| Author | Message | ||
     Jeff Conrad (Jwconrad) Member Username: Jwconrad Post Number: 78 Registered: 02-2002 |
I am suspicious that my oil pump may have lost its prime. How can it be re-primed? | ||
| Joey (Joey4420) Member Username: Joey4420 Post Number: 247 Registered: 04-2003 |
Jeff, why do you feel that you oil pump has lost its prime? As far as I know if somehow it would completely lose prime and didn't prime itself, you engine would burn up for lack of lubricant. Basically if it would "lose" prime, it would just be a dry start, then all would be well. I am sure that a more qualified mechanic will pipe in and explain why I am sitting in left field not paying attention to the game..... | ||
| Geoff 93 RRC (Geoff) Member Username: Geoff Post Number: 100 Registered: 11-2002 |
What year Disco? The '96 up models have a newer oil pump design that isn't susceptable to loosing prime. If you have the older 3.9 engine with v-belts the oil pump is primed using Vaseline pushed into the pump gears. Take off the filter and the hollow bolt the filter screws onto, then the cooler pipe mount. Put the Vaseline in the freezer first to keep it from getting runny. Thinner oil is easier for the pump to initially suck up. Does your oil light stay on? How many miles? You could have a bad sensor or a clogged pickup screen. | ||
| Jeff Conrad (Jwconrad) Member Username: Jwconrad Post Number: 79 Registered: 02-2002 |
I installed a new pump several months ago after a failure of the original. Since then the oil light stays on for about 5-10 seconds after start up. After a recent oil change that time seems to be closer to the 10second range and I am getting a little ticking before the pressure builds up and the light goes out. The truck is a 96 4.0 | ||
| Geoff 93 RRC (Geoff) Member Username: Geoff Post Number: 101 Registered: 11-2002 |
If the oil light goes out re-priming isn't going to help anything. The symptoms sound like worn crank/rod bearings and/or plugged pickup screen. Drop the pan and take a look. Hope for a clogged screen. Replacements are cheap. You could try cleaning it too. What oil are you using? 10W-30 will pump easier. With the pan down pull one of the bearing caps. If you see a lot of copper color on the bearing shell they've probably had it. They could have worn with the original pump failure. Loose bearings bleed off pressure. Not sure what the 4.0 torque specs are for main caps. You will need to get that info first. There are shops that will replace the bottom end bearings so check around. | ||
| Dave_lucas (Dave_lucas) Senior Member Username: Dave_lucas Post Number: 415 Registered: 02-2002 |
Jeff, I had the same thing just happen to me, at the first start in the morning I would get a clacking that sounded like valves, or if I let it sit for more than a few hours I would also get a ticking noise but not as loud as the first start. I dropped the pan today and found a bolt sitting in the pan, the bolt was from the oil pickup and the other bolt in the oil pickup was loose, so you may want to check them. | ||
| Tbow (Tbow) Member Username: Tbow Post Number: 152 Registered: 12-2002 |
You said that it seemed longer after you changed the oil. Before you go through all that, I would first try changing your oil filter with another brand. The backflow or anti-siphon flapper might not be working correctly allowing oil to bleed back out of the system. | ||
| Joey (Joey4420) Senior Member Username: Joey4420 Post Number: 259 Registered: 04-2003 |
Good point Tbow....from what I have read, a bad oil filter backflow valve will kill an engine fast. (Fram is known for bad backflow valves) Of course you could also add some Lucas oil stabilizer that always helps keep things running better IMHO. | ||
| Narinder Pal (Narinder) Member Username: Narinder Post Number: 42 Registered: 03-2003 |
I had the same problem unfortunately, it wasn't the filter, the oil screen wasn't clogged and the pick up tube was secured, wasn't the sending unit, I replaced it ... I wish I checked the rod bearings as I suspect that's the problem now. My symptoms included taking 10 - 15 seconds for the oil light to go out in the morning (longer during winter months). Once warmed up the truck seems to work fine for the first 1/2 - 3/4 hour on the road... after that the oil light will flicker. The oil pump seems to be working fine because it seems to always be pumping oil (don't get significant lifter noise when the light comes on) ... I'm guessing it's my rod bearings now ... bleeding off pressure when it's cold and when it gets hot... does that make sense???? | ||
| Bazzle (Bazzle) New Member Username: Bazzle Post Number: 18 Registered: 09-2003 |
Narinder, the only way to be sure is to hook on a Mechanical aux gauge and do the same run whilst noting oil pressure. Bazzle | ||
| Narinder Pal (Narinder) Member Username: Narinder Post Number: 43 Registered: 03-2003 |
That's my plan... ofcourse Land Rover doesn't use a standard size fitting .... that would be too easy! | ||
| Narinder Pal (Narinder) Member Username: Narinder Post Number: 44 Registered: 03-2003 |
I checked my oil pressure today while the light was on during the morning start .... near 0 psi pressure ... I hate to think what damage I was doing to my motor during the morning starts! When the light went out the pressure went up to about 10 psi ...still very low. I took the pressure relief valve out and on a hunch put it back in with two additional washers in case it was the problem... the pressure shot up to the 28 -30 psi range ... I think I found the problem .... | ||
| Geoff 93 RRC (Geoff) Member Username: Geoff Post Number: 112 Registered: 11-2002 |
Great find. Do you think the pressure relief valve was stuck open and the stronger spring pressure closed it or was the spring worn out? Was the valve gunged up? | ||
| Jeff Conrad (Jwconrad) Member Username: Jwconrad Post Number: 80 Registered: 02-2002 |
Ok Narinder, you have got my curiosity up. Where is the pressure relief valve? | ||
| Narinder Pal (Narinder) Member Username: Narinder Post Number: 45 Registered: 03-2003 |
it's below the oil pressure switch and just above the oil filter. It's connected with a clip. The spring looked good and it wasn't too grunged up but it must have been failing or out of spec. By installing the washers I compressed the spring requiring more pressure for the valve to open. |
