I had a bad engine oil leak from everywhere in my 92f150 4.9L I6. The engine was tight for 9 1/2 years then she suddenly started leaking June 2001-122,000 miles and continued to leak until Sept. 2002-134,000miles. A shop replaced the oilpan,valvecover, and maybe the lifters sidecover GASKETS.In less than 3 months/3000miles leaks have developed, and I returned to the shop for advice on my problem. They checked their work and found all bolts, except two, at the right torque.
Then they said I had alot of "blowby"coming out the rockerarm cover. When the truck is started smoke comes out of the PCV valve and the breather port holes on top of the cover(with both items temporarily removed).I am told that this means my rings are worn or I have some other problem that might cause a compression leak from the combustion chamber into the crankcase.

What is wrong with my engine? Did the pistons cook themselves and my block? What viscosity engine oil should i try? I like My truck, and my driveway, I want to stop the leaks!Can it be done or do I need a Re-build job?

 

Blow-by is when the compression from your pistons gets into the bottom part of your engine and comes out the pvc valve and oil fill cap. Check compression on your pistons and you may find only one piston bad. In other words the compression stroke of your piston blows-by the rings and piston in the cylinder. As for the oil leak the only time I have seen an engine start leaking all over was after someone overheated the engine in a really bad way.


DM89909

71 Ford 4X4 Crew Cab
92 Ford 4X4 Super Cab
93 Ford Standard Cab

 

These guys claim that the extra pressure in the crankcase is going to cause these leaks.I thought the gasket job they did would be good for at least one year.
My engine has been running very warm, but I have never overheated it, and I drive sensibly. If I cut back on the engine temp I wonder if that would stabilize my gasket seals.

 

There is a very good possibility that the shop use "CHEAP" Gaskets. If your PCV system is working correctly, then any "BLOW-BY" up to a certain point will be handled by the PCV system. If the PCV system is clogged and or the BLOW-BY is more than the PCV system can handle then you'll build up some pressure in the crankcase but I wouldn't think enough to cause a gasket to blow out.

For a gasket to leak you need a couple of things. loose bolts (which they allegedly checked and found ok), dryed out gasket material, deteriorated gaskets, OR POOR PREPARATION. Sounds to me like they just tightened everything down and soaked ya for the $$$.

Couple of things YOU can DO!

1.) Replace the Valve Cover and side cover gaskets with QUALITY GASKETS. Victor or FEL-PRO are good. CLEAN ALL SURFACES FREE OF ANY CRUD, OLD GASKET MATERIAL, Goop, oil, etc. Spray all surfaces with BRAKE CLEANER and wipe down with a CLEAN CLOTH/PAPER TOWEL. Use a light film of RTV GASKET (Silicone) on side where the mating surface is NOT MACHINED! MAKE SURE THE COVER SURFACES ARE ABSOLUTELY FLAT!!!!!

2.) Get a compression tester (screw in type) and follow instructions with it. Write down results.

3.) Replace the PCV Valve and make sure the hose to the intake is wide open. Run a coat hanger through the hose to make sure.


Most engines with miles on them will puff or stream smoke out of the PCV valve and breather holes when the PCV system is disconnected. This is what the system is designed to remove and send to the intake for re-cycling as part of the intake charge.

If your compression readings are all within 10%(highest and lowest #'s) of each other then keep on keepin on and re-check at 6 month intervals. Change your oil and put in a 10W30 and a MOTORCRAFT FILTER!
Keep an eye on the gaskets, and enjoy.