Om642 Glow Plug Change

[matthew k]

Hi, I've finally decided to tackle this, I'm in the fortunate position to not need my car for a few days. I've taken off the airbox's etc and intend to soak the tops of the plugs for a while, might as well leave it like that for a few days, I then intend to put it back together, run it up until hot and then try to free them!!

Just thought I'd ask how the connectors are removed from the tops of plugs, are they just push fit, long nosed piller job? Any other advice is obviously greatly received, I'm a bit nervous TBH.

Thanks!

 

[Uncle Benz]

Grasp with long nose pliers alongside the little cut outs in the top face. A little wiggle while you pull straight up

 

[onefortheroad]

As above they just pull off.

 

[matthew k]

Thanks guys.

P.S, is the amount of oil in the turbo and intake pipework a cause for concern? I couldn't detect any play in the spindle, it's done 151,000

 

[bembo449]

looks ok to me , seen far worse than that pal

 

[matthew k]

looks ok to me , seen far worse than that pal

Must say the oil consumption seems to have stopped since I serviced it. I don't know if that's because I switched to 05/40 or the oil was old.

 

[bembo449]

could be either but its usually the quality of the oil pal

 

[mioba]

replace that orange seal. they should be service items and they do wear down becoming flattned being connected to the hot turbo (yours is also forming a lip on the inside), also replace the smaller orange one going to the PCV. They cost no more than a fiver total. Oil leaks from the seal kill the motor below, clean up the motor below and the connections.

The oil is totally normal, turbos - they need oil for lubrication.

 

[matthew k]

replace that orange seal. they should be service items and they do wear down becoming flattned being connected to the hot turbo (yours is also forming a lip on the inside), also replace the smaller orange one going to the PCV. They cost no more than a fiver total. Oil leaks from the seal kill the motor below, clean up the motor below and the connections.

The oil is totally normal, turbos - they need oil for lubrication.

Thanks I will do.

 

[mioba]

And be gentle putting that MAF manifild back on, They are not cheap, you dont want to break the plastic when tightening it back to the turbo. Its not the best design by MB unfortunately.

 

[onefortheroad]

Most of what you see if oil mist from the crankcase ventilation they routed it via the turbo inlet ... when i did my seal I placed kitchen foil over the swirlflap motor as a kinda fail safe if it ever did leak.

A smear of oil or washing up liquid on the red seal allows the batwing to slip in alot easier .

 

[matthew k]

And be gentle putting that MAF manifild back on, They are not cheap, you dont want to break the plastic when tightening it back to the turbo. Its not the best design by MB unfortunately.

Thanks, good advice. Yeah it seems pretty cheap and brittle with age!!!

 

[matthew k]

replace that orange seal. they should be service items and they do wear down becoming flattned being connected to the hot turbo (yours is also forming a lip on the inside), also replace the smaller orange one going to the PCV. They cost no more than a fiver total. Oil leaks from the seal kill the motor below, clean up the motor below and the connections.

The oil is totally normal, turbos - they need oil for lubrication.

At 151,000 it must have been replaced at some point?

 

[onefortheroad]

At 151,000 it must have been replaced at some point?

It looks kinda newish tbh. When you put it next to a new one ,you can feel the difference and they go out of shape as they age.

 

[Larkone]

At a 151000 the PCV valve rubber diaphragm is going to be hard and/or split. I would replace the PCV valve and this comes with an upgraded orange seal at the turbo end, it is better clamped so cannot get sucked intro the turbo. Did mine at around 133K and the diaphragm was hard and has started to split, car ran much better afterwards and less oil in the turbo inlet.
Discussed here with pics of what splits
https://forums.mbclub.co.uk/threads/om642-pcv-upgrade.231147/

 

[Wighty]

At a 151000 the PCV valve rubber diaphragm is going to be hard and/or split. I would replace the PCV valve and this comes with an upgraded orange seal at the turbo end, it is better clamped so cannot get sucked intro the turbo. Did mine at around 133K and the diaphragm was hard and has started to split, car ran much better afterwards and less oil in the turbo inlet.
Discussed here with pics of what splits
https://forums.mbclub.co.uk/threads/om642-pcv-upgrade.231147/

I did mine on your recommendation as well

 

[James Debuse]

Hi, I've finally decided to tackle this, I'm in the fortunate position to not need my car for a few days. I've taken off the airbox's etc and intend to soak the tops of the plugs for a while, might as well leave it like that for a few days, I then intend to put it back together, run it up until hot and then try to free them!!

Just thought I'd ask how the connectors are removed from the tops of plugs, are they just push fit, long nosed piller job? Any other advice is obviously greatly received, I'm a bit nervous TBH.

Thanks!

I did mine a few months back. Like you I was very nervous about it. Watched a few videos on you tube and looked at advice on the forum. I soaked mine overnight with some WD40 penetrant spray as opposed to standard WD. I ran the engine the following day so it was warmed up. I then had a cup of tea and started. I used a deep socket and ratchet with a shortish attachment. I then gently tweaked the plugs clockwise and anti clockwise. This was done GENTLY. Although I didn't have the facility to do so it may be worth getting an airline to blow out any crap from around the plug prior to taking them out. They all came out with no issues. I then had another cup of tea and jumped for joy. When putting them back in I smeared the plugs in ceramic grease. NOT THE TIP. Replaced them carefully and tightened to what I thought felt tight enough. Had a torque wrench but was overly confident in using it. Car starts on the button now with no warning light on the dash. Saved myself about 140 quid.

 

[Oonnzo]

If you do break the clips they are cheap at the dealer. Part number is A0445457928.

2 of mine broke - Even though I was gentle, they were brittle from the heat cycles.

 

[matthew k]

It looks kinda newish tbh. When you put it next to a new one ,you can feel the difference and they go out of shape as they age.

There's some oil underneath, does it look excessive? I'm going to replace them as you suggested.

Thanks for all the help guys,

 

[onefortheroad]

There's some oil underneath, does it look excessive? I'm going to replace them as you suggested.

Thanks for all the help guys,

The area could do with a degrease , you don't want the swirl motor getting damaged. That may of been the result of the previous seal not being changed in time. These sort of things ,givin the damage they can cause mb should be put onto the service sheet at say 30 to 40 k intervals .