Oil leak after BPU

[Scooter]

I was just going to view the seal externally with the camera.

 

Only other 'out there' idea was as you say Chris fit a fine bore fitting and tube in the seal at 12 o'clock (or somehow through the pump casing?) as a air breather to promote flow through the drain (not for the camera as I don't think this is in anyway possible for me personally although it would be interesting to see!)

[Chris Wilson]

If Toyota had not chosen to use an odd sized seal the possibility to use a double lipped one would be available. If there was more room around the front of the pump housing it could be vented direct to the crankcase bypassing the piddlingly small drain hole.

 

In the third image here you can see the three large drains on the Tomei RB-26 pump

 

https://www.ebay.co.uk/itm/TOMEI-OVERSIZE-OIL-PUMP-for-NISSAN-GTR-SKYLINE-BNR32-BCNR33-BNR34-RB26DETT-/201591609618

 

and here you can see the slots that aid draining in front of the seal. Compare to the tiny drain on the 2JZ pumps...

 

https://www.google.com/search?q=Tomei+oil+pump%5B+RB26&lr=&hl=en-GB&as_qdr=all&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjr4Pe85t_bAhVIBsAKHZk6D-0QsAQIkgE&biw=1440&bih=776#imgrc=f66R0X9NQFzQbM:

[Scooter]

Chris, would the Toyota hole being to the side be because the rotation of the crank would cause the oil to pool that side, ie the forces from the crank rotation combined with gravity would cause any oil to pool there. It must have some basis else the common sense approach says put it right at the bottom?

[Scooter]

Also do you know how much 'slosh' occurs in the sump? on braking does the area under the drain see any significant oil?

[Chris Wilson]

Chris, would the Toyota hole being to the side be because the rotation of the crank would cause the oil to pool that side, ie the forces from the crank rotation combined with gravity would cause any oil to pool there. It must have some basis else the common sense approach says put it right at the bottom?

 

Probably just the style of the casting making a hole running vertically impossible or costly. Dunno basically

[Chris Wilson]

Also do you know how much 'slosh' occurs in the sump? on braking does the area under the drain see any significant oil?

 

Having seen several engines run with transparent sumps I can say even at idling and modest RPM it's a maelstrom in there and oil is *EVERYWHERE*

 

Oil is thrown and centrifuged to an amazing degree, sump baffling helps a little, a dry sump helps a LOT! If the side and tip clearance on the oil pump has increased through wear a significant volume of oil will escape, that from the front face of the pump where the crank nose protrudes from it can only get away via the drain. if the voulme is such the drain hole cannot cope pressure builds, and a single lip seal, especially on a worn crank nose (actually the oil pump drive splines are separate, but effectively the crank nose), will start to leak. if enough pressure builds it can be pushed physically forward into the timing star disc. But excess blow by may also cause crankcase pressurisation, which alone or in tandem will add to the possibility of failure of the seal. A worn engine will exhibit both to some degree. A lot of cam cover breather volume will help with crankcase pressure build up.

 

A definitive test would be to measure any pressure in front of the pump, but it would be tricky. I am sure it COULD be done if someone was keen enough to try.

Edited June 19, 2018 by Chris Wilson (see edit history)

[bignum]

I installed an oil accumulator (accusump) to overcome oil starvation issues after running slicks with a basic aero package.tried some plates welded in the sump, helped but didn`t solve the problem completely .

[Scooter]

So essentially and what causes conflicting opinions of various quoted solutions is that there are multiple factors (all generally relating to wear to some degree of another) which combine to over come the weakest link due to a lack of oil flow. So some extra breathing might sort one persons issues out, an extra spring on the seal another's for some a new pump is the only way (this obviously provides the biggest improvement to the problem by removing most of the oil bypassing - does any leak at all from a brand new pump?).

 

The skylines/other setups seem to have more built in leeway (as does even a 2JZ-GE) for oil build up/drainage, ie if the Supra had a pump like this we would see few issues at the same level of pump/engine wear.

[Chris Wilson]

There has to be side and tip clearance in any gear rotor type pump and as such leakage is inevitable.

 

If the crank didn't have to protrude THROUGH the pump it could have a sealed end plate an any escaping oil would descend naturally directly into the sump. Pesky crank drives and dampers ehh? But basically that drain hole was ill conceived in its sizing.

Edited June 19, 2018 by Chris Wilson (see edit history)

[Scooter]

It's all very interesting. So what I am assuming so far as concrete facts.

 

It can't hurt to open up slightly the drain/recesses on a new pump, it's not strictly necessary but it will give you more headroom to delay any reoccurrence?

Other fixes can work in borderline situations but will be more temporary (you will be nearer critical flow levels), as they are just assisting the increased flow at best rather than reducing the oil bypassing.

Careful square 'pressed' fitment into the clean/degreased recess is essential as it leaving the seal flush with the casing

[Scooter]

But basically that drain hole was ill conceived in its sizing.

 

A shame but given the rest of the cars relative lack of foibles I don't think we can be too upset!

[Tricky-Ricky]

It's all very interesting. So what I am assuming so far as concrete facts.

 

It can't hurt to open up slightly the drain/recesses on a new pump, it's not strictly necessary but it will give you more headroom to delay any reoccurrence?

Other fixes can work in borderline situations but will be more temporary (you will be nearer critical flow levels), as they are just assisting the increased flow at best rather than reducing the oil bypassing.

Careful square 'pressed' fitment into the clean/degreased recess is essential as it leaving the seal flush with the casing

 

Unfortunately in my case my std pump had already had the drain opened up to 6mm (about as big as you can safely go) yet due to the amount of pump wear on a 50K engine my seal was just displaced by the pressure build up, Chris may remember my posts and pics on that, but i think the pics are now gone.

But anyway my pump had significant wear, yet still retained the std oil pressure expected, so oil pressure is no indication of pump wear on a good engine, i would presume this is to maintain a good supply film to the mains and rod bearings, so unless these are significantly worn then there would be no tell tale signs.

[Fulcrum2000]

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 yes true with the exception that Grandad is Hulk Hogan. Yes he's old but he was genetically built like a brick shithouse to begin with and enhanced with his 'training, prayers and vitamins'. And like him, the Supra and the 2JZ was over-engineered to take this kind of rag. We'll all pop seals now and again, blow pumps but at least we have Supras at then end of the day hats what I alwas say when I'm paying the latest repair bill anyway. If the engine was made by some other less prodigious car companies (Gimme a V, Gimme an A, Gimme a U....) it would be a new everything every time I imagine

[jagman]

It's all very interesting. So what I am assuming so far as concrete facts.

 

It can't hurt to open up slightly the drain/recesses on a new pump, it's not strictly necessary but it will give you more headroom to delay any reoccurrence?

Other fixes can work in borderline situations but will be more temporary (you will be nearer critical flow levels), as they are just assisting the increased flow at best rather than reducing the oil bypassing.

Careful square 'pressed' fitment into the clean/degreased recess is essential as it leaving the seal flush with the casing

 

 

You still have to look at why the 1jz does not suffer with this problem ? - all the same factors apply , different oil used, high miles,old seals , high boost , crankcase pressure , and so on - what works on the 1jz must point to what does not work on the 2Jz

[Thomas_germany]

Yep running BPU. But was BPU looong before the seal failed.

Edited June 20, 2018 by Thomas_germany (see edit history)

[Scooter]

You still have to look at why the 1jz does not suffer with this problem ? - all the same factors apply , different oil used, high miles,old seals , high boost , crankcase pressure , and so on - what works on the 1jz must point to what does not work on the 2Jz

 

The oil pump is different, perhaps it doesn't bypass the same volume of oil, doesn't create the same/as high oil pressure, do 1jz's have oil squirters?

[Scooter]

So if the pump is a little worn, and if the oil squirters or somewhere in the system is giving more restriction than normal then perhaps the oil pressure is consistently higher than normal, higher pressure and high rpm giving more leakage from the pump?

 

All just guessing.....

Edited June 20, 2018 by Scooter (see edit history)

[Tricky-Ricky]

So if the pump is a little worn, and if the oil squirters or somewhere in the system is giving more restriction than normal then perhaps the oil pressure is consistently higher than normal, higher pressure and high rpm giving more leakage from the pump?

 

All just guessing.....

 

That why there is a pressure relief valve to keep oil pressure within limits, however they have been known to stick.

[Scooter]

Yes but my understanding is it's a built in fail safe, all I'm saying/assuming is if the pressure is higher for some reason a worn pump will leak more than at low pressures.

 

 

Wonder if the relief valve is the same pressure in both 1jz/2jz.

[jagman]

Wonder if the relief valve is the same pressure in both 1jz/2jz.

 

That's the thinking that will provide the solution, it's the differences between the two engines.

The 1jz came out first , all design work was done here and this R &D carried over to the 2JZ , the engines are so similar and to keep costs down of course Toyota carried over material specs,tooling ,and data from one to another , the 2jz was not done from scratch .

The 1J is at least 3 years older so "wear" issues would be higher not lower , the pump /seal/oil pressure/relief . Squirters and so on are I believe too similar .

The 2jz leaks are not a common thing so not any major flaw , but a hidden some have some don't type thing - that's why I thinks it's a harmonic type issue - the block is higher and the crank different and different harmonics which in a very few cars causes leaks and moves the seal lip under the exact right (rare) conditions .

[Fulcrum2000]

Just as an update I thought to myself, why the fudge would I think 'its probably not the oil pump and even though its 25 years old it will be fine' when several people have had this issue and had the same signs as me. Even if it is fine its not going to be 100% after 25 years is it. So I've bought a new pump and its booked in to have it fitted on the 10th. Thanks guys once again for being the voice of reason.

[Tricky-Ricky]

Just as an update I thought to myself, why the fudge would I think 'its probably not the oil pump and even though its 25 years old it will be fine' when several people have had this issue and had the same signs as me. Even if it is fine its not going to be 100% after 25 years is it. So I've bought a new pump and its booked in to have it fitted on the 10th. Thanks guys once again for being the voice of reason.

 

Hallelujah he's seen the light! seriously though, either do it yourself or get someone to open the drain hole out to its either 5 or 6mm before fitting, as a precaution as i found that my pump already had this mod done and it still killed a brand new seal.

[Tricky-Ricky]

Wonder if the relief valve is the same pressure in both 1jz/2jz.

 

That's the thinking that will provide the solution, it's the differences between the two engines.

The 1jz came out first , all design work was done here and this R &D carried over to the 2JZ , the engines are so similar and to keep costs down of course Toyota carried over material specs,tooling ,and data from one to another , the 2jz was not done from scratch .

The 1J is at least 3 years older so "wear" issues would be higher not lower , the pump /seal/oil pressure/relief . Squirters and so on are I believe too similar .

The 2jz leaks are not a common thing so not any major flaw , but a hidden some have some don't type thing - that's why I thinks it's a harmonic type issue - the block is higher and the crank different and different harmonics which in a very few cars causes leaks and moves the seal lip under the exact right (rare) conditions .

 

If it is down to this how do you explain the sheer amount of oil that is expelled when the seal failed, since the oil can only escape from the around the drive gear that the crank runs through, but i see your point, if there is enough oscillation its could muller the pump veins enough to cause the leak in the first place, whoever it still leaves the question is it down to the inherent design, or is it because of a badly worn harmonic balancer pulley....and again why is it seemingly not reported on the GE and the 1JZgte?

[Scooter]

If it is down to this how do you explain the sheer amount of oil that is expelled when the seal failed, since the oil can only escape from the around the drive gear that the crank runs through, but i see your point, if there is enough oscillation its could muller the pump veins enough to cause the leak in the first place, whoever it still leaves the question is it down to the inherent design, or is it because of a badly worn harmonic balancer pulley....and again why is it seemingly not reported on the GE and the 1JZgte?

 

Indeed I 'think' that the setup in the TT's just has a little more of everything going against it, lower chamber (pump seal area) volume, higher pressure (giving more leaking oil for the same level of pump wear?), harsher oil conditions which means neglect (via cheap oil of extended service intervals) can give carbonisation internally causing accelerated pump wear (I personally believe this is why valve stem seals go on the TT's only in general), also over fueling contamination on bpu.

 

So more likely to wear prematurely combined with a lower capacity for dealing with the consequences of said wear?

 

The chamber volume/drainage probably is the most important as with excessive room/adequate draining here none of us would get leaking seals unless the pump was really really goosed.

[Fulcrum2000]

So I got the pump (genuine Toyota) and it has no seals, is this normal, does the mechanic need any extras to fit it? I was expecting a load of rubber seals with it or something? Also do you have a pic of the drain hole I need to mod Tricky?