Oil leak after BPU

Hi All

So I finally got my BPU car back from the mechanics. All but the boost controller its done and wow what a difference! However.... Less than 50 miles in I give it a bit of beans down my local bypass and notice a 'haze' behind me. I think its just because the car wasnt run for a couple of days but then on the next straight I do it again and a cloud of smoke (which is as wide as the car so not just coming from the exhaust). plumes out of the back. This happens every time I accelerate as I limp home. I get back to the homestead, rev it a little, no smoke from the tail pipe, look underneath and quite a large amount of oil is peeing out. Looking under the bonnet it appears to be sourcing from the front of the rocker cover although its splashed a bit this does seem to be the epicentre. At the same time as going BPU I had my valve seals done which were going so all of this area had been exposed. Anyone know what seal, gasket or act of God has caused this? Needless to say its back at the garage....

Did you replace the cam cover seals or have they been replaced at all

Yes I had all belts and I think all seals done at the same time as it seemed to make sense

Definitely not oil residue hitting the exhaust from garage work? Plumes on acceleration automatically suggest turbo seals to me but I take it you never had the problem pre BPU?

My seals leaked but i didn't get plumes of smoke at all, just burning oil smell in the cockpit

Sound very much like a potential turbo problem

take off the rocker cover etc to try and see where it's coming from. Could be Cam cover seals, Cam Seals, of main crank seal in that area. If they hit the cambelt it will be distributed around the front of the engine.

If it's quite a lot of oil id say main crankshaft seal or the cam seals. (although i'd expect the cam seals were replaced when you had the valve stem seals done?)

It's leaking quite a lot of oil from the top so wouldn't imagine it's turbo related especially as all of the seals mentioned here would be disturbed during the valve seal repair. Looks like it needs stripping at the top and seeing what has split or come unseated etc I guess.

No never had this problem pre BPU so chances it's not new seal related and is turbo isn't likely plus power was through the roof even when pluming no signs of tub issues to my mind

Cheers RIC yes it looks like the oil has hit the belts and sprayed from that area. Guess new seals and start again is the order of the day.

If the garage fitted new seals and its leaking then i'd be finding someone else to be honest as

thats basic mechanics

Main crank seal. Mine leaked a little then let go and lost basically all its oil

I would guess Turbos, poorly replaced seal or oil pump (crank seal):-

1.The normal twins run with a back pressure. BPU loses most of the back pressure and old worn turbo seals show their colours.This wouldnt cause oil to leak but would cause a plume from the exhaust

2. Maybe one of the replaced seals has not beem fitted correctly if it has only just started. If its camshaft was the sealant used on the corners?

3. When the oil pump seal (crank seal) goes boy can it let go. I seem to remember Paul selling upgraded seals for worn cranks.

Wouldn't it be very obvious if it was coming from the front crank seal ?

I know people are saying turbos but yes, its pretty obviously leaking form the rocker cover to my eye, and has just splashed elsewhere, I guess that indicates crank seal/cam seal?

Seems strange it gets worse when you accelerate, i'd expect it to be very smokey under the bonnet

and stink in the cockpit of burnt oil if its oil on the manifold.

I'd fix the cam cover leak if thats what it is and brake cleaner all the oil off and

fingers crossed problem solved

That's what is odd if it only does it under heavy load and WOT then it definitely signals turbo seals to me.

Making the exhaust more freer flowing and upping the boost pressure can cause the turbo oil seals to start leaking,

If I was in your position I would do the following in order

1. Fix known oil leaks and thoroughly clean all the oil from the engine.

2. Run car off load. If your crank seal has gone it will show fairly quickly as these do tend to let go and monitor for further leaks. If leaks are hitting the timing belt then it could be cam seal, crank seal, oil pump relief, vvti unit if it is vvti, cam cover.

3. Once all external leaks sorted take the car out on WOT and monitor exhaust for smoke.

Hope this helps

I think the very oddest part of it is the smoke pluming from the back isnt exhaust in my opinion, as I say its the entire width of the car. This to me indicates a seal near the top end has gone, oil is getting onto hot parts of engine and exhaust and causing this 'wall of smoke', its the only thing that makes sense to me. if it were turbos I would think it would affect the performance in some way but it isnt doing. But after a very short drive even though the temp gauge hadnt particularly risen I could hear bubbling under the bonnet, from oil or water I dont know, I would guess water but I have a temp indicating radiator cap and it was only showing about 100 so possibly oil bubbling through the seal somewhere. I took it straight back to the mechanic of course so its frustratingly out of my hands and I wont know anything until he tells me whats what but surely it cant be turbo seals when there's a clear main mass of oil around the rocker cover?

If the cam belts covered in oil i'd be replacing that as well

So quick update: The mechanic stripped the car down, took a lot of the top end off and thinks its the crank seal as many people on here are saying (thanks guys) or MFS as its sometimes called. As with so many Supe parts he has had to get one from overseas but while we're waitign for that at the end of this week he rebuilt it well enough to strike up and when not under load it now isnt leaking, but obviously it still could do under tub pressure.

With this in mind I have a couple of questions for you all, one once this is done will my BPU car be reliable at 1.2 or will this keep going (obviously I will keep an eye both under the bonnet and on temp and fluid levels). mine is one of the first Mk IVs from 93 and I specifically wanted the first model but that therefore makes it the oldest of course. It seems all the other seals in the area are done but BPU puts pressure on and I wondered if it was wise to dial it down to 1 bar or whether it will stand 1.2? At 1 bar its pretty darn quick to be honest but I have a 500 quid Boost controller to take it that last mile yet to install and I'm now wondering whether to not do that or stick with the full BPU program. Anyone out there had similar experience with some sage advice?

The second point is apparently according to the mechanics Supras can have their oil pump 'let go' which causes similar symptoms. According to what I am told this is an engine out seriously expensive problem, and there's an outside chance my issues could be this. Anyone had this happen and what were the symptoms and repair process?

Oh and Dnk cheers, new cambelt is being fitted too, good call.

No problem mate and good luck with it.

I'd have thought you'd have got a crank seal from here in the UK though

So quick update: The mechanic stripped the car down, took a lot of the top end off and thinks its the crank seal as many people on here are saying (thanks guys) or MFS as its sometimes called. As with so many Supe parts he has had to get one from overseas but while we're waitign for that at the end of this week he rebuilt it well enough to strike up and when not under load it now isnt leaking, but obviously it still could do under tub pressure.

 

With this in mind I have a couple of questions for you all, one once this is done will my BPU car be reliable at 1.2 or will this keep going (obviously I will keep an eye both under the bonnet and on temp and fluid levels). mine is one of the first Mk IVs from 93 and I specifically wanted the first model but that therefore makes it the oldest of course. It seems all the other seals in the area are done but BPU puts pressure on and I wondered if it was wise to dial it down to 1 bar or whether it will stand 1.2? At 1 bar its pretty darn quick to be honest but I have a 500 quid Boost controller to take it that last mile yet to install and I'm now wondering whether to not do that or stick with the full BPU program. Anyone out there had similar experience with some sage advice?

 

The second point is apparently according to the mechanics Supras can have their oil pump 'let go' which causes similar symptoms. According to what I am told this is an engine out seriously expensive problem, and there's an outside chance my issues could be this. Anyone had this happen and what were the symptoms and repair process?

 

Oh and Dnk cheers, new cambelt is being fitted too, good call.

There are loads and loads of threads about the crank seal issue, not always with a perfect solution.

Oil pump is one thing, 'blow by' or a generally worn engine another and people talk about modified breather systems etc. Some weep a little oil, some pop the seal out worse and you get significant oil loss as in your case.

So the seal is a weak spot in the system, but not usually the cause (ie the seal itself isn't normally worn out/passed it, it's just over powered by oil or pressure or both and so leaks) hence why replacing a seal doesn't always (usually?) work.

I think you need to be prepared for this seal replacement not to work (I hope it does for you!), and then consider the oil pump replacement option (which is unfortunately expensive as it's labour intensive)

Some interesting chat from stateside......loads of thread on here too if you simply searching for crank seal. Lot so variables with people's car and some fixes work depending on what and how bad something is worn, but the same 'fix' won't work on the same worn thing if it's gone too far, if you see what I mean!?

http://www.supraforums.com/forum/archive/index.php/t-682324.html?

You could pass on the info about the seal being flush and not pushed right in for a start? Then perhaps baby the car and/or lower the boost and see if it, doesn't leak/weeps/pops significantly again and then reassess. The other end of the scale is full engine rebuild and new pump and seal and it won't leak!