Ok...86 Cougar 5.0. Was hearing some kind of air leak coming from the passenger side of engine (back towards firewall) near or below valve covers. This weekend I changed my upper intake gasket and valve cover gaskets to see if it helped, but it didn't. I can hear the air escaping from somewhere but can't find it. Then I noticed yesterday that if I take my oil filler cap off while car is running, there is white smoke or steam coming out of it (like a locomotive steam engine). Steam is coming out at a pretty good rate, but car doesn't seem to be performing that badly. Also, when I took my upper intake manifold off to replace gasket, oil was up in it where it probably shouldn't be. Any ideas?
Sounds like blow-by.
Do it look like a choo choo? Take your hand and cover the oil fill and see if there is any presure behind it. More presure the worse it is.
Yes, it looks like a choo choo. :) What is a blow-by? What needs to be replaced to fix it? Really expensive?
Check to make sure your pcv valve is good, and properly installed. Non-functioning pcv can promote blowby with excessive crankcase pressure. Might be what that "hissing" sound is you hear. :grinno:
blow by is when the piston rings don't seal like htey should, so when the air/fuel is compressed as the piston goes up, some of the air/fuel goes past the rings into the crankcase. from there it goes wherever oil goes, i.e. the valve covers.
do a compression check, there's likely at least one cylinder that's lower than the others. after checking compression on a cylinder, put a few drops of oil in through the spark plug hole and check again. if the compression goes up, the rings are goin bad.
you have to take the engine out in order to change the rings, obviously. so isn't something that can be done in an evening.
Blow-by is when oil sneaks over to the other side of your piston rings into the combustion chamber. Usually requres that you replace the piston rings, which means tearing apart your engine. How many miles are on it?
You beat me to it by a few seconds!
I know that, I was just giving another suggestion. He says he has air escaping from the back of the motor, if you don't vent the crankcase, the pressure is gonna go somewhere...lol :grinno:
I took off the oil cap and put my hand over the opening and the pressure buildup is not bad. I can barely feel it on my hand when I take it off the spout. Car has 106k miles. Everything else is in really good shape. Very little rust, great interior, mechanically sound (except for the obvious problem). I hate to just let it go, but if it's not something I can do myself, I don't know if I want to spend $1000+ to have it fixed. Any suggestions or ideas on how much this will run me?
Cougarman:
It doesn't have a PCV valve. It has a hose going from the oil fill spout to the upper intake manifold, and that is all cleaned out and clear.
The pcv valve is behind the upper intake back by the firewall. :ies:
Here is where the pcv hooks on to the upper intake. The second pic is the hole in the lower intake where it goes. :grinno:
Yup start at the PCV and see if there is any build up in there and hose as well.
Do this motor lose oil over time?
One other possibility: A blown head gasket can allow small amounts of coolant into the combustion chamber. If it is just a small amount, it would still run OK. Remove the radiator cap and start the engine. If you see bubbles, you could have a blown head gasket. Also, is your oil milky? do you get a lot of condensation out of the tailpipe? All of these are blown head gasket symptoms. One other thing, if you do have blowby from poor ring sealing, have someone drive the car and you follow in a chase car. Call em on the cell and have them hit the throttle hard for a few seconds and then let off. if you see a puff of smoke out the exhaust when they let off (white or grey) you probably need rings. This is all assuming you don't have a compression tester. If you do, you should see no more than 10 percent variation between each cylinder. If you do get a low reading, put a teaspoon of motor oil in the sparkplug hole of the low cylinder. If the compression remains unchanged, it is usually a valve that is not closing. If the compression goes up with the oil, you need rings. Disclaimer: If I have gotten any of this wrong, someone please correct me. Just relaying personal experience.
yes it does have a pvc,, just not where you expect to find it :)
This one? That's the PCV system fresh air line. It gets air from after the air filter, but before the manifold (just before the throttle plate is a handy place) and feeds it into the fill tube, through the crankcase, and out the back center where the PCV valve lives. You can't see the valve unless you crawl onto your engine, but you can feel it if you break your elbow so it bends the other way.