Hi guys,

My TR V6 Magna has been leaking lots of oil from the oil cap. I have checked the PCV valve on the front rocker cover and it is clear and venting as it should. So is the vent on the back rocker cover.

I tried a new oil cap and that didn't stop it. Currently i have a super thick rubber seal on with the cap and it has stopped it for now. But after a while the oil finds a way past the seal.

I am using Castrol GTX 20W 50 and change the oil every 5000kms.

Do you guys know of anything else that would cause this problem? I've run out of things to try. I'm a bit concerned that if the pressure is too high in the crankcase that the oil will find another way to escape the engine. I already lose a bit from what it burns.

Apart from that it's a fantastic car and excellent value for money. Comfortable and reliable. I paid $1500 for it 1.5 years ago and it had 150,000kms on the clock. Plus it's great to have a V6 manual. Jumps off the line nice and quick when it's time for a traffic light drag :P

Cheers,

Justin.

You can get new seals for oil filler caps from Mitsubishi.

I also slightly bent the clip on the oil filler cap so it tightened harder.

These 2 stopped leaks for me.

Rob

No hate intended, But traffic light drags arent drags... Keep that sort of stuff for actual dragway events... Dont put someone elses life at risk.

My oil cap used to leak a tiny bit but i just bought an aftermarket one and it seemed to fix it fine.

I tried bending the clips on the cap as well and helped a little bit.

Also tried an after market cap.

Thanks for the advice. But i didn't mean i was street racing. Just taking off quickly from the lights to get in front of a slower car before a lane ends. My fault for not making myself clear.

Cheers.

I've put up a similar post about this recenly after never being able to solve this.

The idea of basic physics is that if there's pressure building up then it has to come out somewhere. I think that the pressure build up in mine has forced a few other leaks elsewhere.

I would be worried about that if you've managed to stop leaking from the cap then perhaps it may find another way out by breaking a seal somewhere.

If the car is otherwise running well then it doesn't seem that something serious is going on.

Mine leaked but a new rubber seal fixed it.

Perhaps the surface of your valve cover isn't as flat and smooth as it could be? Have a feel and see if its rough. Perhaps a swipe with some wet and dry will help the seal? (don't let anything fall through the hole though lol )

In my opinion the oil filler setup on these engines is pretty crappy. The cap seals against a thin piece of sheet metal basically. Hot oil is very good at getting through the smallest of gaps (that's why it's so good a lubricating engines).

Well i just had the timing belt done and all the crank seals were replaced where oil was also leaking. So i guess that didn't help with the pressure build up. I'm eliminating places the oil can leak. I can't work out where the oil is going. Not leaking onto the ground. Must be going into the combustion chamber. The only smoke the car blows is at morning start up or sitting idling for a long time.

Thanks TR300000 i will try what you suggested with the valve cover. Saying that, i'm affraid to break the seal it currently has :P The car is running great and it hasn't caused me any trouble except for making a mess in the engine bay.

although the engine is being replaced in a month or 2, when i am more able bodied i am going to take a good look at some of the 12v 6G72 engines foibles. Having come from a more sophisticated engine design, there are a few little things that could be incorporated that are generic to all engines, just not applied to most mass produced passenger vehicles I always wonder why the PCV system was so tiny on these cars. Obviously perfect when the engine is in perfect condition.

I doubt pressure build up from a failing PCV system has much to do with the leaking filler cap, since i had removed the PCV system and replaced with a recirculated catch can arrangement and this didnt stop the leaking cap.

I think the angled position of the cap, with the recess created by the lip of the rocker cover and inside of the cap allows hot thin oil to catch, 2-3ml at a time and seepage occurs.

30th of Jan the cast comes off, then some rehab, then i might be on my feet

Hi guys,

My TR V6 Magna has been leaking lots of oil from the oil cap. I have checked the PCV valve on the front rocker cover and it is clear and venting as it should. So is the vent on the back rocker cover.

Justin.

I experienced the same problem on my TS V6 early last year, and with the help of the Forum the problem was solved. You mention that both rocker cover vents are both venting. Does that also include the rubber tubing running from the vents?.

In my case, both vents on the rocker cover were partially blocked, but the rubber hoses were also partially blocked, especially the rear tubing. Due to the heat in that area, the tube became very hard and so did the blockage within the hose, that it needed to be replaced. Have not had a problem since.

Ozz

Thanks guys,

I checked everything to do with the PCV system and everything is clear. I think you are right and it may just be a minor flaw with the 12v 6G72. I forgot to mention that the car has done 208,000kms. Is it maybe something that occurs in higher km engines? Perhaps high temps have affected the metal around the cap and there is not a perfect seal.

Anyway i'm sorry to open up this post again. I read all the previous posts from a while back and i tried everything but nothing was working. I will check and see if the surface around the cap is flat and run a bit of wet and dry over it as suggested by TR300000.

Thanks for everyones time. Cheers, Justin.

Also the rocker covers themselves can be blocked, if your going to take them off, spraying the top of them with some carby cleaner might un-gunk them too, like inside the rocker cover theres a maze of something in there....

Cool, thanks man i will try that too. Now to find some time to pull it apart :)

']Also the rocker covers themselves can be blocked, if your going to take them off, spraying the top of them with some carby cleaner might un-gunk them too, like inside the rocker cover theres a maze of something in there....

I'm not to sure it'd be good idea to get carby cleaner inside your rocker covers. It'd be like putting it straight into your sump wouldn't it?

The only thing I'd want in there is oil and oil alone.

I'm not to sure it'd be good idea to get carby cleaner inside your rocker covers. It'd be like putting it straight into your sump wouldn't it?

The only thing I'd want in there is oil and oil alone.
Degreaser perhaps?
Slyts6 did this once cant remember what he used....

Thanks guys,

I checked everything to do with the PCV system and everything is clear. I think you are right and it may just be a minor flaw with the 12v 6G72. I forgot to mention that the car has done 208,000kms. Is it maybe something that occurs in higher km engines? Perhaps high temps have affected the metal around the cap and there is not a perfect seal.

Anyway i'm sorry to open up this post again. I read all the previous posts from a while back and i tried everything but nothing was working. I will check and see if the surface around the cap is flat and run a bit of wet and dry over it as suggested by TR300000.

Thanks for everyones time. Cheers, Justin.

Stem seals are your problem, if you are in Vic I am more than happy to take care of them for you.

I have always used new genuine seals, remember guys, you PCV valve can be bran new, if the cavume tube into the manifold is blocked, the PCV will do jack all

Well i just had the timing belt done and all the crank seals were replaced where oil was also leaking. So i guess that didn't help with the pressure build up. I'm eliminating places the oil can leak. I can't work out where the oil is going. Not leaking onto the ground. Must be going into the combustion chamber. The only smoke the car blows is at morning start up or sitting idling for a long time.

Indicates its the valve stem seals. Had the exact thing happen with mine where I couldnt work out where the TINY oil leak was coming from and the smoke blowing at start-up and at continual idling. Might indicate yours arent as bad as mine were but they'll probably become so.

After replacement all has been fantastic and not a spot of dropped oil or visible smoke. :)

That would be great Mal but i'm in Sydney. Thanks for the offer though :)

If i was going to clean the front rocker cover i would definetly pull it off then clean it.

I definetly would like to get the valve stem seals done. It's embarrasing when i start the car after it has been sitting for a while. Big cloud of bluish white smoke surrounds the car. I don't want people looking and thinking, what a ****box. Heh heh. Cause it's not.

Comes down to time and money in the end. Need to push for a promotion at work.

Cheers,

Justin.

Make sure you can blow through the breather hoses the rear one on mine had an obstruction in it in the form of gunk which made it blow oil from around the filler cap and the front camshaft seal.
Cleaned this out by poking a wire through it and no more oil leaks.

What I am referring to also is the pipe that goes from the PCV into the inlet manifold,. there is a metal pipe and it gets blocked also with gunk