I have a 2001 Disco II with 149,000 mi and replaced the head gaskets, water pump, hoses, belt, etc about 2500 miles ago. I'm noticing performance problems and despite scanning with an OBDII, the only thing that comes up is 3rd gear trans. shift set improperly. It will shift at 52mph.

When the second air system comes on in the morning, if you try to drive it before the system turns off it backfires and will not accelerate at all. Once the system turns off, the vehicle will accelerate.

The other issue is that the engine doesn't have power any longer. When accessing the freeway and downshifting under reasonable acceleration, the Rover goes nowhere and only increases speed at about 1 or 2 mph. The engine is revving very high, but it won't get out of its own way. It also surges as I steadily increase to highway speeds. On several occasions, I pushed the pedal all the way down and the vehicle lost power and the service engine light began flashing intermittently. When I let off the accelerator and slowed down, the engine would respond again.

Lastly, I notice tremendous oil consumption but no leaks whatsoever. It was down almost 3 quarts when I last checked and filled it and the exhaust tip is coated with jet-black soot that feels oily in my hand. It would appear to be burning or leaking it through the exhaust, but I get no smoke whatsoever.

I'm certainly open to ideas. Without codes, it's really tough for me to determine where to begin looking for the problem.

Thanks,

Russell

 

Bad MAF sensor, try cleaning it first with CRC MAF cleaner.
Second check the oil separator in the passenger side valve cover, pull it out and clean it with carb cleaner.
Did you do the head gaskets or did you have them done?
Do you know what motor oil they used?

 

And check oil daily if you are having that kind of loss. Weekly is a minimum check interval for these trucks. They can leak more than you are prepared to pay for if left to their own devices.

 

Thanks for the quick replies. I'll follow up with first trying to clean the MAF sensor and replace if necessary.

I did the head gaskets myself and I have used Royal Purple synthetic since I've had the vehicle, as well as used it when changing the head gaskets. I had also replaced the timing chain, chain cover gasket and oil pan gasket when I did the head gaskets, water pump etc. In looking closely, there are no leaks, no wet areas and appears as dry as the day it was buttoned up after the repairs.

I do note that I had tried using synthetic oil in an old Harley Davidson I have and it started smoking terribly. I had to drain it and go back to a standard weight oil. I suppose I should try a standard high-mileage oil in my Rover to see if the oil problem improves if the synthetic may be the problem.

I'll begin checking the oil more regularly, but it did seem odd that there is wet oil soot at the end of the tailpipe as though it's leaking through the exhaust somehow but not being burned during combustion if such a thing is possible.

Thanks again.

 

General thoughts:

Syn vs non-syn is not all of these problems. Should be "X" w40, as in 10W30 is not right for these engines except in a narrow range of temps.

Perhaps you might review the pages in the RAVE manual about emmissions control for the SAI system - might be an addition vacuum leak in the mix.

Attached are pages from RAVE about transmission control. Sounds like one of your symptoms is related to shift points. Does performance change if in "sport" mode?

Tranny fluid level, when was fluid and filter changed, run RP in there?

Wet stuff in tail pipe may be related to SAI issues.