Rep Power: 0

First let me say I understand that these kind of issues are very popular among civic forums and have spent many hours searching said forums for possible solutions. Without really seeing the car in person its very difficult to make any recommendation I would assume. However, here goes:

I have a 1999 Civic EX sedan with 170,000 miles and Manual Trans. Overall it has been very good to me over the years. However, It has developed a large oil leak. I don't get puddles on the ground, but the engine bay is very messy. I have replaced the following:

Oil Pan seal
Vtec Gasket
Distributor Gasket

in efforts to find the leak. I used UV dye and that didn't help much at all. I see oil in a couple of key areas.

(1) underneath the distributor - however is not leaking externally or internally I am guessing the alternator sits right under there and I can see some oil on the housing.

(2) between the engine and firewall - mainly driver side towards the rear of the engine. With limited visibility it kind of seems like there might be something leaking heavily right above the oil filter. ? I don't know what this could be.

Valve cover gasket does not appear to be leaking oil.

Any thoughts? I would like to do the work myself, but having cleaned it numerous times I can't seem to find where the actual oil is coming from.

Help!

 
Rep Power: 518

The oil pressure sending unit is usually right above the oil filter.

 
Rep Power: 0

I have thought that there might indeed be a leak at or near the oil sending unit (or switch). Wouldn't the oil pressure check light come on in the dash if there was a leak of so much oil from there? There has been a couple times when it appears to be very little on the dip stick. It strikes me as weird as there was no drop in pressure with that little oil in the engine..??

 
Rep Power: 518

Technically, it's a switch.



Nope, the pressure activated switch is still doing its job.

Occasionally a leaky switch loses its calibration and causes the light to stay on when it shouldn't, but certainly not always.

A sump doesn't work that way. You don't lose much pressure until the pump has no liquid left to pump.


The dipstick marks represent only a quart between high and low marks. The crankcase holds about 3.5 quarts.

HTH

 
Rep Power: 204

Hence the term 'idiot light'. The engine oil light comes on just before your engine seizes.

 
Rep Power: 0

Could a leaky oil sending switch really leak much oil?

Is a leak at this switch common?

Would there be anything in the same vicinity that would cause this annoying leak?

Thanks to all for the help.

 
Rep Power: 518

Oh yeah, there's full system pressure behind it at all times.
Old age and high mileage, sure.

We try to keep a few on hand at work.
Get under it and start looking. Take a mirror and flashlight with you.