my car is an 89 Irocz with the 350 TPI. i have a oil leak..seems to be coming from the back of the motor somewhere, more so towards the drivers side.. thought it might be a valve cover gasket problem, and then a manifold problem..

so i did some searching on this site and came up with oil pressure sending unit. i hear its located either above the oil filter or behind the distributor somewhere. do these things go bad and leak? it only leaks while the car is running and will drip a few drops after its all shut off. i dont think my leak could be cuz of a intake manifold gasket/sealing and i can see its not quite a valve cover as it has oil alot farther back behind the motor.

 

It also could be a rear main seal

 

no its not that as when i rebuilt my trans the leak wasnt comin from the rear main

 

its either your oil pressure switch or sending unit. Replace both at the same time, or you'll hate that you didn't. I repalced the switch, 3 days later my sending unit went too. Replace both!

On an 89 they are both on the back of the intake. If you look behind your distibutor there will be a large round thing with a single wire connecting to it, and a smaller thing with two thick guage wires(orange) xnnecting to it. The two wire is the switch and the singe is the sending unit. to replace both all you should need is a 3/4" wrench, 11/16" wrench, 5/8" wrench, and about 2 hours for the first time. Its really pretty easily. I could prolly do it again in about 15-20 minutes now.

 

Try replacing the oil pressure sending unit first. Driver's side near the dizzy, it's a small metal can with a single wire connecting to it.

Or, it may be that the intake manifold silicon bead seal on the china wall has started to leak. That's a hard one to see...

 

this is what i was thinking but i didnt think it would leak like it does if it was intake problem.

i wanna find out soon so if it is a manifold problem, i can get new gaskets and stuff and maybe a AFPR while i'm at it and put it all on.

 

Instead of the shotgun "maybe it's this, maybe it's that" approach, take it to the quarter car wash; pick up a couple of cans of Gunk Engine Bright, or the store brand of the same thing (diesel fuel in a spray can) along the way; soak the whole motor with the degreaser for a while in the car wash bay; and sterilize the motor by blasting all the schmutz off of it, with extreme prejudice. Just don't blast the distributor. Then drive it back home, and look it over carefully, and see where the oil is actually coming from, and repair it.

Just blindly changing parts and messing with different stuff and depending on luck to accidentally hit the right thing, is kinda dumb. That's even dumber than something I'd do.

And, it's a whole lot less of a drag to work on a clean motor, than one that's an inch deep in who knows how long of leaked-out oil funk.

 

well for one thing my motor is clean.. the back of the motor near the dizzy is the part thats leaking, and i'm not wanting to spray that area too much.. so just by thinkin of whats back there, its either the manifold not sealin or the oil pressure sendin unit. the manifold i dont think is capable of leakin as bad as it is, so i believe its the oil pressure sending unit.. and i'm just wonderin if they ever end up leaking when they go bad? but i still have good oil pressure.

 

autozone sells a UV die to put into your oil, ust add the container, drive for a couple minutes and pull over, and get out your handy dandy uv light, and see where the leak is, best method known to man right there.

 

when i got my car i had a good oil pressure sending unit, but it was suuuper loose

see if you can tighten it or loosen it very easily by hand, if you can it needs to be tightened

 

thanks for all the help guys... i'll definately take a look at it this weekend when i get home.

 

dont forget the distributor because there is a o-ring seal gasket at the base and will only leak when the vehicle is running. and sometimes this is over looked

 

And then it could be the china wall on the back side.

 

heres one more suggestion that I found after scratching my head over it for a long time

seems these leaks are hard to find because everything gets covered in the oil

mine was the mounting plate for the oil cooler!!!!!!! it was not tight to the block, you'll see you have two oil lines coming out just above the oil filter, those do not screw into the block there is a mountiing plate there

good luck and let us know

 

well i got home tonight from school and finally got a chance to take a good look back there and its hard to tell where it could be coming from.

its definately back there but i gotta get a better look at it. i'm gonna take a peak from underneath whenever i can jack it up. tommorrow or sunday, i'm gonna try to get in there and look closer

 

spent some more time looking in there.. i got my mirror out and a light and was tryin to get a better look behind the motor. it doesnt appear to be coming from the driver side valve cover, i cant get a look at the passenger side, but i dont believe that is it either. its not coming from the back of the manifold either.

i cant really see the oil pressure sending unit, so i'm gonna have to jack it up and try to look from underneath. its really wet all around the oil filter and above it. when it gets warmer outside and stops raining/snowing, i'll clean it up to get a real good look.

 

my engine is covered in oil in the same exact area, mine is a combination of the rear main seal and oil pan gasket, im just too lazy to replace it yet

 

Update..

so i put on some new brake pads. and while i had the car up in the air i took a look underneath and all over.. couldnt really see much but it appeared to be coming from the back of the manifold/china wall

i got the car inspected finally this week, and the guy said he is 95% sure its coming from the back of the manifold which confirms my suspicion

oh well, looks like i might be getting stealth ram earlier than i thought! lol