Crank Case Oil Seal

[broadside]

As the title says.....The 450 passed it's MOT today but had an advisory about an oil leak from the crank case near bell housing. There are drops of oil on the garage floor nothing much that worries me and the chassis is in great nick because of the oil!! However....the MOT bloke when doing emmissions checks found that at highish revs oil was being thrown onto exhaust and smoking away...... how much of an issue is this as I very rarely rev the engine to the top end?.....I obviously don't want an oil fire....so what's the solution.....renew the oil seal....but this will involve major surgery...is there a way around this or is it time for a rebuild?

Over to the Wedge collective..........

Nige'

Edited by broadside on Tuesday 1st March 22:17

[adam quantrill]

9 times out of 10 you can solve this by making sure the crankcase breathers are working OK and scavenging enough vapour. If the crankcase is under negative pressure you won't have an oil leak!

First take off the breather on the rocker cover and clean out the mesh inside - you can pull it out and clean it off in petrol.

Second make sure there isn't excessive blowby - run the engine and pull off the breather hose - how much vapour is coming out? When it's hot you might get some vapour but it shouldn't be too much. Too much blowby means a piston ring might be broken. You might want to rev it a little bit to see how much blowby you get.

Last make sure the breather air passage into the plenum is not blocked (or the hose for that matter) by blowing into it through a bit of hosepipe - it should be very free, if it feels restricted you'll have to clean it out, a tricky job but not impossible. I have blown a string through the hole and then tied a petrol-soaked rag onto the string and pulled it back and forth through the air passage. I heave heard that compressed air can work, too.

Edited by adam quantrill on Tuesday 1st March 22:25

[broadside]

Thanks Adam.

I cleaned the breather at the weekend, so that is clear. Will check the pipe work but I cleaned all that out last year and it was pretty clear then...not to say it isn't now though so will check. I'll do the other thing you recommend at the weekend too.

My initial thought was that I had over filled the sump as the oil pump had gone dry (been stood for a few weeks) and I refilled it doing the (funnily enough) Adam Quantrill method at the weekend and it took a fair quantity of oil (0.6 - 0.7 litre) to sort it but it did prime first time, this may not have helped the situation though, but the oil level when checked was bob on the max line.

Any other suggestions would be welcome.

Cheers

Nige'

[Wedg1e]

Where's it actualy leaking from 'near the bellhousing'...? Head gasket, rocker cover gasket, valley gasket, crank rear oil seal (not good, you don't want oil on your clutch), sump gasket? If it's the sump you may get away with just nipping all the bolts up, the gaskets do take a set and allow a bit of weeping. Worst case: drop the oil, drop the sump, new gasket, Robert and your mother are siblings.
The rocker cover gaskets are easy but go for the later rubber seals rather than the early cork ones.

[shoggyraminator]

There is also a breather hole on the Pass side cam cover. The bit with the plastic cap stuck over it housing a foam disc. I found this hole completely full of crud and used a brush bristle to poke it clear. It's only a small vent.

[broadside]

Thanks chaps. It is definitely coming from the Rear Crank Case Oil Seal. I will do the pipes and stuff again at the weekend and see if that helps

Looks like a new crank case oil seal will be needed at some stage.

How difficult a job is it?

Cheers

Nige'

[adam quantrill]

Wedg1e said:

crank rear oil seal (not good, you don't want oil on your clutch)

It won't get on the clutch cos it'll go onto the front of the flywheel and then spun off onto the bellhousing.

Goot point about the rocker cover seals - another test is to blow into the breather pipe while attached to the rocker cover (and engine), there should be considerable resistance, like blowing up a baloon, or else there's a leak and you won't get negative crankcase pressure.

[broadside]

Thanks.

I have got rubber seals on the rocker covers and as of last weekend all was still well with them. I think I can live with it but have been quoted around the £600.00 mark to get it fixed which is a bit steep at the mo. Looks like I'll have to go back to being a lap dancer again!!

[adam quantrill]

Re-reading this - if it was the rear oil seal on the crank then it would be dripping out of the bellhousing where there's a small hole in the clutch slave cylinder "blister".

So it's more likely to be the sump, the bolts are known to get loose, just nip them up.

[broadside]

Thanks Adam.

Start simple and work towards the complex stuff if needed.....good advice.

Nige'