Thread: Need help in finding an oil leak!

Trying to figure out an oil leak on my Montana. It has a swapped 2006 3800 series 3, with a top swap from a 1998 series 2. When I put the motor in, I tore it down to a short block and replaced all the gaskets. Well it turns out I have an oil leak on the passenger side down low from the looks of it. It would only happen under boost. Had it on a lift running and never saw a leak. Even put dye in it and I could still never find the leak. I have replaced the front crank seal, oil pressure sending unit, oil filter housing gasket and just recently the oil pan gasket(I actually had the gasket in there and later found out it is only suppose to have rvt) But recently it got way worse and left me stranded on the side of the road twice. It just shot oil all over the belts causing them to come off. That is when I decided to do the oil pan gasket. But now I have a huge puddle of Mobil 1 ep all over my drive way and it still shots oil everywhere. And I still have no clue to where it is coming from. Is there any other spots that would leak oil like that in that area? I need to get this fixed asap! It is my only care that has a/c and that I can get in easily. Since I am now driving around going to job interviews. Any help would be great! Thanks.

I typed that on my phone. So please excuse any grammar and spelling and so forth.

Nope not Power steering fluid. I don't think it would be the valve covers, since I don't see anything up top. I did put a new timing cover gasket in when I first put the motor together 9 months ago. Spent damn near $300 on a full gasket set. But I haven't done it since. And the PCV valve I am not positive. Where is it at? And how the hell whould it cause this much oil to leak? it has been leaking since I put it together 9 months ago. But just recently has it saif FU and leak like a sib.

my car was puking oil like that, turned out to be the front main seal. feel in behind your harmonic balancer, is it wet with oil? that is likely your cause, or could be a busted oil pressure switch on your oil filter housing

Originally Posted by matt5112

Honestly sounds rather impossible. Did you have some push the gas while the thing was in the air?

When idling oil pressure is half that of when on the gas. Itll also be the same when the oil is cold.

Pcv can create a buildup of crank pressure causing something to fail in a way that is typically not possible.

When it was a small leak only under boost I had it on the lift holding it at 3000rpm's and still nothing. Haven't tried it since it became the Exxon Valdez.

Originally Posted by TEK310

my car was puking oil like that, turned out to be the front main seal. feel in behind your harmonic balancer, is it wet with oil? that is likely your cause, or could be a busted oil pressure switch on your oil filter housing

Replaced that sensor, front seal twice and the filter housing gasket twice. and it is hard to pinpoint now since it squirts onto the belts and goes EVERYWHERE.

What is the difference between a 98 and a 06 timing cover gasket set? Apparently they are different. I used the one for a 98 but the short block is a 06. I thought series 2 and 3 were pretty much the same.

If the difference is just one being paper and one being metal, it should still work I would think. The whole short block is a 06 if I remember it right. So yes the front cover is off of the 06. I just used the heads, intake, blower and accessories off of the 98. But here is the thing. When I look up parts for the 2 different years I get 2 different parts. The first one is an 06 and the second one is a 98.

Fel-Pro TCS46077 - Timing Cover Gasket Set | O'Reilly Auto Parts

Fel-Pro TCS45971 - Timing Cover Gasket Set | O'Reilly Auto Parts

And on the 06 I have no clue what that black gasket goes to. It doesn't have it on the 98 set. I am also thinking I need to do the rear set also. Since they are also different. I did notice before I did the oil pan that there was a small leak on the rear. But we just chalked it up to the wrong oil pan gasket and never gave anything else a look since they were all new. I had all the parts as an 05 and they list the gaskets as the same as a 98. They car was marked as an 05 in the junkyard. But now that I think about it, it could of been an early 06 built in 05.

If oil is squirting, then you have pressure. The only places you have pressure i that area are in the oil pump itself and the oil filter adapter area.

It's possible to have a filter gasket stick and then the next filter doesn't seal properly and can shoot all over. Since you are coating the belts..that's what I'm thinking. Very little else will reach the belts.

The way you can fix this, get this puppy on jack stands in the front and pull the tire off the passenger side. Pull the splash shield. Clean the hell out of it. Then have someone fire it up while you have your nose in the wheel well with a light and safety goggles. Just in case she squirts in your eyeball. Then you will know where and how to fix it.

Will Bill, it's not squirting per say. It is just leaking a crap load of oil somewhere and getting all over the belt and pulleys, and then it flings it everywhere else.

I don't think it's going to be the filter since it has had about 4 different oil filters on and has always been leaking. And I always check the oil filter to make sure the o-ring is on it so I don't double gasket it.

And well I already started to tear it down. Already took all the accessories off and looking around the timing cover gasket. Still don't see anything. The one thing I am noticing is there is a crap load of oil behind the crankshaft dampener. But I replaced it when I did the engine, then had someone else do it also when we thought that is where it is coming from. I am just finding it hard to believe that 2 people installed it wrong.

Just a thought but maybe the gaskets and seals are not your problem. Check the mating surfaces for cracks or defects. I have seen where a seal has been removed and its bore has been gouged by the tool used to remove the seal. Look over the timing cover carefully and make sure you have no cracks and if any bolts pass through, use thread sealant on them.

Another thought is the dampener snout. Did you test fit the crank seal on the dampener? Is the dampener snout free of wear marks?

Best of luck.

Well I think I fixed it. I had it torn down looking at the front cover, seeing if I can find anything that looked like it was leaking. Saw the cam position sensor covered in oil and a oil stain that looked like it was running down from it. So I replaced the o-ring and added a little rtv to be safe. Put it all back together and started it up. Ran it for about 2 minutes while revving it up and sticking my head in under the finder to watch from time to time. And as soon as I shut if off when it was getting warm due to lo coolant. I poked my head under the fender and noticed a puddle of oil on the motor mount and frame! It pissed me off and I took the belts and balancer off real quick. Was looking at the timing cover and noticed something was missing. The front crank seal! Looked down at the balancer and it was attached to that! I was like . I guess it was loose inside the cover. But it got me thinking. Why was it still leaking after 2 different seals were installed. The first one was a Felpro seal the came in the set. Then this one that was a Timken seal. So I said screw it and went to the dealer and bought a factory Acdelco seal. And that seems to have fixing the problem. I revved the piss out of it and have saw no oil leaks. I have drove it about 100 since and have noticed no oil leaks. But I have yet to boost the hell out of it. I accidentally got some 87 octane gas in it. And it if even thinks about going into boost it knocks. So I am driving it carefully till that is out of it's system. But I think that has fixed it. But my question is why the other brands of front crank seals were not working/lasting? Just does not make sense to me.

Wanted to give a quick up date. After 3,000 miles or so. Not a drip of oil has been seen. Oil is at the proper level and have not had to add any since then. I have boosted the crap out of it and even took it on a 900 mile round trip in 13 hours. And it is still good. I think I might just stick to Acdelco gaskets from now on.

Sent from my DROID RAZR using Tapatalk 2