Have oil oozing down the rear of the bell housing and ONLY down the rear of the bell housing. When I open the bell housing inspection hatch, the inside is bone dry. I have tightened the outside bolts of the valve covers. Doesn't help. Before I take off the upper and lower intake manifold & valve covers to change gaskets, is there any way to rule out rear main seal before I attempt the job? I ask because if it's the rear main I will probably sell the truck and don't need to go through the extra hassle of manifold gaskets.

Will add that leak gets worse if I really jump on the truck, i.e. kick down revving up to 5k to pass, etc (I know - stop doing that). The leak is substantially less if I drive staying under 3k or so. Does this indicate valley pan more than rear main?

If I keep Disco parked for a couple days with a wiped down engine there will be no leaks anywhere when I return.

I have a 2003 v8 4.6 with 82k, fresh kendall GT1 20w-50 dino oil, 8mm magnacor wires, K&n hp3001 filter, oil separator is new and clean, no overheating issues whatsover, no low oil pressure readings ever, engine runs exceptionally strong and smooth, new Bosch MAF, I do notice a slight hiss/whistle at idle that increases through the entire rpm range. Not the water pump. PAS pump is brand new. Idle pulleys and serp belt is new. Could be vaccuum leak but all vac lines are tight and all accesible intake gaskets (plenum, throttle body) have been sprayed with carb cleaner and no leaks detected. Would a leaking valley pan gasket create that hiss or vacuum leak?

Thanks in advance.

 

My guess would be valley pan or valve cover gaskets. If it were the rear main your torque converter would be wet, well at least the inside of the bell housing. The best way to tell is to try to clean the back of your engine and use a light and mirror or somehow try to see the top of the bell housing. That should tell you where the leak is coming from.

As far as the whistle noise it sounds like a vacume leak to me.

 

First, make sure your v/c gaskets are tight, use an 8mm, 12 point, 1/4" socket and tighten to between 6 and 10 foot pounds of torque, it is a common leak that can flow down the back of the engine.
As for the valley pan or head gaskets, use a mirror and see if you can see where the oil is leaking from.

 

Mike,

I just replaced the valve cover gaskets (a big job with the secondary air) and stopped short of doing the valley pan. Like an idiot, I forgot to at least tighten the valley pan bolts. Regardless, the valve cover gaskets are new and leak free, but the leak down the back of the housing is still there. It's a lot more pronounced if I punch it and go 4000-5000 rpm but in normal driving it seems not to leak as much. I'm willing to tear the engine back down (second time is a charm) and replace the valley pan if that's likely to be the culprit - but if it's probably the rear main, I would live with the leak. So - valley pan or rear main? Remember, the inside of my bell housing is bone dry.

 

you may consider trying a Univeral Products fix for the rear main seal. I can't remember if it is called White Shepherd or not, they have several different products with different names. It will cost you $12 to $20 depending on the source. they guaranty their products so if it doesn't work you can get your money back, if it does work you just saved yourself a Saturday skinning your knuckles. I had what I thought was a rear main seal leak on my 2001 DII, I used the White Shepherd and it seemed to help (my daughter took the truck to school right after I used the product so I haven't had a chance to see how it is holding up). I had a mystery leak on the back end of the engine/front of bell housing on our DI. Like yours, the inside of the bell housing was generally dry but I was getting oil dripping out out of the vent hole on the bottom of the bell housing. I tried the White Shepherd and it didn't seem to help in the instance. I think that I have narrowed the source down to a slight leak on the back edge of the oil pan. It seems to be leaking of the back edge, the two bolts a wet, and then making its way through the seam on the top of the front bell housing access plate, not the bottom inpection cover. It then runs down the inside of the front cover and out the vent hole. Next oil change I am going to reseal the oil pan and see if I can stop the leak. It isn't much but it is driving me nuts, that and the leaking water pump that I replaced 15 months and less than 10,000 miles ago. By the way, I have connection to Univeral Products other than as a customer.

Could you have a bad head gasket that is leaking oil out the rear of one head or the other? Obviously, that wouldn't make the hissing sound, that would be your wallet from the joy of owning a Land Rover...........

Best of luck. Phil

1999 DI
2001 DII

 

I can tell ya whats leaking without even looking at it! EVERYTHING! haha. Ok, most likely your head gaskets are leaking. I would deff. say if your gonna pull the lower intake prepare to do the heads. That is such a common leak. Actually they are all common. The rear of the motor is another problem area. The cross seals in the rear main cap leak alot too. On DI's the cam plug at the back of the block leaks like crazy too. I always say start your repairs high cause fluids leak down so if you take care of that then maybe the lower stuff isn't leaking as bad as it looks. A funny story....These trucks used to come of the car carriers with oil dripping from the oil pan, brand new!

 

It can be either the head gaskets or the valley pan gasket.
Look at it this way, going into the engine again, for the second time, should be quicker.
This time, though, have a full gasket kit in case it is the head gasket leaking.