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Oil pump (crankshaft front) oil seal failures


Chris Wilson

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I would be very surprised if failure was down to vacuum, as i said before, the seal construction would not allow the spring to come off if the seal lips where sucked inwards,

and all my seal failures have been at hi ish RPM and with boost, so PCV is closed and not functioning.

And as Jamie said anyone using the exhaust driven PCV system, ( and there are lots in the US) seal failure would be common place on these motors>

Hydraulic pressure has got to be the answer, especially with the amounts of oil that is first expelled, as the drain is above the sump oil level, so sump pressure would have to be horrendous to force the oil through the drain hole in that volume, so leaky oil pump is my logical conclusion.

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I mentioned that im getting some water in the catch can now and on the other engine i never had a drop, as you can see from the vid it has mixed in with some oil vapour, what would cause the water to get in? seems a lot for just condensation, thinking about it ive had to top up the rad a couple of times but i just put this down to the the system levaling after we have stripped it out.

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Well, I cant see how we are going to bottom this out unless someone starts measuring stuff and eliminating it in a methodical manner.

 

To comment on Jamie's post above, out of all the stuff that comes out of a breather system, water vapour will be a large percentage (certainly more than oil), so on the face of it, that's normal too. However you also mentioned that your rad needs topping up, so hey presto: Two more variables to consider.

 

There are so many Supras out there with so many different combinations or tune, breather system, age, oil pump manfacturer (ffs!). No one is taking proper measurements of the things that we think might be causing the problems, then changing, say the stock system for a modded system and re-measuring and re-observing the leak, then perhaps putting it back to stock and re-observing to see it everything goes back to normal again. So far this is all based on comparing apples with oranges.

 

We'll just end up going round and round and not getting anything resolved.

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Yea i agree, im so f**ked off with this now, the car is going back next week for a engine out and complete strip down and check everything.

 

Just to clarify what I posted earlier, I didn't mean physical strip down and rebuild mreasurements as such but rather measuring the performance of all the systems that people think may contribute to the problem, and doing some back-to-back testing to see if doing X or Y makes it worse or better.

 

I don't think that taking it all apart again is going to turn much up, but of course youcan verify that nothing is obviously damaged before it goes back together.

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The engine has to come out for the oil pump change as doing it from under the car is a pita, im not getting this water in the catch can thing as it never did it before so i want the head off for a check and new gasket to eliminate that, i also noticed that the oil channels on the new block looked different size to the old block and i want this checked also.

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On a side note anyone know the correct torque settings for the arp head studs, from searching about everyone seems to do it differently, arp say 65ft/lbs, searching supraforum most said 80ft/lbs, we decided to go with 75ft/lb as at 65 they did not feel tight enough.

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Oh yeah - I forgot about that. Still not sure how you maintain an accurate and even clamp load using torque tightened head bolts.

 

If you know the material specs for the bolts, and the thread size I can have a bash at working it out for you.

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I have a mate in a parts shop in canada and he has sorced me one of these, sending it out to me monday, gotta be worth a try:)

 

 

 

Don't want to piss on the bonfire, but my first seal that let go was one of these! they may be a tighter fit, and may help to prevent them moving, cant measure as my digital mike is fooked, but they will fail at the lips just like the others.

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Don't want to piss on the bonfire, but my first seal that let go was one of these! they may be a tighter fit, and may help to prevent them moving, cant measure as my digital mike is fooked, but they will fail at the lips just like the others.

 

 

 

Oh well, whats the next step on yours?

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Oh well, whats the next step on yours?

 

 

 

PHR uprated pump ;) modded to relieve oil pressure behind seal (should it become a problem) i think the PRV port is modded as well, and the seal has three screws/rivets to make sure it stays put, although this is not my worry, i think the rotors and body are lapped and checked for clearance + X-rayed for cracks.

If this doesn't cure my problem, then expect to see a thread on SR20DET engine conversion:blink:

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PHR uprated pump ;) modded to relieve oil pressure behind seal (should it become a problem) i think the PRV port is modded as well, and the seal has three screws/rivets to make sure it stays put, although this is not my worry, i think the rotors and body are lapped and checked for clearance + X-rayed for cracks.

If this doesn't cure my problem, then expect to see a thread on SR20DET engine conversion:blink:

 

 

 

Ha, i also know of a brand new phr pump that has failed recently, im not sure the owner wants to come public with it though so ill name no names.

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No it is not a wind up.

 

Brand new from PHR with I might add the new casting pump housing, put it on the car and hey presto leaking from the same hairline crack running down the reilef valve housing as the other new pumps.

 

Really strange sight to see as the oil appears as a line at the bottom and then works it's way up to the bolt then pours out.

 

Shame I did not have a video camara as it is the first time I have ever seen oil go up.

 

Are you on a wind up? do you really want to see someone have the first heart attack on a public forum:blink:
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