OM642 Turbo actuator

[Larkone]

First the background - 2008 CLS 3.0CDI, bought with 118K on the clock. Ran well but about four times, when it was hot, I got the famous juddering that is normally associated with a fault with the turbo actuator. Took the actuator off, opened it up and cleaned out the black carbon dust that had accumulated from the motor brushes. Having cleaned it I lubed the gear wheels - plastic and metal - with dry PTFE lube. Problem didn't re-occur once.

Then had it mapped and was very happy with the improved performance. However I started to notice when it was hot (after an hour of driving) that the performance was sluggish when you put your foot down. This was beyond the normal turbo lag. It would take longer to build up a full head of steam and not take off in the same way it did when it was not so hot.

So this last weekend I took the actuator off, opened it up, gave it a brief clean - wasn't really dirty even though mileage is now 139K. Decided that maybe the PTFE lube couldn't take the heat so instead I lubed the gears very sparingly with some Molybdenum Di-sulphide grease that I use to lube airguns. When I say sparingly, it was less than the equivalent to two match heads in quantity. This week I have already done 500 miles and the difference in performance is staggering. Even when hot (over two hours running) the mid-range pull is amazing and very quick to kick in - normal turbo lag excepted. It is also consistent at all engine and vehicle speeds that I have tried so far.

Unfortunately I do not know the make of the grease as I purchased it from a guy that makes airgun upgrades and he keeps it secret but it is highly regarded in the airgun world for lubricating. It resists dieseling in airguns so can take heat, is very sticky and I am told it has a high Moly Di-sulphide content. I thought the tiny tub I purchased for £6.00 was expensive but as I only used about 20-30p worth on the actuator gears for the performance gain it was a bargain.

Hope that helps others with actuator issues.

 

[Larkone]

You can get the grease here:
TbT ‘Bum-Slide – Tinbum Tuning

I have no affiliation or connection to this company, I just use their products.

 

[streethawk]

How easy was it to disassemble actuator? Just screws or clips that can break?

 

[Larkone]

Metal clips and they are strong enough not to break. I removed mine, stripped it, cleaned and lubed and back in the car in 30 minutes. Tip is when you remove the circlip on the actuator arm tie a piece of fishing line to it first, then you won't have to take the engine out when you drop it.

Good set of pics here on how to remove and open up.
Turbo Actuator Again - MBWorld.org Forums

 

[TerenteMM]

First the background - 2008 CLS 3.0CDI, bought with 118K on the clock. Ran well but about four times, when it was hot, I got the famous juddering that is normally associated with a fault with the turbo actuator. Took the actuator off, opened it up and cleaned out the black carbon dust that had accumulated from the motor brushes. Having cleaned it I lubed the gear wheels - plastic and metal - with dry PTFE lube. Problem didn't re-occur once.

Then had it mapped and was very happy with the improved performance. However I started to notice when it was hot (after an hour of driving) that the performance was sluggish when you put your foot down. This was beyond the normal turbo lag. It would take longer to build up a full head of steam and not take off in the same way it did when it was not so hot.

So this last weekend I took the actuator off, opened it up, gave it a brief clean - wasn't really dirty even though mileage is now 139K. Decided that maybe the PTFE lube couldn't take the heat so instead I lubed the gears very sparingly with some Molybdenum Di-sulphide grease that I use to lube airguns. When I say sparingly, it was less than the equivalent to two match heads in quantity. This week I have already done 500 miles and the difference in performance is staggering. Even when hot (over two hours running) the mid-range pull is amazing and very quick to kick in - normal turbo lag excepted. It is also consistent at all engine and vehicle speeds that I have tried so far.

Unfortunately I do not know the make of the grease as I purchased it from a guy that makes airgun upgrades and he keeps it secret but it is highly regarded in the airgun world for lubricating. It resists dieseling in airguns so can take heat, is very sticky and I am told it has a high Moly Di-sulphide content. I thought the tiny tub I purchased for £6.00 was expensive but as I only used about 20-30p worth on the actuator gears for the performance gain it was a bargain.

Hope that helps others with actuator issues.

Was the juddering happening with a cold engine? Mine does.

 

[OneForTheRoad]

Was the juddering happening with a cold engine? Mine does.

granted the actuator could stick at the gearing , but a lot of other factors put the engine into limp mode which is when the actuator actually sticks to disable boost . have a scan and see what error codes flag up .

 

[wu56Shoozz]

Was the juddering happening with a cold engine? Mine does.

Yes, it does this...Its a sickly Kangarooing..I put an new actuator on mine and all is well...

 

[Larkone]

Was the juddering happening with a cold engine? Mine does.

No, only when hot. But that doesn't mean if yours also has a problem it will manifest itself in exactly the same way.

 

[wu56Shoozz]

Do what OFTR has suggested - get the codes properly read. It can manifest itself as a serious of Codes, I had 5 or 6 serious codes, Actuator failure, Overboosting, TPS Sensor, O2 Sensor to name but a few.. an O2 Sensor can also give "Rooing"..

 

[TerenteMM]

The garage told me the following codes show up:

Back exhaust pressure sensor
o2 sensor
actuator jamming (4 times)
and something about inlet shutoff motor (apparently some oil leaked on the motor)

They told me to replace turbo, shutoff motor, back sensor, o2 sensor and all the hoses (1.400 pounds).
As i mentioned above, the jerking happens with a cold engine on hard acceleration but not all the time. wu56Shoozz suggested to replace the actuator, i had the exact same thing in mind but the garage told me that won't work and i found previous posts on the forum saying the exact same thing. Apparently this actuators are calibrated to a specific turbo (doesn't make sense).

 

[OneForTheRoad]

The garage told me the following codes show up:

Back exhaust pressure sensor
o2 sensor
actuator jamming (4 times)
and something about inlet shutoff motor (apparently some oil leaked on the motor)

They told me to replace turbo, shutoff motor, back sensor, o2 sensor and all the hoses (1.400 pounds).
As i mentioned above, the jerking happens with a cold engine on hard acceleration but not all the time. wu56Shoozz suggested to replace the actuator, i had the exact same thing in mind but the garage told me that won't work and i found previous posts on the forum saying the exact same thing. Apparently this actuators are calibrated to a specific turbo (doesn't make sense).

The back pressure is where I'd begin. If you take off the electrical connector you'll lose boost but the rooing will go away. A new one is around £50 and is a very common problem.

 

[lordlee]

Interesting as ours would do similar - absolutely fine on short trips but when hot in traffic it could start to play up. No codes though - apart from the O2 sensor which we replaced and we've not seen a CEL since.

 

[jshodgson]

The garage told me the following codes show up:

Back exhaust pressure sensor
o2 sensor
actuator jamming (4 times)
and something about inlet shutoff motor (apparently some oil leaked on the motor)

They told me to replace turbo, shutoff motor, back sensor, o2 sensor and all the hoses (1.400 pounds).
As i mentioned above, the jerking happens with a cold engine on hard acceleration but not all the time. wu56Shoozz suggested to replace the actuator, i had the exact same thing in mind but the garage told me that won't work and i found previous posts on the forum saying the exact same thing. Apparently this actuators are calibrated to a specific turbo (doesn't make sense).

I was quoted similar for my E320. I tried an actuator rebuild from eBay for £100 and it solved my juddering.

 

[TeddyRuxpin]

Bumping this thread... I have light judder at around 1500rpm (1300-1800rpm) on very light acceleration on my OM642 engine. When you accelerate harder (but not hard enough to kick down) the problem isn't there.

No CEL, no fault codes and the car doesn't seem to have any issues other than this light judder on light throttle/low revs. It could be MAF sensor, gearbox issue, etc, but I'm wondering if it might actually be the actuator as this is the rev area where the turbo starts to kick in. Could also be a sticking EGR valve...

@Larkone - were you getting the same issue?

Time to do some research on how difficult it is to diagnose/clean/repair/replace the turbo actuator....

 

[clk320x]

Bumping this thread... I have light judder at around 1500rpm (1300-1800rpm) on very light acceleration on my OM642 engine. When you accelerate harder (but not hard enough to kick down) the problem isn't there.

Could be Torque Converter

 

[Tuercas viejas]

Could be Torque Converter

Or lock up clutch solenoid meaning the transmission needs full H/D service and new solenoid.
You are In good company with some Dodge/Chrysler products with the same transmission unit .
Tuercas viejas

 

[Larkone]

@Larkone - were you getting the same issue?

Time to do some research on how difficult it is to diagnose/clean/repair/replace the turbo actuator....

I was getting quite violent kangarooing under acceleration when the car was hot.
Update on this - after 30,000 miles since cleaning I started to feel the car wasn't responding as well. When you kicked down there was considerable delay before the turbo picked up. I have now replaced the actuator with a refurbished one (TurboVanes). Amazing difference, car is really smooth, turbo picks up quickly with much less lag. The other benefit is even on short local journeys it is consistently showing an improvement of 3-5 mpg. Worth the £96 it cost and comes with 2 years warranty

 

[jshodgson]

I was getting quite violent kangarooing under acceleration when the car was hot.
Update on this - after 30,000 miles since cleaning I started to feel the car wasn't responding as well. When you kicked down there was considerable delay before the turbo picked up. I have now replaced the actuator with a refurbished one (TurboVanes). Amazing difference, car is really smooth, turbo picks up quickly with much less lag. The other benefit is even on short local journeys it is consistently showing an improvement of 3-5 mpg. Worth the £96 it cost and comes with 2 years warranty

I used TurboVanes. Excellent customer service if needed. I got a replacement actuator about 2 years after I bought one from them as my garage said it had become faulty. Replaced with no hassle at all and super quick.

 

[TeddyRuxpin]

I was getting quite violent kangarooing under acceleration when the car was hot.
Update on this - after 30,000 miles since cleaning I started to feel the car wasn't responding as well. When you kicked down there was considerable delay before the turbo picked up. I have now replaced the actuator with a refurbished one (TurboVanes). Amazing difference, car is really smooth, turbo picks up quickly with much less lag. The other benefit is even on short local journeys it is consistently showing an improvement of 3-5 mpg. Worth the £96 it cost and comes with 2 years warranty

Hi @Larkone, was this under heavy or light acceleration?

Mine is intermittent and only under very light acceleration @ ~1500rpm

I just changed the intercooler hoses which I thought/hoped would solve this intermittent issue, but nope. Only happens when warm though.

 

[Larkone]

Hi @Larkone, was this under heavy or light acceleration?

Mine is intermittent and only under very light acceleration @ ~1500rpm

I just changed the intercooler hoses which I thought/hoped would solve this intermittent issue, but nope. Only happens when warm though.

When it was hot and it was random - pointed to a set of gears in the actuator that had dried grease and carbon all over them binding when they got very hot.