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.

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!?

Hey Dudes,

Gutted!!!

My thread has gone back to the start!! cos of them damn hackers!!

Anyways, it was going good to see all the E36 3.0L boys on here!! John, started a rollcall but we were all cut off!!

I am taking my car into the local stealer for an inspection 1 service, I am gonna get them to look at the cold running probs. It goes in on the 6th October so I will let you know the results, feck all no doubt!

Dude,

Mine seems to be gettin worse now the cold weather is here in the mornings.

At the service they are inspecting the valves so I can rule that out if it is the same when I get it back. It seems like the cold running circuit to me. It feels like the car has no choke.(I no fuel injection doesnt have choke it just richens the mixture to start with) When I start it first thing it goes up to 1250rpm then drops down around the normal tickover. When I drive it then pull up a junction when cold the tickover drops down to about 700rpm and hunts, sounds like it drops a cylinder then comes back on. it keeps doing this until I pull away. It only does that when it was real cold out 4c in the morning.

I dunno if you have ever driven a car that has had a manual choke back in the days?? it's the same as that you know when you run it without enough choke it starts to die and kangeroo's thats what mine is like. It does it if you go above 2,000rpm then dies then kicks back in. definately aint right in my opinion. When the coolant temp guage gets near the middle of the range it sorts itself out.

I dont think it is the pumps on mine cos it doesnt feel like it runs with choke at all.

It is starting to get on my t*ts now!

Nice one Liam,

Mine goes in on Monday so I will see what the BM stealer says. Keep us informed dude.

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!

Dudes,

I got my car back from the service, they couldnt pin point the problem. When they ran the codes off of the DME or whatever it had 2 fault codes for the oxygen sensors. They wiped the codes and tried running it a few times with no errors!!?? I wonder if the errors occured when the cat sh*t itself?? Any ideas??

I dont really fancy buying 2 new oxygen sensors as they are around £180 for the pair and if it dont make any difference then it's money down the drain, yet again!!

I havent driven it from cold yet so I am not sure if it is any different with new plugs, correct valve clearances.

I will let you know how it runs tomorrow

 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!

Pardon my ignorance folks,

Sorry to be hearing about your cold running problems Mono, hope you source the problem soon!

But whats this D-Tox everyone keeps mentioning? Is it some kind of fuel additive and does it make much of a difference? If so, where can I? get my hands on some? Thanks in advance!

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!!!

Cheers mono,

I'll give that a go, and see if it makes any difference to mine. Will get back to you.

Dudes,

An update. I took my car to the local stealers to get new O2 sensors an a oil leak sorted.

I got the car back and it seems to run a bit better now, it still hesitates around 2,000rpm but doesnt seem to misfire like it used to do. It still doesnt feel 100% right but I have given up now!

It's strange as with some of the really cold nights below 4C it seems to run better. The tickover seems to hunt a bit but it's driveable now

I was thinkin of the supersprint Decat pipe cos I hate the cat! it sounds sh*t cos it's cheap quality and it is probably affecting the running to.

It's strange cos no one has come back to me with a resolution!!?? be good if I sort it myself, gonna get one of those manuals and feck about with it. Is there anyway to test the coils?? As I have a sneaky feeling it might be one of those playing up??

Hi Guys,

All 3.0 M3's have a slight hesitation characteristic during the warm up phase, mainly around 2200RPM. This is a consequence of the combined effects of emission requirements and the VANOS operation. The severity of this "characteristic" can be greatly affected by outside influences such as incorrect valve clearences, throttle banks out of balance and individual cylinder mixture adjustment. These 3 items must be 100% before you go any further and should be done only by a BMW dealer, and preferably by a BMW technician who has been working on this engine since it's introduction and therefore received training in these areas.

Other factors which could also contribute to this problem are as someone suggested, coil problems (easily checked by BMW dealer using oscilliscope) - although I would expect faulty coils to cause worse problems when the engine is hot. Induction air leaks allowing unmetered air into the intake system - could cause lambda faults to be stored in DME and uneven idle when hot depending on severity of the leak - try spraying around the area where the inlet manifold joins the head with a little WD40 or brake cleaner when the engine is idling hot. Any variation in idle speed could indicate a problem in this area. Also, the throttle potentiometer should be replaced at every Inspection 2 service on the S50 engine and can cause all sorts of problems if defective. 

Finally, might sound like a silly statement but make sure all the basics are OK such as spark plug condition, air and fuel filters etc.

Hope this helps.

Andy.

Hey Andy,

Cheers for the info, My car has full Stealer history. It had the inspection 1 service 3 weeks ago which they did the valves and plugs and checked the cold start issue, the DME came out with fault codes for the O2 sensors, that's why i changed them. The potentiometer was changed at the last inspection 2 bout 15K ago.

I was wondering do they ever balance the throttle bodies at any of the services?? mine dont look like thay have ever been touched?? I know from owning bikes that it is key to balance these regularly as it affects idle etc... but never really seen this on cars???

I would like to get em done, any thoughts and if this is a item that is done  in a service as I suspect it is not!

Hi Mono,

No, this is not done at the time of service. It would push the cost of servicing through the roof ! Following the set up of the throttle banks the CO should also be adjusted as these engines have a tendency to "lean off" over a longer period of time. This is a dealer job. I carry out this on any E36 M3 if a customer is complaining of rough running. It's also a good excuse to check the throttle butterflys for distortion (More carbon deposits in front of one butterfly compaired to the other in the same throttle body) as this can cause additional running problems. Also a good time to replace the fuel hoses at the back of the block as these really suffer with the heat. Ensure the intake 'O' rings are replaced when the intake manifold is removed too.

Andy.

 Dude,

That sounds great!! where bouts are you cos you can come and sort my car out!!

I'm in Jersey ! Sorry Man.

 never mind!!

Hey dont you have a 7mph speed limit over there?? or is that guernsey??

It's a 40 MPH limit - But France is only an hour away on the boat, my father has a house there, and they don't have speed cameras !

Andy.

 cool,

Sounds like I would be there on my bike then!

Yeah, I take my VFR837R over for a good thrash now and then. Great roads and very little traffic too. You just have to watch out for those bloody French !

Andy.

 cool!

The french are better than the brits and there are less of them!! + the women look better to!!

Dudes,

After havin the car back for a while it is getting worse!! it is even doing it now when warmed up!!

It is booked back in at the stealers for 2nd December until they sort it!! It will be going in for 3 days this time cos I want it fixed!! I have even offered to take them out for a spin to show em what it is doing so no excuses, this time!!

I wonder what the problem is??

p.s. everytime I pop into the stealers I always see a 3.0L coupe in!!! strange or what!!??

Dudes..... me again!!

I am taking my car to Ajec racing in Gloucester tomorrow to have a look at my motor. The problem seem to have extended to when the car is hot now with a misfire at 2-2500rpm then clears at 3000rpm.

It has been into the stealers for a total of 8 days now and it aint fixed.....to be honest I would have done a better job of it myself.

Anyways, wish me luck at hopefully my problem I have had for 7months will be resolved!

Still not sorted, took it there today 180 mile round trip  oh yeah and on the way in the gales and pissin rain a stupid bitch decided to go into the back of me motor at the lights!!! her foot slipped off the clutch apparently!! luckily there was no damage!! feck knows how cos I went flying forward!

The car came back with 3 faults O2 sensor, knock control, carbon canister vent valve flap. There is nothing wrong with the O2 sensors cos they are new and also the knock control sensor triggers when the engine aint running right as well.

The guy reckons one of the coils is breakin down, didnt have any new coils lying around so tried a few second hand ones but still had the same problem but misfired differently! To be fair the guy was a nice dude and knew his stuff. I reckon it is the coils to......

So I ordered a carbon canister vent valve flap and 1 new coil, I am going to put it on each cylinder and see if it sorts it. The 6 coils are £300!! so I dont want to throw more money away!

christ knows how to fit that vent flap thingy just hope it is simple.

Why cant anyone sort me car!!!! I am ending up doin it me self again!!

Dudes,

I got my car back yesterday after being in at Munich Motors in Wokingham for the last 6 days........my problem has been solved!!!!!!!!!!!!!!

They found the source of the fault that no one has been able to sort for the last 6 months!!!

It ended up being a faulty ECU!!! swapped it out with another and it works great!!! still a little bit spluttery no and again but I have put some D-tox in and reckon it needs a good run to burn off the sh*te where it has run properly for so long!!

Cold start is good, tiny bit lumpy but at least I can drive the fecker now!! instead of kangerooing up the road like a mofo!! hehehe

They did loads of checks on the motor which they spent hours doing!! and it was getting frustrating trying to find it.

The compression test was good  ,  They checked the valves and helicoiled 3 stripped bolts on the rocker cover that the BMW did!! Also had to change the plugs as they hadnt been touched by the dealer.....both of these items should have been done 2000 miles ago on the last service!!

My next step is to name and shame William Jacks of sunningdale for the diabollockal work they did and didnt do!! what do you reckon guys a letter to BMW UK customer services??? Any advice on doing this and anything you reckon I could get in compensation for being put through misery/ stress and financial hardship for the last 6 months!!

Hi

Glad to see you are sorted at least that is good news.

Chris.

Cheers guys,

I have had to buy a brand new set of coils and adapters £400!! today as that was the reason why the out put shorted out on the ECU.....apparently this is a common fault on some of the BMW ECU's which is common on misfire type problems where these poxy coils are involved 

So all in this month it has cost me over £1000 to get this problem sorted out!!! I am hoping that that is it!!!!

I would rather be spending that sort of money elsewhere!!

Dudes the way things are going financially I might need some help to rob a bank if anyone is up for it