What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Still another leak

mouse

mouse

1/2 ton status
Joined
Nov 10, 2003
Posts
1,447
Reaction score
1
Location
Great Falls Mt
I rebuilt the engine a couple of weeks ago, I have all the leaks taken care of but one. I guess that what I get for buying a cheap gasket set...

I have a leak at the rear of the engine. There is a bit of oil on the starter, and some on the trans dust shield. I replaced the oil pan gasket again, this time with the one-piece Fel-pro gasket (its nice!). But the leak remains. The rear main seal is nice and dry. I guess I'm down to valave cover gasket (I'm using rubber gaskets that have the steel reinforcement) or an oil galley plug on the back of the block. Its hard to tell with the clean engine and clean oil.

Any tricks to narrowing down? A guess to what it might be? I'm a little short on time to look at it close this week. I don't feel like pulling the engine again. I guess this time it will be the trans, if I can't locate it...
 
You can try carefully dusting with a small amount of baby powder. Just keep it out of the intake.

Did that to locate a trans leak and it worked well.

ADDY: always had problems with hard to see leaks at the rear edge of the valve cover. Run your finger under there and see if you get oil on the tip.
 
I just finished helping my buddy find his leak it sounds similar to what your experiencing I felt on the back of the engine come to find that the back of the intake manifold gasket had blown out so it was coming from there!!!
hope that helps..... :D
 
I have had this happen also.
The first time it was the distributor gasket.
The second time was when I learned that silicone and gaskets were not meant to be used together.
The Rocker cover gasket "squirmed out" due to the use of silicone.
Lesson learned; Either use one or the other… Not both.
 
I'm going to second the distributor gasket. Also look at the brass fitting that T's into the block for your oil pressure sending unit. Those get ragged from removal and leak.
 
Some great ideas to check. The intake and sending unit "looked" clean, but who knows without feeling since its fresh oil.

Thanks.
 
It looks like the leak is from the passenger valve cover. I found fresh oil (enough to fill the end of my finger) on the back lower corner, directly over the starter. It is dripping straight to the starter, which made it hard to find.

These old valve covers are bent, and are in poor shape. Do you think I can get a good seal with the GM performace stamped covers (they claim heavy duty construction) or spend the extra $$ on the cast aluminum?

I hate oil leaks!
 
I went with the steel GM covers from Summit but I also added the longer chrome retainers that go on the 4 cover studs. They are much bigger than your small stock retainers and should help improve the seal.

I have never owned the aluminum covers so I can't be of any help there.
 
I use the edelbrock cast aluminum valve covers. (i use the ones without the edelbrock logo they are cheaper sold at Summit )

Ive used stamped steel and will never go back. Its worth the extra money because of one less headache and they look great. If your leak is small I would endure with it a little longer to save a few more pennies for a better item.
 
You guys talked me into it. I ordered the least expensive cast aluminum covers I could find - the summit brand covers at $62.95ish. I don't need (or like) the extra shiny polish look, but its something I can deal with. After all, I wouldn't want to be accused of building a show truck!
 
I found something other than valve covers that work great !!!!I use those edelbrock performance valve cover clips !!! Thet are a long bar with a hole to go into where the valve cover bolts down . they are chrome and about 3 inches long ? You see them in all the parts stores . I have used those on a number of 350's including my own and never had a leak !!!
 
Well I installed some Summit cast aluminum valve covers and there is absolutely no leak on the valve covers. The black rubber gasket is nice and dry all around.

But

I still am getting oil on the starter and down into the tranny dust cover. There is a little oil on the bottom off the passenger side exhaust manifold. I got a new distributor gasket, as the old one (1 yr old) looked wet.

My list as to possible causes of this leak is getting short. Recap: new oil pan gasket, valve covers, and distributor. Whats left: intake, rear main, and head gasket.

With a flashlight the intake looks dry. Run my finger on it-feels dry.

Rear main is the only thing that looks dry under the dust shield. Oil is primarily on passenger side.

Head gasket-the engine runs great. I have no miss. I could hook up the compression tester...

I idled the engine for 45 minutes waiting for it to leak after changing the valve covers - nothing... Went for a drive, came home, parked, and the starter was dripping with oil. Not a steady drip, but wet, and enough where I'm starting to get a oil stain on the concrete driveway. I guess it only leaks when warm and the engine is at the highest oil pressure. I am running a high volume oil pump, with a resulting higher pressure too.

I think its the crappy Summit gasket set I bought. All I've replaced have been with Felpro.

Ideas?
 
did you eliminate the oil sending fitting at the rear of the intake on the block that supplies the oil pressure guage?

The only areas i can think of are those already listed. As you can see on the pic the rear of the blok makes a nice channel for oil to run down on either from the intake, oil guage fitting, or distributor.

01010005.JPG
 
also if the oil is new it would be very hard to see where its coming from. I still wouldnt rule out the valve cover ast a small leak on the cover just above the header or manifold could get past you
 
I can get a good look at the oil sending unit, its dry. Any chance of a head gasket? I think this weekend I'll start by pulling the intake and go from there. If its not obvious, off go the heads.

Yeah, its new oil. I changed it 3 times since putting the engine in - about 300 miles. I run it this week and see where it gets wet. The front drive shaft is getting "lubed" now as well.

I would love it to be a valve cover gasket. I've got a couple of cheap cork gaskets laying around. Its free, so its worth a try...

Maybe I'll get some pics up...
 
Heres the leak. Kinda hard to get the camera angle right, but you can see it.

Plus, a bonus shot of the new (and already dirty) valve covers - not bad for $65...

leak.JPG

valve covers.JPG
 
valve covers look nice :thumb:

sorry but I think it has to be a valve cover gasket leaking or rear intake manifold. I just cant see a head gasket leaking oil by without other symptoms. and i would not rule out the oil pan gasket. ill be curious to see what you find out
 
You must log in or register to reply here.

Latest Posts

Top Bottom