Hey guys. I am dealing with a oil problem. I have a 69 Mustang Mach I with a 351 windsor engine. The engine have just less than 10000 miles on it. Few miles after I finish the restauration of the car, maybe 3000 miles I put sinthetic oil in it and I notice after a few rides that the main seal start to leak and the valve cover with the oil fill cap start to leak oil too (I don't see any oil vapors, just pure oil). I never could find the problem. I put a bigger piece of sheet metal under the valve cover to see if that could help to keep the oil inside, but din't it work. Somebody told me to try with a new PCV valve and I did it few days ago but the problem is still there. I am a little lost with this. I´m a mechanic, I did the whole restauration on the car, even the engine. Any ideas? Maybe a broken ring? The car run perfectly strong . I run a compression test and everything seems to be fine. Is really a pain in the ass to clean the engine everytime after a ride. I'll appreciate any help. I must say that I am from Argentina so is not so easy to get parts for this car in case that I need it, that's why I can take everything appart to find the problem. I have to get a clue before. Thak you a lot!
have you posted before this.. i seem to recall a similar issue a few years back...i have found a few tidbits of info over the years since...with the engine idling.. warmed up... not on fast idle... pull the pcv from the valve cover ... with a tachometer hooked up to monitor the RPMs. if you block the END of the pcv .. the engine RPMs should drop between 50 and 70 RPMs if the PCV is the proper flow rating for the motor. if it drops more than 70.. the PCV flow rating might be TOO MUCH...if it drops less than 50 rpm.. the PCV flow rating might be too small.. do you have a vacuum gauge ? there are fuel pump testing gauges that read from 15 pounds of pressure to 30 inches of vacuum. you might want to pull the engine oil dip stick.. adapt the vacuum gauge hose to the top of the dip stick tube.. with that hooked up.. you can now monitor the Crankcase vacuum or pressure with the system assembled.. have the vacuum hose long enough to lay the gauge on the windshield.. take it for a drive to verify you are NOT building pressure OR Vacuum in the crankcase...
Oh man, I can't believe you remind me, *** yes, I'm the same guy with the same freaking problem. I'm here again because I could finally get a new PCV expecting to resolve the problem but... So, I'm back in the game. What you say I think can help me very much to see what is going on, I gonna try it soonest I can. Thank you very much for your help. I'll be in touch and share the results.
Thank you man for your information. I have those Ford Racing aluminun valve covers with one of those filler cap with little holes all around on the bottom. I don't think that the solution is to connect a hose to the filler cap, in that way you just solve the cleaning problem but you don't solve the real problem, I mean, why I got all that oil coming out from the valve cover filler cap. For some reason the oil needs to find a way out of the engine and the only reason that come to my mind is crankcase pressure so... why there is such pressure? Well, that's my question.Anyway, thank you again for your time. We keep in touch.
Thank you again for your information. I wasn't able to do anything yet but i gonna try it soonest I can. I can't post a picture of the engine from my computer so maybe I have to post some pictures in the site you say to go from there so yo can see them. About the blowing, I have to say that what is coming out of the breather is not oil vapors is just oil spit all around, most go to the valve cover because the speed of the car. Thtat is what I can completely understand, I mean, when you have an engine that's allready worn out you can expect vapors blow and some leaks too but with my engine I don't feel that's the problem, I think it must be something else, something that I'm missing. Well, we'll see. Thank you, man. Be good.
Yes, is a push in type breather like the one on the top of the picture. It have little holes all around the bottom out from where supposte to breath-
Oh boy I have seen and heard this many times before. Unless you built the engine to run on Synthetic Oil I would never use it in an older engine. Even if it is a fresh build. Synthetic oil is too slippery for our older cars.I wouldn't even fool around and waste the time. Do as Wayne recommends and see what you get for vacuum or pressure readings. If none of the above give you the answer your looking for I would either pull the engine or if you can pull the engine apart and hone the cylinder walls for the correct finish for the correct type piston ring your using. Check the valve seals and maybe replace them. I would go back to using regular 10/30 oil. I use 15/40 diesel oil in my 1986 Monte Carlo SS. It still has the Zinc that the older cars require. I know I'll get a lot of boos but it works for me and the other guys can use Joe Gibbs $8 a quart. I'll use my $1.95 a quart.Thats what I would do pull the engine out and go through it again. You could have a broken second ring or a stuck oil ring,or 2 rings lined up with the parting lines over each other. It doesn't take much for an engine to consume oil. I had a company car. 1977 Ford Torino with the 400 modified engine. That engine use a quart of oil every 500 miles. The Ford dealer told me it was normal. I drove that car for 80,000 miles and it consumed a quart of oil every 350 miles when I got my next car. I had only GM cars after that and never had a GM engine ever consume any oil between oil changes.
Thanks, man. But, my car doesn't consume the oil just spit it out trought the breather. I have heard before what you say about synthetic oil and old cars but I allways try to get the most information that I can before take any new step with any modification to the car, so most people that work with engines say thtat the best oil is the best for the engine, and I believe that so. Anyway, here I am, with what seems to be something more that a PCV problem. I could't do anywork on the car yet so I have no result to share with you whatsoever. The soonest I have somethig I'll posted. Thank you again.
change the BREATHER to ONE with a HOSE outlet... run the hose to the carb side of the air cleaner so the low pressure will allow the vapors to be consumed by the engine...
I understand what you say but if you do it you gonna have oil in the air cleaner instead of vapors because that's what coming out from the breather. You can run a hose to whatever you like but that ain't gonna solve the problem, I mean, the oil gonna keep coming out. I thought that maybe I can run a hose to something like a reservoir, you know, something that capture the oil connected somehow to the oil pan and relief the pressure, I think I see something like that in this magazine sometime. I don't know if I am being clear.
but the versions with the tube out the side are usually filled with steel wool also.. as an oil particle trap...if you mount the breather fitting close to the carb inside the housing.. when you are heavy into the throttle.. when the bypass flow is HIGH.. all the vapors will be pulled right into the carb to be burned ... gm and other brands used breather filters... with a plastic fiber pad.. kinda like fiberglass insulation.. this caught the oil vapors and filtered the air that usually goes the into the breather as the PCV pulls air in through the breather most of the time... other than during heavy throttle activity.. plastic fiber pad.. think something like a machine floor polishing pad... a giant fiber tortilla about an inch thick to clean the surface.. this type of stuff can be the oil vapor trap if you want to create something.. or use chore boys.. which are a course machined steel wool for dish washing..