I recently bought a new-to-me 2003 Monte Carlo blue Discovery that runs pretty well. I have sorted out several issues thus far (codes for evap and o2 sensors). I have driven it at least 500 miles since I purchased it a few weeks ago. It has been well cared for overall. It does have what appears to be a liner tick and occasionally a little bit of a rough idle when warm, but I have been working through things one at a time.

It had a minor oil leak from somewhere in the front of the engine and maybe a bit of seepage somewhere in the back. I wasn’t overly concerned however because it seemed quite minor. I changed the oil last weekend with a 10w-40 Castrol blend and added a bit of oil stop leak. Since then the oil leak has become much much worse. It now is leaking so much oil that it is smoking from oil burning on the exhaust and I can’t really drive it. Not sure how it could suddenly go from being a minor issue to such a massive leak so quickly except if a seal is starting to come apart completely.

Valve cover gaskets were recently completed by the prior owner and are clean. Valley pan has some build up from what I can see from the top, but doesn't seem to be gushing. Oil pan may be seeping, but mainly seems to show oil from elsewhere. I cannot really see the underneath the front of the engine well because it still has the plastic shield, but it seems like there is a lot of oil coming from up there. It seems to be from below the water pump. It’s been a while since I’ve dealt with a Rover V8 in a Disco - I am thinking front cover and/or crank pulley seals? Any other ideas?

 

Either main front seal or timing cover

 

 

The other possible leak point low down in the front area of the engine bay are the oil cooler hoses (my P38 leaks there and I am planning to fix them at some point).

 

Just did the PCV mod on my motor, the old oil separator/baffle was broken off inside the hose and plugged (couldn't blow through it), and the port in the valve cover was completely plugged. The motor was spewing oil and at all ends.....

 

Thanks for all the tips. Mine doesn't have the external oil cooler being an 03, but I will check the plugs to make sure they are not leaking. I'll check the PCV - when I took off the air intake hose there was some gunk in the area where the PCV hose attaches.

 

Is the baffle and restrictor plate still in the pass side valve cover tube?

 

I checked into this. The PCV baffle was completely caked full of gunk (really bad). O'Reillys had their version of the PCV308 part nearby (MGD PCV308 for $4 or so), so that should be coming later today. I have a feeling that the oil leak is more just crankcase pressure building up and letting out the seals. I'm hopeful I won't have to replace any, but we will see!

 

Don't forget to make sure the oil filter is tight!

 

One the first things I did was change the oil filter. I was having some oil light at start issues, then I looked underneath and saw a cheap Fram oil filter. Got that replaced by a Mobil1 filter ASAP and the oil pressure light issue has gone away since.

The PCV definitely helped the leaks, the top of the engine appears to have stopped leaking altogether. However, I still am getting smoke from the cats, especially after I drive for 10+ minutes at 70 mph. At first I thought leaking oil was hitting the cats, but all the oil from the engine at the back seems to be dried up - I am pretty sure that was coming from the valley pan because of the PCV. But the valley pan seems to be a lot drier now.

Now I am wondering if maybe the cats are going bad. Floorboard gets really hot when interstate driving. Maybe the cats are gone and smoking?

It also has developed an idle misfire. Fine at all other times except when rolled up to a stoplight once warmed up. Thinking maybe that might be coils?