My 93 fd is leaking oil near my top left spark plug, i think I know where it's coming from but I don't know for sure what its called or does. Can someone help me out.















It's at the bottom left of the first couple pics. Can it possibly make all the bottom of my engine bay wet with oil as well?

 

the thing at the bottom left with the wire coming out of it is the knock sensor.
It cant leak oil, its just in a threaded hole. It is filled with a weird goo like substance which could make it look like its leaking oil..

 

the oil filler neck is the highest thing right there that could leak oil. It might just be the seal.

There is also a banjo bolt on the top front of the engine close to there that could be leaking oil as it is the supply to the twins.

 

You sure that little piece doesn't leak oil? When I changed the plugs I followed the oil up the side of the engine and it was right underneath that weird knock sensor.

 

its not oil like mentioned before but more of an insulation. It is very common for this "insulation" to liquify and drip onto the spark plugs in a goo form. I think I ended up re-insulating mine with just some silicone and have been fine since.

 

Is it best if I just replace that little piece? The car is 21 years old lol
I keep getting oil underneath the subframe of the engine so I thought maybe it was coming from the little piece and spreading underneath there with the air flow.

 

Yep very sure, the knock sensor is just in a threaded hole that goes no where.
It does not screw into an oil gallery or anything.

The knock sensor itself is filled with some weird grease/silicone like substance, which can seep after some time.
It cant "leak" any "real" oil though, so your leak is elsewhere if you actually have a leak

 

Crap -_-

When I installed my midpipe I wiped a bunch of oil off the bottom of the sub frame where the engine is at then going underneath there like a week later oil was there once again.
How notorious is it for the oil pan to leak?? Maybe that's it?

 

I have read that almost all FD have a leaky oil pan.

That's only what I have read though, because personally mine has never leaked.

 

Knock sensor melts and makes residue like that. Remove it, clean it, and epoxy or jb weld the end. The oil pans always leak unless they are properly sealed and have a brace installed.

 

Keep in mind that oil leaks often look like they are coming from the pan.

Last winter I fixed 4 oil leaks that all looked like they were from the pan.

None of them were.

The oil all runs down the engine, on to the subframe, drips on the ground and gets blown in to the cover under the transmission.

Recently I forgot to drain the catch can, which then started to blow oil out the vent.
Guess what?
If you are under the car it looks like the pan is leaking.

 

Where are the most likely places for oil leaks (other than the pan)? My engine compartment is nicely rust-proofed with oil

 

yea i would like to know the other places too....

 

Oil pan
Turbo oil feeds and drains
OMP where it attaches to the block
Oil fill neck (lines that go to PCV can also look pretty nasty)
Oil filter pedestal
Oil level sensor (I guess this could count as the pan too)
And rarely the lines that go to the oil cooler (copper crush washers deal to the block)

 

Oh. And all of those can look like an oil pan leak when they drip down to the pan

 

Great info!

 

Add to that:
oil injection pump, lines and gaskets
oil injector connections. Those can leak down to the exhaust manifold and create a bit of smoke.
Any oil lines to/from the turbo(s)

Basically, any two parts that are connected where oil can pass through.

The key is to find the highest point on the engine where you can find oil.

Doing so may require some dis-assembly