By Drew Adia on Saturday, August 25, 2001 - 07:50 am: Edit

Hello all,

I have a 95 disco with 193,000 miles on it. The engine sounds like the valves are tapping. Almost sounds like a disel engine. The sound has been there for quite some time now, but really has not been getting any worse. By now it is annoying and a worry. Can anyone shed some light to this situation and how serious is this problem? Does this need to be fixed asap? How much will the repair cost? Any input will help. Thanks

By Drew on Saturday, August 25, 2001 - 11:12 am: Edit

sounds like bad rocker arms. do you have oil presure?

By Drew Adia on Saturday, August 25, 2001 - 03:39 pm: Edit

How can you tell if you have oil pressure? The oil light is not on.

By Norm Orschnorschki (Norm) on Saturday, August 25, 2001 - 08:56 pm: Edit

193,000 miles is quite a lot on these smallish aluminum block motors, especially since the truck weighs 4500 lbs and drives full time 4WD. Might be time for a rebuild -- although that might not solve the problem, especially if the motor has been overheated. Better yet, chuck the old motor before it blows up and put in a new 4.6 L with a chip.

---Norm

By Drew on Sunday, August 26, 2001 - 06:55 am: Edit

Norm,
Pretty expensive solution for an old vehicle. Is the tranny capable of the engine upgrade? Do you know of anyone that has done this swap and how does it work for them? Thanks for the feedback.

By Robert Mann (Oldscout) on Sunday, August 26, 2001 - 09:36 am: Edit

At 193k your near the end of your motors life. The noise could be many things, from piston slap, worn lifters, and/or worn rocker arms,ect . The oil pressure could be very low, and could be the cause of your problem. The light is triggered at 5-7 psi. The old rule of thumb is 10lbs for every 1000 rpms. If your motor had only say 15lbs at highway speed you wouldn't have a oil light and the pressure/flow is not up to your motors needs and rapid ware and noise would be the result.

What are your compression test results like?

By Drew on Sunday, August 26, 2001 - 09:47 am: Edit

Robert,
I will have a compression test done to find out. Thanks for the input. What if the compression tests are OK?

By Robert Mann (Oldscout) on Sunday, August 26, 2001 - 10:31 am: Edit

If your compression test is ok, I would go by a cheap mechanic stethoscope. There about $5.00 at harborfrieght.com . Using the stethoscope find the loudest cylinder and then pull the valve cover and check the rocker,push rod and lifter. A magnetic lifter puller is a cheap tool to have for this job. DO NOT mix up any of the lifters,pushrods or lifters! They must return to there original position. With the valve cover off rotate the engine by hand , watching for even rocker movement on all rockers.
Stethoscope:
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=41966

By rattle on Sunday, August 26, 2001 - 11:50 am: Edit

could be just the lifters not pumping up check your oil

By Drew on Sunday, August 26, 2001 - 02:49 pm: Edit

Thanks Rattle. The oil levels are OK.

Robert that sounds like a relatively simple trouleshoot. I'll try that after the compression and oil pressure test.

By Norm Orschnorschki (Norm) on Sunday, August 26, 2001 - 06:50 pm: Edit

I guess it depends on what shape the rest of your rig is in and how much you like driving it as to whether its worth dropping in a new 4.6 L, although it would seem that you've taken pretty good care of it to get that many miles.

After the years of abuse my wife dished out to the original 3.9 "B" motor, I put an RPi 4.6 long block w/ Tornado chip in my '95 Disc. I now have 5000 miles on the clock and have been quite happy with it -- it's a BIG improvement over the 3.9. This is the motor LR should have been using all along, and I understand it will be available on 2002 Discos. So far the 5 speed manual transmission has held up, even with previous wear to 2nd & 3rd synchros from my wife's chronic speed-shifting.

If you're interested, check out the RPi website. They have a whole section on Rover V8 problems which may be of interest.

---Norm

By Javier Velador on Monday, August 27, 2001 - 09:38 pm: Edit

I have the same knocking on my '94 Disco with 130K miles. It used to be faint, but after the last oil change, it has overheated some and now the knocking is even louder. You can really hear it when the engine is warm and idle. Once it revs up over 1500, the sound goes away.

The engine oil level is OK, though the tranny oil is a little low. My guess is that that may not affect it.

Thanks all for the input. Oh, and what was the website, Norm?

By Drew on Wednesday, August 29, 2001 - 06:44 pm: Edit

Javier, I believe the web address is rpiv8.com. Do you know how urgent it id to get this problem fixed?