvenience?

Cheers folks.

 

[Rupes]

The genuine article will probably have either a convincing-looking brand stamp and part number - either BMW or OEM like Bosch, Siemens VDO, etc

I guess a fake might have a name you've never heard of, or a carelessly misspelled copy of a proper brand name (a bit like shopping in Lidl)

 

[645Kiai]

Hello Guys, a quick update on my car.

After my last update (thermostat and vacuum leaks) the engine was running rubbish and impossible to find what was the problem. :jaw-dropping

So I finally decide to put it on Bmw and the guy just called... A connection wasn't plug properly, so they put it back and the engine "run perfectly" according to him (can't wait to see that)

Nevertheless I will need to wait few more days as they need to change something regarding the brake (a recall wasn't made)

I hope everything will be right and I will post a last message just FYI after I got the car back.

Thanks for your support and daily help :thumbsup

 

[Rupes]

That's good news.

It'll be really interesting to see which plug they're talking about.

 

[Timm]

Phew - that engine didn't sound healthy!

 

[645Kiai]

hi guys

So the problem was a connection on the e-box which was loosen...

nevertheless, after doing the recall about the brake the guy called me and say "we detected a small misfire when idle" (really? that s why I put it on a bmw garage lol)

bc of lack of staff and bank holiday he didn't have the time to do it so I took back the car and here is the diag (which looks much better)

the Bmw garage also mention a oil leak somewhere (but need further investigation) and the fact that they is NO microfilter housing rubber (but I truly doubt is a problem for now)

Tbh when I drove the car back, it sounds great. It the first time the engine is actually working that well.. the error message take much more time to come (when it comes) then it disappear

So I'm still thinking of a tiny vacuum leak that I can't see without really testing tool (bc that is my perso DYI test)

Or maybe it's coming from this oil leak... last idea it maybe around the fuel injector as the misfire is still on the cylinder 5

 

[645Kiai]

Hey again
I ve been playing with thé vvt minub from zero to 0.49 and no more error code
Talking about this :

What s this for ? What does it change ?

Cheers

 

[645Kiai]

I found the oil leak, very common it seems on the vacuum pump

It here :

Can I just seal it with silicon for now ?

Thx

 

[Hsurf]

Replied on your other thread but didn't mention that I wouldn't use silicone, at least, not for this application.
Also be sure where this leak is coming from, if it's where the pump meets the timing cover or the front plate of the pump itself then the seals on your other thread will work, if it's definitely coming from that top hose you've circled then you could be looking at a new pump, you really don't want oil being pushed through to the brake booster, that really will be expensive.

 

[645Kiai]

just to be more accurate, the leak is coming from here (red) I think from the vacuum pump ...

does it mean that it's better to change the vacuum pump ?


thx

 

[Hsurf]

You won't know for sure until you pull the pipe off there and inspect the inside, if there is oil in there then that's not good, take off the other end of the pipe from the brake booster to make sure it's not made it's way to that too.
Unfortunately I don't know of a serviceable item on that part of the pump, maybe someone else here knows.
Oil (believe it or not) can creep up over time and would pool there, personally I'd pull the pipe and inspect as mentioned, then clean that whole pump up, give it a run and look to see exactly where that leak is.

 

[645Kiai]

Hi everyone,

I'm back on the DIY 645ci Misfire cyl. 5 and... after :
spark plugs
ignition coils
gaskets or O ring here and there
thermostat
and later on, vacuum pump

I STILL HAVE THE misfire error code Misfire cyl. 5

I also check the wire on the ignition coil, to be sure... but nothing...

so this evening I swapped the fuel injector 5 and 6 but the misfire is still on the cylinder 5

I have NO more idea... (expect the compression test but I m not sure that I can make it myself so far)

anyone maybe?

FYI

 

[645Kiai]

do you mean that the vvt is broken ? are we talking about this :

If yes, how can I test it because it looks like it does his job (but I'm not a expert at all Lol) Can I swap it with the other one?

Regarding the throttle, are you talking about this :

If yes, how can I test it? Why are you so sure about these 2 issues ?

thanks a lot for your input

 

[Rupes]

Can you take it back to the BMW dealer who was supposed to fix it?

 

[645Kiai]

no I can't, I moved country in the mean time (uk to France)
but I will go to a bmw dealership here

 

[mojojojo]

What is cylinder 5 roughness like on a cold start?

 

[mojojojo]

I bet it isn't bad. Once it switches to non throttle operation it get much worst

If that is the case then probably looking at some wear on the valvetronic set up like lobes or levers.