*UPDATE* - Rough cold running on M3 E36

Hey Dudes,

I have only had my car for a few weeks now. I have a question about the cold running of my car.

The car starts fine and ticks over okay, when I drive off it seems to be really sluggish. If you push the accelerator too much is starts to splutter and pop a bit as if it is missing. If you back off from the throttle it sorts itself out. (I am going real slow at this point)

Once the temp guage is past the quarter mark it runs fine. Is this normal?? bot worried when the winter comes round that it could get a lot worse!! any ideas.

Edited by MONO

Hi,

Sounds like CTS (coolant temp seneor). If the CTS or its circuit fails then the ECU will not know that the engine is cold. The ECU defaults to a hot running fuel control map and so it will run poor at lower temps but well at normal temp.

It would be worth your while fitting a CTS first as they are cheap.

 

Alan.

Hey dudes,

Thanks for the input, I have noticed the previous owner has a reciept for a coolant sensor! wondered if he fitted it??

Yeah, I have been told it is common. I was wondering about changing the plugs for a hotter plug?? wonder if that would make any difference. Anyone else tried this??

With mine you have to drive like a granny for the first half mile or so and get the gear changes/ revs just right otherwise it starts coughing and spluttering! It's really annoying as I have a massive hill outside where I work. It's can be a real struggle!

It would be great to find someone who has sorted this problem! there mst be someone with a 3.0L that has sorted it surely..... Oh yeah why havent BMW sorted the problem!?

Things definately getting weirder; just finished the tank of fuel with D-Tox in it, cleaned the k&n panel filter and readjusted the supersprint-disconnected the battery for 3 hrs, wired back up and started the car, no indication of cold hesitancy!!!

Might be coincidence.

Also, I was at the new 5 series launch talking to a BM techie who said the M3s were prone to wear in the 2ndry air pumps-these kick in just as the choke comes off and circulates warm exhaust air round the engine bay to quickly heat the engine up-if its worn then it doesnt work and for a while the choke is off and the engine isnt properly up to temp. What do you reckon?

John

Hey Mono,

I have the E36 Evo but it does have as similar problem to your car. It is very lumpy (feels like not running on all 6 cyls until it is warm), but only between idle and 2,000 rpm. So to get round the problem until it is warm I just stay I just keep the revs between 2000 to 2500.
It is annoying in heavy trafic though, but I suppose I have got use to it.

I have spoke to lots of people about this and the general consent is (as has been said)that it is either a temp sensor or the secondary air pumps.

I am a couple of green lights away from a service, and still have the BM warranty. I am planning to get them to sort it out at service time and will ley to you know how I get on.

Hey Dudes,

I have just dropped my car off at the stealers tonight, it is havin an inspection 1 service. I have asked them to check out the cold running problems to

I will let you know what the outcome is!! fingers crossed!

 It's the same!!!

Now what???? anyone got any advise??

Hey John,

I tried that a few months ago, it hasnt changed mine. My car has a fault but it's one of those annoying problems that might never be solved. I dont really want to throw money at it if it isnt gonna cure the problem. I wonder if it would be worth gettin these oxygen sensors from a breakers??

The BMW stealer couldnt guarantee me that that this is the fault!! As it didnt happen after they reset the codes!

What do reckon the chances of that!!

I had some advice off someone saying that if there is a problem elsewhere then it will trigger a fault at the O2 sensors if it aint running right so it might not necessarily be this!!

Feckin car!

Hey Dude,

You can get Comma D-Tox from Halfrauds, it's £15, you put it in a full tank and just drive as normal. It is recommended by BMW.

I put it in mine and it didnt make any difference, but mine is running sh*t anyways. I am gonna book it in to get the oil leak sorted and new oxygen sensors. I am hoping it waill sort it. Apparently O2 sensors are only good for around 60-90K, mine has done 71K now.

I was chattin to my mate who is a ferraro mechanic and he says that ferraris blow them every 10-15K and they can cause loads of problems!!!