271940 engine spark plug change - C200 Kompressor

[johnsco]

Today was the day for another "first-time" job in the refurbishment of my recently-acquired C200 Kompressor.
I had obtained the spark plugs from MB Newcastle - Very efficient and helpful service.

MB Pt. No:

A004159450326 (Set of 4)

Bosch No on MB plug - F6NPP332

The plugs that I removed were Bosch F6MPP332
Checking the Bosch numbering system table, I can't really determine any difference between the two Bosch Part Numbers.

This car has been pretty-shabbily maintained - as mentioned before.
I feared the worst - and was not disappointed [Actually, I was quite disappointed].

I removed the plugs from a warm engine (It was a cold day).
Plug #1 must have been fitted by a gorilla.
It is much too tight ...... Frighteningly-so.
I was afraid that the steel thread on the plug would pick-up and damage the thread in the head.
I gave it an application of Unilease penetrating oil - Then very carefully worked it back and forth until it started to come out.
[Lessons in foul language for the neighbours].

Fortunately the other three plugs were less tight than #1, but were really all too tight.
The good news is that all came out without damage.
I lightly coated the threads of the new plugs with Rocol "Never-seize".
All went back together correctly-torqued.
All the coil packs and the HT tubes were in good condition - Nice and clean with no burning.

I measured the spark gaps on the old plugs.
All were pretty-bad.
The worse was 1.22mm.
They must have been in for years.
The new plugs were the correct gap of 0.8mm

Result !

 

[grober]

http://www.porshaw.com/images/Bosch_SuperPlus_DesignationCodes.pdf

 

[W1ghty]

Good job buddy , as you say , they need to be the correct torque on the 8 bolts that hold the coil packs down because the rocker cover has rubber seals underneath that will leak oil into the spark plug well‘s if they are too loose .
When MB originally changed my plugs 6 years ago , one of the bolts was missing which I found out much later . That incident pretty much started my diy servicing career after that .
What mileage had the old girl got on now ?

 

[markjay]

http://www.porshaw.com/images/Bosch_SuperPlus_DesignationCodes.pdf

That's the difference according to grober's table:

The old plugs had electrodes that were protruding 1mm less into the combustion chamber.

 

[johnsco]

Good job buddy , as you say , they need to be the correct torque on the 8 bolts that hold the coil packs down because the rocker cover has rubber seals underneath that will leak oil into the spark plug well‘s if they are too loose .
What mileage had the old girl got on now ?

I found that one of the coil-pack hold-down bolts at plug #3 was quite loose.
Fortunately - No harm done - There was no oil in the plug well .
All eight bolts are correctly torqued now.

Present mileage is around 95,000 miles.

The old plugs had electrodes that were protruding 1mm less into the combustion chamber.

Thanks for this guys.
I see the difference.
It's certainly burning cleaner now.
There was a bad smell of unburned fuel before I did the plug change.
However - The old plugs were in pretty bad shape, which may have accounted for it.
There's another job I need to do soon ...
The temperature gauge is reading low when the engine is fully-warmed up.
This is probably causing it to run rich and may have been adding to the petrol smell.
I've got a thermostat on order.
The old plugs were pretty black indicating a rich mixture.

At some point, I'll post a list of the many jobs I've had to do on this car.
I picked it up pretty cheaply and I've not spent a lot of £££ on it - But I've certainly given it a few hours.
Tomorrow, I'm going to have a crack at the famous "bouncing lock" problem on the passenger-side door.
That should be fun !.
I know how to do it and I've got the part.
Here's hoping for a fine day.

 

[markjay]

The thermostat is at the front of the engine and very easy to replace.

If you syphon-out the coolant from the expansion bottle, then tilt-up the car on a jack in the right direction, before removing the thermostat, then you won't lose any coolant, and you can reuse the coolant you removed from the expansion bottle.

Just note that the thermostat housing is made of plastic, and will need to be reused, so prise it out with care, twisting it from right to left gently (after removing the securing bolts).

 

[johnsco]

Many thanks Markjay for your helpful comments re. the thermostat replacement.
I've watched one of the how-to vids of the job, where the guy drains the coolant from underneath the rad.
I had a look at the job and my first thought was that the height of the bottom of the xp tank is about the same as the height of the stat.
I'll do it as you say.
Thanks also for your thoughts about the plastic housing.
I've ordered the Wahler stat, which comes with the two "o" rings.

At some point soon, I'm going to seek your advice regarding the timing chain and cam-gear question.
Together with my very-experienced mechanic friend, we've had a long hard listen to the engine and we can't detect any trace of problems.
Service history for this car is totally absent.

Despite having worked on a large number of engines thru-out my life, I'm a half-decent engineer, but I'm completely self-taught when it comes to cars.
I've refitted engines from mini 850s to Chevy 350 cid V8s
This engine is totally different from anything else I've ever owned or worked on.
I'm learning all the time and I'm still getting my head round what makes it tick.
Is there a good write-up about the 271940 engine ?
It would be a real help.

Most of the past 20 years, I've run MB diesels.
I've some experience of a type 126, 380SE and also a 210-facelift E430 .... both cars that the former Mrs J. used to run.
[She liked big MBs]

This C200 is a refreshing change from my reliable work-horse of the last 8 year - the E280 cdi.
I actually love this car, which I got for the present Mrs J.
It's got a lot going for it.

 

[markjay]

What year is the car? Unfortunately the timing gear on early M271 Komptessor engines fails within warning.

The teeth on the camshaft sprockets wear, until the chain jumps a tooth (at engine startup) and it's curtains. The chain doesn't stretch prior to that and there's no unusual noise. The o my way to check thus is by removing the camshaft cover and inspecting the sprockets. Or just leave it and hope for the best... If the sprockets are worn, BTW, the remedy is new (modified/hardened) sprockets, chain, guides, and tensioner.

Other common issues on the M271 are 'oil in loom' - the two camshaft position sensors at the front of the engine can leak and oil can get into the ECU via the wiring loom, split vacuum hose under the air filter housing causing rough idle, and blocked crankcase breather.

 

[markjay]

See also:

The Complete M271 Engine thread. ( Revised and Updated ) | Engine

The Complete M271 Engine thread. ( Revised and Updated ) People are forever asking about how to mod their M271 C180 Kompressor so I thought some work was required to help guide us all! Hope this helps someone. The Complete M271 Engine thread. As you know a number of people regularly...

forums.mbclub.co.uk

 

[johnsco]

OK - Thanks Markjay.
The car is year 2005.
VIN: WDB 2037422 A683846 ENGINE No: 271940 30 413832

What is involved in removing the camshaft cover to inspect the sprockets ?
Is it a job I can easily do myself ?
As I said, I'm still finding my way around this engine.
Sorry if this seems an obvious question.
Thanks.

 

[W1ghty]

OK - Thanks Markjay.
The car is year 2005.
VIN: WDB 2037422 A683846 ENGINE No: 271940 30 413832

What is involved in removing the camshaft cover to inspect the sprockets ?
Is it a job I can easily do myself ?
As I said, I'm still finding my way around this engine.
Sorry if this seems an obvious question.
Thanks.

I did my cam/rocker cover removal myself the other year , I’m a self taught diy’er as well . It was straightforward, getting the cover out from under the cross top of the engine wiring I found fiddly but it allowed me to check for wear . Everything seemed alright on mine and that was at 70-80k ish ?

You also need to check the wiring plugs to the cam magnets , they can leak oil that wicks along into engine management systems . Fitting “wire blockers” prevents this happening .

Supercharger oil is worth changing as well .

Im sure you know gearbox atf and filter every 40k miles . You and I have the same two cars . I’ve had both of mine for 10 years each

Check the rear subframe for rust holes , they have been failing , there is plenty on the forums explaining it all .

Rear diff oil is a cheap job using Fuchs sintopoid 75/85 FE , you need 1.3 L .

 

[johnsco]

Having had a search around the forums and vids - I guessed that this wasn't going to be easy !

 

[W1ghty]

Having had a search around the forums and vids - I guessed that this wasn't going to be easy !

Which bit ?

 

[johnsco]

Which bit ?

Actually getting to inspect the timing chain and sprockets ....
and - if necessary - renewing them.
It looks quite a job.

 

[W1ghty]

Actually getting to inspect the timing chain and sprockets ....
and - if necessary - renewing them.
It looks quite a job.

Inspection was ok , just the price of a new gasket set . Renewing them is a whole different story .
I just do regular oil changes and listen out for noise on start up . I’m very reluctant to pay £1500 to have them replaced on what is a £3k car .
I am on 86k now

 

[johnsco]

Hi W1ghty
I have some advantage in that I only paid £1200 for the car ... I've spent about £250 servicing it item by item and generally knocking it into shape.
Although I've thrown some hours at it, I'm now fully-retired, so the hours are free.
So - I don't have too much to lose value-wise.
For now, I'll probably adopt your approach - Enjoy the car - And hope I don't get my fingers burned.
I'm not good with cold ... I don't have anywhere under-cover and warm to do jobs ... And it's the wrong time of the year.

I'll do the thermostat replacement ... I'll fix the bouncing lock ... I'll give the car an oil and filter change using some decent oil.

Meanwhile, I'll find out a bit more about checking the chain and sprockets.

 

[W1ghty]

Hi W1ghty
I have some advantage in that I only paid £1200 for the car ... I've spent about £250 servicing it item by item and generally knocking it into shape.
Although I've thrown some hours at it, I'm now fully-retired, so the hours are free.
So - I don't have too much to lose value-wise.
For now, I'll probably adopt your approach - Enjoy the car - And hope I don't get my fingers burned.
I'm not good with cold ... I don't have anywhere under-cover and warm to do jobs ... And it's the wrong time of the year.

I'll do the thermostat replacement ... I'll fix the bouncing lock ... I'll give the car an oil and filter change using some decent oil.

Meanwhile, I'll find out a bit more about checking the chain and sprockets.

That’s an interesting project for that price !
Do check the cam magnets plugs for oil though , because it can cost Big time !

 

[johnsco]

I'll add the cam-shaft magnets to my urgent "To-Do" list and get the parts.
There is a small amount of oil leagage from both magnets.
It's an easy job, and for not-a-lot of money, it's well worth doing.
Do you have a Pt. No. for the extender connectors ?

Thanks W1ghty and Thanks Markjay for your invaluable advice.

This is a great Forum !!

 

[exvolvoman]

When I bought my C180K with 118k miles, first major job was to replace timing chain & sprockets, still going good now at 231k.
Found this engine fairly easy to work on for usual service items although alternator replacement proved a pita, regular oil & filter changes seem to make a diference, I also try to run on Super Unleaded where possible although I've been assured it will be ok on E10

 

[W1ghty]

a2711502733
Thats the wire blocker part number