Had my car in at a Benz indi today for a rough idle and his Star computer came up saying the timing in my car was retarded.

Does anyone have any ideas as to what could be causing that.

The idle is rough and the exhaust is very deep, so it definetly feel like a timing issue, only thing is it runs great off idle.

 

There is a adaption where you can do the crankshaft/camshaft timing, try that first. It seems the camshafts are in the right place and the sensors are reading them correctly so possibly your crankshaft sensor has gone faulty and is not reading correctly so it doesn't know the correct reference for the timing.

 

I was thinking (hoping) that was the case but from what I understand Crankshaft sensors mainly cause problems with starting and when driving.

The car has no issues when starting and drives normal.

This was also given shown in the paperwork as faults, however after clearing them they did not return, only the ignition angles and manifold pressure show up.

The purge valve would have been me disconnecting it yesterday just for testing.

 

Think i'm going to buy a Crankshaft angle sensor.

The Powertrain Control Module (PCM) controls camshaft timing from signals it recieves from the Crankshaft Angle Sensor.

That may explain why it says both my Cams are in an incorrect position and also the Ignition angle is -9 instead of somewhere between 0-20.

Either that or the PCM has issues?!

CAS is $120 from the stealer and they have them in stock.

Ill report back tomorrow.

 

If it was the crank sensor, than why does the second print out only refer to the left bank? Both banks would be out of timing and the car would run like crap throughout the rpm range...? Something has thrown the ignition timing off as well... So maybe crank sensor?

Trouble with these cars is there is so much electronics...


Your ignition is running at -9 at idle. Mine idles at 14 ish. -9 is way too low for idle, no wonder it barely idling, it's throwing the spark way too late and that's why the exhaust is so deep.

Second print out, says left bank is off timing. I'd check adjusters on that side.

Do you have a tune? Is the car stock?

 

Car had a tune 18 months ago, also has dual 3in exhausts from Cats back.

Was running great up until about 6 weeks ago.

The faults in the 2nd printout I posted up were cleared by the mechanic and did not return, only the -9 ignition angle. No CEL's at all either, only those stored faults.

Still not happy at idle though. Its hard to tell in a 63, but I think its using even more fuel than normal.

Yeah my ear drums are ringing when its idling! Exhaust note sound like its laboring at idle. Even my Mrs noticed it.

You know your car has issues when your Mrs says something

 

Not looking too promising, the timing is off on the left bank and the mechs say that happens as the tensioner is on the right bank and usually tightens the chain enough for the right side.

They are looking at that middle centre timing cog to see if its worn.

If it is, that's an engine out and full strip down of the front

 

never seen that (the center cog) worn out on the 63 motor. that was only on 272 and 273 motors. I think someone had your engine apart and maybe didnt torque the cams gears propery or the bolts stretched. or maybe they didnt replace the special diamond coated washer since there is no dowel pin or anything. Ever have your headbolts done?

 

No, still thrashing it with the original headbolts

Do have an update, they re ran the codes and different ones are appearing now.

Would you believe its those damn intake manifold gaskets! (again, had those done 2 yrs ago)

There's a vacuum leak on cyl 2 & 4. New intake gaskets are being fitted tomorrow and the mechanic is confident thats the only issue.

Will update when I know

 

intake gaskets set mass air flow/fuel calculation/rich/lean/misfire codes. Not camshaft too retarded or advanced. Your problems are not over yet.

 

I agree.

 

Find out monday now, parts didnt arrive till this afternoon.

Anything major and she's going to the Auctions!

I have driven 60 klms since the codes were erased and they haven't come back.

Not sure, I wish the codes had a date of then they appear. I was giving it some through the mountains the other day.

Whatever it is, it hasn't been enough to trigger a CEL

 

Maybe the rough idle was from the leak and those were old stored codes?

 

I went straight to the top and asked Weistec with this question.

They kindly replied. Makes me feel more confident.

"P0023 and P0021 would not be caused by leaking intake manifold gaskets.

In all our experience with the M156 engine we have not seen excessive wear in the timing components.

the M156 engine has variable cam timing. what could be happening is that there is either an electrical problem with the cam timing on the left bank, or both of the cam phasers are failing.

once the intake manifold gaskets have been replaced, continue to drive the car and see if the problem persists. If so it will be time to look into everything related to cam timing on the left bank"

 

The cam adjusters don't last forever. I replaced mine on two engines around 60,000km. They were very noisy.

 

Update on this:

The right side EGR valve is worn and letting gas in all the time, most likely causing the rough idle.

The timing issue is a partially stuck intake runner. Its not smooth in its adjustment.
Have to take the intake manifold off again and see whats going on inside

 

Post pictures if you DIY it

 

I have both these parts if you need replacements. I think the dealer will rape you there.

 

interesting info here and i would really love to get my hands on more of the info posted as an attachment in the first post - showing the specs of the various moving bits - like idle ignition timing / cam timing etc etc - where is that info avail / what book does it come out of even ?

 

In the end the issue was with a gummed up EGR valve. The slider in the intake manifold also needed lubing as well.

Too bad there are no competent mechanics in QLD to diagnose this. All they could do was plug in their computers and when things didn't make sense, start changing parts at my expense.

I ended up pulling the car out of one shop and paid $700 to have it transported to Sonny in NSW and he had the issues found within 3 hours.

 

Ummm, the 156 has no EGR valve.

Maybe you are referring to some other component.

 

Was the valve next to the power steering oil tank.

Just looked it up, it's known as the diverter valve

 

Sonny knows his stuff. Merc mechanics just do not seem competent to me. Sure they know how to plug in a computer but thats where their thinking seems to end though.

 

Maybe your guys down under need more training. That's a pretty general statement to make.

 

Went through 2 shops before i pulled it and sent it down south.

Non of these were Mercedes Dealer, both independant Merc 'specialists'

The last one I took it out of told me they service 3 S65's and that my car was 'less complicated'

Anyway, its all been done with now.