i've got a 88 TPI iroc-z, and the wholeback bumper and lower part of the wing gets completely covered in some greasy substance (which i assume is oil) problem is, it also has little black chunks of stuff in it as well... kinda feels like a very fine black oily sand... there is no smoke at startup nor at all as far as i can tell, and the oil seems pretty constant on the dip stick so far... what is this? it had ruined a few good pairs of jeans when taking out or putting up the TTops right at the knees from brushing up against it...

 

HOLY CRAP! i have the same problem. mine alomost looks lke it dripped in cetain spots. it always comes back after it is washed off too. but I have a film on the whole back bumper. The under side of my car is dry. I cant figure it out either.My 97 ws6 did this too.

 

This is a WAG (wild a$$ guess)

Check your tail pipe(s) for soot (black crap, looks like charcoal).

You may be running rich for whatever reason.

Just a guess

 

It's more then likely oil, I had this same problem when I was going through a quart of oil every 3 weeks. The oil was leaking out of the oil pan, there wasn't a good seal on it and as I drove the air going under the car would sweep the oil all the way back and the turbulance would deposit the oil on the bumber. About a week after washing the car, the back bumper would be black (suppose to be silver). I would start looking for oil leaks at the oil pan, filter and intake end seals.

Jim

 

Hee-hee same problem here. Oil stayes normal but the back part is covered with it.
I eaven almost got killed because of it. - I had to back up and had to be wery exact, so I asked my girlfrend to stand behind the car to tell me when is enough. So as soon as I fire up the car all hell breaks loose behind me! ! So I shut off the car and go to see whats up , and she almost killed me -her jeans where covered with spots of whatever comes out of the pipes.

 

continuing my guess from earlier:

Part of my WAG involves the chemical reaction inside the catalytic converter. among other things that I can't remember right now, the cat produces water.
Mix that with a rich condition and Voila, Black oily liquid that gets all over the back of your car.

If I'm wrong, chalk it up to the past time in my Sig.

 

Change your rear end fluid recently? I bet it's leaking and spraying up there when you drive. Better get it before your rear end overheats. I hope it's not whining already.

 

i did some snooping last night... i'm dripping oil underneath the car...it's not from the drain plug or the oil filter. It left a drip patteren that went from one side of the engine to the other, but there isn't any oil on the oil pan on the drivers side, but on the passengers side, the bell housinga nd starter motor are coated in fresh oil - i've been told this might be the oil pressure sunder unit, and might even be the rear main seal... what do you guys think?

 

Nope, end seal. If the bellhousing and starter are covered then the oil is dripping from the top of the engine down the bellhousing and on to the starter. The oil pressure sending units are on the drivers side of the car so little chance it's that. The rear main seal is not likely either because the oil wouldn't go "up". It would drip down and under your car and the starter and bellhousing would be dry.

 

ok, i'm a little confused, what's the difference between the rear main (around crankshaft right) and the "end seal"? Is it the rtv sealant of where the intake manifold meets the block?

please tell me it's alot easier to fix than the rear main....

 

Yep thats it. I had a problem when I just put RTV in there without a "seal". I put a cork one in (I know, I know, sorry but it was all I had.) and the leaks stoped. It is easier then the rear main. It just means taking the intake off.

 

If this is a new motor, or if you've taken the smog pump off, check the 2 bolts on the front of the block at the lower right, right around the corner from the fuel pump flange... the upper one goes straignt into the fuel pump drive rod hole, and will leak mercilessly at higher RPMs (like cruising). If there's no bolt there, put a short one, like ½" long, in it with some silicone on the threads. If you use too long of one it will hit the fuel pump rod and the engine wil not run because the pump rod wil be captivated.

 

I'll check those things when i get home... i just recently bought this car, so i don't know a whole lot about it... but the engine was rebuilt at 89k miles, and now has 20k on the new engine (rebuilt with all stock parts) The guy i bought it from claimed that it didn't have this oil problem until after he drove it 4 hours to meet him, after sitting for about 45 days... it was also given an oil change by walmart either before he let it sit, or before bringing it halfway to meet me...

Are there any tricks to getting all the way to the intake off? this is my first tpi car, and i've gotten as far as taking the whole carb off of my old 86, but never the intake... what should i have with me to make this job easy (tools, gaskets, seals)
should i drain the oil/coolant/etc?

i'm not sure if my chiltons outlines this very well, as the book as sitting at home and i'm at work - can this be done in about 3-4 hours of light for someone for the first time?

 

id definatly say oil leak. I had this problem too, except with the oil.. and coolant and transmission fluid when i got my car. All where leaking from every place imaginable (trans was just a bad gasket, though) and flowing down along parts of the floor pan. As soon as they hit the bumper portion, theyd get blown into a fine mist and picked up by the turbulence of the car and get all over the place. Check for leakes of all sorts everywhere in the engine compartment. The floor pan wont look "wet" because the air flowing underneath wisks all the crap along.

Also check the distributer. They like to leak around the gasket.

 

Also try checking the gas tank and all the lines around there... Its a long shot but gas can form a greasy film too.

 

My car runs very rich and as a result develops black spots on the bumper right above the pipes. If you want to know if you're burning oil, check the plugs for little black spots. My guess is they're going to be coal black so it won't matter much.

 

When my first trans died, and Lee Myles put one in, the torque convertor grenaded a few days later. They replaced it under warranty, but the whole underside of my car got showered with trans fluid- as well as the top of the rear bumper.

I just wonder what the people behind me on the highway were thinking when they got blasted with trans fluid! :sillylol:

Oh did I mention that $1300 trans only lasted a year and a half?

 

ok guyslisten to this, I looked at my FRONT bumper today and it hasoil drips on it. it is on the foglight and rigth below it on the ground effects. Itis oilbecause I smelt it. I cant figure it out. There is no oil under the car either. it looks like oil dripped from the sky on my car.it this is not the first time it has happened either

 

GEE, then I'd look for an OIL LEAK from somewhere. In case you needed to be told that.

A good method for finding a leak, is to use a good degreaser on everything underneath the hood (and transmission, and rear end, if they are suspect). Once the engine is completely clean, and degreased, occasionally open the hood to check for new looking oil.
It didn't drop from space, and if it's reaccuring, then its probably your car.

 

My engine is bone dry. it is brandnew and there is no oill eaking anywhere. I know for a fact of that

 

maybe youve picked it up on the freeway or highway. Ive picked up all kinds of things including a bath in diesel oil while passing a truck (windows open of coarse...)

 

I dont think I am picking it upon the road. It always comes back about 3 times a month. maybe its those old planes leaking oil, you know the ones we use to fly in.

 

Do you have an oil cooler? That could be it, if not and you know that you are not leaking oil and you arn't picking it up from the street then it looks like the oil fairy has payed you a visit. There is no other explanation.

 

I have absolutely no idea how oil could get on your front bumper, unless maybe you drive around backwards at high speeds. Maybe someone is playing a trick on you

I'd also advise cleaning everything off really well, then looking around every day to find the problem.