Oil Leak from center of VVT exhaust cam pulley. O-ring?

Post by **Brick Head** » 20 Nov 2010, 02:34

1999 V70 XC 265k - Decided to do a complete timing belt job with all seals etc since I knew there was evidence of an oil leak behind the TB cover. Once I got everything off there is no leak from the intake cam seal or the crank seal but there is lots of oil coming from the middle of the exhaust cam pulley. Assuming all of the oil was coming from the exhaust cam seal I commenced removing the center cap (well sealed with a green o-ring) and oil literally poured out and continued to ooze for 20 minutes. My parts guy said more than likely most of the oil isn't from the cam seal but an o-ring that is on the VVT sprocket shaft. Guess what? It is not available separately but you have to buy a whole new pulley with a shiny new o-ring for $319!!

Before I purchase a $319 o-ring I'd like to hear some other opinions...

Thanks, Curt

Post by **MadeInJapan** » 20 Nov 2010, 21:16

Can you take that apart and see what size that o-ring is and see if you can't find one that's the same size?

Post by **Brick Head** » 21 Nov 2010, 01:15

I'll probably have to do that. Any idea what the o-rings are made of to withstand the heat and oil? I'm figuring plain old black rubber won't cut it.

Also assuming I will need to invest in a cam lock tool before removing the pulley or is it keyed? Is marking the pulley position on the shaft accurate enough?

Thanks, Curt

Post by **MadeInJapan** » 21 Nov 2010, 09:40

I'm not sure but seems that my mechanic said you do have to use a cam locking tool if you take that thing off. Good luck

Retired MVS Contributor · Post by **Retired MVS Contributor** » 21 Nov 2010, 10:10

I was going to alert you about the temperature, but you've already got a good grip on this...Do you need to remove the pulley?...It looks like the green O-ring on that center plug you pulled is the only one you need to replace...

If you can't find a ring on the internet, you might try an aircraft parts house if there is an airport nearby...They carry a wide variety...

Post by **JDS60R** » 21 Nov 2010, 10:12

Stop
That chamber is supposed to be filled with oil.

If you took out the chamber plug and it was leaking from there then you are fine. If you close it and the leak stops you are fine. The VVT valve (on top) regulates the flow to that chamber and the oil is used to push the VVT to put the cam where the computer wants it to be.

If you have a leak behind the VVT you will need to disassemble and replace the cam seal. If there is a leak from an inner o ring that you can get to you should remove it and measure it carefully. Then contact http://www.marcorubber.com and have one made of Viton.

You will need a stout cam holding tool as the VVT removal consists of removing a nut that is on at 90 ft/lbs.

I have never seen an inner VVT seal fail. I do not know if you can get it out of the unit or if you will need to replace the entire unit. But if its an o ring - marco can make it.

Just for clarity - you think the cam seal is fine but the leak is coming from the back of the VVT? Is that correct?

Post by **JDS60R** » 21 Nov 2010, 10:24

Here is the removal procedure and toque specs.

I would be triple sure that its the VVT and not the exhaust cam seal.

I make super strong cam holders here from angle iron and flat tabs. You can make one at home cheaply. mine looks like this and it never budges. I use high strength magnets to hold it tightly to the cam. I hand grind the ends down so it just fits. Its far more precise then needed but I like it . By the way - the specs in the Haynes manual were a few mm too wide but it still worked. The shorter one is the one I use every day.

Post by **Brick Head** » 21 Nov 2010, 13:21

JDS60R wrote:Stop
That chamber is supposed to be filled with oil.

If you took out the chamber plug and it was leaking from there then you are fine. If you close it and the leak stops you are fine. The VVT valve (on top) regulates the flow to that chamber and the oil is used to push the VVT to put the cam where the computer wants it to be.

If you have a leak behind the VVT you will need to disassemble and replace the cam seal. If there is a leak from an inner o ring that you can get to you should remove it and measure it carefully. Then contact http://www.marcorubber.com and have one made of Viton.

You will need a stout cam holding tool as the VVT removal consists of removing a nut that is on at 90 ft/lbs.

I have never seen an inner VVT seal fail. I do not know if you can get it out of the unit or if you will need to replace the entire unit. But if its an o ring - marco can make it.

Just for clarity - you think the cam seal is fine but the leak is coming from the back of the VVT? Is that correct?

Thank you for the clarification!

Once I saw this volume of oil inside the cap I assumed that it was the major leak and not the cam seal. I'll have to poke around some more to verify if the leak is truly coming from the shaft but the cam seal would appear to be a more likely suspect.

Again, thank you for your help.

Curt

Post by **JDS60R** » 22 Nov 2010, 20:58

I like to clean everything up first and then use a dye in the oil or baby powder to find the source of the leak. Either way you will have positive proof of where the leak came from. Please take a pic of the leak if you can.