I am trying to chase down an oil leak on my 85 Iroc 5.0 TPI. Car sat for 17 years in a garage inside.
It has a slow to moderate drip on the driver's side near the oil filter. It looks to be running down the air tube that runs to the driver's side exhaust manifold. Any suggestions?
Seems to increase with RPM's. I have tried to look at the rear of the engine near the distributor from up top but can't see anything. I had the distributor out and the intake manifold. Doesn't seem to be leaking from either one.

Thx

Pete

 

Oil pressure sending unit; on top of the block, behind the intake manifold, kinda under the distributor, driver's side.

 

Ok. Thanks.
I’ll try that first and see if it fixes it.

 

There is no try. There is only do. Do or do not.

Smart place to start would be, take the car to the quarter (dollar bill? credit card?) car wash along with acoupla cans of engine degreaser (just the basic kind, NOT the "foamy" or "thick", just yerbasic diesel fuel in a spray can), soak the whole thing real good with that and wait 10 or 15 minutes, clean it up with the wash function being careful of course not to spray the distributor directly, and eyeball where the oil is coming from, once the whole scene of the crime isn't drenched in like 2 quarts and 50,000 miles of built-up schmutz. Always easier to know you're on the right track when you can actually see what's actually leeeeeeeeking. Not to mention, it's AHELLUVALOT LESS of a PITA to work on something, when you don't have to swim through 2 feet of the accumulated funk of 10,000 years just to get there.

 

Ok sounds good. Thanks

 

^^That^^ is the answer. Get it CLEAN...then it becomes obvious where it's leaking from.

 

Just hard to get that area clean. It looks pretty clean from up top. It’s underneath that is greasy. Would be tough to get it clean without a lift.

 

The more I think about it, i bet its the "china wall" at the rear of the intake manifold. I had the intake off and I bet I didn't use enough RTV on that area. Looks like I will have to tear it down again and this time use the Permatex Gasket Maker. Ugh !!

 

If it's the china wall and you've gotten the top/rear of the engine clean, it should be quite easy to see....as shown in the pics in this thread about a China Wall leak repair, HERE

 

Well, I took the distributor cap of and used a mirror. The "China Wall" is dry so it isn't the intake seal !!!
It is dripping from the Oil Pressure Sender area and dripping on the air tube going to the driver side exhaust manifold. Right where I saw it from underneath. Where would it leak from the oil pressure sender? The fittings it screws into look dry. What is the 2 wire sensor beside it ?

 

Best way to find out would be remove it and LOOK. Probably the crimped seam.

 

The earlier TPI arrangement used a sender for the gauge and a separate switch for the EFI fuel pump secondary power. Later versions incorporated the functions into a single unit.

 

In which case, if there are 2 sending units of whatever purpose there, CLEAN IT ALL UP at the car wash, and see which one is leeeeeeeking.

Yes.

I've seem em leeeeeeek from the crimp where they squoze the metal part around the plastic; from the electrical pins themselves, if the sender just crumbled from old age, internally; from the insulator material around the outside, if it cracked and failed; so ... yeah. It can leeeeeeek from the oil pressure sender WHEREVER it feels like leeeeeeeeking. Kinda pointless to belabor that point, beyond mere curiosity. If it leeeeeeeeeeeks, it LEEEEEEEEEEKS, and it no longer matters "from where".

Clean it up, see where the oil is coming from, replace it. Or, just replace both of those parts, since if one failed, the other which is EXACTLY THE SAME age and likely made from the EXACT SAME material and has been exposed to the EXACT SAME conditions for EXACTLY THE SAME length of time, whichever one HASN'T failed YET, will probably fail, right about the time you get the first one all changed out, get all the schmutz and the funk of 10000 years off your hands, and close the hood. In about a week it'll be right back like it was, except it'll be the other one. Kinda like hard drives... "they" say there are 2 kinds of hard drives in the world: ones that have failed, and ones that haven't failed YET.

 

I’m replacing both. Should fix the leak. Will tighten the adapter that goes into the block too

 

If by this; "The fittings it screws into look dry"
You are actually referring to this; "the adapter that goes into the block"

Then why oh why on God's green Earth would you eff with it
If the piece that screws into the block looks dry, why would you risk snapping that off by tightening it if it isn't presently leaking

The very first rule of mechanical repairs; "If it ain't broke, DON'T eff with it!!!!!!"

........ Your Welcome

 

thanks.
just made sure it was not loose.
I understand your reasoning.
just don’t like to do things twice !