[mihneagtt]

Hi guys!
I recently bought an 07 335i and I have a problem with it. The idle is kinda rough sometimes and by rough I mean it has some moments when it "shakes" as if the cylinders were out of sync or something. The duration of this "shake" is very short but it repeats over and over randomly. I feel like it's worse at cold starts, but i can feel it even after it has been warmed up, just not as violent. Also, under light throttle between 1.5-2.3k rpm it doesn't feel smooth at all, it's like i'm constantly varying the throttle input even though my foot is steady.
Mods:
JB4 pump bef on 95RON (91 octane)
downpipes
dci's
I recorded some logs:
Cold start
https://datazap.me/u/mihneagtt/cold-...log=0&data=1-4
Light throttle
https://datazap.me/u/mihneagtt/light...le-cold-engine...
WOT on map1
https://datazap.me/u/mihneagtt/wot-map1-jb4-bef?log=0...
The car doesn't have any codes ATM, did have some regarding the vanos solenoids which would also throw the car in limp, i cleaned them and no more codes. Also had a 29E0, but i deleted it and it didn't come back yet. The car also smokes randomly, i have no idea why.
Sorry for the long post, but i've tried to supply as much information as i could. Thank you very much !

[sbsk518]

Originally Posted by mihneagtt

Hi guys!
I recently bought an 07 335i and I have a problem with it. The idle is kinda rough sometimes and by rough I mean it has some moments when it "shakes" as if the cylinders were out of sync or something. The duration of this "shake" is very short but it repeats over and over randomly. I feel like it's worse at cold starts, but i can feel it even after it has been warmed up, just not as violent. Also, under light throttle between 1.5-2.3k rpm it doesn't feel smooth at all, it's like i'm constantly varying the throttle input even though my foot is steady.
Mods:
JB4 pump bef on 95RON (91 octane)
downpipes
dci's
I recorded some logs:
Cold start
https://datazap.me/u/mihneagtt/cold-...0&data=1-4
Light throttle
https://datazap.me/u/mihneagtt/light...le-cold-engine...
WOT on map1
https://datazap.me/u/mihneagtt/wot-map1-jb4-bef?log=0...
The car doesn't have any codes ATM, did have some regarding the vanos solenoids which would also throw the car in limp, i cleaned them and no more codes. Also had a 29E0, but i deleted it and it didn't come back yet. The car also smokes randomly, i have no idea why.
Sorry for the long post, but i've tried to supply as much information as i could. Thank you very much !

What maintenance has been done?

I had similar issue with rough idle / start but problem was fixed by replacing injectors (had mix of index 5 and 7s - changed to all index 12), plugs and coils, and walnut blasted the intake.

Random smoke could be anything but usually related to VCG or turbo seals. Upgrading the stock PCV to the RB one could help also.

[mweisdorfer]

Originally Posted by mihneagtt

Hi guys!
I recently bought an 07 335i and I have a problem with it. The idle is kinda rough sometimes and by rough I mean it has some moments when it "shakes" as if the cylinders were out of sync or something. The duration of this "shake" is very short but it repeats over and over randomly. I feel like it's worse at cold starts, but i can feel it even after it has been warmed up, just not as violent. Also, under light throttle between 1.5-2.3k rpm it doesn't feel smooth at all, it's like i'm constantly varying the throttle input even though my foot is steady.
Mods:
JB4 pump bef on 95RON (91 octane)
downpipes
dci's
I recorded some logs:
Cold start
https://datazap.me/u/mihneagtt/cold-...0&data=1-4
Light throttle
https://datazap.me/u/mihneagtt/light...le-cold-engine...
WOT on map1
https://datazap.me/u/mihneagtt/wot-map1-jb4-bef?log=0...
The car doesn't have any codes ATM, did have some regarding the vanos solenoids which would also throw the car in limp, i cleaned them and no more codes. Also had a 29E0, but i deleted it and it didn't come back yet. The car also smokes randomly, i have no idea why.
Sorry for the long post, but i've tried to supply as much information as i could. Thank you very much !

Throttle body, perhaps

When's the last time you had the intake valves walnut blasted?

[mihneagtt]

Originally Posted by sbsk518

What maintenance has been done?

I had similar issue with rough idle / start but problem was fixed by replacing injectors (had mix of index 5 and 7s - changed to all index 12), plugs and coils, and walnut blasted the intake.

Random smoke could be anything but usually related to VCG or turbo seals. Upgrading the stock PCV to the RB one could help also.

I have 4 index 10s and 2 index 12s in the car right now. Maintenance wise, the previous owner said that he changed the valve cover, the OFHG, new turbos, rb pcv and that the walnut blasting was done recently. Sometimes i can also smell some burnt oil inside the cabin, i've heard that can be because of a cracked valve cover. Is it possible that the valve cover has been installed incorrectly or something like that ?

Thank you for your answer!

[mihneagtt]

Originally Posted by mweisdorfer

Throttle body, perhaps

When's the last time you had the intake valves walnut blasted?

Is there a way to check if the throttle body is bad?

The previous owner said the walnut blasting was done recently, less than 15k miles ago.

Thank you for your answer!

[mweisdorfer]

Originally Posted by mihneagtt

Is there a way to check if the throttle body is bad?

The previous owner said the walnut blasting was done recently, less than 15k miles ago.

Thank you for your answer!

It's either that or your injectors are bad. You'd get codes for a bad throttle body. You may or may not get codes for rough idle due to bad injectors.

Pull your plugs & see if they are wet.

Is the idol rough on cold start after it sits all day or over night? That's a tell-tale that you have bad injectors

[mweisdorfer]

Originally Posted by mihneagtt

I have 4 index 10s and 2 index 12s in the car right now. Maintenance wise, the previous owner said that he changed the valve cover, the OFHG, new turbos, rb pcv and that the walnut blasting was done recently. Sometimes i can also smell some burnt oil inside the cabin, i've heard that can be because of a cracked valve cover. Is it possible that the valve cover has been installed incorrectly or something like that ?

Thank you for your answer!

If you had a leaky valve cover, you'd see oil dripping from where the VC has its leak. Take a telescopic mirror with an led light on it & look at the Firewall side of the VC where it meets the head. Tell us what you see.

[mweisdorfer]

You can get new injectors on Facebook for $1200.00 with a lifetime warranty.

https://www.bavarianmagazine.com/pro...mw-13538616079