Engine stumbles on cold start, restarting causes it to run normal

[upallnight]

PM sent.

[Clockwork]

I hae a similar symptoms and I was told its the Valvetronic Intermediate Lifters causing this on ONLY cold weather start-ups (with a cold engine).

[upallnight]

Originally Posted by Clockwork

I hae a similar symptoms and I was told its the Valvetronic Intermediate Lifters causing this on ONLY cold weather start-ups (with a cold engine).

OP has a 2001 X5 which doesn't have valvetronic intermediate lifters.

[Spunbearing]

Yeah, no Valvetronic Intermediate Lifters here. I did read a couple of posts where people suggested it could be the VANOS system needed a rebuild because there is a certain position they need to go into for starting. I don't know why restarting the car would cause the issue to go away.

[Clockwork]

Originally Posted by upallnight

OP has a 2001 X5 which doesn't have valvetronic intermediate lifters.

ahh dually noted.

[Spunbearing]

OK, just to give you guys an update, I have done a couple of things to see if I can narrow down the issue. I put some fuel injector cleaner into the gas, put some lifter cleaner into the oil and swapped out the ICV with the one in my 330ci. I though swapping out the ICV fixed the issue but it came back the next morning. It does seem to be somewhat better though but that is probably because the ICV was cleaned before I put it in.

Should I try swapping injectors? My fuel pump is original and tested at 50psi when running but could it be slow to build pressure on start up? A simple test for this would be to turn on the key and let the pump run for a few seconds before starting right?

After restarting the X5 it appears to run great which is what is driving me crazy. It is like a splinter in my mind! I am shooting for 300k on this beast.....

[Ricky Bobby]

I will say I basically had the exact same issue - is yours intermittent or on every start? Mine was very intermittent and only happened under certain circumstances (upon cold start very rough running and threw misfire and ran on 5 cylinders. Restarted car and was perfectly normal!)

I have replaced the following
-SAP line and vac lines between SAP and manifold
-vac lines from intake F connector
-vac lines behind manifold
-spark plugs (NGK iridium used) and oem Delphi ignition coils

I haven't had a reoccurrence since, although I also have avoided the situation which usually made it come up which is an extremely low run time on cold start (2 mins or so) and then shut down - think starting the X to pull out of the garage to wash the car then pull in when done. When I used to do that it did happen quite frequently when going to start the next day. I think upallnight said to avoid that since it can flood the cylinders quite easily.

Hope that helps

[Spunbearing]

Thanks Ricky Bobby,

I think I am getting to the point where I am going to have to take the intake manifold off the car to check the more hidden vacuum lines. Not really looking forward to doing that.

I need to try my mechanics stethoscope and see if I hear anything.

[Ricky Bobby]

You can reach them if you have small-ish hands like me, but you will be working blind for the most part.

There are 2 or 3 vaccuum caps on the back of the manifold as well which I replaced.

[upallnight]

Originally Posted by Ricky Bobby

You can reach them if you have small-ish hands like me, but you will be working blind for the most part.

There are 2 or 3 vaccuum caps on the back of the manifold as well which I replaced.

Stopped over a Spunbearing last friday and connected my bluetooth scanner to his car. At first non of the 02 sensor was providing any data and the engine had a chugging noise to it.

I attributed the no data to the fact that the engine was in open loop so the 02 sensors had no input into the operation of the engine, but in open loop the engine should have been running smoothly base on predetermine data. One thing that stuck out was the throttle showed 0.

0nce the engine did warm up it went into close loop and the 02 sensors were reporting data as it should. The long and short term fuel trim were within the operating parameters.

The only thing that was still a problem to me was that the throttle was still at 0. On my X the throttle data showed 9%.

Anyone on this forum ever have a throttle body go bad on them? What were some of the symptoms?