M104 oil leak

[ms500]

My 300TE has an oil leak, there are always two spots of oil wherever I park it, and the tray underneath the engine is black with oil.

I had a look through the service receipts and on one of the invoices for a service from an independent garage, dated 2001, the mechanic has written 'advisory - oil leaks should be investigated' so this has been happening for some time.

The car has covered 204k miles and has a full MB dealer service history upto about 180k.

Other than that, the car seems to drive fine, the temperature sits just above 80 and the oil pressure stays at 3 when driving.

Although on random occasions there are some puffs of white smoke coming out of the exhaust, not always when cold.

I think it may need a new head gasket, but is there anything else that could be causing this?

 

[BlackC55]

Loads of things can cause leaks. The best thing to do is to clean it all off and then investigate.

 

[bolide]

You'll find the sh1t-shield under the engine is loaded with oil. You need to remove it, steam it clean, carefully clean the engine & box, steering box & inner wings inc the self-levelling reservoir and then you may be able to find the source of the leak

Slight gearbox leaks are optional on older W124s. Engine leaks come as standard

Nick Froome
www.w124.co.uk

 

[Roger Jones]

Check the classic leak spot: rear offside of the block, with tell-tale dark streaks on the underside of the car. If you're getting white smoke, I believe that's a sign of water in the combustion process, so a head-gasket failure seems possible, although it may be something else entirely. Any oil in the coolant?

If it is the head gasket, it will be £50ish parts and 8 hours labour (so get an indie to do it, not a main dealer). Do get the head checked and skimmed if necessary; my mechanic has yet to find one that didn't need skimming (M103 and M104). He gets the skim done for about £80. If the whole job is done properly, you can look forward to another 200k of happy TE motoring; if you skip the skim, you may get another failure within a wallet-shreddingly short time.

 

[Vlad]

Can I just clarify...in your post you mention M104 which is for the 280 and 320 engines but you also state that your car is a 300TE which would be a M103 engine.

If its is a later 320 with the M104 you should also consider the timing cover seal which virtually leaked from new...its a complex seal and takes skill to get it to seal properly. It tends to show up on the front offside just above the alternator. Not expensive to replace, but get somebody who has done them before.

If its a M103 then look at the rear as stated by Roger and they can also go at the front offside, again above the alternator.

 

[ms500]

Can I just clarify...in your post you mention M104 which is for the 280 and 320 engines but you also state that your car is a 300TE which would be a M103 engine.

It is an early M104, the 3-litre, 6-cylinder 24v engine. Model number M104.98x

http://en.wikipedia.org/wiki/Mercedes-Benz_M104_engine

If its is a later 320 with the M104 you should also consider the timing cover seal which virtually leaked from new...its a complex seal and takes skill to get it to seal properly. It tends to show up on the front offside just above the alternator. Not expensive to replace, but get somebody who has done them before.

Yes, I heard that was another potential leak area, I'll take a look when I get it back tomorrow..

 

[gt-83]

good advice........had mine done a while ago, apparently even main dealers struggle to seal this well......i found a very skillfull guy who fixed mine 3000 miles ago......no leak return yet, a hefty bill though

 

[Ian B Walker]

When putting the upper timing cover over the "U" shaped seal I always use either Vaseline or Grease. NEVER EVER try to super glue them in place.

 

[jaymanek]

super glue, in an engine!!! hope no one would do that!!

 

[Ian B Walker]

super glue, in an engine!!! hope no one would do that!!

Trust me Jay, I have had a few with glued in seals . Not easy to clean up to fit correctly.

 

[kth286]

It IS classed as a 104 engine - the 3 litre 24 valve.

Also the next engine the 320 24 valve is another 104.

Mercedes issued a TSB instructing the oil fill to be reduced to 7 litres from 7.5
litres for all 104 engines. The later literature had 7 litres for the oil fill.

You should not fill more than half way between min and max on dipstick on level ground.

In addition to the areas already mentioned, the front crank oil seal often wear after highish mileages.

 

[grober]

For those interested is this sort of thing.
FOR SALOONS

300E 12v single cam engine M103.983
300E-24v twin cam engine M104.980
320E --- twin cam engine M104.992

 

[Vlad]

As its a 3.0 24v I would suspect its a leak coming from the rear offside....I had a similar leak on my SL which uses the same engine and it was dripping oil, albeit slowly, from the head gasket....they tend to dry out and fail with age even though the mileage on the engine can be quite low...ie mine had only done 65,000.

 

[Smiley]

Superglue in an engine....I would never ever have believed it; sitting here open mouthed!

 

[Roger Jones]

Just a few details from the MB E-class owner's bible:

"The front timing covers are known to leak on both the M103 and M104 engines. When this happens, the cover must be resealed with the correct factory sealant, MB part number 002 989 45 20, along with a new rubber gasket at the bottom of the cover . . . When resealing, apply the sealant to all mating surfaces between the cover and the head . . . Install a new profile gasket to the cylinder block. Once the gasket is in place, coat the top of the gasket with a thin coat of engine oil . . . Reseal the [M104 gasket] the same way as the M103, with sealant on all mating surfaces except the profile gasket channel . . . the M104 engine involves significant disassembly of various components . . refer to the factory repair information."

 

[Roger Jones]

" Mercedes issued a TSB instructing the oil fill to be reduced to 7 litres from 7.5 litres for all 104 engines. The later literature had 7 litres for the oil fill."

Correct. I always try 6.5 litres first and check the dipstick. 7 litres is the specified refill quantity (less than filling a clean new engine, which takes about 0.2L more), but always seems a touch too much.