Missfiring 335i HELP

[Luis Malhou]

Hi All,

Just looking for some advice. My 08' e90 (pre LCI) started miss-firing on start-up when cold. After a few minutes it goes away. When started up when car is still warm it doesnt occur.
I dont drive the car much and its just come off motorplan 3 months ago although its on 95000km.The injectors and fuel pumps were replaced while under motor plan.

Anybody had this problem, whats causing it. Once car has idled for 3-5 minutes its perfect and runs well. No water usage, no oil usage. No smoking ect.

Id like some advise before i book it in otherwise I KNOW the dealer will try smoke me!!

Im old school as you know so these new electronics do baffle me somewhat

Thanks

 

[Nikhil]

Im no expert but maybe a faulty coil or spark plug?

 

[Low N Slow]

does it idle erratically? is the car heavier and feel sluggish

 

[SP33DYV]

When was the last time plugs were replaced?
And I had something similar with my e46 325i and ended up being a coil.

---

Im no expert but maybe a faulty coil or spark plug?

SNAP

 

[Dusty]

While back also experienced misfire but only under hard acceleration, idling was normal. Read the error code and changed spark plug on cylinder that was indicated and problem was solved. Can be sparkplug or coil. Easy fix.

 

[bmsportzn135i]

^ what theyve all suggested. I would also say change out all 6 plugs and coil packs.

 

[Low N Slow]

makes sense...those 335i plugs are good for a 100k mileaage....seems like you are due for a change

 

[Luis Malhou]

driving the car pulls well and my wife gets over 800km on a tank highway driving which in my mind is excellent. Only miss-fires when cold or stood overnight.

 

[M3_devil]

I'm experiencing same issue now. Only happens when car stood overnight.

At startup it misfires but after 30sec it is clear again. My car sparkplugs had done less than 5000km. Will see what errors it brings up under diagnostic check.

Let you know.

 

[SP33DYV]

makes sense...those 335i plugs are good for a 100k mileaage....seems like you are due for a change

They should be replaced at 50k km and again at 100k km.

 

[Josh-ZN]

x35i's and misfiring seem to go hand in hand. very common problem, but the simplest checks are what the guys have already said. I have done all that and my car still has an odd misfire from time to time, especially in the morning.

 

[hoosain]

mine does it as well for about 10-20 seconds after a morning start

 

[Fayz]

Your cars injectors are leaking.When were they replaced?Remember that all new parts installed by the dealers come with a 2 year manufacturer warranty.So take the car back have and them replaced.

My car had the same symptoms,what happens is when the car stands overnight or for an extended period of time,the injectors leak fuel onto the pistons,similar to when a car gets "flooded".That's why the car miss's on startup as it's burning the excess fuel away.If the car stood for a short period of time,then not enough fuel has dripped onto the pistons causing the miss.

Leaking injectors cannot be picked up via diagnostic tests.Take the car back to the dealers who normally serviced the car and tell them to replace all the injectors under warranty with the new latest uprated versions from Germany and if they try and give you the run around then make a big stink right there. :thumbs:

 

[George Smooth]

Hi All,

Just looking for some advice. My 08' e90 (pre LCI) started miss-firing on start-up when cold. After a few minutes it goes away. When started up when car is still warm it doesnt occur.
I dont drive the car much and its just come off motorplan 3 months ago although its on 95000km.The injectors and fuel pumps were replaced while under motor plan.

Anybody had this problem, whats causing it. Once car has idled for 3-5 minutes its perfect and runs well. No water usage, no oil usage. No smoking ect.

Id like some advise before i book it in otherwise I KNOW the dealer will try smoke me!!

Im old school as you know so these new electronics do baffle me somewhat

Thanks

Do u lock the car at night? If you do leave it unlocked and see if the misfire is worse in the morning. This will exclude the leaky injector if misfire is constant.

 

[bmsportzn135i]

Hi All,

Just looking for some advice. My 08' e90 (pre LCI) started miss-firing on start-up when cold. After a few minutes it goes away. When started up when car is still warm it doesnt occur.
I dont drive the car much and its just come off motorplan 3 months ago although its on 95000km.The injectors and fuel pumps were replaced while under motor plan.

Anybody had this problem, whats causing it. Once car has idled for 3-5 minutes its perfect and runs well. No water usage, no oil usage. No smoking ect.

Id like some advise before i book it in otherwise I KNOW the dealer will try smoke me!!

Im old school as you know so these new electronics do baffle me somewhat

Thanks

Do u lock the car at night? If you do leave it unlocked and see if the misfire is worse in the morning. This will exclude the leaky injector if misfire is constant.

Im now quite curious! George please explain to us, how this will help in excluding the leaky injector?

 

[abee335]

Hi All,

Just looking for some advice. My 08' e90 (pre LCI) started miss-firing on start-up when cold. After a few minutes it goes away. When started up when car is still warm it doesnt occur.
I dont drive the car much and its just come off motorplan 3 months ago although its on 95000km.The injectors and fuel pumps were replaced while under motor plan.

Anybody had this problem, whats causing it. Once car has idled for 3-5 minutes its perfect and runs well. No water usage, no oil usage. No smoking ect.

Id like some advise before i book it in otherwise I KNOW the dealer will try smoke me!!

Im old school as you know so these new electronics do baffle me somewhat

Thanks

Do u lock the car at night? If you do leave it unlocked and see if the misfire is worse in the morning. This will exclude the leaky injector if misfire is constant.

Im now quite curious! George please explain to us, how this will help in excluding the leaky injector?

---

Had the same problem as you described turned out to be injectors.
they tend to leak over night. bmw gave me a quote of R22000.00 for all six
injectors.A GREAT car to have but a kak one to maintain on parts especially
once you out of plan.:yuck:

hence traded my car in before i got bankrupt:blab:

all the best

 

[Luis Malhou]

Just came back from BMW, since I know the service manager he organised a diagnostic at no charge.

1. injectors are confirmed to be new type as they were exchanged at the dealer where i bought the car before they sold it to me.
2. No injector is leaking or faulty
3. No stored faults
4. Could be a coil pack which they have had before.

They did a reset of the systems to see if it could just be a error lying around. If the problem persists he said he will keep the car overnight, then hook up their tools prior to cold starting it the next morning. So lets see if the reset works.

 

[George Smooth]

Hi All,

Just looking for some advice. My 08' e90 (pre LCI) started miss-firing on start-up when cold. After a few minutes it goes away. When started up when car is still warm it doesnt occur.
I dont drive the car much and its just come off motorplan 3 months ago although its on 95000km.The injectors and fuel pumps were replaced while under motor plan.

Anybody had this problem, whats causing it. Once car has idled for 3-5 minutes its perfect and runs well. No water usage, no oil usage. No smoking ect.

Id like some advise before i book it in otherwise I KNOW the dealer will try smoke me!!

Im old school as you know so these new electronics do baffle me somewhat

Thanks

Do u lock the car at night? If you do leave it unlocked and see if the misfire is worse in the morning. This will exclude the leaky injector if misfire is constant.

Im now quite curious! George please explain to us, how this will help in excluding the leaky injector?

If you don't lock the car the low pressure pump will keep priming as the car is in standby mode and not sleep mode. If there is a leak it will prime more often causing fuel to sit in combustion chamber causing a bigger misfire than you would have from the normal one prime you get.
Other potential issues if the misfire is only during the cat warming cycle is a lambda giving a wonky reading. A blocked cat. Carbon build up.
I would also have the plug gaps checked again, quite often ppl do not go back assuming they are new but I know of a forum member who had "not so new" plugs put in his car.

 

[bmsportzn135i]

Thanks man! Thats quite interesting to know!