Front crankshaft oil seal?

[nickwilliams]

I replaced the timing belt on my 300 tdi engine a few weeks ago, including replacing the front crankshaft oil seal and the idlers. This weekend was the first opportunity to run the engine since and I find that oil is fair tiddling out of the timing case breather plug hole.

It's inevitable that I'm going to have to take it apart again to cure it, but before I do would anyone care to comment as to whether this is likely to be anything other than a case of replacing and correctly seating the front crankshaft oil seal? Is there anything else which might cause a gross oil leak out of the timing case? FWIW, the leak only occurs when the engine is running - it does not leak a drop when stationary.

Nick.

[jad]

are you sure it was the crankshaft oil seal leaking and not the Camshaft oil seal leaking? and did the new seal come in a blue box?

[nickwilliams]

I did not disturb the camshaft seal. Before I changed the timing belt, there was no (significant, at least) leak. I don't recall if the part was OEM or not, TBH, and I no longer have the packaging.

[jad]

make sure the next one is a genuine seal. It should be fine..... Im not sure if your engine can leak oil from anywhere apart from the cam or crank shaft seals. Sure someone will correct me if I am wrong

[landmannnn]

Maybe you replace oil seals like I do.

Badly.

[JonB]

Perhaps someone had the timing case off the block & failed to fit the small round gasket that seals the tensioner bolt?

Did the tensioner bolt have gasket sealer on the thread?

I had exactly this & had to strip it down further to rectify the problem (the gasket is not very obvious on the exploded diagrams in the service book)

Jon.

[nickwilliams]

Now that's interesting. I found myself with the wrong kit of bits for the idler pulleys so I had to make a bush and washer and replace the bolt that holds them into place so that's got to be a prime candidate. Is the gasket anything fancy? I make most of my own gaskets but if it's a special item then I'll need to order it along with a new crank case seal.

Nick.

[JonB]

the gasket is nothing special (part no ERR394)... but it is fitted between the block and the back of the timing cover (the part of the cover that the injection pump is connected to)

If it had been removed in the past & the gasket not fitted then there would have been gasket compound on the tensioner bolt which would have mostly stopped the oil.

The 200tdi engine does not have the extra pulley that the discovery 200tdi has (at least neither of mine did) & i am not sure if that is a possible place for oil to get in.

Other things to check are the 2 o rings on the cam gear wheel retaining plate and any damage on the gear wheels where the seals run.

Jon.

[nickwilliams]

the gasket is nothing special (part no ERR394)...

I don't think that part number can be correct - it should have four numbers, not three. Do you mean ERR2344 ("Washer-sealing", item No. 28 in drawing B238 of parts book STC9021)?

Nick.

[pat_pending]

Once you take off the front cover it should be obvious where the leak is from. Only use genuine seals, a lot of the pattern ones are unbelievably poor quality. I'd also check you've been supplied with the right seal, the inner crankshaft oil seal and not the outer dirt seal that the crank pulley runs in. I seem to remember they are physically the same size but the outer seal has no oil scroll or garter spring and will not seal against oil if fitted in the inner position.

[JonB]

Parts Catalogue RTC9932CE (1987 110) shows part 26 (ERR394, part of gasket kit STC363) .in the 200tdi section as Gasket Cover/Block.

Perhaps this parts catalogue is showing old part numbers?

Its the only parts catalogue i have for 200 tdi defender engines.(attached)

Jon.

[nickwilliams]

OK, I understand now. Yes, the equivalent part for the 300tdi is ERR2344.

[Alex]

OK, I understand now. Yes, the equivalent part for the 300tdi is ERR2344.

I am nearing the end of a build on a 300TDI, and i have a few bits left over from the gasket kit, one of them is the ERR2344 washer, i pulled the bolt from the adjuster and looked down the hole, it looks like it does not go all the way through the cover, the front cover is marked HRC2631 and the 300TDI repair manual makes no mention of the ERR2344 between the block and the cover, is the ERR2344 not required with the HRC2631 cover ? or does it go behind the stud hole or another location ? I don't want to strip the front end off again, unless i have to, hope someone can help.

[nickwilliams]

I meant to post a follow up to this but I've been travelling a lot...

I stripped the front end down and it looks like the problem was that I'd damaged the crank seal when I fitted it. I replaced both the front crankshaft seals (the one in the block and the one in the timing case cover) with genuine parts. This appears to have cured the leak from the front, but there is now a (much smaller) leak coming out of the bell housing drain. Bugger. I think I'm just going to live with that one for the present.

I looked at changing the tensioner bolt seal but could not face the major strip down that taking the rear timing cover off entails (it requires removing the sump pan, inter alia). There was no sign of a leak coming from the tensioner bolt and I had not disturbed it so I decided to leave it.

Having looked at it, I'd also be surprised if the tensioner bolt goes through into the crank case - it seems to me more likely that the washer is simply intended to seal the timing case to the block to prevent water getting in when wading. But I don't know for certain.

Nick.

[cackshifter]

There is also a leak path along the crank under the crank timing pulley that the O ring behind the crank timing pulley is meant to seal. It's quite easy to damage the O ring on the keyway cut into the crank pulley as you tighten the crank bolt, in fact I don't see how it totally seals at all, as it's trying to seal across the back end of the keyway in the pulley. I'd say if you are changing the belt make sure that the O ring is in good condition, if in doubt replace, and/or take out the keys and have a trial assembly to make sure it will get squashed when you tighten the pulley.

Nigel

[Les Henson]

Take the timing cover off and then start the engine. From cold you will be able to run the engine for a minute or two to identify the leak.

Les.

[nickwilliams]

There is also a leak path along the crank under the crank timing pulley that the O ring behind the crank timing pulley is meant to seal. It's quite easy to damage the O ring on the keyway cut into the crank pulley as you tighten the crank bolt, in fact I don't see how it totally seals at all, as it's trying to seal across the back end of the keyway in the pulley. I'd say if you are changing the belt make sure that the O ring is in good condition, if in doubt replace, and/or take out the keys and have a trial assembly to make sure it will get squashed when you tighten the pulley.

Nigel

I think I'm losing my marbles! When I posted earlier I had completely forgotten about the 'o' ring which seals between the timing belt sprocket and the crank shaft. There wasn't one when I took it to pieces and this probably accounts for the leak.

The 'o' ring sits inside the rear of the sprocket, far enough back that it's beyond the end of the key way. It can easily be stretched over the key with a little care.

Nick.

[nickwilliams]

Take the timing cover off and then start the engine. From cold you will be able to run the engine for a minute or two to identify the leak.

Les.

I did consider this, but since I was doing the job with the radiator out (it would be difficult to see any leak clearly with it in place) I was worried that I'd start emptying the sump out through the oil cooler connections.

Nick.

[cackshifter]

I think I'm losing my marbles! When I posted earlier I had completely forgotten about the 'o' ring which seals between the timing belt sprocket and the crank shaft. There wasn't one when I took it to pieces and this probably accounts for the leak.

The 'o' ring sits inside the rear of the sprocket, far enough back that it's beyond the end of the key way. It can easily be stretched over the key with a little care.

Nick.

Yes, that's LR's theory as well. It's true it's clear of the back Woodruff key itself. Getting it in place isn't a problem. However the keyway in the crank pulley goes to the back of the pulley, and the O ring sits against the end of the keyway at the back of the pulley. The crank pulley keyway on mine had punched a bit out of the O ring. I'd at least make sure the entry to the keyway on the pulley had a slight chamfer to give the O ring a chance to not get cut, as for an admittedly small bit of pulley circumference you are just relying on the O ring (ie nothing behind it on the pulley side) blocking that keyway; it gets squashed into the keyway and the edges can be sharp. I admit the oil has to make its way through some tight spaces, but that is what it does.

Nigel