Thread: Oil consumtion issues

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Have a chevy 327 in a 1968 C-10 pick up truck. Rebuilt the motor about 2 months ago. Should have about 2000 miles or so on it by now. I can detect no oil leaks anywhere. No oil seams to be on the drive way where the truck is parked at. Don,t see any leaks around the vale covers or timing cover. But I keep having to put oil in the motor. It may loose around a qt. or so in about a 100 miles. There seams to be a strange thing happening where the intake lays on the gaskets at the front of the motor. It looks as though oil is leaking though the gaskets on both sides at the front. It apears to be dark and thick, Kind of gummy. I had the thought that the PVC is pulling oil out of the vale cover into the intake. And it is leaking though the gaskets. And that maybe this is where my oil is going. I,m thinking about removeving the pvc. Now on the vale cover that does not have the PVC, There is a air vent. I,m thinking of just having two air vents and no PVC. Or should I close the air vent and only let the motor vent though the PVC? What are some ideas on this issue? Thanks, John.

If that is where it is leaking I think I would pull the intake and reseal it. removing the pvc realy isn't the way to go. I use permtex form-a-gasket for intakes.

for front and rear seals on intake use permatex liberally and use the performance gaskets for the ports....... if you still have oil seapage then you are have some extra pressure in the crank case such as ring leak of valve guides....removing the pcv(pvc is a type of plastic used for making pipes) is really not going to help you and actually could cause other issues.... and plugging one side is definately a bad idea.... you can blow gaskets if you dont allow proper crank case ventallation

You should be able to do a little Sherlock Holmes to figure out what is going on. That much oil is either (1) leaking, (2) being sucked into the ports and being burned or (3) Exxon is stealing oil from you at night.

Leaks are easy to spot at that high of a volume. Pour a quart of oil in one spot every 100 miles and you have a major mess....seems like you have eyeballed the thing....have you crawled underneath an looked up? Do so before you eliminate leaks.

Regarding #2, pull the plugs and look at them. If you are burning a quart per 100 miles, you should see some plug discoloration. One common leak on a small block Chevy occurs when people put RTV on their intake gaskets and the lower side slips down when the manifold is torqued. This leaves an open path from the valley into the intake port or ports. Sucks oil big time.

As for #3, if you see any guys in a tank truck hanging around your neighborhood.......

if you do see oil on your frame or anything, buy an oil dye kit and use a black light to find the leak, makes it a whole lot easier, specially if you have a garage you can fit the car in to block out some of the light.....

if its burning it, you should be able to smell some oil with that high of consumption.... but run a compression check, if you get low numbers then you should run a leakage check on each cylinder with a low number to isolate weater you've got bad rings or not..... once thats eliminated... go ahead and pull the intake manifold..... trying to give this in an order that will keep you from pulling things apart without need