M52 OBD2 stalls at operating temp

[Leo_328i]

Hey guys,

I've had my car off the road for 2 years now and am having a lot of difficulty getting it to run correctly. This is for an E36 328i but you guys seem to be pretty good with understanding how everything works with these motors.

It basically starts up fine, then soon it starts to misfire - you hear little pops in exhaust but its not too alarming. Then as the temp needle goes up the car starts to drop and surge whilst idling till it gets so bad that it just stalls altogether.

I've been trying to diagnose this problem for the last 2 months and cant figure it out - the following has been done:

1. Headgasket changed
2. MAF sensor changed
3. Exhaust 02 sensors changed
4. Inlet manifold checked for leaks
5. Coil packs swapped
6. Fuel filter changed
7. PCV changed 20,000km ago
8. Spark plugs changed 5,000km ago
9. Fresh oil

EDIT: Engine also pings at WOT over 4000rpm

EDIT: TPS sensor changed

Anyone got an idea?

[hoveringuy]

I'd start with the very basics. Compression test, fuel pressure and how do the spark plugs look?

After that the usual suspects are MAF and vacuum leaks, but you've already checked those.

[samiam3356]

Change the temp sensors out. Sounds as if you may have a couple issues going on. Are the injectors suspect?

[Dissembler]

How did you time the engine after you did the headgasket?

I had a similar issue with mine up until yesterday. It idled like old american iron and would stall everytime i let off the throttle. Also misfired horrible when the engine got up to temp.

I retimed the engine with the proper bmw timing tools and used a dial indicator to get true TDC of the motor. Problem is now gone and it runs smooth as silk.

[Leo_328i]

How did you time the engine after you did the headgasket?

I had a similar issue with mine up until yesterday. It idled like old american iron and would stall everytime i let off the throttle. Also misfired horrible when the engine got up to temp.

I retimed the engine with the proper bmw timing tools and used a dial indicator to get true TDC of the motor. Problem is now gone and it runs smooth as silk.

Did not use BMW tools. I did it by eye using the arrow that points up 90 degrees on the cam sprocket. Will probably go back and get this tested - shes got S52 cams installed but the standard BMW cam tools will still work yeah? Hope you didn't hit any valves!!!! I dont think I have cos the engine has seen 6000rpm and I'm sure I'd know about it at that speed.

Spark plugs look fine, were changed only 5,000km ago. All injectors seem to be firing fine too - but will get this tested as well.

EDIT: What would usually happen if you unplugged the vacuum line to the fuel pressure regulator? On mine theres no change in how it runs..... I think I might have done a shit job with the vacuum lines?

[328ijunkie]

You never mentioned the temp sensor.