BMW E90 - are my injectors leaking?

trixiebust

Hi,it's a 318i petrol. For the first couple of minutes of driving the car seems like it's blocked up,but once the engine is warm it runs fine. Lots of black soot in the exhaust tip & soot on the tips of recently changed plugs too.

Would it be possible that the injectors are leaking overnight & it's causing the engine to run rich for those first few minutes?

I've changed an 02 sensor,plugs, coils,air filter but it's still the same. Any ideas??

rex-x

Might be time to try a mechanic?

biko

Rex
This is the DIY forum.
You're supposed to help..

rex-x

biko wrote: »

Rex
This is the DIY forum.
You're supposed to help..

I would consider that helping, they have clearly been firing the parts cannon and getting nowhere? I'm all for DIY but sometimes you have to call it quits

trixiebust

I'd consider some of those preventative maintenance,but you're obviously entitled to your own opinion. I came here looking for help, if you're not going to offer anything decent,why post anything in the first place?

swarlb

trixiebust wrote: »

I'd consider some of those preventative maintenance,but you're obviously entitled to your own opinion. I came here looking for help, if you're not going to offer anything decent,why post anything in the first place?

I would doubt if the injectors are leaking to the point that fuel is draining into the engine.
Possible that your valve stem oil seals are leaking oil.

Tea drinker

Black smoke not blue when you start it?
MAF and it's wiring? Just to check it
Can you run those 318 with MAF disconnected? See how it behaves.

Does the temperature gauge perform normally

trixiebust

Tea drinker wrote: »

Black smoke not blue when you start it?
MAF and it's wiring? Just to check it
Can you run those 318 with MAF disconnected? See how it behaves.

Does the temperature gauge perform normally

Thanks for the responses...


Smoke is white until engine has warmed, I haven't checked the MAF ( going to give it a clean today). To me it seems to run too rich,but only for the first few minutes. Like it's burning off excess fuel from sitting too long.

I had a code for an ageing cat, but my mechanic got it to regenerate. It's come back again. Car jerks & shuudders badly under load.

DublinDilbert

If it feels down on power, it is possibly un-metered air getting in, so not enough fuel being delivered. I can't remember if the E90 has a PCV valve, but this is one area i'd be looking at for un-metered air getting in.

mullingar

trixiebust wrote: »

Thanks for the responses...


Smoke is white until engine has warmed, I haven't checked the MAF ( going to give it a clean today). To me it seems to run too rich,but only for the first few minutes. Like it's burning off excess fuel from sitting too long.

I had a code for an ageing cat, but my mechanic got it to regenerate. It's come back again. Car jerks & shuudders badly under load.

Wtf?

A 318i petrol? Regenerating?

You can only regenerate a Dpf filter on a diesel. Not a catalytic converter.

I wonder if you have a partially blocked cat? Geet a different mechanic Do a simple manifold vacuum check to see if it's indicating a blocked cat

w211

Not enough data to say what is wrong. I have obd2 scanner and I can read the live data what is wrong. Sure it does not tell the full story but it shows more than here just the speculating. Only 1 question, you replaced only 1 O2 sensor but typically are there 2 on 1 bank. If you have 2 banks then 4. Sorry I do not know how many 318i have without the vin code.

trixiebust

After unplugging the MAF the thing runs 90% better. Idle has calmed down a good bit & power seems to have increased too.

New one on the way!

w211

trixiebust wrote: »

After unplugging the MAF the thing runs 90% better. Idle has calmed down a good bit & power seems to have increased too.

New one on the way!

Without maf your engine runs but you will destroy your cat soon. The computer does not know exactly how much air it sucks in. The poor gas mileage, lack of power and other problems. Clean the maf or replace it.

trixiebust

w211 wrote: »

trixiebust wrote: »

After unplugging the MAF the thing runs 90% better. Idle has calmed down a good bit & power seems to have increased too.

New one on the way!

Without maf your engine runs but you will destroy your cat soon. The computer does not know exactly how much air it sucks in. The poor gas mileage, lack of power and other problems. Clean the maf or replace it.

I have one ordered,will be here in the next few days. But everything seems to run better when I unplug it. Power has definitely increased,my MPG hasn't changed either....