i just found this website and plan to stick around. To give you some background on my mazda. It's a 1989 B2200 5-speed with 174,000 miles my grandparents gave the truck to me about 6 years ago they said theengine was rebuilt at some point. I have been driving it sparringly for about the last 2 years. Over that time the truck has accumulated some problems. As of recently I have fixed most of them but theres been one problem that has been eluding me. My problem is that the engine pushes oil out the hose that goes in the top of the valve cover to the air cleaner housing. At first it was doing this rarely and when it happened it would be blowing blue smoke like CRAZY!!! As of recently the truck has been doing it more and more. To alleviate the burning oil I took the hose and routed it into the windshield washer fluid resevoir. This has let me know when the problem occurs. I've noticed that when I drive at 65mph + I can feel the truck fighting the back pressure in the crankcase. It feels like it oscilates a little. this even happens at any speed if you keep the trottle input consistant. Just a side note the truck idle has been inconsistant and it ranges from barely running to a pretty high idle.

I have done a lot more than what I have listed but this post it long enough already... Whew

Thank you for any input

 

Welcome jiggityjoe87!!
1. Have you checked or replaced the PCV valve?
2. Could the oil returns in the cylinder head (by the push rods) be clogging w/gunk?
3. Have you checked, replaced or cleaned the EGR valve?

 

1. I have replaced the pcv valve and its is functioning just fine
2. I still need to check that out
3. I have not been able to check out the egr valve but I found one at the junkyard and will install it when I get home.

Would the egr valve cause excessive crankcase pressure if it wasn't functioning properly. And could I just disconnect it without any check engine light or problems

 

I'm not completely sure myself, but I know a faulty EGR can cause all sorts of problems, especially idling problems such as the ones you describe.

 

well I replaced the egr with a unit from the junkyard. That evened out the idling issue but when I was driving home from college. The oil coming out of the valve cover is still happening. Enough so that I have routed the hose into the windshield washer resevoir. and it filled it up 3 times full of oil. I had to stop periodically to dump it back into the engine.

 

obviously there is a plug somewhere. I have both the PVC removed as wellthe nipple in the middle of the valve cover. that is they are not hooked up to anything and anything can get in or out. I have no oil shooting out of mine. well actually I did when It was at an angle when I was backed up a hill unloading my dirtbike. But you shouldnt have that problem on level ground. somewhere something has to be plugged. get yourself a manual for the truck, it has a diagram of the venting of the engine. i'll go take a look next time im on the ****ter but thats my best guess.

 

take the oil cap off and see how much blow by you have. if its a lot then do a compression test and see what that looks like.

 

Most likely you're rings are shot, like said do both a dry and wet compression and leak down check. If you remove the oil cap while the engine is running and there is a plusating noise comming out of it that sort of sounds like a tail pipe you can be almost certain of it. This truck does not have push rods and the oil return passages are big enough to put you're thumb in, if you have one of those plugged you better be tearing the engine apart, hahaha.

 

Very good suggestions, Kyrasis6!!
Obviously, you are more familiar w/these engines than most of us.
I like your avatar too.

 

I checked under the valve cover and the only passages for the oil to return to the oil pan are on the passenger side and there are two possible passage ways one goes all the way down and another just ends into a chunk of metal so it really doesn't seem like it would drain much but it has too or else it would be full of oil and thats not the case.

And also what do you mean by a "wet" compression test I only know that I need to remove all the spark plugs and take the air cleaner off and then floor the gas pedal to make sure I get as much air in the cylinder as possible.