Leaky oil pan gasket update.... oppinions please! (LONG)

[Guest bastaad525]

Will this car never cease to drive me crazy?

 

I got around to replacing the oil pan gasket on Friday. I ended up following the Fel Pro tech/customer service rep's suggestions for how to install it. He said for their pan gaskets, you either want to install it completely dry, or use some Permatex High Tack on one side only, to hold it in place during installation. Knowing how hard it would be to install dry w/o the gasket moving all over the place, I opted to use the High Tack.

 

Well the job went off pretty smoothly, though it took a bit longer than I thought it would. Upon removal, it was obvious where the leak was coming from (well... MOST of it), there was some damage to the gasket at the rear. Otherwise, everything cleaned up nicely, getting the 'old' gasket off was a snap. The pan wasn't warped, but some of the bolt holes were dimpled in... fixed that with a hammer and anvil. Otherwise the pan checked out straight using a level.

 

So I finished the install and drove home. Parked and reached under the engine to feel around... what's this??? Fresh hot oil on the bottom of the trans bell housing!! WTF???

 

Well it wasn't until tonite that I was able to get under the car again to see what was going on. And I'm completely baffled by what I found...

 

The gasket/pan looked completely dry all around(score one for me!). The oil appears to be coming from between the block and the plate that covers the front of the bellhousing. It was pooled up at the very corner of the block, right in front of the clutch slave cylinder and under the starter. It's kind of hard to describe... but it definately was NOT coming from the oil pan. The wet oil was at the very corner of the block... about two or three inches away from the corner of the oil pan, and there was no trail/trace of wet oil from the pan over to the corner of the block, this seems to be coming down from INSIDE, thru the tiny hairline gap where the block butts up against the front cover plate of the bellhousing, then it dribbles down the front plate/cover (only at the side though, not all over it like it was before replacing the pan gasket) and ends up at the bottom of the bellhousing. I wish I'd had my camera at the time... hopefully I'm describing it well enough.

 

So what do you guys think, rear main seal? I just had that replaced (again), when I had the tranny pulled (to replace every seal and gasket on that as well). I trust the shop that did the work, these guys are great, and have done A+ work every time I've taken one of my cars to them. They are a Z specialist place, as well, and know their stuff. As it turns out, the seal that was in there was fine, according to them, but I figured, since they had the trans out, might as well replace that again as well.

 

But anyways, even if it is the rear main, I thought that would leak down INSIDE the bellhousing, behind the flywheel, and come out thru the little hole at the very bottom/front of the bell housing (as I've had a leaky rear main before, and the oil was very obviously coming out here). But I can't think of any place else oil could could leak from to come out where it is. I checked above that area to see if maybe it was leaking from between the head and block or anything like that and there was nothing. I'm gonna check the hard lines that supply the turbo with oil right now... maybe a small leak there somewhere? I'm assuming there's no other seals/plugs on the back of the block, inside where bellhousing covers?

 

If I can't find anything I'll take it back to the shop and see what they think.. if it's the rear main they gave me a 6 month warranty... though I have a feeling getting them to fix it as such is gonna be a pain in the ***. As good of work as they do, I've NEVER dealt with a shop that would re-do work again for free without making a fuss about it. We shall see....

[510six]

There are 2 little square plugs that fit into the rear main cap and if not install right or they have been damaged they will leak.I always coat the plugs lightly with black silicone.As far as the pan issue is concerned I ONLY use a NISMO comp gasket for the pan.It is a soild paper type gasket , use High Tack on the bottom and nothing on the top and it saves some major headaches.

[zbloke]

There are 2 little square plugs that fit into the rear main cap and if not install right or they have been damaged they will leak

 

Too right, I thought I had a leaking rear main oil seal but on closer inspection it turned out to be the rear main bearing cap side seals, replaced them and no leak

 

Tim

[Cody 82 ZXT]

Too right' date=' I thought I had a leaking rear main oil seal but on closer inspection it turned out to be the rear main bearing cap side seals, replaced them and no leak

 

Tim[/quote']

 

Same here. I thought it was the rear main seal but. after replacing it I have since found out it is the little plug things.

[technicalninja]

When I install a rear main cap I lightly coat a section of the sides and out to the seal bore with Pookie (Aviation form a gasket non-drying-Permetex) to help this spot seal properly. The factory S.M. covers this as well. You have to keep it away from the bearing and install the side seals properly. Many aftermarket gasket kits have piss-poor side seals which are hard to install properly (they don't go all the way down because they are to thick). I try to use the factory ones if I can.

 

Another place that can leak is the rear main galley plug which is beside the starter about 5" up the block. These only leak if they have been taken out and replaced with a pipe plug (done during a engine rebuild to allow access to galley). I have never seen a leak from a factory plug but a leaking one of these pipe plugs cost me a rear main seal job followed by 2 oil pan/rear main cap jobs followed by ripping tranny out one more time to fix leaking plug. All done in the chassis. Really makes you look "good" to your customers. By the last tranny removal I was beating book time by 70%. Practice makes perfect! Anger gives you energy!

 

Bet your becoming pretty quick with the oilpan job on the Z. (Sorry- couldn't help myself)

 

Your leak could be either as they both come out the same spot. If you are still running the original plug I would focus on the rear main cap first.

 

Hey-you can install that last main-bearing pair (if you kept them) while your doing this.

 

Sent you a P.M. Did you get it?

Rick

[Guest bastaad525]

...........

 

Well... that sucks.

 

Okay so then where I described the leak is coming from makes sense for it being one of these two things? Was I correct about when the rear main seal itself leaks, it comes out from inside the bell housing? Or could it still possibly be the rear main seal as well?

 

So there ARE other things that can be leaking back there... I guess good and bad news... good news if it means these guys DID do a proper job on the rear seal install (and if the pan gasket isn't leaking)... bad news if there was something else back there they could have fixed like that galley plug (which I highly doubt, given how thorough these guys have always been with both of my cars, also because as far as I know the block has never been at a machine shop and I know I didn't remove it when I did my in-car rebuild), and even worse news if it is indeed coming from the rear main cap (which is something I possibly could have fixed myself when I had the pan off). They would have seen if that galley plug was leaking when they had the trans and flywheel off yes?

 

Honestly, right about now I'm inclined to just leave it be and let it leak. It's a really small leak anyways, much less than before I replaced the gasket, and is probably exacerbated by the fact that I'm running 10w-30 synthetic (why is there no 10-40 mobil 1???). I'll just keep an eye on it... if it starts getting worse I guess I'll have to deal with fixing it at some point.

 

I really don't feel like doing the pan gasket AGAIN any time soon... seriously being on my 6th one, and that I finally got it NOT leaking, I'm reluctant to trade one leak for another one Not to mention the fact that I'm still pretty sore from doing it And anyways, I thought the rear main cap was very difficult or impossible to remove with the engine and trans attached to each other? Because of that, when I replaced the main bearings, the rear one was the only one I skipped.

 

I'll call that shop tommorow and ask how much they would charge to pull the pan and replace the main cap seals... I hope it won't be TOO much more than just doing the pan gasket... though somehow I doubt it...

 

and no, unfortunately, I didn't keep the last pair of bearing caps I ended up using one of the halves to replace one that got damaged when i was having trouble installing the front most bearings and cap.

[zbloke]

The way I diagnosed the leak was from the side seals and not the rear main was to remove the starter motor and chack for radial oil stains on the engine side of the flywheel, indicating oil was leaking past the rear main seal and being thrown around, no radial oil stains..............so side seals it was and the way you describe the oil pooling under the starter motor, well I'm sure thats where mine collected too, they are easy to change just pull the old ones out with a pair of pointed nose pliers a smear of sealer on the new ones and tap them in...............just a pain in the butt dropping the oil pan to access them.

 

Tim

[Guest bastaad525]

zbloke - thanks for the addt'l info. Yeah the more you guys say the more it sounds like this is NOT the rear main. That's a good idea about pulling the starter, finally something quick and easy even if it's only to check. It also sounds even more like if it WHERE the rear main it'd be leaking down INSIDE, between the block and the flywheel, and would be dribbling down and coming out from the drain hole in the bell housing, which it's definately not.

 

GRRRRR it just pisses me off to know this is something I probably could have fixed while I already had the pan off!!!!

 

Let it leak for a while... I'm tired of fussing with it. I dont' drive it that much anyways.

 

Can someone clarify about applying silicone/sealer to the side seals? I dont' understand where you guys are applying this. The seals fit tightly into the sides of the main cap right? wouldn't the silicone just get rubbed off as you inserted the seals into the cap?

 

If I can do it w/o removing the rear main cap, I suppose I COULD make it a point to get around to doing this sometime relatively soon... after I've 'recovered' a bit. Technicalninja hit the nail on the head when he said I AM getting pretty good at R and R'ing the pan, and now that I found a method for installing the gasket that works.

[zbloke]

Can someone clarify about applying silicone/sealer to the side seals? I dont' understand where you guys are applying this. The seals fit tightly into the sides of the main cap right? wouldn't the silicone just get rubbed off as you inserted the seals into the cap?

 

I checked some side seals tonight and they have a small grove along with a couple of very small ribs on the 2 wide sides of the seals, the sealer would be held in the grove/ribs some would be rubbed off as you tap them in but not all

 

Tim

[technicalninja]

I would not slide a pair of seals in without removing the rear main cap.

Most of the sealant would get wiped off, the area that is most important would get the least amount of sealant, and it is not possible to clean the old sealer out of the area without removing the rear main cap. I would give it a 50% chance of sealing your leak if you just slid another set of seals in. Also this way does not allow you to apply sealer between the cap and block which I believe is more important than the rubber seals themselves.

After the pan is removed it is not all that difficult to remove the rear main cap but it will take a special tool. A small slide hammer with an adaptor to 8x1.25 mm thread. My slide hammer is adapted to a pair of Vise Grips which I lock on a bolt that I have threaded into the rear main cap. Works great!.

After removing the main bolts on rear cap a few STRAIGHT wacks on the slide hammer will remove cap. Some people have probably removed this cap by using prybars but I don't recomend it.

Carefully tapping the cap back into the block can be done with a small hammer and it helps to have a couple of long threaded studs to screw into the bolt holes. These studs help giude the cap back into position. The job can be done without them but they make it easier (especially up side down in the car).

 

Now, If this was my car I would remove engine, mount on stand, and fix it properly for one more time ONLY. If my memory serves me right you had a less-than-steller mechanic do your last rear main seal and the oil leak is a problem that has re-occured more than once.

I would re-seal rear main cap, replace rear main seal, inspect seal register (surface) on the crank and polish or "Micro-Sleeve" it, and reseal the pan without the oily mess. I would also seal the front of the tranny while I was at it. I understand your living arrangements limit you to what you can do to your car. I feel your pain.

Always remember- oil is cheap!, As long as it is not leaking onto something than could be damaged by it it will do no harm and protects against rust!

My dumpster-on-wheels 95 Grand Voyager has leaked badly since I bought it 4 years ago. It's bad enough now that I will not park in friend's driveways and I will be fixing it sooner rather than later but I have driven it 50K plus miles like this. As long as its not getting on the clutch and its' not sliming the bottom of the car badly I might not fix it.

How often do you have to add oil? Does tha car leave a puddle every time you park it?

You can also look up into the PP area through the clutch fork hole in the tranny. Just peel the rubber boot out of the way.

[Guest bastaad525]

"As long as it is not leaking onto something than could be damaged by it it will do no harm and protects against rust!"

 

That fact has not been lost on me!! I made a crack like that to my friend when we were under there doing the pan gasket... there is soooooooo much oil all over the underside of the car from other leaks past, floor pans and such are all pretty thoroughly coated... and I said to him "hey at least I dont have to worry about my floor pans rusting out!!". I only wish it had spread a bit more to my frame rails

 

You know... of all the cars I've owned, I think that just about every single one of them has had an oil leak of some sort (including my current daily driver Sentra SE-R!). I never cared... just topped it off when needed.

 

This is the first car I've cared enough about it to do something. And do some more, and some more... AGGGGGGGGGGGHHHH!

 

Well there is the one thing about the leak that DOES worry me. The oil is getting blown back, along the bottom of the tranny, and IS getting onto stuff that could possibly be damaged. For instance, the trans mount was TOAST, the rubber was cracked completely thru, and could be seperated. I just replaced the mount when it was at the shop with the transmission out getting it completely resealed (now THAT was leaving puddles everywhere I parked). It might have just been old... I have no idea what condition it was in when it went in with the turbo motor swap, but it was also SOAKED in oil, so I am pretty sure that contributed to it.

 

Question - since I run pure synthetic Mobil 1... that isn't at ALL petroleum based right? I don't even know if the petroleum is the factor... what I"m getting at is, about that transmission mount. Is it possible that since I'm running synthetic it would be less harmful or not harmful at all to rubber stuff like that mount? That thought just occured to me, thought I'd ask...

 

The oil seems to be getting on other stuff too... like onto the drive shaft getting flung around. The WORST is when it gets onto the exhaust while driving OH MY GOD... free high *wooooooooo head spinning*. That was a REALLY bad problem when that one mechanic you're thinking of that I don't go to anymore, replaced the pan gasket for me and installed the new one RIPPED. Me and Tim240z removed that one later and you could tell he knew it was ripped, due to the EXTREME abundance of silicone he had put in that very area apparently to patch it up. Dumbass. It was leaking so badly I was putting a quart a week.

 

I dunno I guess the trans mount is the thing I worry most about if only because I just bought that new one (a real Nissan one too!) and is probably the only thing at risk of being damaged/affected by the oil. It's not really sliming everything that badly any more, mostly gets on the tranny, pools along the bottom front of the bellhousing and a light coat along the bottom ridge of the trans, and that's about it. It's a minor leak, and rarely even leaves any oil on the ground after being parked and if it does it's a couple drops. Seems to me the oil doesn't want to drip but rather just sticks to the bottom of the trans Anyways, I've driven a couple hundred miles already since doing the pan gasket and oil change and the oil level hasn't seemed to have gone down at all, so it's a slow leak. And I"m not worried about it getting on the clutch as this is definately an external leak, like I said there's no sign of oil coming from the inside, from that little drain hold at the bottom from of the bellhousing. I'll probably do as Zbloke suggested real soon and pull the starter to check the engine-side of the flywheel just to be sure.

 

Otherwise I'll just keep an eye on it... if I get any puddles or have to start topping it off a lot then I'll fix it or get it fixed. REALLY not looking forward to doing that rear main cap though... another problem is what do I do about the bearings??? You can only buy them in sets, and as I said earlier I don't have any left over a set is pretty pricey though for just replacing one. And no, pulling the engine to do it 'right' is definately NOT an option for me, it'll have to be from under the car.

 

 

 

Z-bloke - thanks for the clarification on the side seals, that gave me a good picture in my head

 

Oh and Technical Ninja thanks for that little bit of moral support these leaks have been bothering me so badly... but you and a couple other guys have really made this point of saying... you know... it's not that bad... really it's nothing to stress over, just go back to enjoying the car. I appreciate that.