Guys I just recently bought a 90 Civic LX sedan with that super weak 1.5 in it and knew the engine was smoking and using oil when I bought it. Oil all under the hood on the engine and everything else. Not too bad and prolly a valve cover gasket I'm assuming. Will replace and see. I went to check the air cleaner and noticed oil around the edge of it. Hmmm. I then took the cover off of the top of the throttle body or whatever it is called and noticed oil down in the bottom of that housing that goes on top of the throttle body. I am assuming that the oil is coming from the tube that goes from the valve cover to the hose that goes between the air cleaner and throttle body? Any ideas/suggestions? Thanks guys.

 

thats my guess... and that means alot of blow by at the rings.. you should do a leak down compression to see if your in specs.. you prolly have bad compresson (hopefully in all 4, instead of just 1).

 

A catch-can should help keep the oil from entering the throttle body. You can find them on ebay for practically nothing, or you could make your own if you want.

 

Hmmm. A catch can? Never heard of one of those. How do you make one or search on eBay for it?

 

On the compression test, I did a static and dynamic test and the readings were fairly close across them all. On the static test I got between 122-127 on them all. On the dynamic I got around 70-80 at idle and 110-120 on the quick hit of the throttle. The problem I encountered when I tried to do the quick hit of the throttle was that the idle ran up so I'm not too sure how accurate my readings are. I tried a trick that maybe some of you guys have heard of. I took out all of the spark plugs and poured equal amounts of injector cleaner down each spark plug hole and let it sit for a day. Was supposed to blow it all out before putting the plugs back in and starting it but apparently all of it had seeped past the rings into the oil pan. I started it up and it smoked for a few minutes and then it stopped smoking. SO FAR! The guy that told me about the trick said it is an old secret that supposedly softens up the rings and then when you start it and run it, the rings heat up and reseat themselves. Like I said so far its not smoking anymore. Wonder if this will also stop the oil blow by if that's what is allowing the oil into the hose I mentioned above? Guess we'll see. I'm open to any other suggestions/remedies. Thanks again.

 

yes tricks like that can work.. sometimes just a little oil will do the trick..

but.. your not understnanding what a leak down compression is.

a compression test shows you alittle, but can hide alot of variables.

leak down.. will tell you exactly where its comming from. where you're acutally loosing pressure/suction. the basic concept is to pressureize the combustion chamber. add say 40PSI of pressure in the cyl. and see how much is lost. this requires 2 gauges, incomming pressure, and exit.

no engine will hold 100% pressure, but they're are limitations. ide have to get the book, but its like 2-4% or soemthing.. so thats like 5PSI.. give or take.

but.. the wonderfull thing about leak down.. it tells you where your loosing your pressure. either ring blow by.. very possible, or if you have a bent valve, you'll be able to hear it out of the muffler, or intake manifold. (engine is workign backwards)

hope this helps.

 

Ah ha on the leak down test. I had read about that somewhere. The problem is that I do not have an air compressor nor the guages to do that kind of a test and it would prolly be a small fortune to have a garage do it wouldn't it? Thanks for the great explanation of a leak down test. I just changed the PCV valve and it was plugged closed almost totally. When I pulled the hose off of the top of it, there was gunk and flakey kinda stuff all plugged into the top of it. What would/could be the results of that on the engine performance ya think?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dbailey &raquo;</TD></TR><TR><TD CLASS="quote"> I just changed the PCV valve and it was plugged closed almost totally. When I pulled the hose off of the top of it, there was gunk and flakey kinda stuff all plugged into the top of it. What would/could be the results of that on the engine performance ya think? </TD></TR></TABLE>

the PCV valve is only to recirculate oil/air crap back into the oil supply. if you look to see where the other end of that PCV valve goes to, it goes to a big black box on the back of the block.. evventally back into the oil pan.

PCV. Possitive Crankcase Vetilation.

you still have blow by.. its only allowing the little bit that it has back into the engine.

you still need to do a leak down compression. call local HT heads and see if they can help you. i persoanlly dont' have a set of gauges, but what i do, is take the fitting off the compression tester hose, and push air through that, (regulated a 40psi on a gauge) and listen for leaks.. if its noticeable, you'll hear it.

 

thats a super bling JDM Cusco oil catch can.. not really nessisary, but a must for all the JDM heads.