Disco II engine oil consumption - help

[Colorado Rover]

Have a 2004 disco II with Bosch engine. Had oil changed at 52,150 and dealer service done as per manual. No problems noted from service. Checked oil after service to be sure topped off at 6.8 qrts, it was. Checked oil at 58,322 was low by 3.5 qrts. (i was following dealer service intervals on oil, but that will now change to every 3000 ) Having oil changed today (58,420) and replaced with 15/40 for summer heat. Dealer suggested this too. I plan on monitoring every day for 1 week and then every 500 miles to see what consumption rate is. no visislbe oil leaks on engine or underneath, except for slight oil residue on top of left valve cover near PCV valve tube. There is also no visible blue smoke or burnt oil odor. Do these engines use oil? The dealer told me it was not uncommon to see 1+ qrt usage between oil changes.

[Carpe]

Tighten down your valve covers with a 6 or 8 mm spanner - you'll be amazed at the difference. I believe there are a total of 4-6 bolts squished in between the plugs. That's also what causes a significant percentage of the oil spots underneath a rover. You might also check your drain plug seal and replace that.

[Colorado Rover]

Thanks. I will definitely look at that to see if any difference occurs in oil consumption.

[Colorado Rover]

Well - valve cover bolts were tight. The dealer could find no leaks. Using 1 qrt per 1000 mi since oil change with 15w 40. There is no blue smoke.

I removed hoses from top of valve covers that go into air intake - wet oil in the hoses. I am not noticing a PCV valve. Have I missed something? Are there PCV valves on the Disco. WHile looking on line for parts to verify the pCV valve I found an oil separator - where does that go?

[Carpe]

You know, as much as I hate to say it, that's not terribly atypical of Disco's. My SI certainly burned through 3 quarts per oil change (3k miles), and my SII probably burned through 1. I could speculate and guess, but that'd be wasting both of our time. I'm sure there's someone out there smarter than me that could start to answer this. Certainly the guys on Discoweb would know where to start.

[Colorado Rover]

Thanks Carpe - What you provided is the type of information I am looking for. This is my first Rover (I have no idea why a waited so long) and I know that they can be particular, but I was not sure about the oil issue. What you describe is very similar to what the dealer told me too. I have been monitoring every day now and it seems it will average out at 1 qrt for every 1600 miles or so. It also appears that highway driving uses a little more oil. So, if this is normal and not out of the realm of a typical Rover I am ok, but while I still had an extended warranty I wanted to get on the issue.

Thanks again four input.

[Colorado Rover]

Well, I think I found the issue. After noticing the oil residue inside the intake manifold from the passenger side valve cover vent tube to recirculate gases, etc, I began pondering what was done with the PCV valve concept. It appears that Bosch/Land Rover redesigned the PCV valve concept, replacing it with a short vent stack with a small hole in it to regulate vapr flow back into the air intake. Perhaps not bad in concept, but with the advent of emissions controls and restrictions the recirculation of the air back into the air intake for the engine to breath allows oil vapor/mist into the intake perpetually. It would seem that the air flow through the intake creates a vacuum on the vent stack hose from the valve cover, which causes oil to be consumed, depsite the equalization of pressures in the intake and engine when driving. The typical PCV valce with the ball detent prevents this vacuum when the pressures are not required to be vented from the engine.

Remedy - I got a PCV valve for a 4.6L mustang (figuring engine pressures would be similar) as a tester. I rigged up the PCV valve on a hose and attached it to the vent stack and then reconnected the hose back to the intake. THere was good vacuum at idle, as expected. After driving the disco there is no visible oil consumption on the dipstick, which had been 1/8 quart or more every 100 miles (checking it daily). As I noticed oil residue only on the passenger side I am only testing the PCV valve on that side. Of interest, the other vent stack on the driver side valve cover is at the front of the engine and not the back. There may be something to the location of the vent stack and allowing oil vapor to collect on the inside top of the valve cover and not entering the intake. Now I only need to clean the inside of the intake. BG makes an intake cleaner you spray with engine running - more research and talking with BG, but this is likely next step and BG usually has good products.

Anyway - hope this helps anyone else having oil consumption issues. Thanks to all who replied adn pndered the issue.

[mferdinand]

I think you need an oil separator part LLJ000010 ... inside the tube running from the vent stack.