What are all the possible locations for an oil leak???

[tmorgan4]

I've about had it with trying to track down this damn oil leak. It's a BAD leak. If I park the car for more than a minute in the same spot I've got a large PUDDLE under the car. The entire steering, front differential, oil pan, bottom of the transmission, and other parts are COVERED.

My first guess was a warped oil pan since I welded it (didn't clamp it down, MIGed it) and I figured it was warped. I bought UV leak kit and added the dye to the engine oil. Now under a black light I can see oil EVERYWHERE. Sure enough, I got the oil pan off and the flange was warped. I got it straightened, and a Nissan tech told me not to use the red Nissan sealant (I guess it's known for leaking?) and to use Permatex Ultra Gray. Got the engine oil pan installed today. It's still leaking, and not from where the oil pan meets the engine.

I'm trying to think of all the possible locations that could do this. It only leaks while/after being driven. If I leave it overnight, there's about the same puddle as if I leave it for 5 minutes. It seems to stop either when the engine is shut off or the oil cools down.

Parts as high as the engine mount coming off my subframe are covered in glowing oil. It also smokes after driving it since oil is finding it's way onto the exhaust. The wrapped section of the manifold is clean but I have oil dripping down the bottom of the cat.....

I checked my valve covers and those don't seem to be leaking. Most of the oil is underneath the engine, and no traces of leaking down the side or back. The bottom of the oil pan and steering are absolutely COVERED.

What other parts do I need to look at? I'm about to take it to a shop!

[Chrispy300]

How about around the oil filter?

[T45]

It's possible that it's coming from your oil filter housing as it bolts onto the block, and also the oil pressure sending unit port. Both are on that side of the engine.

[SuperHatch]

Valve CoversFront Main SealRear Main SealOil PanOil Pressure SenderOil FilterOil Filter HousingVTC SolenoidsTiming Chain Upper/Lower CoversHead Gaskets

Can't really think of anyhting else off the top of my head.

[npez]

my vote if I had to guess without looking at it is front main seal leak. I had the same exact problem albeit with a different car with the same symptoms (oil all over the bottom of the engine, cats, upwards towards the heads, etc.). The oil you're seeing up higher is most likely blow-by (mine was all the way up to the cylinder heads) from the air underneath the car. I cannot envision the pressure sensor leaking that much oil and most of the other stuff would be pretty visible. The oil pan shouldn't be leaking at the flange at least as you stated that whether you drive it or turn it off the puddle is about the same. As the oil doesn't reach the flange with the engine off I wouldn't think it would be from there.

Also if you look at the lubrication diagram for the VH you'll notice the main gallery feeds oil in a Y pattern the two top tips of the Y going towards the heads and the bottom going to the crank. Now when you turn your car off you have no oil pressure. So if that oil (from the Y) gravitates downwards and your front main is leaking, I could envision that oil ending up on your driveway.

Just a thought - I'm not in the "business" but that was an experience from my past.

Thanks,Nick.

[tmorgan4]

Appreciate the feedback. I know this isn't a problem that can usually be diagnosed over the internet, but it does help having someone else give their input on what it could possibly be.

The front main seal does sound like a VERY good possibility since the engine is covered along the bottom all the way from the front to the back. I'm nearly positive it's not the head gaskets, valve covers, timing covers, or anything else "high up". I can't trace anything down the side of the block, so it must certainly be something lower. I need to take a look at the front main!

Thanks everyone. I will try and get some pictures later. It is a MESS. I can't even park it in front of my parent's house.

[qsiguy]

My advice is get a good steam clean or a case of brake cleaner and go to town. Clean that thing up so you can start with a clean slate, so to speak.

It's a long shot but I had an oil change done once and the old oil filter gasket/o-ring stuck to the motor so when the new filter was installed there was two o-rings. Leaked like crazy...

Good luck.

[T45]

Like ^ said, a cleaning is definately in order. Pick a day, spray the oil down with the purple degreaser and wash it off. Then after it dries use a coule cans of brake cleaner to get the remaining resudue off. Then start is up in the best possible light conditions to see the dye (night with blacklight?) and then get under it and wait until you can see a leak. Turn engine off and investigate further. Maybe this will help.

[tmorgan4]

That definitely seems like the best approach. I'm frustrated as hell that an oil leak has me stumped!

I'm sure it's NOT the front main seal after looking at it. The balancer and surround area are clean. I think it's actually coming from somewhere on the driver's side of the engine. One of my power steering hoses is soaked all the way up by the oil filter housing, but I can't find any oil coming out of the housing.

It also LOOKS like it's leaking from the flange again, but I think it's just an illusion since the little gap between the pan and engine are filled with glowing dye. I think it leaks down and finds it's way into the crack, but it's not actually coming from there. I hope it's not the damn oil pan AGAIN.

[tmorgan4]

I'm getting more and more discouraged by this project every day. I went out to move it to the shop today and it won't start. Turns over all day long, building fuel pressure...what the hell? It ran fine last night when I shut it off. This used to start EVERY time within half a second of turning the key...even when I had huge vacuum leaks and other problems. Now it's leaving me stranded, AND it leaks oil.

[tmorgan4]

This engine really seems to have a mind of it's own.....

After being pissed off that it wouldn't start, I went at it again and tried starting it with the MAF unplugged. After a good 15 seconds of cranking, it comes to life. I tried plugging in the MAF but it just died instantly. I ended up unplugging it again and driving across town in limp mode. That was fun with a 2000rpm redline. When I got to the shop it was idling perfectly without the MAF. I plugged it in again and it runs perfectly, all the way to redline.

[Mettler]

Call a priest tbh...

[T45]

Well there's your problem...

[tmorgan4]

Creepy.

[T45]

Ah, I forgot that movie was made before you were born. You should have seen the sequel though right?

[tmorgan4]

It doesn't look familiar.