Rb25 Oil Leak,

[DaveO74]

Hey Guys,

Dunno if this is the right section but here goes.

About 2000ks ago I did an engine bay paint and pretty up when I upgraded my Turbo, Injectors, clutch etc on my 33 gtst. Everything has been fine up until the last week or so (Or I should say I only noticed it a week or so ago) when I noticed oil droplets on the garage floor. Not heaps of oil but oil drops none the less.

Last night I went for an approx 70k drive so I thought I"d put some paper down and see if I could find the source of the leak when I got home.

I pulled into the garage and turned the car off and looked under it to find a droplet about the size of a twenty cent coin on the paper under the part where the gearbox attaches to the engine (The bellhousing?)

Now if had a look and a feel around the engine (albeit at night) and I cant seem to find the source of the leak. Its not the sump plug as I first thought it may have been when I first noticed spots and I am thinking that maybe when I painted the cam covers and put them back on it hasnt sealed properly and oil is somehow running down the back of the engine and to this spot. Is this possible?

Ive had 4 dyno runs in the last few months including a full day at the mechanics checking over all my work to make sure I put everything together ok and nothing was said so I figure this is a new leak.

Any ideas?

If its something major like a big end Id hear it wouldnt I?

This is a meticulously maintained car so it has got me baffled.

Ive added a pic to show where the oil drips from

and others to show how clean I keep the bay (So i would notice a leak)

[08r3308]

that engine bay is real clean good work

maybe degrease the whole lot under there and have a look in few days where its coming from

[260tech]

Rear main seal?

[ARTZ]

Rear main seal?

+1.. Should always be done if replacing the clutch, just so u dont have to pull the box out again

And congrats, thats a sweeeet looking bay

Edited September 18, 2009 by doozooby

[DaveO74]

Yeh I was thinking rear main seal after doing a search, is it a hassle to fix if thats the prob?

EDIT:I think you just beat me to the answer to my question doozooby

[ARTZ]

Ha ha...

It is a pain, its the seal where the gearbox shaft goes into the engine, not an expensive part , the one for my ute was 15$ from memory. but a pain to get at..

you'll now if ya clutch starts slipping cause its covered in oil...lol

Edited September 18, 2009 by doozooby

[DaveO74]

Mmmmmm, Might have to drop into the mechanics next week to check if this is the problem then. Weve got the Putty rd cruise up here next month and Id rather not risk it

[GT-RZ]

Did you look at the cam covers at the rear? the half moon rubber seals at the back ALWAYS leak, check for oil down your block around the back and sides.

[260tech]

^^^ Good call there. And.........old Holden rear mains practically leak from birth but don't seem to do much by way of degrading the clutch performance. My old ute don't seem to care one way or the other at least. See how it goes, if it is rear main & has only just started it probably isn't a major issue. Buy drip tray from supercrap for garage floor.

Cheers GW

[DaveO74]

Thanks for the input guys.

Ill have a really good look over it this arvo to make sure it isnt leaking from the cam cover area.

By the sounds of it tho its the rear main.....shouldve just changed it when i did the clutch. Lesson learned

[Wacky Dee]

mine's sweating oil to the general sump area all around ... mechanic looked at it and it looks like the rocker cover gaskets / halfmoon seals need replacing and it seems pretty common on skylines. Check the rear of the rocker cover near the firewall ..

[(B1) MR_fanny]

mine used to leak from the same spot too at the gearbox. i thought it was the rocker gasket so i got that cleaned and replaced. prob came back later and got it re-cleaned and tightened by another workshop and it's still back. I then had the car up on a hoist and the mech pointed out it could possibly be coming from the oil line from under the turbo to the block so when you drive turbulence disperses the oil around the back of the block making it look like its leaking from the rocker gasket. I have yet to get it fixed but it does make alot of sense.

[sneki81]

are you sure its definetly motor oil??

mine drips oil from the same spot but its not motor oil (bit more redish)

think mine is coming from one of the power steering lines.

[DaveO74]

Did you look at the cam covers at the rear? the half moon rubber seals at the back ALWAYS leak, check for oil down your block around the back and sides.

Well just had a good look over and under the car in the light and I "THINK" GT-RZ win the prize for this one. Just under the half moon on the passengers side is covered in fresh oil, cant see it but when I wiped my hand over it could feel it.

I went around and re-tightened all the cam cover screws and I was suprised that they were a little loose (Could tighten about a 1/4 turn) Maybe cause I put new gaskets and Half moons in when I did the mini rebuild they have now "seated" a bit???

are you sure its definetly motor oil??

Yeh man definately motor oil

Just to be cautious I have cleaned all the bell housing and as much of the block as I can reach and I will take it for a spin tonight and have another look after she gets really warm for any other leaks, but Im hopeing Ive found it so I dont have to take the Gearbox out again. That was a bitch to do without the "proper" tools.

Ill keep you guys posted on the results

Thanks for the help peeps.

[ARTZ]

mine's sweating oil to the general sump area all around ... mechanic looked at it and it looks like the rocker cover gaskets / halfmoon seals need replacing and it seems pretty common on skylines. Check the rear of the rocker cover near the firewall ..

Yep, mine leaks here too

are you sure its definetly motor oil??

mine drips oil from the same spot but its not motor oil (bit more redish)

think mine is coming from one of the power steering lines.

And here

Edited September 19, 2009 by doozooby

[ARTZ]

Did you look at the cam covers at the rear? the half moon rubber seals at the back ALWAYS leak, check for oil down your block around the back and sides.

And here

mine used to leak from the same spot too at the gearbox. i thought it was the rocker gasket so i got that cleaned and replaced. prob came back later and got it re-cleaned and tightened by another workshop and it's still back. I then had the car up on a hoist and the mech pointed out it could possibly be coming from the oil line from under the turbo to the block so when you drive turbulence disperses the oil around the back of the block making it look like its leaking from the rocker gasket. I have yet to get it fixed but it does make alot of sense.

Not sure about here

I just keep coming back here to see what a clean engine bay looks like.....

Edited September 19, 2009 by doozooby

[DaveO74]

Thanks man I try to keep it clean