Hi
I just bought a OM603 non turbo 300 SDL and noticed an oil leak which seems to be coming somewhere near the front of the block near to the power steering unit.

Where should i be looking? What's the typical area where there are leaks here?


thanks for your advice



MJ in Morocco

Usually from the power steering pump or lines right above it.

Also possibly from the injection pump bottom plate.

Front of the engine could also be the timing case cover.

N/A OM603 300SDL? I was under the impression the w126 only ever had the turbo versions of the 603/617.

Well the OP is outside of the USA, so it is entirely possible they have a non turbo 603.

The rest of the world gets many more diesel engine choices than the USA does - even to this day - since you can still get diesel in most of the rest of the world except the USA.

But back to the OP's point, I would look at the cover seals on the I/P if it is engine oil or the power steering pump if it's power steering fluid.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

yes, cos in the states you only have the turbo version.
thanks for the tips in nay case.

How does the injector pump get its oil? Should i be concerned if its leaking?

yes, non turbo OM603 is European.

The injection pump is internally lubricated by engine oil. There are oil passages through the front end of the IP where it attaches to the engine.

There are cover plates on the IP, on the side, and the bottom. These have gaskets that get old and leak. They are relatively easy to change, with the IP installed, but you want to make sure that you don't get contaminants in the IP.

There is also an o-ring around the neck of the IP that can leak. This requires removal of the IP to change it, so you have to be prepared to reset the injection timing.

Clean the area really well with solvent in a spray can (we call it 'brake cleaner' here in the US) and you should be able to find where it's leaking from.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

thanks very much. Great advice. I was just having a look now with a torch and it seems that its coming from one of the main flywheel bearings (or the only one in fact) and being flung all over the AC comp. Will check again.

best

MJ in Morocco

Front crank seal is fairly common leak point on the 603 turbo.

__________________
92 e300d2.5t
01 e320
05 cdi
85 chev c10

You're right.

There was no N/A 603 in a w126.

In fact the diesel w126's were only sold in the US and Canada. It was not available in Europe.

What the op has is prolly a gasser that had a n/a 603 put in it from like a w124 or w463.

Question to OP: what are the first 9 digits of your vin? then we will know for sure what it is/was

Also, as a cheeky footnote, why do the 205/65 tyres on mine look so small? And a crate of guiness if you can tell me what that weird vacumm pump in the boot is....lol

The vac pump in the boot/trunk is for the pneumatic door locks. Hold over from the 123/first generation 126 era locks that operated from engine derived vacuum.

If you lock or unlock the doors you should hear it whining for a few seconds.

This is the same system used on the W124 and it can be retrofitted with a keyless remote.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech