xliemx717

my 2001 S600 has a misfire comes on when car is at operating temp, only at idle in gear at stop light. goes from right bank misfire, to left bank misfire or both. turn engine off restart, no misfire. sometimes when you turn off and restart CEL goes away. coil packs, transformer, spark plugs, map sensor, air change over valves have all been replace plus ECM has been checked/repaired. any clues? anyone?

tusabes

Dump it, it will bankrupt you
These were the worst years

wallyp

While we tend to assume that every problem is a computer problem on our cars, there are times when the problem is just a normal car problem...

Check carefully for vacuum leaks. While it is usually a safe assumption that any 928 owner knows how to check for vacuum leaks, get a 4' piece of rubber or plastic hose, stick it in your best ear, and probe the idling engine for a hiss. Stay away from moving and hot parts!

Get a couple of large bottles of Techron (the expensive version) and run it for a couple of tanks of fuel to clean the injectors.

Open the hood in the dark and watch and listen for spark going to ground on the coils or plug wires.

Is the oil due for a change? Sometimes, the intake valve stems will build up deposits and tend to drag just a little as they close. That should not be the problem with the proper oil, changed at the proper intervals.

indymerc

do you have any codes?
what quality of air mass sensor is fitted?
are the oxygen sensors switching?and make sure they are plugged into the correct side as ive come across this before!

Girl600

i agree with tusebaes this has been my worst nightmare! A pure money pit SMH! save me too!

tusabes

There's a reason the early 600s have lower book resale value than the 500s or even 430

xliemx717

just to update everyone, especially the tower of knowledge, tusabes IMO tusabes nada, i went back to the starting board and replaced the spark plugs with autolite platinum plugs total $70, and now everything is OK, smooth idle, no misfire and not CEL. Now, i must quickly dump the heap on someone before it does it again...............

xliemx717

I also have a used right side coilpack, nothing wrong, transformer box, nothing wrong, for sales. make me an offer.

kraut56

$200.00?

Welwynnick

What's the part number?

Nick

xliemx717

sorry, should've put the part #
coilpack 2751500580
transformer 000 150 01 58 Q1

Nardulli

there is a ECM software update that helps with the random misfire at idle. My 03 S 600 is now known as "Lucifer". fast as hell and pure hedonism - UNTIL IT ISN'T. Just did both coilpacks and plugs. Now the ABC light came on this morning. I think I will park it and drive my GTO for a while. Grrrrr....

kraut56

How would you "classify" the misfires?
I get intermittent CEL(comes and goes) for intermittent misfire #12 cyl, but I never notice it as power loss. The odd "mini" shake at idle, but nothing drastic.

Anybody know what the ECU update is, and to what V12 engines it applies?

thnx

Nardulli

I found a MB dealership with a service manager who was actually a mechanic for 20 years, so I feel very lucky. Most MB dealerships seem to have shirt and tie guys with no knowledge at all whose job seems to be bull****ting people.

But I digress...

We were talking about my S600 and he mentioned the software update and that he put it on one of the newer models as well as mine - a v12 biturbo - and that somehow it cured a problem at idle with fuel getting too hot in the fuel rail. I don't know how that sort of heat build up can be moderated with a software update, but I will ask him.

I have other cars, and my own shop - the S600 is really way to complex for me to do much beyond basic maintenance. Although I found changing plugs to be a real pain in the A**.

I also found that plug gap is critical with this engine - way more sensitive to than the small block GM engines I mess with.

kraut56

[QUOTE=Nardulli;5609081]

But I digress...

We were talking about my S600 and he mentioned the software update and that he put it on one of the newer models as well as mine - a v12 biturbo - and that somehow it cured a problem at idle with fuel getting too hot in the fuel rail. I don't know how that sort of heat build up can be moderated with a software update, but I will ask him.

Since I have an intermittent cyl# 12 misfire at idle, I am very interested as to what this ECM software might be; my very willing factory dealership claims there is no ECM software update applicable to my car.

Could you perhaps find out?

thnx

Stock545i

Interested in knowing what the cure was. I ended up getting rid of the car and am a proud owner of a New LH side coil pack which ran me north of $1360 at the local dealership with no returns.

wallyp

You do realize that you can sell the coil pack here, right?

Stock545i

Yes, I looked up the classified section and listed it on there last night.