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Oil pump (crankshaft front) oil seal failures


Chris Wilson

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Greg have you ever thought about fitting one of these?

 

That's an interesting theory about the seal backing up against the pump housing and blocking off the drain hole.

 

Anyone know if this is actually feasible though? I haven't seen how they actually fit together.

 

And how does this explain the failure of the original Toyota factory fitted seal??

 

How about..... Original seal plus oil pump get a bit worn. Pump wear allows leakage past the rotors and this fills the void behind the seal. The drain hole copes initially, but with a flow of oil through it eventually it begins to constrict due to varnish/sludge formation... meanwhile the pump is leaking more and the FMS is wearing more.

Eventually there comes a point where the pressure behind the FMS from the oil (combined with perhaps increased crankcase pressure) causes the inner lip (which has worn against the crank and the spring pressure relaxed due to this wear) to move out sufficiently to dislodge the spring. Result = major oil leak.

 

A new seal is fitted, but pushed back too far against the pump housing and blocks off the oil drain hole, so all oil leakage (still on the old pump) pressurises the seal area. This causes the seal inner lip to again move, dislodging the spring and causing a large oil loss again.

 

Possible failure mode???

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Greg have you ever thought about fitting one of these?

 

My first seal that failed was this one,NOK BH4513E so i am inclined to think its bull,the second which also failed was the std one NOK BH4513F, and as for the bits on the back preventing the oil drain from being covered up, well they are maybe 5 thou and would do no good whatever, in fact if you drive the seal far enough back to cover the drain, you have effectively ruined the seal as seal is 6mm thick and the seating is 15mm deep, so the inner seal lip would be pushed outward n by the crankshaft;)

Also the article seems to concentrate on the actually seal being displaced rather than failing, so i would say that they haven't been fitted right, as the lip should fail before the whole thing is displaced, and as previously stated, the seal can't physically move very far due to the timing trigger wheel.

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That's an interesting theory about the seal backing up against the pump housing and blocking off the drain hole.

 

Anyone know if this is actually feasible though? I haven't seen how they actually fit together.

 

And how does this explain the failure of the original Toyota factory fitted seal??

 

How about..... Original seal plus oil pump get a bit worn. Pump wear allows leakage past the rotors and this fills the void behind the seal. The drain hole copes initially, but with a flow of oil through it eventually it begins to constrict due to varnish/sludge formation... meanwhile the pump is leaking more and the FMS is wearing more.

Eventually there comes a point where the pressure behind the FMS from the oil (combined with perhaps increased crankcase pressure) causes the inner lip (which has worn against the crank and the spring pressure relaxed due to this wear) to move out sufficiently to dislodge the spring. Result = major oil leak.

 

A new seal is fitted, but pushed back too far against the pump housing and blocks off the oil drain hole, so all oil leakage (still on the old pump) pressurises the seal area. This causes the seal inner lip to again move, dislodging the spring and causing a large oil loss again.

 

Possible failure mode???

 

Nice theory, which the last part is partly true, but, as i said in the last post you can't drive the seal in far enough to block the drain without it damaging the seal and you would have to drive it a fair way past the face plate, which would be very apparent;)

I still firmly believe that in most cases its down to pump leakage coupled with the fact that the drain hole is inadequate after a certain leakage point is reached, hence the seal is overcome with the pressure

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Right here is a bit of disturbing news.

 

As I have mentioned earlier in this thread that we have had problems with new Oil seals leaking and have passed this information on to Toyota, as yet no reply.

 

Over the last few weeks we have been supplied by Toyota with 2 brand new Oil pumps, both car's on 1st start up leaked Oil from what we assumed was the front Oil seal, both were replaced with new ones but again as soon as they were started Oil dripped again although on one of the engines the drip stopped and did not appear again this we put down to the oil seal actually sealing, however after a couple of hundred miles the owner reported oil dripping out under the car and we had it transported back to the workshop to investigate.

 

So in order to see why the oil was leaking the front covers were removed and the engines were again started, to our horror the leak was not from the from seal but from the Oil pump.

 

On the front of the pump is the vertical shaft that holds the relief valve spring which is retained by a bolt at the top of the pump, the oil would start to seep from the bottom of this shaft and go upwards towards the bolt and on reaching the top would then flow quite rapidly down the side of the pump and come out under the crank giving the appearance that it was from the front seal.

 

After removing the pumps and looking at another older pump it seems that changes have been made to the casing of the new pumps, you can clearly see that the castings on the new pumps are different from the old pumps.

 

After speaking to Toyota they confirmed that the casings have indeed been changed and have been sent the faulty units for inspection.

 

The really big problem here is that the only way you can check to see if the new pump has a fault is to fit it and run the engine, now the pump fits at the front of the engine and is quite simple to get at but due to some clever design the only way you can install or remove the pump is to drop the sump down due to a 15mm lip and dowel on the bottom of the pump, this is a major pain and quite labour intensive.

 

Today we had a new pump sent over and checked the shaft and low and behold the same casting fault lines were clear to see so we sent the pump back.

 

We are now in the hands of the Toyota experts.

 

As always I will update you with any news as soon as I get it.

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That sounds like something i read on one of the US sites when i was researching this, it seems a common fault was that the O ring that seals the bolt that holds in the PRV spring is prone to leaking,

But unfortunately this is not so in my case and i suspect a lot of others.

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After speaking to Toyota they confirmed that the casings have indeed been changed and have been sent the faulty units for inspection.

 

As is normal in a vehicle's production life, once a vehicle has started production its back to the drawing board to try to find cost savings for virtually all components. Sometimes this works out fine and there is no discernable difference between the initial production part and the cost reduced part, however other times it can cause all kinds of issues.

 

And the durability testing that goes into the cost reduced parts is nowhere as intense as the pre-production testing.

 

I didn't think Toyota were into this penny pinching at all! Perhaps they changed the design or production of the pump as they changed supplier?

Maybe new old stock is the way to go with oil pumps?

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They might well have changed from the original series producton supplier to a purely aftersales one. This design must be getting on for 17 years old so the original tooling is probably fooked.

 

Interesting. I'd like to see some pics of the old and new pump bodies if possible.

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my car is in the workshop now due to this faliure of the pump and have seen the new pump greg is talking about and like he says you can clearly see some faint hairline cracks in the casting which is the same as where the appear to be leaking from the two pumps that have failed

Greg has very very kindly supplied me with a pump from his drag car known to be in good working order to get me going again as was not happy to fit another new part

its now over to toyota and for me to fight for my labour cost i have had to pay out:(

 

but thanks again to Greg for helping me out yet again!!!

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Just going to stir the pot on this again,;)

Been doing some more thinking about this, and this is still going totally on the premise that its oil pump pressure related,

 

I have read various ideas and theories, and the main ones i would go with are:

 

1: that the main reason for seal failiure is pressure behind the seal, caused by to much oil escaping from the pump, which cannot escape from the under size drain hole.

Solution, enlarge the drain hole.

 

But at this point we need to find the reason for the escape of oil from the pump, which could be as simple as worn rotors/casing, but i have heard of this happening to new pumps, and low mileage pumps? So next we look at design errors, well you wouldn't expect Toyota to cock this up would you?

but its obvious that there must be a reason for the escaping oil!

2:I have also read that there are opinions on the std PRV port aperture being to small to adequately control the pressure delivered by the pump at high RPM, i also think this could be a distinct possibility.

 

Solution, open the port size up, this would also cause the PRV to dump pressure slightly earlier, there is also the possibility of shortening the PRV spring to reduce pressure at high RPM but this would be trial and error!

 

3: That there is a possible restriction or user added restriction in the oil circulation system, can't see what would do it as the filter pressure relief is separate to the filter, so that excludes running crap filters, can't see a sandwich plate doing this either, the only other possibility is crud/gasket material causing a bottleneck somewhere, but again this would lead to other symptoms such as staved bearings so imminent failiure.

 

My one last thought/question on the subject is why is the 2JZ GTE oil pressure so high? in most cases it seems to go well over 100 PSI from 3,000 RPM up wards, the std engine journals are not particularly highly loaded, at least not until you start producing 500BHP + so why the high oil pressure? is it to compensate for low volume due to the size of the oil galleries, AFAIK excessive oil pressure is not needed and can cause wear related problems?

 

Just a few more thoughts, would anyone care to add some more?

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If someone gets a realsitic number of sample oil pumps that have suffered a failed seal, opens them up and measures the wear it, and compares them, casting wise, to the so called latest pumps, then this should put this to bed.

 

My money is on pump wear, possibly caused by internal contamination.

 

My money is also on it NOT being an issue with the oil relief valve port size, t's enormaous as it is. I have cars with 200 to 300K miles plus which have never had an oil seal fail or be changed, so I doubt it's any production fault. There should be all but sod all oil to drain down the front leakage drain hole, unless the pumps *uggered.

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  • 2 weeks later...

Im have oil pump/seal problems with mine now, brand new oil pump failed, steve manley has reconised there is a problem with the new batch of oil pumps and is not selling any at the moment, so we fitted a seconhand oil pump that we knew had no issues on a previous engine, 2 blown front seals in as many days:(

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Im have oil pump/seal problems with mine now, brand new oil pump failed, steve manley has reconised there is a problem with the new batch of oil pumps and is not selling any at the moment, so we fitted a seconhand oil pump that we knew had no issues on a previous engine, 2 blown front main seals in as many days:(

 

More info needed please. Post internal pics (DETAILED AND BIG) of the failed new pump. Fullest list of modifications and their history too. Are you monitoring oil pressure? Any recent oli system changes, like oil coolers, mods to oil coolers, remote filters, blah blah?

 

I have a new pump here and I can detect NO diffrences, internally or casting wise, witha 1993 OE pump.

 

Unless people strip the failed pumps down I don't believe a proper conclusion will be reached.

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Let me get this clear please. Are you saying a new pump failed, and you then had an old but previously trouble free pump fitted, and that old one then blew out 2 front seals, or are you saying the new one blew out 2 front seals, but when you fitted an old one, the problem disappeared? Please clarify, may be being dense, but your post seems ambiguous to me, sorry.

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Let me get this clear please. Are you saying a new pump failed, and you then had an old but previously trouble free pump fitted, and that old one then blew out 2 front seals

 

Thats correct, the car is with turbofit and they are going to be looking into it in the morning, ill post up if i find anything else out.

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is this since the new/different turbo?

 

going back to the point that this seems to be purely a TT problem and usually a single turbo one, can it be anything to do with the oil path/ways/route/flow with the single as opposed to the stock feeds to the twins?

 

Does the flow rate and or restriction through a turbo matter?

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Hi Chris, sorry I do not have any pictures of the new pumps as the two failed units were sent back to Toyota for inspection.

 

There is however an easy way to tell if you have one of the new pump case's, as you look at the pump look to the top left hand side of the pump on the old pump case the top left hand edge is smooth, on the new pump case there is now an extra threaded hole at the top left hand side.

 

We can only assume that this new fixing point has been added for the engine in the Lexus series.

 

Also we have recently put in a brand new 2JZGTE short block from Toyota and noticed that there is now extra engine mounting points on the block again we assume this must be for the Lexus series.

 

As for Jamie Ps problem the new pump that was fitted to his engine failed and was replaced with an old but known oil pump, a new oil seal was fitted on start up and idle there were no signs of any leaks however after a drive oil was leaking from the seal, after a front end strip down it was found that the seal had moved forward, using the Tool supplied by Toyota the seal was put back in place and the front put back together again.

 

On start up and idle again on leaks but after a short drive the leak was back, at 8.30pm we decided to give up for the evening and await the delivery of some new front seals in the morning at which time we will strip the front down again and do a very close inspection.

 

Just a note:

 

We have now heard back from Toyota and to be honest it is not a very good response.

 

In a nutshell they have admitted that they are now having the oil pumps made by another manufacture but at this time cannot do anything other than replace the pump on warrantie, whilst this is no more than we are entitled to under the consumer act I cant say that at the moment I would take a new pump as without a way to test them off the car it is a shit pile of work to put it on and find the same problem.

 

At this point in time we are down by 5K in parts and labor with no way of getting any of this back.

 

The public relations officer at Toyota was quite shocked at the tale but said that his hands were tied and unless there were more returns that there was no more he could do.

 

Shit month really:(

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The public relations officer at Toyota was quite shocked at the tale but said that his hands were tied and unless there were more returns that there was no more he could do.

Serious stuff.

 

So do we need a "calling all people with oil pump changes in the last 6 months" thread to determine some kind of failure ratio?

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