Excessive crank case pressure?
 

I just fired up my car yesterday and was wondering how you tell if you have too much crank case pressure? It's a 306 that I put about 500 miles on last year in another car and now I have it in my 91 vert with a Vortech. I'm getting a bad oil leak from the front of my oil pan gasket, its a new Canton 7qt pan and a Felpro 1 piece pan gasket. I used the pan on this motor last year and had no problems and now it leaks, it also seems to be leaking from my rear main as well. The rear main has about 500 miles on it and was not removed during the motor swap. I'm wondering if the leaks are a result of excessive pressure in the crank case?

Thanks,
Rich

Make a good hit on the motor and see if your dipstick pops out of the tube. Always found that excessive blow-by will make the dipstick come out.

if you have breathers on your valve covers there shouldn't be excessive air coming out. the dipstick tricks works well to.. pop your oil cap off and see if you have any ruching air.. there shouldn't be any.

How do you know if you need a breather cap? Is a tube going from the oil fill tube back to the TB not good enough?

I never said you needed a breather, if you have aftermarket valve covers alot of guys run cotton breather elements.. there shoudl be no air coming outr of there

So if you DO have a breather cap and there is steam coming out (coolant level is fine and constant, no discoloration, oil color fine and slow burn of 1/2 quart after 3k miles) to the order of lets say what a mug full of boiling water would produce.

When I had a hose from the sealed valve cover tube running down under the car, it looked as if something under the car was burning and there was respectable amounts of light smoke coming out, especially after a good highway run. When I installed a breather, it changed to the gentle steam described above.

Is this normal or excessive? She's got 140K. Time for new rings?

That is a bit excessive.. there shouldn't be steam, or water vapor in there at all, does it turn to a white milky mess as it drips? what does the inside of the valve cover cap look like. the tube should be installed on the intake cause it pulls and burns off the fumes. ( efi car ) carb car, either under the air cleaner or install a breather is best.

I'd be willing to say...from what the underside of the aircleaner used to look like (well oiled) when I used to use that hose as a pcv system...that this steam is ....vaporized oil. I thought that pumping vaporized oil through my intake was not the best policy in general and slapped a breather on there. The breather seems to have a draft side of it cause it has a brown triagular stain on one side of the drum looking breather.

It's gotten worse since I've been running 3k rpms for longer periods of time with my 4.56's.

ytea, that doesn't sound very good, oil won't vaporize. its will burn or solidify. sound to me like its time for a ring job. are you running a EGR valve on your manifold?

The EGR is there but blocked off by the carb spacer. It just could be coolant since the coolant level DOES seem low. Funny thing is that would all make sense but the oil looks perfect. Gold/dark gold and dark brown when I change it. Very oily and not creamy at all.

I also notice the oil pressure drops after an hour of operation and it drops an overall notch. I DO run 3k rpms for extended peroids of time. Hmmmm. Maybe this is that thermal viscosity breakdown they talk about in oil commercials.

What grade oil are you running? That lucas oil additive does wonders.. I run it in my Buick, and the oil pressure registers at 120lbs. baried the gauge. I ran it in my 85 5.0 too and the pressure rocketed up and stayed there.

I ran lucas oil addative once, in my old saab 9000. I said "hmmm, I see this stuff everywhere, lets give it a shot". I was driving around a few hours later when I heard BANG! I looked behind me and saw quite a mess forming trailing me. It was engine oil. Apparently the oil pan bolt had shot out (under pressure?!? ...????) and taken the threads in the pan with it and I was now decorating the road. I cannot imagine why the lucas oil would cause this to happen but I cannot see this being a coincidence.

Actually, isnt oil clinging to parts a bad thing? This is why folks get scrapers and windage trays I believe. Am I right?

I tried synthetic but it goes right past the rings and out the tailpipe cause it's too thin. This is why I run dino juice. If I'm gonna shot oil out my tailpipes, I want it to be $1 a quart oil and not $5 a quart oil

Saab guy, awsome.. I have had many saab, turbo's all of them... I ran that stuff in my saab to with no problem at all... i wouldn't understand how you got enough pressure to blow out a bolt.. that kind of presure you would blow out a gasket, seals, hell the entire motor. That wasn't from the lucas... just a coincidence. I would try it in the 5.0, if it does anything, suit the company for a new motor then.. problem solved.. hehe... yea synthetic on older rings blows out.. I however only ran synthetic.. maybe in your case i would 20W50.. especially if you in the 3k range alot.

My 89 9000 had 210K miles on it and was spotless but the clutch repair would have cost more than the cost of the car, so I let it go.

Would 20w50 synthetic end up being thinner than 10w30 dino? Would I gain hp that way? I know the oil being synthetic in and of itself is worth it for the added protection but would the higher rating end up being detrimental?

20w50 synthetic turns out to be about a 10w40 of regular oil... The synthectic is way better for protection.. I use Royal Purple 20W50 synthectic... Royal purple is the latest oil out there that I seem to have seen a quiter running motor. With 60K now its quiet as can be. The oil is accually purple. looks cools about 5 bucks a bottle... They make a racing application oil for High HP motors which is a little more expensive, A buddy uses it in his LS1 and it looks great with plenty of oil pressure.


My saab turbo 16v had 140K

My 900s 16v had 216K

My 900 8valve had 240K

all with 5spds.. the turbo would give some of these 5.0L's a run for the money.