i have an oil leak. my main question is where is the oil sending unit on an 85 LG4 set up? I did the valve cover gaskets, wasn't the problem. the leak seems to be coming from the back left side, and drips down off of the inspection cover. and also drips onto the exhaust in the same vicinity (it shouldn't look like your front tires are smoking on rwd car, right? ). i don't think it is the intake manifold. it isn't the oil pan gasket. is there anything else i should be looking at? i'm trying to find that it isn't the rear main seal. that would be nice.

 

look to the rear drivers side of the distrib. If it is there you will see it. If not there it is on the oil filter housing.

Also, alot of times it will leak from the distrib. base when that little gasket goes south. And that leak (the v6's get it ALL THE TIME) looks just like a rear main leak...

 

Yeah i used a rubber oring instead of the paper gasket. makes a world of difference. Just dont get it thick :P no one sells it for that application just kinda have to walk around the hardware store ;P

 

alright, thanks. so a possiblility is to have to pull the distributor to replace a gasket, if it isn't the sending unit?

 

Yes, it is a possibility.

It's also a possibility that the sun won't rise tomorrow. A remote one, perhaps; but a possibility just the same. But I'm not going to worry about it too much.

Just like you shouldn't worry about the dist gasket. Your car has a V8, which uses a flat paper gasket, which rarely rarely rarely "goes bad" of its own accord, unlike the inadequate O-ring they used in the 6-cylinders, which dries out and turns to dust. About the only time the V8 one fails is when somebody has pulled the dist out and it accidentally gets caught on something as they stab the dist back in, and they fail to notice it. Forget the distributor for the moment, and "pick the low-hanging fruit", so to speak.

Just change out your sending unit. That's the HIGH probability item, right there. It's less than $20, and only takes a couple of minutes to replace, and almost ALWAYS fails, sooner or later, by LEAKING PROFUSELY. Rather than being concerend about some VERY LOW probability thing like the dist gasket and continuing to do nothing except watch the oil stain on your driveway grow larger, go directly to the HIGHLY LIKELY thing and knock it out.

You will also find that it's a whole lot less unpleasant to work on your car, if you buy yourself a couple of cans of engine degreaser, the kind that's diesel fuel in a spray can; the store brand at AutoZone or Advance, or Gunk Engine Bright. Then take it to the quarter car wash, and let it cool down for a few minutes so you don't start a fire on your exhaust manifolds; soak the whole engine down; wait a few more minutes; soak it again; then car wash the motor. Clean it from underneath as well as from above. Maybe even use a pair of ramps to get the front end up to where you can get under it a bit. Just BE SURE not to spray the distributor directly, especially around the base. Use the low-pressure seting of the car wash when washing around the ignition system and sensors. It's amazing how much easier it is to work on a motor that's not an inch deep in slime and goo from 20 years of leaked-out oil all over everything you touch.

If the sending unit doesn't fix it, then the next most likely thing is the seal across the back of the intake, where it meets the block. Once you have the OPSU replaced and the engine cleaned up, it'll be alot easier to spot the source of any remaining leaks. They show up much better against a background of cleanliness, than they do against 150,000 miles of accumulated funk.

 

not to get off topic but could someone tell me the year of your car and the color of your wire going to the sending unit?

and possibly the color of the wire going to the temp sensor?

no one is responding to me on my electronics post. and i figured if everyone is standing around their sending units they could check out the wire.

thanks.

 

Oil pressure gauge sending unit wire is dark blue; temp gauge SU wire is dark green.

Year doesn't really matter. That's been GM's standard color code since at least as far back as the 50s.

 

yes, i know, that is the plan. i didn't think distributor gasket, never heard of it being a possibility. so the plan is to clean it up, hopefully see that the oil sending unit is leaking, and replace it. it is smoking pretty good from the back of the block (the oil burning off), and i don't think this would happen with a rear main seal leak, but i could be wrong.