OM642 Turbo Actuator - free movement / play?

[Willber]

Morning.

I have an E280 with the OM642 engine. It kangarood for the first time ever last week and when scanning showed 2510-1 and 2616-2 (actuator and back pressure sensor) The engine light didn't come on, but it went into limp mode. I restarted the car and all was fine.

The actuator has already been replaced with a rebuilt one some time before I bought the car.

I've got a replacement back pressure sensor on the way but I wanted to know if it is normal to be able to move the actuator arm up and down approx 10mm when the car is switched off?

The actuator moves with the ignition on, but I am wondering if the play in the linkage is normal or suggests the cogs inside may be worn?

Can anyone with the same engine check if theirs does the same, please?

Thanks!

 

[bembo449]

pop the bonnet , and flick the ignition on and off , you should if its healthy ? here the turbo actuator flick / flack , refurbed ones do fail again aswell so dont presume because it was done once it wont be the fault

 

[Willber]

As per my original message - with ignition on it moves as it should do. What I'm asking is whether it is normal to have some free play / movement in the linkage when the car/ignition is switched off

Thanks

 

[bembo449]

no not really pal , sounds like the gears inside may be failing hence why no EML

 

[M80]

As per my original message - with ignition on it moves as it should do. What I'm asking is whether it is normal to have some free play / movement in the linkage when the car/ignition is switched off

Thanks

I would think not, but I'm not familiar with that model.

More importantly though, is it held solid at tickover? Or is there still free movement?

 

[Larkone]

OK just checked mine and the free play is about 3-4mm at the end of the actuator arm that connects to the link to the turbo. However if this is connected to the turbo then that free play would be at the turbo vane end surely or have you disconnected your actuator from the turbo arm?

 

[Willber]

I would think not, but I'm not familiar with that model.

More importantly though, is it held solid at tickover? Or is there still free movement?

Just checked it - it holds a constant position at idle, but when I try and see if there is any free play like when it is switched off, some movement is there. It almost feels like it bounces around a bit when i try and take up the slack in the linkage.

 

[Willber]

OK just checked mine and the free play is about 3-4mm at the end of the actuator arm that connects to the link to the turbo. However if this is connected to the turbo then that free play would be at the turbo vane end surely or have you disconnected your actuator from the turbo arm?

Hi, just posted at the same time - apologies!

Upon 2nd look I'd describe my free play as about 3-4mm too actually.

The play is in the actuator side from what I can tell. I'll try and get a video later.

 

[Larkone]

Just checked it - it holds a constant position at idle, but when I try and see if there is any free play like when it is switched off, some movement is there. It almost feels like it bounces around a bit when i try and take up the slack in the linkage.

Take the actuator off (piece of fishing line around the circlip before you try and take it off the arm), open up (clips) and (carefully) clean the position wheel with a wipe of IPA, wash out the black dust (from the motor brushes) that collects on the gears and re-grease with some high temp silicone grease. Put back together and see if it is any better. Many say this doesn't work, at 120K miles I found that it improved mine and lasted for about 30K miles before it started to start to play up again so changed it for a refurb unit.

I think the amount of play you are seeing on the arm is normal.

 

[mioba]

10mm - thats alot.

Had mine refurbed by midland turbo - down the road from me.

They told me they do loads for mercedes. The cogs are made of butter. They use better plastic in the cogs (worm drives).

While i was there a MB inchcape nottingham van pulls up to collect an order - no doubt MB charging **** loads to thier customers (new turbo prices).

I also had midland turbo refurb a turbo for me on a VW T25. It came back looking ****** brand new.

 

[Willber]

Its actually about 3-4mm in further inspection.

Replaced back pressure sensor and all seems fine. Will see how it goes.

Think i might have oil cooler leak so that will be another thing for the list!

 

[Wighty]

Its actually about 3-4mm in further inspection.

Replaced back pressure sensor and all seems fine. Will see how it goes.

Think i might have oil cooler leak so that will be another thing for the list!

The back pressure sensors have a hole underneath that blocks up with sooty gunk . “Sometimes “ they just need spray cleaning with carb cleaner .

 

[Willber]

Do you mean the bit into the turbo / exhaust or on the sensor itself?

 

[Wighty]

Do you mean the bit into the turbo / exhaust or on the sensor itself?

The sensor itself , top right of the pic

 

[Willber]

Ah, ok. I thought you meant it was worth cleaning out the bit which the sensor screws into also

 

[Wighty]

Ah, ok. I thought you meant it was worth cleaning out the bit which the sensor screws into also

That’s a much bigger hole , I’ve never had to though .

 

[Willber]

Just to revisit and update this - its not normal to have the free play described at the actuator end. I eventually removed and cleaned up yhe actuator and found the worm gear is worn with pointy teeth. I have ordered a replacement from Turbo Vanes so will report back when fitted.

 

[Willber]

New actuator fitted and car seems much better. More responsive and seems to be getting better MPG during shorter journeys. I dare say it feels quicker too! I think the actuator will have been dodgy for a while. I assumed (because it had an Actronics refurbished sticker on it) that it would be fine, but removing and opening up was a worthwhile exercise!

I guess I'll see how long the new one lasts....

Got a 250 mile round trip this weekend so will get a better feel for it but so far seems to be running much better

 

[Willber]

Saw 41mpg at motorway speeds last weekend eventually dropping to 40.5 overall. A lot of that is down to the endless A1 and M1 roadworks but its definitely getting better MPG which makes sense as its not working as hard at lower revs. I also had a flat spot around 2k rpm where it would noticeably have more urgency which has now gone. Think that will have been due to turbo vanes not opening / closing properly due to old actuator.

Need an O2 sensor now and hopefully should be right for a bit.

 

[M80]

Need an O2 sensor now and hopefully should be right for a bit.

I can't see that wanting to come out.
I would start treating with Plusgas, hoping the hot / cold cycles will help.
Might be worth manipulating with a spanner also.