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Having some problems with oil consumption on a 95 Honda Civic LX. Bought this car from some friends(they buy cars from auctions and fix them up to sell). The car had some front end damage and may have been sitting around for who knows how long. That's the theory anyway. The car seems to be going through oil when it is run at higher rpm's when you get it out on the highway, 60-75 mph. I did notice some hot oil smell when we first had the car, seems to be a bit better now. The friend put some kind of oil additive in the engine with the first new oil and ran it for a week or so and then changed it and put some Valvoline High Mileage 10 w 30 and some Lucas oil additive. The car runs great but the oil consumption is more than it should be. We took a 100 mile trip last night and it used a quart. The car doesn't smoke or drip. The engine has 156,000 on it. There seems to be some improvement, the first week we had it it went through a quart(5 w 30)with about a 50 mile trip. Might be better now because of the thicker oil. We used the car around town and the oil level stays pretty good(might be going down a little). Any ideas on what to try or look for??

My concern is it is my daughters car and she want's to take it to college after break. The college is 2 hours away and mostly highway driving.

Thanks for any input!  

check that the crank case breather hose from the valve cover..  make sure it is not blocked...

check the pcv hose from the valve cover to the intake manifold.. that it is not clogged.. and that the pcv is not totally blocked..

also... check for leaking oil pressure switches on the back of the motor near the oil filter..

make sure that who ever did the last oil change did remove the oil filter gasket/seal....   sometimes they stick.. usually not on the later models..  but when they get stacked double.. they blow out... letting all the pressurized oil out... usually at high rpm...

you might also examine the bottom of the car for a leaking rear main seal...    there might not be much oil coming out but it does happen...    the crank and cam oil seals also get bad..   sometimes the distributer housing Oring leaks...  the last spot is the valve cover gasket...  they get overtighened and smash the seals above the spark plug tubes..

so take a look... see if there is any external oil leaks...  

Thanks for the information waynep712. I will start checking those areas later today.
I hope I can find where the leak is coming from. I truly appreciate the information.
Thanks again!!    

Checked the crank case breather hose from the valve cover. It was OK, not blocked.
Didn't see a pcv valve or hose from the valve cover to the intake manifold? Did a visual of the upper part of the engine, no leaks noted. Didn't look under the car at the oil pressure switches or check the rear main. It was cold and I got lazy and didn't feel like getting the ramps down from the attic. Will take a look at a later date. I decided I would let the car warm up and rev it up in the garage to see if I could notice anything. No visible leaks when I revved it up but I did notice some blue smoke coming from the exhaust at higher rpm's. So I'm assuming now that it is burning some oil at the higher rpm level which would explain the oil consumption. My hope is that it will improve over time but not sure if that's a possibility or not. I will post back with any new information. Any input about where to go from here will be greatly appreciated. I will give my daughter a oil checking lesson before she leaves. She said she wants to learn how to do stuff like that anyway. Thanks! Happy New Year Everyone!!  

Heard from my daughter after she got to school. She checked the oil and said it was down roughly 3/4 of a quart. The trip was a 2 hour 100 mile trip. About 60 mi. on divided highway(70 mph speed limit)and 40 on a two lane road(55 mph speed limit). Slight improvement but could be due to slower driving speed. We will see what happens on her next trip home. This might be a good time to buy some oil stock, HA HA!!  

Well my daughter came home for the weekend and I checked the oil after the 100 mile trip. It went through only 1/2 a quart which was encouraging that there was some improvement. I changed the PCV valve and also the hose from the intake to the PCV because it was collapsed right before the intake. I also took a look underneath and didn't see any major leaks, just a few minor spots around the oil pan. Didn't see an oil pressure switch near the oil filter??? Still getting the black sooty crap coming out of the exhaust. My daughter headed back up to school and she called me after she got there and said the oil was just a little above the second mark on the dipstick so it used just under a quart again. It was really cold(below 0)when she came home so I'm assuming that was the reason for less oil use. So I guess I can rule out the PCV valve as a contributor to the issue. Thanks!!    

copy and paste this link for a diagram of the oil system

http://econtent.autozone.com:24991/znetrgs/repair_guide_content/en_us/images//0900c152/80/06/17/c0//large/0900c152800617c0.gif

there is an oil breather chamber there also... that you might want to check.. but i think it is wedged in deep under the intake manifold...  those have been know to leak oil also... they are designed to catch the oil splash out of the crank case.. to prevent it from being burned when the pcv pulls the vapor out of the crank case...


the hose problem may have added to the problem...

it is possible that the piston rings are baked to the pistons from a prior overheat before you bought it...

there had to be a reason that it was at the auction...    going going going gone..  out of somebodys hair..

the nicest thing about those... is ... the motors are not that hard to replace... a day or two...   and if you ever plan on doing a clutch.. be sure to replace the flywheel also.. they are not a lot of money... and the few remaining parts stores that grind them... sometimes do not restore the proper step height... causing all kinds of clutch problems...  just been there and done that too often...  see i get to fix them after several other shops have been in there.  

Thanks Wayne, nice oil system diagram. That explains why I didn't see the oil pressure switch, it is hidden above the oil filter. I could kind of see the oil breather chamber when I was working on the PCV Valve.

Are you saying that if the oil breather chamber is bad that the engine could burn oil??
Or do you mean that it would just leak and drip oil??

I'm assuming that if the piston rings are baked to the pistons that it would be very expensive to fix that and that is why you mention replacing the motor.

It's sad because the car runs and drives so nice.

Thanks again!!  

there are several things that we might have talked about  before..

perhaps you can pull the breather vent hose... where ever it is.. with the engine idling.. place a finger or thumb over it.. see if when you pull your finger off in 5 to 10 seconds if there is suction in there..  if so .. that would indicate the pcv is working..

if you get pressure out .. the rings are done.. or the pcv is still not working...


compression tests ...  easy to ***  please don't pour oil in the cylinders... like somebody else did. one small squirt is enough only in any cylinders that are found to be low will seal the piston rings for this test..  too much like the other guy.. and you are causing a false reading. and breaking parts..

.  if you find any cylinders low... ( i will have to look up the specs ) then go on to the cylinder leak down test

the cylinder leak down test...  this takes not only the tester.. but an air compressor that puts out 90 psi or so... and is far enough away to not make too much noise when doing the test..

the pistons being tested have to be at top dead center or  the crank  will turn over when the air is applied..  #1&4 can be tested with the crank shaft timing mark at 0.. you will have to figure a way to get the crank half a turn exactly and not have anything in the way...

if you find cylinders that leak down...   listen to the oil filler cap opening.. see if there is any air coming out...  that might indicate that the rings are stuck.. or the pistons scuffed..

air out the exhaust would indicate bad exhaust valve., intake .. bad intake valve..

many mechanics have the skills to pop the head off.. pull the pan.. take out the pistons and rods.. clean and replace the piston rings.. put some new rod bearings in it .. put it back together with a new head gasket..  perhaps having the head surfaced also..  sometimes it is just little more to get an imported used motor installed..  

Thanks for the reply Wayne. I appreciate the information. Will try the breather vent hose test the next time she is home. As far as compression and cylinder leak tests I will probably find out where to get that done. Not sure if it would be worth putting the money into motor repair or replacement. This summer she will be using the car mainly in town and then oil consumption isn't as bad then.

Thank you!!!    

Well as a last ditch effort I tried a Piston/Cylinder soak with Marvel Mystery Oil.
Here are the details of what I did.

http://www.marvelmysteryoil.com/index.php/forums/viewthread/178/

Here is where I got the idea.

http://www.saturnfans.com/forums/showthread.php?t=23676

Thanks for any feedback!!