Engine cutting out after approx 10 mins.

Hello All,

I have a 01MY P38 4.0 HSE which has started to cut out after running for approx 10 mins. Problem started some time ago with a stumble or split second cutout, but would then continue to drive. This problem occasionally caused other faults such as gearbox fault (most likely due to lack of speed or RPM signal from the Engine ECU). Occasionally it would crank but not start, until the unlock button on the fob was pressed a few times.
This problem has now progressed to car starting when cold, running normally for approx 10 mins and cutting out. It will not start and cranks, and no amount of lock / unlock signals from the key fob will restart. Leave it for about 3-4 mins, press unlock and it will re-start and run no problem from then on - be that 10 minutes or 3 hours of driving.
Key fob is working normally; locking and unlocking and no low battery warning as appeared on the display.
Initially thought this was an imobilisation problem with the BeCM, but on speaking to Turner Diagnostics (who were very helpful) they advised the problem was not BeCM but door locks and white plugs in the footwell. LHS door look was giving problems in not activating the interior lights, so ordered up a new LHS lock, fitted it and cleaned the relevant white plugs.
Have tried EKA, and clearing any faults via Blackbox Faultmate, however problem persists.

I am about to buy a RHS door latch and change it as well, but thought I may post a little essay here to see if anyone had similar experiences.

Any thoughts or assistance would be greatly appreciated.

Regards,

Ken

Fuel pump? Crank Position sensor? Engine Temp Sensor?
RHS Lock Actuator (not door lock) might be?

Thanks for the reply Stopover.

Engine temp sensor changed today.
Fuel pump and crank sensor? Possibly, but engine runs fine after re-start?

Door actuator I'm buying this week and will replace during the week.

I'm now planning my driving around the 10 mins, as I know it will cut out and if I'm somewhere I can roll off the road, no problem, but it is getting rather annoying.

Ken

I don't know enough about the RR BUT if it was a 'normal' car I would say to look at the coil. When they get hot sometimes a break is made inside and when it cools down the connection is re-established. As I said I don't know enough about the RR, it's probably something much more difficult to find! I am presuming the engine is not overheating.

I see you have the Faultmate MSV2....

Put it on Live Data esp. for the Crank Position sensor (if you can) and see if the signal drops out or is erratic

Diagnostics Live Data or it is all guess work. but as above, ignition electronics or crank sensor would be my guess

Beat me again ant, you are just getting tooooo fast.

Datatek said:

Beat me again ant, you are just getting tooooo fast.

Click to expand...

Folks,

Thanks for the replies. I'll get a friend to travel with me to examine the live data, as watching that while driving may not be advisable

What is pointing me toward immobilisation is the fact the it will only cut out once, approx 10 mins after starting from cold. Once it restarts it will run all day without interruption.

Engine not overheating.

Ken

Don't think it is the immobilser...as this only affects the start sequence not sure it will affect the engine once it is running...Rick-the-pick is the man for all things BeCM!

KMCE said:

Folks,

Thanks for the replies. I'll get a friend to travel with me to examine the live data, as watching that while driving may not be advisable

What is pointing me toward immobilisation is the fact the it will only cut out once, approx 10 mins after starting from cold. Once it restarts it will run all day without interruption.

Engine not overheating.

Ken

Click to expand...

Sounds to me as if it is something related to warm up sequence. When ECU shuts down fast idle and choke, maybe idle control related.

Wammers,

Thanks for the reply.

Something in the warm up cycle had occurred to me as it seems to occur when the engine temperature has reached normal operating conditions. Idle control may be a problem, but would this also cause non starting when the engine is warm? Only seems to start when unlock button on fob is pressed.

One other thing I should have included is that the engine ECU registered a fault
P1668 = ANTI-THEFT ALARM SERIAL LINK FAULT DRIVE CYCLE A, WHICH HAS OCCURED 4 TIMES
Which may be steering me towards immobilisation issues!

Ken

KMCE said:

Wammers,

Thanks for the reply.

Something in the warm up cycle had occurred to me as it seems to occur when the engine temperature has reached normal operating conditions. Idle control may be a problem, but would this also cause non starting when the engine is warm? Only seems to start when unlock button on fob is pressed.

One other thing I should have included is that the engine ECU registered a fault
P1668 = ANTI-THEFT ALARM SERIAL LINK FAULT DRIVE CYCLE A, WHICH HAS OCCURED 4 TIMES
Which may be steering me towards immobilisation issues!

Ken

Click to expand...

If the ECU temp sensor is duff yes it will cause bad hot starting. The sync code is sent when ignition is switched on otherwise engine won't start. Never heard of it disconnecting when engine is running. But stranger things have happened i suppose.

Have you checked your engine bay fuze box. i.e. disconnect battery remove the fuze box and all connections pull and check all relays and fuzes for corrosion and burning ..Double check the multi connectors for same and make sure nice n tight when replacing ..Just something Ive just done to mine as I was getting the very same symptoms as you mine was also multi missfires & check engine in the end...Seems to be all sorted now (said in a whisper)

wammers said:

If the ECU temp sensor is duff yes it will cause bad hot starting. The sync code is sent when ignition is switched on otherwise engine won't start. Never heard of it disconnecting when engine is running. But stranger things have happened i suppose.

Click to expand...

I never heard of it affecting a running engine either...the Sync Check is only considered during the start sequence....the BeCM tells the Engine ECU it is OK to start the car...in theory once the engine is started, you should be able to disconnect the BeCM as the engine function is controlled through the Engine ECU/ECM hence why it is there....


Big PS: Don't try disconnecting the BeCM with the engine running or battery connected to test the theory....bad things will happen to the rest of the car!

grogblossom said:

Have you checked your engine bay fuze box. i.e. disconnect battery remove the fuze box and all connections pull and check all relays and fuzes for corrosion and burning ..Double check the multi connectors for same and make sure nice n tight when replacing ..Just something Ive just done to mine as I was getting the very same symptoms as you mine was also multi missfires & check engine in the end...Seems to be all sorted now (said in a whisper)

Click to expand...

Mine boiled down to a ever so slightly lose crankshaft censor .
It finaly threw up codes on crank and cam sensors with check engine of course.

All,

Many thanks for all the replies and advice - finally got it sorted.

It was the crankshaft position sensor. Changed it and the car has been running sweetly since (hope that doesn'd jinx it!!)

Ken

Glad you got it sorted and thanks for popping back for the update - it really does help others looking for solutions to similar issues!!