Got a front oil leak driving me crazy. Have changed the seals 3 times, and still leaking. It is a 96LT1 so it has a CPS, and changed the o-ring on that yesterday, and still have my leak. Ruined 3 water pump seals before I discovered you need a special tool to install it. Last time, I changed the Opti seal and the crank seal as well as put a speedi sleeve on the crank hub. I do not believe the crank hub is leaking.

It is not leaking at the intake or valve cover gaskets

I think the leak is at the Opti, and I have changed it twice. I am using my OEM Opti with 117K miles on it, after a failed AIP Opti. I have a couple bottles of dye in it and using a black light,l but it is difficult to see, water pump seal is now not leaking. ANY REASON THE OPTI WOULD LEAK ?? It is pretty hard to install, and seems to "snap in" after much effort and removing the cap so I can manipulate the rotor to align the pin.

 

Have you checked the 02 sensors ?? Sometimes they can make it run funny, not sure about oil or anti freeze leaks

 

Any signs of timing cover to block leak, you say you have tried the dye method. Have you cleaned the area with brake clean and inspected again after seal changes?

 

did you use some lube on the seal and opti when you installed the opti? or any of the other seals for that matter?

 

 

Yes I did oil the seals, and now see that FelPro says to install dry. Can't imagine it would make that much difference, but who knows? Supposedly the new seal material will make it's own Teflon coat ?? I did oil the crank hub seal, as it is still rubber. Anyway, guess I will take it apart again, think I will go ahead and pull the front cover this time. Wow!! I have never ran into anything like this before, and I have been "bustin bolts" for over 60yrs.

 

Nature of the beast with the LT1. They are a little...."leaky"....

 

It doesn't appear to be leaking around the cover itself. It is really hard to see anything until you get it apart, and I have had it apart several times. Looks most like the Opti seal is leaking. I did oil the Opti and water pump seals, and now find out that FelPro instructs to install them dry, and the seal will coat the shaft with Teflon ?? Anyway, think I will go ahead and take the timing cover off unless I see something very obvious. Thanks for the reply

 

Yes, well I could handle a little..."leaky"..., but this thing leaves a puddle every time it's shut off

 

you need to remove the oil pan too. to get the timing cover off

ask me how I know................John

 

Yes I am familiar with the oil pan part. Changed the gasket on it a few months ago, went with the 1 piece FelPro. Big job, but appears to be dry now. Just the front won't stop leaking. Thinking I may just put on a new Opti. and see if it stops leaking. Really think that is where it is leaking. Wonder if the drive off the camshaft might be "wobblin" ??

 

I agree w/the suggestion of getting it really clean...then observing.

How much running does it take to generate the leak? If you get it really clean, let it idle up on jack stands while you observe from below...as soon as you see ANY oil, shut it down, drain coolant and pull the pump...it should be fairly obvious where the leak is originating from.

Sounds like a PITA though.

 

Mine was pouring oil out from everywhere.

It turned out the PCV valve was clogged causing the crankcase to be pressurized. It had to go somewhere.

It was blowing oil out the dipstick tube.

 

Thanks tom. I just got it back together on Sunday for the 4th time, and didn't start it up until Monday, waiting for the RTV to cure that I put around the Opti. seal before I pounded it home. I noticed that my Opti. had some slack in it, and you could get some movement if you "wiggled" the drive out near the O-rings. I put in a new Opti. and installed the seal dry as instructed by FelPro. Let it idle up to temp. twice, and see from underneath that I still have my leak. Only thing I haven't done yet is replace the cover, and think I may do that, as it leaks when it gets warm, so maybe something opening up then. I have a buyer for it if I can get it to stop leaking, so maybe I will just reduce the price until some young mechanic has to have it "as is". Getting real expensive, Sunday was over $400, and expect that the timing cover replace will be $500 or so. Maybe time to just move on to another project, the car won this time ??

 

If you got it all cleaned up and it's already leaking, I'd pull the water pump and see where it's leaking from.


It sounds like it's leaking pretty fast. Maybe you could narrow in on the leak now, clean it up again, then run it for a few minutes w/the WP off to observe (and reduce WP removing labor).

 

Thanks Tom. I may give that a try. Each time I have had it apart, it looks dry above the Opti. and cannot see any sign of oil til I remove the Opti. then looks like oil is running out of there. I was thinking maybe crankcase pressure, but this last time, I just let idle until it came up to temp, twice. Maybe firing it up with the WP and dampner removed, might be able to see something. Do I need MAF and Coolant Temp Sensor hooked up to run it a while ?? This thing has really got me baffled. The Oreilly auto parts oil dye really doesn't show up that well under the light.

 

'96 is OBD II...It should run w/o the MAF (it has MAP too), but you probably need to have the CTS hooked up. Can you just flop the WP to the side and keep the harness plugged into the CTS?

 

You likely have checked and rechecked this but my experience is that the culprit is often a bad seal at the bottom of the timing cover front of the oil pan where the gasket turns down from the pan/block rails. A lot of extra sealant in that downturn is most helpful.

 

Hi tom. Good idea, just let it run til it starts to leak a bit. I jacked the motor up some, and could look up with a light, and see that it is totally dry on the driver side of the timing cover, and the leak is coming down the passenger side. I had high hopes when it looked like it was coming from around the 2nd bolt up from the bottom, but now believe that the oil is more likely just running down a "rib" on the front of the cover, from behind the Opti. I have changed this seal 3 times, and now a new Opti, and still leaking behind there, and no way to see back there until you remove the Opti. and of course everything looks fine. the dowel pin that the Opti slips over is the front of the cam, so small chance that it is "wobblin" Can't remember if this thing was originally leaking up there when I changed the pan gasket, been so long ago. I can't see that the Teflon part of the seal would be leaking, so that just leaves the metal "outer" that goes into the timing cover. May be a small crack that opens up when warm ?? Anyway, thinking about putting some RTV or JB on the front of the cover where the seal goes into the cover. No harm that, as I'm going to change the cover if the leak doesn't stop. What you think, Ultra Black RTV or JB ???

 

Yea, thought about that, and "re-snugged" the front bolts. It has a new Felpro one piece gasket, and is thick rubber in the front where it fits in the timing cover groove. Real dry up there on the front of the pan. really think it is coming from behind the opti., and I have changed that seal 3 times...makes no sense.