C180 motor questions

[para alpha]

I was told this morning after noticing some dark coloured smoke from the exhaust through the past month that my motor is dyeing! There is low compression on the middle 2 cylinders! Not surprising due to the cars age and mileage (1994 and 116,000).

So I have spent most of the day trying to find a low mileage replacement engine...

I have been offered a low mileage (28,000 miles) motor for £350. The trouble is it has an engine code of 111.921. my motor is a 111.920. My question is, will it fit and work?

All help will be appreciated.

Thanks

John

 

[BlackC55]

It will probably be best to fit the exact enging for ease. Check the miliage and make sure ts legit. There are loads of dodgy engine suppliers out there.

I am very suprised the engine is worn out after so little mileage.

 

[nick mercedes]

I was told this morning after noticing some dark coloured smoke from the exhaust through the past month that my motor is dyeing! There is low compression on the middle 2 cylinders! Not surprising due to the cars age and mileage (1994 and 116,000).

So I have spent most of the day trying to find a low mileage replacement engine...

I have been offered a low mileage (28,000 miles) motor for £350. The trouble is it has an engine code of 111.921. my motor is a 111.920. My question is, will it fit and work?

All help will be appreciated.

Thanks

John

111s are normally fairly bullet proof.

 

[BlackC55]

What compression figures do you have?

Is it blue smoke?

 

[para alpha]

It will probably be best to fit the exact enging for ease. Check the miliage and make sure ts legit. There are loads of dodgy engine suppliers out there.

I am very suprised the engine is worn out after so little mileage.

I'm surprised to be honest. I know the Mercedes engines are well engineered. I had an old Cavalier GSI on 160K and that was running well before I broke it for spares.

I have searched high and low for a good low mileage engine and this is the only one I have been offered. I will keep on looking! I have been told it was out of a 2000 model car.

 

[para alpha]

I was given these figures:-

cylinder 1 # 12.5 bar

cylinder 3 # 9.5 bar

cylinder 4 # 10 bar

cylinder 2 #13.5 bar

it was blue smoke! I was just hoping it was just valve stem seals but after being told that the compression was low that was the clincher!

I have received an email from the guy with the low mileage motor. Apparently the 111.921 was introduced in 1996 (If this info helps) I forgot to mention that the guy who did the compression test said he did notice a little back pressure from the dipstick???

 

[BlackC55]

9.5 is a little low but not that bad.

 

[Dieselman]

Two adjacent cylinders is normally the head gasket gone. Worth checking.

 

[para alpha]

Two adjacent cylinders is normally the head gasket gone. Worth checking.

I'll go and see a mate tomorrow and get the header tank dipped!

 

[para alpha]

header has been dipped, all OK! had the oil and filter changed (all for £55), no water in the oil? again my mate commented on the back pressure before I even said anything. He did an oil change on the car about 4 months ago and it indicated low on the dipstick when he checked it (Before the oil change)! He said it shouldn't have used that much in 4 months + mileage, which makes him think its the oil control rings on the middle 2 which are the worst.

 

[Dieselman]

It seems incredibly low mileage to have worn the rings and bores unless it's been doing Lots and lots of short journeys and cold starts and running rich.
I note you say black smoke not blue.

In addition it seems odd to be two adjacent cylinders unless it's had localised overheating.

Before condemning it try running flushing oil through it to see if it unsticks sticky rings but they should give blue smoke.

 

[para alpha]

It seems incredibly low mileage to have worn the rings and bores unless it's been doing Lots and lots of short journeys and cold starts and running rich.
I note you say black smoke not blue.

In addition it seems odd to be two adjacent cylinders unless it's had localised overheating.

Before condemning it try running flushing oil through it to see if it unsticks sticky rings but they should give blue smoke.

It's Blue smoke... I took it for a bit of a blast the other day, took my 3 year old daughter to Blackpool for the day (Not that you can do much damage in a C180) to see if it unsticks anything, I don't think it did! I may use a fuel additive to see what happens. Do you have any recommendations on what to use to flush the motor? Short journeys? I don't use it for short Journeys, I don't see the point! The shortest journey it does (since I have had the car) is a about 20 miles round trip... Would 20 miles be considered a short journey?

Thanks
John