[m3matty]

Hi folks,

My M5 is a 2001 with 103K. It's running alpha N and the IAT relocated. It drives and runs beautifully.

However, I've noticed that the last few times I've used it the friend who's following me in their convertible reports that it produces quite a lot of black smoke when I give it a boot full. I can see the plume in my rear view. Friend says that it's like following a steam train with the smell and soot but without the steam.

I'm thinking oxygen sensors (front or rear?) and the oil separators. Right path?


Thanks

 

[vantaam5]

Does it run one of our tunes?

 

[m3matty]

Hi Vantaam,

We met the other week. I was the silver M5 with M interior that turned up and had the steering software upgrade done!
Yes, it runs one of your tunes.

 

[vantaam5]

Any chance you can drop by?

Would like to check a few things like O2 sensors and T-stat

 

[m3matty]

Sure, no problem. Can I come by after lunch on Friday? Say 13:30?
Thanks

 

[vantaam5]

Sure,I am at the unit

 

[m3matty]

Thanks, see you then.

 

[///DeafM5]

Great service right there. I wish I had this kind of service in New England area.

 

[newoldschool]

Interested to hear the follow-up

 

[m3matty]

I had a new T stat a couple of years ago and the water and oil temp gauges all continue to read higher than they did before the stat was replaced.

 

[m5 deamon]

deaf you do but I am down here in ny lol

 

[m3matty]

Post update:

I visited Evolve last Friday and met with Sal and Vantaam again. Great guys.

Whilst Vantaam was busy working on a Porsche (we won't hold that against you), Sal took the opportunity to drive my car round the block. It was quite interesting to get his thoughts on my car which is pretty much stock except for the Eisenmann Sport exhaust and Alpha N remap.

He noticed that my steering was not as tight as it could be which confirmed the decision I had already made to replace the tie rods and centre link. Other than that he said it was a good, stock car with no major issues. He was complimentary about my interior (M interior half leather half alcantara) and double glazing which I didn't realise was so rare.

Once Vantaam was available he connected up his laptop and diagnosed that the idle control valve should be my first area of investigation especially as I had a code already for this. I hadn't connected the dots and didn't think that the smoke problem could be related to the ICV but when he explained that a sticking ICV can confuse the ECU into putting too much fuel in at idle, it explained why I would get a puff of smoke when I set off. At the same time both Sal and Vantaam spent a good half hour just chatting with me in general about cars while talking me through the other jobs I should do while I have the plenum removed. The list is long and includes the Vanos seals so these are jobs for the Winter. Vantaam also spotted that my belts were badly cracked, which is something I had completely overlooked with my efforts focussed elsewhere with the car. The belts have since been changed so disaster averted. Thanks for the heads up, Vantaam!

I also got to meet his new, red, low mileage purchase (very clean) and also saw the supercharged M5 from the front cover of BMW Car magazine a month or so ago.

I really did appreciate the time they spent and refused to take money from me this time around! I guess they know it pays for them in the end and I'm sure my wallet will get a beating soon enough.

Thanks Evolve! See you soon

 

[D-RodM5]

Recorded a video of my exhaust and noticed the small puffies of black smoke near the top end of hard acceleration, otherwise the car runs fine. I might have a sticky ICV too? Anything I can do to relieve this?

 

[caspian65]

Could a sticky ICV not throw a code but just do the black sooty exhaust? I have the same issues with my car. Evolve headers, cats, relocated IATS and alpha-n.

 

[///DeafM5]

For its worth, my 2000 M5 puff some smoke between shifts. Also black soots always will be seen during WOT, as it is typical for most bmw to do this. My cousin's stock ZHP sedan does this too.

 

[68FB]

Could a sticky ICV not throw a code but just do the black sooty exhaust? I have the same issues with my car. Evolve headers, cats, relocated IATS and alpha-n.

Do you mean the tailpipes are black and sooty, or you are seeing black, sooty smoke?

 

[caspian65]

Do you mean the tailpipes are black and sooty, or you are seeing black, sooty smoke?

Both, but only smoke when getting on it hard.

T-stat and housing replaced about 2 years ago, KTMP reading normal on highway.

Very gassy smelling exhaust.

 

[68FB]

Both, but only smoke when getting on it hard.

T-stat and housing replaced about 2 years ago, KTMP reading normal on highway.

Very gassy smelling exhaust.

You have to be running 10:1 AFR or less to blow black smoke which is way too rich. And gassy smelling exhaust is obviously not normal.

A bad ICV would not cause this.

Evolve has good support. Have you told them about this?

 

[caspian65]

You have to be running 10:1 AFR or less to blow black smoke which is way too rich. And gassy smelling exhaust is obviously not normal.

A bad ICV would not cause this.

Evolve has good support. Have you told them about this?

Thanks. Yes, mentioned to them in the past, but my time has been limited to work on the car. What I believe is the secondary vacuum pump comes on when cranking up cold and runs for about a minute, it's kind of loud. Maybe a big vacuum leak somewhere? Idle is relatively smooth. Changed out pre O2 sensors when it started running rough about 6 months ago. Changed out all the vacuum hoses under the plenum, but that was about 3 years ago and 40k miles driven since then. I run w/out the MAF's plugged in.

 

[Bimmerbear]

Dude, you're describing two different conditions. A puff of smoke when you set off and a puff of smoke when you give it a boot full are two entirely different things. Which is it? ICV wouldn't have anything to do with cruising around and suddenly flooring it.