Thread: Continuing my quest to get my disco rwc

Originally Posted by Tjhastings

The main big issue is either a rear seal or sump gasket. The mechanic told me to clean up the oil and id be able to tell. Where does the seal leak ?


please and thank you in advance

What engine and gearbox?

300 tdi diesal And manual transmission

They can leak from a few places.... Give it a good wash down. Then check the back of the rocker cover, the vacuum pump. the sump etc. If the leak is from the rear seal then it's gearbox out, I'm afraid. Or the engine, I guess.

I’ve ordered a sump gasket as a start , was trying to work out where the rear main bearing would show itself ?

Here. That thing you see sticking out is a flywheel locking pin. The hole it is screwed into would be where the oil from the rear main would show. Trouble is, the rocker cover can leak into the bell housing and come out there too.

IMG_5284.jpg

This one was leaking from the vacuum pump, mainly. Stuff gets everywhere........

Sorry the pic is upside down...

Originally Posted by Tjhastings

I’ve ordered a sump gasket as a start , was trying to work out where the rear main bearing would show itself ?

Generally not needed, and most 300tdi's will be sealed with sealer(ie. no gasket).
Generally not the sump gasket, even tho it may look like it.
Main culprit for incorrect sump gasket leak misdiagnosis is the front main seal.
It won't look like it because as you drive, the force of air under the engine pushes the oil leak back along the sump gasket, and so it 'looks' like thee sump, but it's really the cleaner looking front seal.
Front seal is a mongrel of a job, in that it requires the timing belt to come out too!

Like in Tins reply where he showed you the location of the drain plug/crank locking pin location, there is also a drain plug up front basically middle of motor directly under the timing case(on the timing case).

Hopefully you have the wading plug, small bolt to plug the front and rear drain plugs(which are always left off in normal driving) .. somtimes the plugs(bolt) is kept in the glovebox.

First you need to degrease and thoroughly clean engine bay to remove all traces of oil build up.
if you have the wading plug, install it up front and go for a drive to see if you still have any oil leaks under the sump. Dont' leave the front drain plug in too long, if it is the front main seal leaking tho!! If you leave it in and the oil build up rises too high, it can damage the timing belt. This drain plugging up is just to see if it stops the flow of oil leak under the engine.

I had three main leaks that all looked like 'sump' leaks.

1. front main seal
2. oil cooler line o-ring
3. vacuum pump

Other leaks that can travel down and look like sump leaks are from the cyclone/breather hoses on the drivers side of the engine. The hoses all turn rock hard and can leak quite badly from the top of the engine all the way down the RHS of the block.
Also the o-ring on cyclone can harden and flatten and it leaks from the bolted connection to the side of the head too.