Ok here is the situation. I have a 96 civic EX original engine with 200K well maintained miles. I have done all regular maintenance on it and am about to do the timing belt, all other belts, tune up and so on. It has a new clutch and tranny shifts beautifully. It has a rough idle(at times), but I am hoping it goes away with the timing belt change and tune up. The real problem is it consumes some oil. I find I have to add about 1-2 quarts for every oil change(3500 miles). It started off slow of course and now I have to keep checking the oil all the time. I don’t see any puddles on the ground and no real signs of oil leaks on the engine so I assume it is being consumed through the combustion chamber. My question is how can I find out what is worn. I did a compression check on all 4 cyls and they are all within specs. They are suppose to be between 135 and 185. Mine ranged from 177-181. I assume since the compression appears good the valves are ok. Could it just be valve stem guides (seats)? Could it be the piston rings? What is a good way to tell without taking my engine completely apart?

I have heard of valve jobs causing even more oil consumption on such high mileage engines due to the tighter upper end and causing the piston rings to fail. I would hate to do something to fix this problem and just end up making it worst. Any help would be greatly appreciated.

edit: I am trying to asses if this engine can handle the addition of a turbo or SC.

 

I just got done dealing with the same problem. You are doing all the right things. compression sounds good! how did your plugs look when you took them out to do a comp test? any oil on them? Let me tell you what i did. I started out by letting the car sit over night. In the morning i had my wife watch the exhaust when i started it up. If it is bad valve guides it should give a puff of smoke right away. If not, they are probably not to blame. The other thing is, next time you are driving, get on it and watch rear view mirror for smoke behind you...May not be much but if there is, even knowing that you have good compression, it doesn't mean your oil rings aren't bad. They can go and you still will have good compression. I just got finished rebuilding my type r (b18c5) motor. Rings, pistons, pins, bearings, seals, valve guides, valve job, etc. No more smoke! It was alot of work and took alot of time, but for a $5k motor, it was worth it. The only other suggestion is to take your valve cover off and adjust your valves to specs. Mine were off by 4 thousands and it made the car idle rough and alot of other wierd stuff including burning oil. I'm not a super tech but i know this from having the same problem (started burning a little and before I knew it, about 1qt every 300 miles. My oil rings had collapsed.) Hope this was a help!

 

I forgot to mention the plugs looked fine. No excess carbon deposits, no signs of oil (or black tar like stuff), nothing like that. They looked as good as any other plug with about 30-40K on them. I will be chaning them as well after the next tank of gas is gone(FI cleaner).

However, thanks for the response. I have heard of the those test, but I never tried them. I guess it is time to get some assistance on start up and maybe I'll let someone else drive my car and step on it while I follow on another vehicle. That did help and what I am trying to avoid is the rebuild. I have put synthetic most of the life of the engine and maintained it pretty well so I suspect it should be good for another 100K miles. I don't know about the turbo or S/C though. I doubt the internals can handle the added compression for long.

 

i had that problem, but i never got it fixed because i wanted to get a swap, but it could be so many things, you should just take the motor apart.

 

I've been an auto mech. for 25+ yrs -all cars --last week a dizzy broad had her car towed in ---ran it out of oil [ for the 2nd time ] couldnt get it started this time --97 dx -d16 engine--bought it for $300 hah ha ha dropped motor out --ripped it apart -gotta do some more checkin -let u know if i find anything -gonna toss used engine in & RIDE [just gotta keep eye on oil]