Blown front crank seal :(

[Scooter]

i would say over 90% of Supra owners are on some type of 10/40.

 

Your seal is probably like you said earlier largely down to age.......when you get it fixed you could then use the 10-30 that is reccommended on the oil filler cap if you like?

 

I can't really see it making the difference between a blown or not blown seal, but frankly what do i know! maybe its a contributing factor?

 

I seem to remember that 0-50 & 5-whatever weight oils were getting bad press not long ago for being too thin at high temps and leaking past seals etc, so you can't win can you!

 

I recently did a cambelt and crank seal change on the Aristo and it took a days DIY, its back on 10-40 oil and i'm just seeing how it goes. I think at 106K miles and it just running stock boost its down to age too, but may look into the breather system side of things too..............oil type is way down on my worry list..............

[Tricky-Ricky]

I've wondered about this myself.

Also Toyota's firm recommendation on SAE 30 (thinner than average)

 

Maybe it's also related to the low idle speed it settles comfortably once warmed up. The designers must have had a lot of confidence on the oil pressure. (which could turn into a problem once their redline is exceeded)

 

There are other question marks I've still got about the design. Like why they went to such lengths to keep the engine bay freakin hot (ambient+25C ~ ambient+35 typically, depending on vehicle speed). I've tried to undo this - with not much success ultimately- until I realised that it pulls so much better once the underbonnet temps get silly. Looks like they relied on this heat for full atomisation.

 

 

I agree, it seems a paradox, big engine, thin oil, high oil pressure and loads of heat, and the RPM limit of a tractor!

the oil pressure has me scratching my head as well, ok normal 20-30psi at idle but by 3k i'm seeing 90+psi:( so not only has the engine got to deal with any blow by there might be but anywhere there is limited oil drainage is also in danger of seeing over pressure, at least logically thinking, i may be wrong there, but it seems to me that if you add these up and then chuck high or slightly over high oil fill levels into the equation, the weakest or most stressed oil seal (front crankshaft) is going to let go, i have certainly see oil seals on other engines pop through over filling.

I keep compeering the 2jz with the RB series and there are a lot of similarities,

oil pump crank, valve train, yet the RB will rev to 8.5K and is not a square bore and stroke, oil pressure is a lot lower and under temps are lower to, admittedly the RB runs throttle bodies, so intake velocities are better, but i cant see having such high engine/under temps necessary for good fuel atomisation.

[JohnA]

I use 5w40 fully synth but don't delve into the red.

I would be very reluctant to use 15w50 or such, despite various 'experts' professing about thin oil going through seals and other urban myths.

I've never had problems even with Mbl1 0w40 smoking from any turbo of mine.

 

In my view, when the manufacturer recommends 30, there must be a reason for this.

 

My crank seal is aged more than most here and still doesn't weep or cry despite the abuse. Crank ventilation follows the stock paths of course, and yes there is a healthy amount of blowby:blink:

 

(right, now the Turbo Gods will punish me and it will blow next thing tomorrow:search: ...)

 

...admittedly the RB runs throttle bodies, so intake velocities are better, but i cant see having such high engine/under temps necessary for good fuel atomisation.

Did they aim the RBs for Europe/US though?

Toyota had to deal with emissions regulations, and this one stinks of emissions technology to me.

[JamieP]

Just blown my front seal while mapping to 7400rpm

Anyone have a part number for the uprated seal? need one urgently!

 

 

 

Sorry for dragging this up but did you go with th uprated/ tighter NOK crank seal Charlie?

[b_have]

I didn't Jamie, just refitted an oem seal. Think my failure was reving to 7400, back to 7200 now and no probs.

[JamieP]

I didn't Jamie' date=' just refitted an oem seal. Think my failure was reving to 7400, back to 7200 now and no probs.[/quote']

 

 

Ok thanks mate.

[Chris Wilson]

My Supra TT ran fine with no issues on Motul 300V 15/50, that's what I use in the Skyline and the two Zeus cars. They specify these thin oils for less drag and better MPG, especially from cold starts.