| Author | Message | ||
     Scott Willard (Scott_willard) New Member Username: Scott_willard Post Number: 1 Registered: 03-2004 |
Hi all. I just acquired my first Land Rover, a 98 Disco. Unfortunately, the previous owner(s) didn't do a good job with the maintenance on this vehicle and it has some problems that need to be fixed straight away. The most pressing of these problems appears to be the oil pressure. At purchase, the oil pressure light would come on above 2K RPM. I searched these forums for this problem and found that the oil screen has a habit of clogging. So, I pulled the oil pan and cleaned the oil screen. The oil pan had a layer of tiny coked oil balls on the bottom of it but there was no metal mixed in with it. The oil screen was partially clogged but it wasn't too bad. I cleaned everything and reassembled. After adding oil and changing the filter I started the car. At this point the oil pressure light came on IMMEDIATELY and stayed on. Next I replaced the oil pressure light sender and restarted the car with the same result. No pressure was indicated. The lifters also started clacking loudly at this point. At this point I purchased a set of shop manuals on CD and started reading. According to the manuals, I should check oil pressure. If this fails it says to rremove and evaluate the oil pump. That's what I plan to do now. One note, I unscrewed the oil filter after changing it and it was full of oil as if oil had been pulled from the pan (sump) and deposited there. I only primed the filter with about a 1/2 pint of oil before installing it. This has been the ONLY sign that I have any oil pressure at all. This is where I would like to seek the advice of experienced owners. Questions..... 1) Is there anything that I should do BEFORE pulling the oil pump to resolve this? 2) Are there any special tools that I will need to buy that can't be worked around? There was a tool mentioned for removing the main seal and also a "Woodruff key". What tools should I buy? 3) What size are the threads for the oil pressure indicator light? This is where I'll tap the pressure gauge. One other comment.... this car is displaying the check engine light as well. This is undiagnosed as of yet. I have a OBDII code reader and datalogger on the way. By the way, I'm VERY impressed with the way these cars are put together. The underside of this Disco looks like a tank. Thanks, -Scott | ||
| Narinder Pal (Narinder) Member Username: Narinder Post Number: 61 Registered: 03-2003 |
Before you get into pulling the front cover off to get to the oil pump, do yourself a favour and pull off your valve covers and see what you find. If your car didn't have regular oil changes and/or the ventilation tube is clogged up.... prepare yourself for a scary sight. I bet u that under your valve cover you will find dried oil sludge everywhere, clogging everything. You will have to thoroughly clean the motor (right down to the valley gasket), it's alot of work but doable | ||
| Narinder Pal (Narinder) Member Username: Narinder Post Number: 62 Registered: 03-2003 |
do a search on "dirty lil motor" for some pics of what i am talking about | ||
| Scott Willard (Scott_willard) New Member Username: Scott_willard Post Number: 2 Registered: 03-2004 |
Interesting. I wouldn't be surprised if that is the case. Still, if it has fresh oil and the oil screen is clear, shouldn't the oil pressure indicator light show pressure even if the upper part of the engine is blocked? The pressure light is right there in the front case with the pump. I wasn't able to find your pictures but I'll keep looking. I'll pull the VC's tonight. Thanks, -Scott | ||
| Scott Willard (Scott_willard) New Member Username: Scott_willard Post Number: 3 Registered: 03-2004 |
Narinder, I pulled the valve covers and the valley gasket tonight. Good grief. This thing is UNBELIEVABLY coked up. I've never seen so much coked oil. If I could find the previous owner, I'd kick him in the nuts. Anyway, can you summarize the cleaning process that you used to bring your car back to life? I did the search that you suggested but didn't come up with anything. Thanks, -Scott | ||
| Don Johnson (Dl_johnson) New Member Username: Dl_johnson Post Number: 6 Registered: 02-2004 |
The post he is taking about is here. Scary stuff. ../17/36162.html> | ||
| Geoff 93 RRC (Geoff) Senior Member Username: Geoff Post Number: 288 Registered: 11-2002 |
The pressure relief valve for the oil pump must be stuck. You can pull it out, check it and the spring, and clean the bore. A wire brush and a shop vac can help get rid of the oil residue. Poke a wire down the oil drains in the heads. Carb cleaner dissolves the goo pretty well. You probably need to drop and clean the pan again if you clean the valley area. Change the filter after restarting the engine for a few minutes and then again after 50 miles or so. Be sure you change all of the breathers. | ||
| Ron Brown (Ron) Senior Member Username: Ron Post Number: 796 Registered: 04-2001 |
"The pressure relief valve for the oil pump must be stuck. You can pull it out, check it and the spring, and clean the bore." I don't think this is possible on a Disco I 4.0 as the pump is in the front cover. Here is what I would be inclinded to do. Clean out the valve covers of sludge as best you can. fill it up with about 50% diesel or kero with 50% oil and turn it over with the starter about 50 times (intermittently to not kill the starter) I might also overfill and let it sit overnight and turn over a couple times. Then drain and fill with cheap oil and run it at idle. it will clatter for a minute or two but you should get oil pressure. I would then add a quart of resoline or similar and drive it (gently) for a while (200 miles or so). Change it again and then drive it a bit and see what the oil looks like. The other main consideration is the check engine light, if its valves (odds are pretty good) you will be pulling the heads anyway so you can clean them seperately and also gain access to the oil passages in the block and flush them out. Ron | ||
| Geoff 93 RRC (Geoff) Senior Member Username: Geoff Post Number: 289 Registered: 11-2002 |
Ron, on the 4.0 the pressure relief valve is just above the oil filter on the front cover, accessible from outside by removing the circlip. | ||
| Narinder Pal (Narinder) Member Username: Narinder Post Number: 63 Registered: 03-2003 |
I had the exact same problem with my 1997 Disco...I used an engine friendly solvent, a hi speed drill with a suitable attachement to break up the sludge, a shopvac to suck it up... it was alot of hard/dirty work. I got it cleanned up...put it back together and ran the truck for about 10 mins, changed the oil. Did this a few times. Then I dropped the pan, checked the screen, put it back together...drove the truck for 500km's and changed the oil again. The truck has been working great since the job and I have great oil pressure. Make sure you check the breather tube because it is likely clogged and part of the problem why u have so much sludge. | ||
| Scott Willard (Scott_willard) New Member Username: Scott_willard Post Number: 4 Registered: 03-2004 |
You guys have mentioned the breather tube a couple of times. I assume that this is the rubber tube that goes from the rocker cover to the intake plenum. FYI, it was completely blocked with coked oil. Nasty. | ||
| Geoff 93 RRC (Geoff) Senior Member Username: Geoff Post Number: 290 Registered: 11-2002 |
Yep. If the breathers are not clear the stuff has no place to go so it distills out in the engine. Can also cause oil leaks since crankcase pressure is affected. |
