cold start

[enemigo13]

It's hard to start engine when it's cold, I must crank several times to make it start. It starts very easy when engine is warm, but when temperature arrow sits at the beggining of blue mark, engine does not start easilly :( No errors in the ECU exept "crankshaft position sensor" which appears only after cold start. Changed crankshaft position sensor to brand new - no changes at all - the same error appearing only at cold start.. Changed ignition coils - no changes. One interesting fact - if engine is cold and I turn on-off ignition, then I try to start, and then again several times I turn on-off ignition, then engine starts fine (from the second crank). If I don't do that I have to crank it 3-5 times to start the cold engine.. I discovered that there is no spark when the engine is cold. But why it throws "crankshaft position sensor" error? Maybe crankshaft sensor does not send signal that the crankshaft is rotating so there's no spark? But why it's only when the engine is cold? What should I check? Anyone had a similar problem? Could it be ECU fault? How to check it? Thanks for any answers..

[/\/\3 Power]

I was just about to post a thread about this same thing. I got my M3 Saturday and I noticed when the engine is cold It has to crank a few times, when its not cold it cranks right away. Also when I cold start it, it wants to stall when I start to move and give it gas? Anyone have any answers? Thanks

[enemigo13]

check the errors on ECU, I think you'll have "crankshaft position sensor".. But as I wrote it's not worth to change it NO changes at all, so the sensor was OK ..


I was just about to post a thread about this same thing. I got my M3 Saturday and I noticed when the engine is cold It has to crank a few times, when its not cold it cranks right away. Also when I cold start it, it wants to stall when I start to move and give it gas? Anyone have any answers? Thanks

[/\/\3 Power]

I just searched cold start and apparently there was a defect on the S52 engines that can be fixed at a dealer, they update your software.

[enemigo13]

software update helps for rough idle then cold as I understand? But if you have to crank several times maybe it's not software problem?


I just searched cold start and apparently there was a defect on the S52 engines that can be fixed at a dealer, they update your software.

[enemigo13]

no ideas at all? :(

[Estrl M3]

no ideas at all? :(

I try to let it warm up a bit before taking off... Hasn't needed any extra cranks though.

[c170b]

Any luck tracking down the cold start problem. My 96 328i began giving me the same problem. 36F took 30 plus attempts before starting. Once started, no problem. 60F between 6-12 attempts. Runs fine after starting. Fires first time when the engine is warm or hot.
Engine showed no error codes (hot).

[fsmtnbiker]

If turning the key to 'on' a couple times helps to make it fire up faster, you've got a fuel delivery problem. The fuel pump primes for 2-3 seconds each time you turn the key on, so apparently it is taking more than that to get fuel pressure built up in the system. You might try changing the fuel filter first, but it is more likely a tired pump or a bad check valve in the pump allowing the fuel in the line to flow back into the tank.

[Razziel24]

maybe a dumb question, but is your battery ok ? mine was dying a few months ago, and the symptoms were the same......

[c170b]

The battery is good, spins the starter fine. The car runs great once started. I'm gonnal check the fuel system, but why would it start first time under warmer conditions if the system was not up to proper pressure. I'm thinking intake manifold sensor and/or airbox sensor gone bad making it think it's warm, not giving rich mixture under cold conditions.
Thanks for your inputs !

[M13]

Updates?

[c170b]

Here's the latest !
It took a half a dozen start attempts at 63F a couple of Sundays ago to fire off. Up to temp, shut her down, cool down about 1 hour, temp gauge is in the top of the blue. Restart attempt failed - said the hell with it. Didn't make any additional attempts. Bringing the 328 to German Motor Works (good folks, Norcross Ga.) Expect to have problems the morning of the drive in. Outside temp is 35F. The 328 fires off on the first attempt. Cars been in the shop for several days and to date the car fires off first time - so still trying duplicate the failure - stay tuned.

[yafayu]

I have the same problem as well. Hard starting(3-5 attempts) during the cold weather(blow 48F) but once it starts then runs fine. Sometime even die when the engine temp is blow the normal(middle) when you give gas

This problem is bothering me about a year now hope someone can point what's wrong with it

[c170b]

German Motor Works never could duplicate the failure (they had the car over both holidays). While the 328 was in the shop I had them replace the fuel filter, engine and tranny oil. Starts are back to normal. The reason I assumed cold start problems was because initially the problems occured in lower temps (lower 30's F). Prior to taking it to the shop, that theory went out the window, so who knows !

[Volf]

I just searched cold start and apparently there was a defect on the S52 engines that can be fixed at a dealer, they update your software.

Search FTW!

[c170b]

Thanks !
Whats FTW ?
Latest: Couple of mornings later, 32 F, whaling on the starter before finally starting. Sytmoms are back. Went to work. Lunch time the 328 would'nt start at all. Towed the car around the corner tback o German Motor Works. They deemed it the fuel pump. R&R fuel pump. Following morning around 32 F,quess what. It's not the fuel pump !
Once it starts again I'll bring it to a dealer for the software upgrade.

[///w3fl3x]

Battery are less efficient when it's cold out. Once the car starts it doesn't depend on the battery anymore.
Have it checked to make sure it's still good.

You should look into the battery too. My 3 series battery is like this. It's a fairly new interstate battery too. I think i might have something drawing power from my battery when my car is off though. :dunno

[Blink21Me]

I had the exact same problem last month, during that time I had a crank position sensor error, CEL was on... When it's cold the car wouldn't start as easy as it used to; it would take ~a couple extra seconds before the engine starts, and when it does, it would stall when I give it gas. It even died on me once when I tried to take off...

I brought the car to Edge, had them replace the CPS instead because I almost stripped the freaking Vanos Solenoid Switch when I was DIYing it, they reset the Check Engine Light, then the problem is gone. Car now starts right away when cold, and runs so smooth... I also searched and found that the software has to be updated by the dealer... I was going to ask Edge about it but I forgot about it when I was there... I just don't know if Edge voluntarily updated the software that fixed the rough cold start idle...

[c170b]

The 96 328 began giving me the same problems in warmer temps. Got to be where it would not start period. Anyway had it towed to the dealer. Stay tuned. Should now something soon.

[c170b]

Narrowed down to the fuel pump relay. Next is to isolate lack of signal from either pump or ECM.

[c170b]

Turns out to have been the fuel pump relay(s). Had them both replaced. No more start problems.
United BMW, Duluth, Ga. did an exellent job in troubleshooting the problem. Thanks Roger !