V6 CDI Inlet Port Shut Off Motor Replacement

[M80]

In preparation I think it’s worth dropping the belly pans. The 1st time you drop a bolt or socket the pans have to be dropped anyway, this way now you just pull out the belly pan to recover the dropsy. Then put the belly pan back to catch the next.

When feasible I prefer to remove the item and screw bolts back where they came from to reduce the confusion of “where’s this one from”.

Setting up with torches, grab claw, extendable magnetic led and masking tape were very useful.
A roll of ‘heavy duty’ kitchen type roll from the £ shop worked a treat, as did a few pairs of the blue nitrile gloves.

To clean I spray white spirit onto the towel and wipe.
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The fault was the car going into limp home mode.
Various fault codes were present but many due to the under bonnet fuse number 54 (15 amp) having been blown by the inlet port shut off motor.
A known problem is the air intake duct is sealed to the turbo Intake spigot by a rubber seal. This seal allows oil to pass that finds it’s way onto the shut off motor below, causing it’s eventual failure.
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Remove engine cover.

Remove heat shield above turbo,
3 bolts, image (b).

Remove o/s heat shield support bracket (engine hoist point),
2 bolts

Remove air filter retaining bolts,
2x2, 4 bolts in all.

Loosen jubilee’s on air filter to air intake duct, ease air filters sideways away from engine,
2 jubilee’s.

Unplug 2 MAF’s at air intake duct,
image (a).

Remove PCV inline heater from air intake duct and unplug, this will need to be moved away from the work area,
image (a).
If you wish to replace the rubber seal consider that this is supplied c/w a heater, £22 +vat.
Mine was passing oil and was an unreliable seal into the duct.
A new one will be more difficult to push into the duct on re-assembly.

At air duct to turbo spigot loosen the jubilee, and ease air duct backward and off,
image (b)
We are now up to the 3rd revision in design of the air duct (approx £250 +vat). The new style rubber seal between air duct and turbo intake spigot, ‘the cause of the issue’ is now shorter but also fatter. On re-assembly pushing the seal onto the spigot is very difficult, maybe the later design makes for this to be easier ? Don’t loosen the jubilee to much at re-assembly as it offers support to the plastic surround and can prevent it splitting.
I ran a bead of silicon sealant around the inside of the air duct where the seal sits, looking at the old seal there was a gap between the seal and the turbo intake spigot (see image (o)). This would allow the oil to pool and eventually run, I hope to prevent any repeat of this.
image (n) & image (o).
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[M80]

V6 CDI Inlet Port Shut Off Motor Replacement (Part 2)

At the turbo actuator carefully prise off the spring clip at the top linkage, separate linkage from actuator. Tape the linkage to prevent the bearing coming out and to stop the linkage being a nuisance,
image (d).

Remove the bolts from the back of the actuator bracket that bolt it to the turbo, remove actuator,
3 bolts.

At the exhaust output elbow at the rear of the turbo loosen the lower clamp and ease off the joint. This can be left on the elbow when removed,
1 bolt, image (e).

At the back of the turbo loosen and remove the top 2 bolts of the exhaust elbow. Only loosen the lower bolt as the lower of the flange is slotted, the elbow will than lift away.
Good luck with the lower bolt, it’s a bitch.
3 bolts, image (f).

On re-assembly the new gasket has 2 locating plastic pegs. I removed the n/s peg and prised the o/s peg for easier removal when the elbow had been fitted. The 1 peg and the lower bolt are good enough for locating,
image (c).

Remove the EGR exhaust flexi feed pipe. Some caution there are 2 gaskets that might want to fall.
Protect the manifold hole with masking tape.
4 bolts total, 2 long ones into the head,
image (f).

It’s possible at re-assembly to pass the bolts through to the gaskets to hold the gaskets in place while the flexi pipe is re-installed,
image (c).

Remove bolts from exhaust into turbo manifold, be aware of the 2 gaskets that may fall,
2x3 bolts, 6 bolts total, image (g) & image (c).

On re-assembly prepare by 1st checking orientation of the 2 gaskets to understand how they go at 1st attempt,
image (c).

Remove bolts clamping lower bracket to lower exhaust side of turbo exhaust intake manifold,
2 bolts, image (f).

At re-assembly replace these 2 bolts and tighten prior to replacement of lower bolt on o/s exhaust into turbo manifold or the lower bolt will obstruct. The other 5 exhaust bolts want to be close to tight prior to tightening the lower bracket to turbo 2 bolts.

It may be easier to remove the low vertical bolts that hold the lower bracket to the block, the lower bracket will lift out with the turbo assembly as will the turbo actuator. For re-assembly I found removing the lower clamp and actuator reduced weight and made for easier re-siting of the turbo assembly,
image (g).

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[M80]

V6 CDI Inlet Port Shut Off Motor Replacement (Part 3)

Now to top and front of engine.

Unclip coolant pipe from front of the intercooler to turbo pipe.
Unscrew horse shoe retaining screw at top of intercooler and withdraw horse shoe, some leverage may be needed.
At the middle area of the intercooler pipe remove the tall post bolt,
1 screw, 1 bolt, image (h).

At the bracket to the front of the turbo remove the bolt into the turbo, the bolt down into the shut off motor, and the 2 bolts into the head. Remove bracket,
4 bolts total, image (j).

Remove bolts that clamp the turbo onto the turbo tower,
2 bolts, image (b).

The turbo should allow enough play to remove the intercooler pipe.

At re-assembly it may be preferable to replace the black ‘o’ ring onto the intercooler and the green ‘o’ ring onto the turbo output spigot.

At the fuel rail link pipe remove the 2 clamp bolts and ease the clamps and rubbers off the link fuel pipe,
Loosen the fuel link pipe at each fuel rail, some leverage will make it possible to remove the fuel link pipe, too much leverage could cause the pipe to kink.
2 bolts. 2 nuts, image (j).


Loosen the rubber fuel pipe jubilee’s at the fuel filter and slide rubber fuel pipes backward,
2 jubilee’s.

1 more bolt to remove and the fuel filter can be lifted out.
1 bolt.

The turbo now needs to be angle rearward so that access to the lower tower bolts can be gained, remove the lower bolts, remove the tower while manipulating the turbo.
4 bolts, image (b).

There is likely to be some muck around so carefully remove any obvious muck and protecting the oil ways with some tissue is a good idea.

It should be possible to lift out the turbo c/w the exhaust turbo manifold,
image (b).

On re-assembly the gasket clips to the underside of the turbo and stays in place. The lower gasket sits on dowels in the engine block,
image (b) & image (g).

Protect the exhaust into turbo manifold holes, I used kitchen roll,
image (g).

Unbolt and remove lower bracket if not already done earlier and if desired,
2 bolts, image (g).

The under turbo wiring loom duct is held by a plastic clip sitting onto a bracket near dip stick, into the engine hoist point bracket, and 1 bolt into the head.
The duct can be moved a good way to create work space,
1 bolt, image (k).

With snipe nose pliers apply gentle pressure to plastic insert above motor arm pivot points.
It’s easier on re-assembly to insert the retainers into the motor arms rather than at the outer port linkages.
Ease down by pulling from below.
Be aware that the plastic inserts are in 2 halves and may separate when removed.
2 pivot retainers, image (l) & image (c).

Unplug and remove Inlet Port Shut off motor,
2 bolts, image (m) & image (b).

Being cautious not to contaminate the turbo tower oil ways there is now likely to be much muck from the escaped oil to be cleaned.
I used kitchen roll to protect the oil ways.
Check the ports open / close freely by manipulating the below head linkages.
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I would suggest that there is a good days work to replace the shut off motor and rebuild. This depends on how easy or (more likely) difficult the bolts come out.
Many are very difficult to get to, and big hands would be a disadvantage.
I didn’t rush, carried out the task in an organised way and took a lot longer.
Total cost for parts at 10% discount for asking, £255.36 Incl Vat.
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[S.Speed]

Martin that is one of the best "How To's" I have ever seen..
Its such a pity the Haynes manual arent written / photograpphed to your high standards..
Seriously, my hat is well and truly taken off to you..
Very well done mate.

 

[Developer]

Martin that is one of the best "How To's" I have ever seen..
Its such a pity the Haynes manual arent written / photograpphed to your high standards..
Seriously, my hat is well and truly taken off to you..
Very well done mate.

I take Simon's hat off to you too Martin - very comprehensive.

 

[mobeyone]

Thumbs up from me too.

That is a lot of work, was there a lot of oil around when you removed the motor?

 

[M80]

Thumbs up from me too.

That is a lot of work, was there a lot of oil around when you removed the motor?

There was a lot of work involved, I was fore warned and helped by reading previous threads by others.
The main reason for the DIY was to help others because as you think you've got there there is more to come, a bit like climbing to the 1st summit only to see another behind.

There weren't great amounts of gunge but it is awkward to get to and clean.

Thanks to those that helped me resolve my problem, I wouldn't have guessed that it was the motor blowing the fuse and bringing up the many mis-leading codes.

 

[mobeyone]

Do you mind if I ask what was happening? And what codes you were getting?

I have a 280 and it's been diagnosed three times but the only fault that comes back is the o2 sensor. It hesitates slightly when accelerating and the gear changes are sometimes a bit clunky/lazy but usually fine.

I've just had the oil changed on the box but I'm going to have the level checked just in case it's not right.

 

[M80]

http://forums.mercedesclub.org.uk/showthread.php?t=93135

This shows the lead up.
The promised delivery by EPC of the Lamda didn't happen and as Alex says it doesn't seem important.
I wonder if there might be any effect on consumption when cold though ??

Many of these boxes have an occasional hesitancy. A clunk from 2nd to 1st seems to be known although I have to concentrate hard to pick it up on mine.

I haven't used the car enough since repair to comment much on improvements, it does seem more responsive but that could well be placebo. It also fires up when cold more readily.

 

[mobeyone]

Thanks)

I had the O2 sensor changed but it's made no difference to be honest. Tech mentioned that there maybe oil in the loom but I'll have that looked at when it's in next. Do you know if there are two O2 sensors on the v6?

I picked up a motor of eBay for 130 and plan on doing this when I have it serviced as its something that will need doing..

 

[M80]

Just one Lambda at the exhaust front section, on the lower elbow.

If you change the seals on the air intake, that is prevent the oil from escaping, the rest of the work (motor replacement) shouldn't be necessary.

 

[oceanlord]

oceanlord

Martin, I would like to add my thanks for your excellent "how to" article on changing the air inlet control box. My CLS had its replaced by my local main dealer at 36,000 miles.
However at the current 39,000 miles I realised that the red seal into the turbo was leaking oil again.
I have replaced this myself and can only think that the main dealer had not tightened up the jubilee clip enough. (the seal wasof the new shorter type and the plastic inlet was not cracked.
The point of writing this is to say that it is almost impossible to see if there is an oil leak but you can check for it if you make up a curved piece of (coat hanger)wire (curvature to match the diameter of the inlet) and wrap it with some soft kitchen paper. the wire can then be passed down through the small gap either side of the inlet and rubbed under the low point of the seal to detect an oil leak.
I do mine about once a month at the moment.but rather that than limp home again.

 

[prm]

Why do some leak and others don't i wonder. Recently had mine serviced at 68,000 miles and they checked the seal for leaks and all was well and apparently dry, thank God.

 

[bpmail1]

Martin, I would like to add my thanks for your excellent "how to" article on changing the air inlet control box. My CLS had its replaced by my local main dealer at 36,000 miles.
However at the current 39,000 miles I realised that the red seal into the turbo was leaking oil again.
I have replaced this myself and can only think that the main dealer had not tightened up the jubilee clip enough. (the seal wasof the new shorter type and the plastic inlet was not cracked.
The point of writing this is to say that it is almost impossible to see if there is an oil leak but you can check for it if you make up a curved piece of (coat hanger)wire (curvature to match the diameter of the inlet) and wrap it with some soft kitchen paper. the wire can then be passed down through the small gap either side of the inlet and rubbed under the low point of the seal to detect an oil leak.
I do mine about once a month at the moment.but rather that than limp home again.

Hi ... may i ask you how much you paid to replace air inlet control motor (m55 is called..)
just asked because today they told me i have the same problem on my car.
Yesterday i felt a smell like "electronic components burnt" into the car. After a while the MIL lights come on and the performances changed.
The car didn't gone in limp mode but it loss the immediate boost when you accelerate it got weak at low RPM while push normallu at hight RPM...
so today i took to MB dealer that with stra diagnosis give me the news.
I hope the motor burnt himself and not beacuse of mainfold flap sticked or locked because in that case it would cost much they told me ...
....my car is 145000 km
thanks for moral support

 

[bpmail1]

replace M55 without remove turbocharger.. is possible!!

it is possible to dismount the M55 component without removing the turbo.
It takes time and solid nervous system but is possible

- remove plastic collector that connect filters with turbocharger
- remove diesel filter
- right side (car direction) release screw that hold the plastic electric channel that pass below inlet turbocharger
- left side (car direction) remove metal L bracket that hold M55 to intake air mainfold and turbo

M55 motor is hold in place by 3 screw
1 and 2 easly visible and 3rd hidden

1 left side attached to L brachet already removed in previsious step
2 right side close to diesel filter
3 right side again pull-up a bit the plastic electric channel you will find 3rd screw that hold M55
To remove screw 3 you need a 8mm hex to work from diesel filter gap and one or two bottles of beer to stay quiet.

Than M55 is free from screw but still attached to mianfolds air intake links by 2 clips in 2 points
Right side Front lie the first to be removed Right side Back the other is behind M55 below turbocharger intake

Important do not pull or use BFA (brute force approach) in this phase because you risk to brake air mainfold links that moves flaps

while removing you will brake the clips 99% .. or better they will brake them selves while trying to clamp it because are "coocked" by warm and oil...
not that bad because are sold as a spare parts (number 105 into attached doc)

to set the new M55 you will need and L rod to push the clips from behind and other one or two bottles more of beer to set the rest of screw...

Note:
remeber to replace inlet turbocharger gasket to prevent as much as possible oil leaking
and remeber to check that flaps moves free. (in case not problem gets a bit serius and you will have to remove many more parts including turbo..)

 

[lesmon]

Parts List for IPSOM (Inlet Port Shut Off Motor)

Has anyone put together a (comprehensive) parts list with part numbers of what's needed for M55 Motor replacement??
Will be grateful if one cane be posted

 

[M80]

All parts disturbed are noted in the 3 posts.
The obvious replacements are the motor and orange air duct seals. Some are replacing the 2 seals now as a matter of course at each service.
I have opted to apply a bead of silicon sealant around both of mine, and to re-silicon at each service.
Replacement of gaskets, as described, is a personal choice also. I replaced all that were disturbed.

 

[purplehaze]

Thanks, and question

M80, many thanks for a really instructional post, with excellent photos! That was a big help.

I just finished replacement of the IP motor, pcv, air filters (while in there), diesel filter, oil filter, and all new gaskets, O-rings, etc.

Started up fine.

During test drive, ran fine, but still sluggish, as if the turbo wasn't really kicking in. Just like default/limp home mode, before all the work. Then a high pitch whistle began during minor acceleration, and while maintaining speed. It ceases at idle.

Did you need to clear codes or something, to get the 'Check Engine' to go away, and for it to perform properly - or did it just start working again?

Any clue about the whistle, and what I may have botched?

Thanks!

Glenn

 

[M80]

I will have cleared all codes after the works were carried out, one reason being that if there was still issue the codes present would help diagnose.
For the whistle I would look first at the air intake system. If there is a dislodged 'o' ring on reassembly you might get that ??
Others may well have suggestions here.

BTW welcome to the forum and good luck.

 

[Alex Crow]

......Any clue about the whistle, and what I may have botched?

Thanks!

Glenn

You need to be sure that the red seal in the intake pipe, and the green o-ring in the oulet are properly in place and secure.
We have seen both these seals misplaced in the past, especially the red one.