Recently purchased with 190K 4 cyl non v-tech good maintenance. The owner said there was a small oil leak. I know about most of the usual leaks as I have owned civics in the past. This engine has the distributor leak but does not have valve cover leaks.
This leak is unusual as it starts when the engine is cold and developed during warm up. Then after driving about 10 miles it stops.
I have had the car on jack stands cleaned every thing.
It is not the oil filter or sensor. It appears where the oil pan meets the lower timing cover. The first time I looked at it I had the engine idling, and watched it begin to seap. I cleaned everything and felt all the suspect locations and nothing. Then it all of sudden it stopped leaking! I should add that judging from the amount of oil under the car and on the suspension it has been leaking for some time.
I suspect it is coming from one of the seals under the timing cover but as of yet have not removed the cover
For a closer look. I think it is very unusual that it stops which tells me heat is closing a gap some where. This , I believe is not characteristic of cam seals etc. I did seperate the lower timing cover at the base by removing the bolts and expected oil to at least pour out but it did not and did not come out when it was idling. Does anyone know what gasket or seal in that area of the engine would seal after getting hot?
Also, there is no indication of overheating in the past to indicate the head gasket and I don't believe it to be
a "pourous" engine leak. Thanks in advance for any
Input.

 

Two options on something like this:

A) do nothing with the understanding that it's probably not enough oil loss to require more than a qt. between changes and therefore probably isn't doing any harm to the timing belt.

B) do everything, and by that I mean it's nearly time for a timing belt at that mileage which should include all four oil seals. it doesn't really matter which seal is leaking. digging deep enough to find out is half way through a timing belt replacement.

As far as I know, the block porosity issue only applied to coolant leaks. also, the oil that goes through the head gasket is just draining back to the pan (i.e. no pressure ...other than the orifice port between cylinder 2 and 3) so a leak is super unlikely there.