oil pan leak

[citiboy]

It's included on the doc folder. Anyway, here it is 414618.

 

[4speedfunk]

You might want to check your PCV system. I cannot speak for the LS or 5-cyl. motors but, traditional high-revving small blocks are famous for this problem. The problem becomes more pronounced when compression ratios rise above 11:1 and a tell tale sign is that the oil dipstick mysteriously climbs out of the tube about 3 or 4 inches any time you rev over 5,000 rpm. If you notice the dipstick repeatedly climbing out of the tube...you got pressure inside the crankcase. Newer motors have a rather tight-fitting dipstick compared to 60s & 70s motors, so I'm not sure this would be noticed. The cure on old-school motors is to install multiple vents on the valve covers, or an evac system on the headers to remove the pressure build-up. Obviously, modern emission laws don't allow this but the principle cause is the same...too much pressure inside the motor.

The PCV's job is to remove pressure from the crankcase, and if all is well...there should never be any pressure build-up inside the motor. Valve covers and oil pans are directly sealed to the crankcase and they are, in theory..."non-pressurized" as long as the PCV is functioning. But if a PCV gets clogged (or removed)...a motor will leak like a sieve! Not only will it leak oil externally...it can also leak internally, pushing oil past the rings and valve seals, resulting in increased blow-by. This is common on high-mileage motors...sludge and goo gets built up and restricts the path that pressure would normal be vented from. The pressure has nowhere to go and seeks different paths...dipstick tube, seals, gaskets, rings, etc. Front & rear crank seals are usually the first to go...long before a pan or valve cover gasket starts to leak.

I have no idea how to troubleshoot a modern PCV system. I say "system" because it is no doubt more than just a check valve at the base of the carb...and its probably computer controlled. Might be worth checking if you have an exceptionally leaky motor.

 

[Cyouincourt007]

Any update?

 

[High Five H2]

I haven't looked at it in a while, and I haven't gone on any long drives so it hasn't been leaking. I wanted to change the front main seal myself but it requires 4 different specialty tools. I put UV dye in it a few weeks ago, and I finally got under it the other day with a UV light and there is glowing oil on the rearmost 3 oil ban bolts on the driver's side, so there's definitely a slow leak there. I'm mostly concerned with the fast intermittent leaks that happen when I go on long drives that I think are from the front mail seal. There's a bit of oil underneath the pulley, but not enough for me to think there's a leak. But, I also cleaned off the engine really well and I didn't go on any long drives.

I don't think it's the PCV thing, the symptoms don't really match, but I'm going to check that out anyways.

I have a bit of free time right now because I'm in between jobs. I start my new job in a week. I was helping my dad with a rear main seal leak in his camaro, and when that was done I was going to really look into it. I really wanted to finish his camaro and I got down to taking the transmission out, but he's being really slow and he isn't getting a tranny jack so I can't really work on it until we put it back together. It's seriously like 2 hours worth of work before I can put it all back together myself but my dad is being lazy or something.

I think I'm going to put more UV dye in it tomorrow and then go on a long drive and see if that's where it's leaking from. I'll try and take pictures and see what you guys think.

 

[Mr_Rich]

You might want to check your PCV system. I cannot speak for the LS or 5-cyl. motors but, traditional high-revving small blocks are famous for this problem. The problem becomes more pronounced when compression ratios rise above 11:1 and a tell tale sign is that the oil dipstick mysteriously climbs out of the tube about 3 or 4 inches any time you rev over 5,000 rpm. If you notice the dipstick repeatedly climbing out of the tube...you got pressure inside the crankcase. Newer motors have a rather tight-fitting dipstick compared to 60s & 70s motors, so I'm not sure this would be noticed. The cure on old-school motors is to install multiple vents on the valve covers, or an evac system on the headers to remove the pressure build-up. Obviously, modern emission laws don't allow this but the principle cause is the same...too much pressure inside the motor.

The PCV's job is to remove pressure from the crankcase, and if all is well...there should never be any pressure build-up inside the motor. Valve covers and oil pans are directly sealed to the crankcase and they are, in theory..."non-pressurized" as long as the PCV is functioning. But if a PCV gets clogged (or removed)...a motor will leak like a sieve! Not only will it leak oil externally...it can also leak internally, pushing oil past the rings and valve seals, resulting in increased blow-by. This is common on high-mileage motors...sludge and goo gets built up and restricts the path that pressure would normal be vented from. The pressure has nowhere to go and seeks different paths...dipstick tube, seals, gaskets, rings, etc. Front & rear crank seals are usually the first to go...long before a pan or valve cover gasket starts to leak.

I have no idea how to troubleshoot a modern PCV system. I say "system" because it is no doubt more than just a check valve at the base of the carb...and its probably computer controlled. Might be worth checking if you have an exceptionally leaky motor.

FYI: LS1's were notorious for sucking up oil in the PCV system. A lot of the F-Body guys adapted some kind of catch can; otherwise all the oil that was sucked up puddled in the bottom of the manifold. I had the same problem in my Firebird's LS1 until I swapped out the LS1 for an LS6 which had a redesigned PCV system. The LS6 had a baffle arrangement in the valley cover under the intake manifold and I think this defeated the previous problem.

 

[High Five H2]

5 months later update: I'm pretty sure it is the oil pan. the 2 rear bolts, the really long ones, were loose. I went in a torqued all the oil pan bolts to the correct specification. The 2 in the rear were loose, in fact there were stripped. I started tightening up the one on the right, and it never did get tight, until it just randomly snapped off. So, that's pretty cool, I guess. I turned the left one a few turns and it felt stripped too so I just left it alone. I supposed I'll have to go in and either rethread the holes or drill them out and add those coil thread things.

Oh yeah, I cleaned off the engine really well and then coated it in talcum powder. The only fresh oil after a few days was around the oil pan gasket. So it's probably that.