common oil leak sources?

[mossberg]

I'm going through a quart of oil every 1k miles. There was some obvious leaking around and under the distributor, so I replaced the distributor O-ring and distributor shaft seal (there was a little oil in the distributor cap). This made no noticeable difference in the amount of oil I'm losing.

I don't see signs of oil leaking from the valve cover gasket area. When I replaced the spark plugs, there was no oil in there, so it's not the spark plug grommets/seals.

I've looked at the VTEC solenoid (viewed from top and side), but it's not very oily around there, though maybe I need to get under the car to see the backside of the engine to spot a leak from the solenoid?

The funny thing is that I don't get oil spots on the ground under the engine. I would guess that if the rear main seal had a significant leak, I would see obvious oil spot on the ground. So this gives me hope that the leak won't be very expensive to fix (rear main seal will get done if I keep the car long enough to need to replace the clutch disc).

Where I do see oil is on top of the transmission (manual trans) housing. Does that provide a clue as to where the oil could be coming from? My guess is that this oil comes off when the car is moving, resulting in the lack of an obvious oil spot on the ground when parked.

What are the most common oil leak sources on these 6th Gen I4s apart from the dissy, valve cover, and VTEC solenoid?

 

[Enne]

The oil pan gasket is prone to leaking but you'd see spots of oil under the car if that were the case. Did you replace the inner o-ring inside the distributor along with the larger outer one?

 

[mossberg]

What is this part? It sits on top of the transmission housing and looks pretty grimy. Not sure oil is fed through it though (and I haven't noticed any issues with the manual transmission, so I don't think I'm losing transmission fluid).

 

[mossberg]

The oil pan gasket is prone to leaking but you'd see spots of oil under the car if that were the case. Did you replace the inner o-ring inside the distributor along with the larger outer one?

Yeah, I'd think a leak from the oil pan gasket would leave quite the mess on the floor. But next time I'm under the car, I will take a look around the oil pan, just to be sure.

Yes, I replaced the o-ring that sits between the engine and distributor, and the shaft seal inside the distributor (the one that prevents oil from traveling along the dissy shaft and leaking into the distributor cap).

 

[BlkCurrantKord]

What is this part? It sits on top of the transmission housing and looks pretty grimy. Not sure oil is fed through it though (and I haven't noticed any issues with the manual transmission, so I don't think I'm losing transmission fluid).

That is the shift arm cover. There is no gasket there.

 

[Nam1911a1]

I have a slight oil leak somewhere that causes the top of the transmission to be grimy and dirty. I go through about 3/4qt of oil every 1k miles but I accept that because most of it is oil being burned off because I take the engine to 6k a lot.

 

[Eclipse99fwb]

There is a oring there in the picture on the shifter housing but it wouldnt be leaking oil it would be gear oil from the trans. If ur losing a quart every 1k with no obivous leaks its being burnt up from bad piston rings most likely. The rings on the f23 are known to go bad, my car goes thru a quart every 1k from this. Not really worth a tear down just check your oil every week and top off as need be in my opinion.

 

[mossberg]

If ur losing a quart every 1k with no obivous leaks its being burnt up from bad piston rings most likely. The rings on the f23 are known to go bad, my car goes thru a quart every 1k from this.

Do you notice blue smoke or smell burning oil?

Have you done a compression test? Is your gas mileage good?

I don't have the obvious symptoms of lots of oil being burned (blue smoke, oil burning odor, poor gas mileage, poor power). I have to do a compression test at some point.

Not really worth a tear down just check your oil every week and top off as need be in my opinion.

Agreed. If it's the piston rings or rear main seal, I'll just add oil as needed for as long as I keep the car. If it's a gasket I can get to without too much trouble, then I'd rather perform the repair once than have to check and add oil so frequently.

 

[Eclipse99fwb]

Actually no i have zero smoke from the tailpipe but this probably due to such little oil being burnt off. Not sure how many mile you have but its common for high mileage motors to burn some oil and a 1quart every 1k isnt bad at all. If it was a rear main leak you would have oil coming from the flywheel inspection plate. I havent done a compression test due to being lazy lol i work at honda speciality shop so it would be easy for me to do one day. Truth be told f23 motors are very cheap so if my motor ever goes i would just swap it for another so i haven't been concerned with my compression. Now my mpg (not sure what it is) isnt as great as it first seemed 2 years ago but this may be due to my driving habits and denvers city traffic sucks (lots of idling). Also my evap canister has been leaking gas vapor so it is slightly at fault too. I agree with you if you find a gasket leak fix it or it will get worse. If you cant seem to find the leak pick up some oil dye from the autoparts store and add it to your oil. After about 300-500 miles check the motor with a uv light for the dye. If yohr motor is dirty from previous leaks clean it before.

 

[mossberg]

If ur losing a quart every 1k with no obivous leaks its being burnt up from bad piston rings most likely. The rings on the f23 are known to go bad, my car goes thru a quart every 1k from this.

Actually no i have zero smoke from the tailpipe but this probably due to such little oil being burnt off.

I guess I'm confused. If the oil is being burned up due to bad piston rings, wouldn't you get blue smoke from the tailpipe?

Not sure how many mile you have but its common for high mileage motors to burn some oil and a 1quart every 1k isnt bad at all.

Seems from what I'm reading 1qt every 1k miles is pretty bad. Mine has 155k miles, so I don't think I should be burning this much oil (and I think it would be obvious if it was mostly burning - smoke, smell, poor performance), which is why I think it's a leak(s).

If it was a rear main leak you would have oil coming from the flywheel inspection plate.

Didn't realize the 6th gens have an inspection plate. I'll check it out, thanks. But I figure if it was the rear main seal, I'd see the evidence on the floor.

I agree with you if you find a gasket leak fix it or it will get worse. If you cant seem to find the leak pick up some oil dye from the autoparts store and add it to your oil. After about 300-500 miles check the motor with a uv light for the dye. If yohr motor is dirty from previous leaks clean it before.

Yeah, I'll get the dye once I've had a chance to get under the car and take a look at the back of the engine - I suspect (and am hoping) the VTEC solenoid gaskets and/or VTEC oil pressure switch o-ring are leaking.