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Oil leak after BPU


Fulcrum2000

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Not yet but where is he based is it a case of leaving the car with him all day to bang a pump in? If he's good and reasonable I'll do it for piece of mind as I've spent so much on my Supe already it's well worth it

 

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Not yet but where is he based is it a case of leaving the car with him all day to bang a pump in? If he's good and reasonable I'll do it for piece of mind as I've spent so much on my Supe already it's well worth it

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You have a few options re the car imo, you could get the 2nd cat put back in and run it for a while at lower boost and/or drive it on the first turbo and mostly part throttle just to check the seal is fine under these conditions.

 

I would personally do this with the undertray off so you can just assume the pressup position to keep checking. If all ok I would then gradually up the acceleration/throttle inputs, so just try in say '2' driving up to 5000 rpm but not at full throttle, check and then 5000rpm and hold this for a number of seconds, check, then perhaps a full throttle 2000rpm to 6000rpm pull, check.......

 

If you see any oil then fit the tray and drive it only under the previous conditions it was fine for, as at least then you can almost certainly drive it to someone to do the pump? You have to assume from Tricky and everyone's advice that jumping in and blatting it could very easily result in the same massive leak. Treat this seal fitting as at least offsetting the cost of trailering the car somewhere and you get something out of it even if it doesn't fix the issue.

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Cheers Scooter I will see what the mechanic has done when it comes back and kid gloves it whilst I figure out what to do. Sorry Swampy I dont know what I'm talking about on fitting times, I just went on Toyota who said it was a one dayer but maybe they have a team of umpa lumpas all in a line with buckets or something to speed it up.....

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Hi Ric

 

So you've gone the same route as me, all seals but not an oil pump? So we're both in the same boat of fingers crossed I guess? Are we feeling lucky......

 

I suppose time will tell but the specialist i've used says my pump is OK and the seal was worn. Mine was only weeping it's not been pushed out at all.

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So as an update, the mechanic stripped it all down and found the FMS hadnt blown but it was as old as time itself and harder than a maths test from Carol Vorderman. So we potentially have a traditional seal failure. It had only lost a litre of oil but managed to decorate its underside with it. He's tested the pump and pressure is normal too. i'm thinking of having it done anyway though to be honest, it will be far from perfect and will likely just be the next thing to go in the next year or two anyway. Just been ringing round and getting the price to tumble under a grand now and I would pay that for piece of mind. Obviously I cant go to 1.2bar until I know my oil pump is tickety boo.

 

As a side post when I was going BPU I did a ton of research, and I mean a ton. At no point did anyone say 'get your oil pump done or you'll spray Castrol all over the county'. With this in mind are there any other things which really should be done in addition to the normal BPU advice to stop the world around my car going either black, smokey or on fire?

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So as an update, the mechanic stripped it all down and found the FMS hadnt blown but it was as old as time itself and harder than a maths test from Carol Vorderman. So we potentially have a traditional seal failure. It had only lost a litre of oil but managed to decorate its underside with it. He's tested the pump and pressure is normal too. i'm thinking of having it done anyway though to be honest, it will be far from perfect and will likely just be the next thing to go in the next year or two anyway. Just been ringing round and getting the price to tumble under a grand now and I would pay that for piece of mind. Obviously I cant go to 1.2bar until I know my oil pump is tickety boo.

 

As a side post when I was going BPU I did a ton of research, and I mean a ton. At no point did anyone say 'get your oil pump done or you'll spray Castrol all over the county'. With this in mind are there any other things which really should be done in addition to the normal BPU advice to stop the world around my car going either black, smokey or on fire?

 

You found the problem, your car seems to be maintained well, I'd do the seals and drive away.

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are there any other things which really should be done in addition to the normal BPU advice

 

If you are talking about preventative maintenance then look at the following unless the have already been replaced.

 

Water Pump

Thermostat

Tensioner

Idler

Idler Bolt

Idler Washer

Timing Belt Tensioner Hydraulic Capsule

Crank Sprocket

Oil Filter

Crank Pulley

Crank Washer

Crank Bolt

 

Additionally you could add;

 

Coil Pack Clips

Coil Packs

Turbo Link Pipes

 

How much do you want to spend?

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Yes I'm starting to think that too. I've since asked 3 other mechanics including two that have seen it (one of which is a tuning specialist) who all say there is no way the oil pump could have any bearing on my problem so phew. I might get it done as a matter of course down the line and of course if it fails I will report back but it seems it may be fine after this. Thanks for sharing your experience Thomas, are you BPU?

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Yes I'm starting to think that too. I've since asked 3 other mechanics including two that have seen it (one of which is a tuning specialist) who all say there is no way the oil pump could have any bearing on my problem so phew.

 

It's certainly good to be optimistic but others are talking from experience, so them saying 'no way' it could have any bearing on the problem is a bit worrying really?

 

I mean the drain hole is there because the pump can pass some oil, so as the pumps wears more oil can pass, if enough leaks there is only so much flow rate it can cope with hence it will leak. Tricky's situation proves that the oil pump can cause the issue as he tried so much before replacing it and resolving his issue.

 

Like I say I hope it is all resolved with a seal replacement just don't count your chickens!

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I guess you can never count your chickens (if you've ever tried counting chickens it is actually quite tricky). I'm not saying I wont do the pump, truth is I intend to keep this car for a long time so ultimately everything is going to get changed and eventually probably the whole engine. I've got a list of things I want to do to keep it healthy as long as my arm but I will give it a couple of weeks of VERY careful scrutiny after the mechanic has finished testing it with pressure devices and rev patterns etc to confirm its pukka now and gives me it back. Its handy to know one of the mechanics I spoke to has maintained a Supra for another owner in Mablethorpe from new till she sold it last year and has seen it all and he said the same on the pump not causing it but I agree that doesnt mean it hasnt. I like to rely on the forums good advice along with boots on the ground around my smoking car and just do what I can for the best.

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Another thought is excess crank end float will cause a seal to ride up and down any wear ridge on the crank and cause leakage. It would be interesting to compare front seal leakage against manual and auto transmission cars, especially manuals with a high spring pressure clutch fitted, or a poor fitment with no free play, that gives the thrust bearings some grief. I find my high tension front seals work in cases where even a brand new stock one leaks, but of course it's a crutch, but it's a relatively cheap one! Raising the boost on a none rebuilt 20 year old engine is akin to putting Grandad on steroids and Viagra and dropping him at the local knocking shop with a grand in cash. Great fun, but the potential for an early, if rapturous demise is high.

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I just wanted to keep the theory chat going re the seal issue.

 

I was thinking is the oil drain the only 'air gap' to the chamber area behind the seal? If oil fills the drain hole, would this create a slight vacuum in the chamber and thus resist flow/cause bubbling back up through the hole? from the atmospheric pressure sump air?

 

I am thinking turning over a full bottle of water vs turning over a same bottle but with a base vent to stop the vacuum, the vent one will empty quicker/flow faster.

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Another thought is excess crank end float will cause a seal to ride up and down any wear ridge on the crank and cause leakage. It would be interesting to compare front seal leakage against manual and auto transmission cars, especially manuals with a high spring pressure clutch fitted, or a poor fitment with no free play, that gives the thrust bearings some grief. I find my high tension front seals work in cases where even a brand new stock one leaks, but of course it's a crutch, but it's a relatively cheap one! Raising the boost on a none rebuilt 20 year old engine is akin to putting Grandad on steroids and Viagra and dropping him at the local knocking shop with a grand in cash. Great fun, but the potential for an early, if rapturous demise is high.

 

LOL!

 

I have quite a while ago read some disturbing theory's on crank end float on the US forums causing all kinds of issues, i believe it was mostly due to the US supras needing the clutch pedal to be depressed for starting, so extra wear from lack of oil pressure etc, and a manual with a heavily sprung clutch is going to do thrust washers no favors

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I just wanted to keep the theory chat going re the seal issue.

 

I was thinking is the oil drain the only 'air gap' to the chamber area behind the seal? If oil fills the drain hole, would this create a slight vacuum in the chamber and thus resist flow/cause bubbling back up through the hole? from the atmospheric pressure sump air?

 

I am thinking turning over a full bottle of water vs turning over a same bottle but with a base vent to stop the vacuum, the vent one will empty quicker/flow faster.

 

Your kind of on the right track, to me the whole thing relies on the fact that if you try and force a larger quantity of oil through a 3mm drain hole there is only a limited amount that can pass before the oil backs up and pressurizes the void, which i might add is pretty small, and the only moveable thing is the seal, either the lips which results in spring displacement, or the whole seal.

 

Add to this the fact that most owners migrate to 10w40 oil as a minimum and often 10w50 or even 10w60 which is often advocated by some tuners, and this compounds the problem with oil flow through a small hole, considering the std recommended oil by Toyota is a 10w30.

 

I am not saying that all oil seal weeps are pressure related, as a hard seal will eventually weep either by its inflexibility or wearing the crank itself, however if you think about it logically a seal suddenly leaking enough oil to cover the underside of the car is no going to be a simple weep, as if the oil pump is not actually leaking enough oil to cause seal failure, its certainly not going to supply enough bypassed oil to cover the underside in a matter of seconds or a minute or two.

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Agreed, I am pretty sure my stock car with a weeping seal is only getting overcome in extreme conditions ie very high rpm or lower rpm when cold or perhaps even only when cold/oils thick, perhaps only in winter etc etc etc.

 

When it's like this the margin is small so one of the crutches might work better/longer for me.

 

Re the oil and viscosity I did wonder whether the less viscous oils might leak more and therefore partly/fully offset there extra flow advantage?

 

I am tempted to get a cheap endoscope, clean mine up, even remove the lower cambelt cover and then road test it to see under what conditions it leaks.

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A cheap low pressure gauge or home made manometer on the dipstick tube will tell you if crankcase pressure may be an issue. Looking for oil under any pressure in the void in front of the seal is trickier, but may be possible with some small fitting and a fine bore tube, never really checked that possibility out.

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