So I have a 2002 Honda Accord 5 spd manual, 4 banger. I've recently noticed I am losing about a quart of oil between changes (3000 Mi). Funny thing is there is no oil on the garage floor where I always park the car, and there is no sign of oil leakage on top or on the bottom of the engine. Is that symptomatic of a rear main oil seal leak or am I maybe burning up some oil. The car has about 120,000 miles on it. I would be very grateful for any advice.

 

Lack of any evidence of a leak says that it's either burning or getting into your coolant. You'll want to rule out what you can...

Rear main leak will drip down the end of the block, unseen inside the bellhousing of the transmission. Kinda between the flywheel & the block. It would become visible by leaking out through a small hole at the very bottom of the bellhousing. If you're losing that much oil, there's no way for that much to accumulate in there without dripping out. Maybe it only drips out while driving?

Open the radiator cap (when the engine's cool). Look for any ugly brown sludge crap. That would be oil mixed into the antifreeze. It's possible for that to be in the radiator & not in the overflow bottle.

The other place would be burning in the engine. You kinda get that by eliminating other possibilities. The oil has to go somewhere, it can't just dissappear.

 

Thanks very much for the info. I'm going to get the car up on blocks, go under again and find where that oil is going. I'll let you know what I find out...it'll probably be a week before I get a chance to look at it again. I think I'll do a compression test too.
I noticed a fellow from a couple of years back on this site was complaining of a similar problem. It looks like this could be a weak point of Hondas. What with all the problems that Toyota is experiencing, you wonder if these Japanese cars are as tight as they are held out to be. I have babied that car for as long as I've owned it.

 

Well ya have to consider that up until 98 Hondas had different cylinder walls and cylinder ring hardness. [I've no doubt Mr Honda rolled over in his grave when they made that change !! ]
Now we have a "composite" cylinder sleeve, [2 mpg more for CAFE ratings].
Also the lighter weight oil, [again a couple more MPG] also can evaporate when hot and get sucked up thru the PCV system.
1 qt every 3k miles is not beyond the normal.

 

Well thanks for that Hondadude. Your words are comforting. What caught my attention though was that this loss of oil seems to be something new. I checked the coolant and that is a as clear as tap water so I don't think the oil is getting into the water jacket. I think I'll still get under the car and look harder for signs of leakage and do a compression test. If nothing shows up I'll just keep a closer eye on the dipstick......which I never used to have to do.
If you don't mind, could you tell me what the compression should be?

That's very interesting about the cylinder walls and rings being made out of new softer material. I guess my dream of getting 200,000 miles out of this thing without having to do major work may have been a pipe dream.
I really do appreciate the great feedback from this forum.

 

Well I've looked all under the engine and absolutely no sign of oil leaks, so I did a compression test. Looking at the engine from left to right the readings were 195 Lbs, 195 LBs, 200 Lbs, and oh oh ......175Lbs. I've always read that if there is a difference between any one cylinder of more than 10 Lbs then you've got a problem.
So can I assume the oil loss is from that 4th cylinder?
Is a ring job the next step?

 

Just for yuks, the cylinders are numbered from #1 at the pulley end to #4 at the flywheel/trans end. So your low compression is cylinder #1.

How did you do the compression test?
Engine warmed up.
Disable fuel supply.
Remove all 4 spark plugs.
Crank the starter with the throttle wide-open.
Continue cranking until the gauge quits climbing.

Can your low #1 be blamed on throttle position being uneven between the cylinders? Or maybe the battery was winding down so the cranking RPM was different?

Then do a "wet" compression test - repeat the compression test after putting a spoonful of engine-oil into the cylinder. If that brings the compression up, it would point to rings. If that doesn't make any difference, look at valves.

 

Well I guess they never should have let me loose with tools. I didn't warm the engine, didn't disable fuel supply, and didn't open the throttle to full. I'll try again next weekend I guess.
I've seen some threads that say oil loss in an otherwise healthy honda can come from a plugged PCV valve. Is that a possible culprit?

 

Doing a compression check like you did isn't bad, really. It's just a little less reliable so it's good to do it again just to be sure.

Yes a plugged PCV system can cause oil leakage - by increasing pressure inside the crankcase. PCV valve is pressed into a rubber grommet in the valve cover - it looks like a plastic elbow connector for a rubber hose. Remove it & shake it. There's a spring & plunger inside, you should hear/feel it rattling as you shake the valve. If it sounds all muffled like it's full of sludgy oil, get a new valve. They don't cost too much.

There's another breather hose from the valve cover over to the rubber air intake duct. Make sure that's not plugged with crud. Also make sure the hose from the PCV valve to the intake manifold isn't plugged.

 

You say that a plugged PCV system can cause oil leakage. I'm assuming then that that leakage would be visible. Because my problem is that there is no visible oil leakage anywhere on the motor or manual transmission case.
Thanks very much for the information on the compression test. I'll get onto that and re-do it. I guess to stop the fuel from flowing, I would remove a fuse for the fuel pump?