| Author | Message | ||
     Trevino (Trevinorungbull) New Member Username: Trevinorungbull Post Number: 7 Registered: 12-2003 |
I was reading on a oil change procedure and if not followed then the engine will lose the prime. what is the prime and the affects of losing it? how then do you regain it? The procedure I read was, drain oil, replace oil cap, refill engine with new oil, then replace the old filter with a new filter and with oil inside it. Normally I just drained oil, recap, removed filter , drain and replace filter then replace with new oil, is this wrong? | ||
| Kit (Kitscott) New Member Username: Kitscott Post Number: 3 Registered: 10-2003 |
I'm not sure if I have the terminology right, but here's my interpretation of the prime. The idea is that if you drain the oil, AND the filter before refilling the engine with oil, your oil pump will end up with air(?) in it and, from that point on, will not circulate oil throughout your engine. I know I have read the procedure for regaining the prime, but I can't seem to find where I read it. I thought it was in the owner's manual but can't seem to find it. At any rate, it's out there somewhere. In fact, isn't there an oil change write up in the tech section of this site? Anyway, if you do some searching, I'm sure you'll be able to find it. I don't know where the oil pressure sender is, but if you lost your prime, you'd probably get an indication that you had lost oil pressure from the dash light. Good luck, and HTH. Kit | ||
| Phillip Perkinson (Rover4x4) Senior Member Username: Rover4x4 Post Number: 613 Registered: 02-2003 |
yes your are correct drain oil replace oil. remove old filter after you have put new oil in the sump, then replace old filter with a new filter thats been filled with oil. then start let run for a sec, then check top up blah blah blah | ||
| Matt (Doc175) Member Username: Doc175 Post Number: 221 Registered: 11-2002 |
Do you need to follow the same steps on a Tdi? | ||
| Greg French (Gregfrench) Senior Member Username: Gregfrench Post Number: 664 Registered: 11-2002 |
What happens if it isn't primed? | ||
| Dean Brown (Deanbrown3d) Senior Member Username: Deanbrown3d Post Number: 1228 Registered: 02-2002 |
On the D2, I never prime the filter. And it doesn't say to do this in the service manual either. Dean | ||
| Axel Haakonsen (Axel) Moderator Username: Axel Post Number: 696 Registered: 02-2003 |
Not really, that's what I alays do, too. I take the gasket off the filter, coat the gasket with fresh oil and put it back on the filter to create a better seal, and fill the filter with oil before I install it, though. If you don't fill the filter, it will take a few more seconds to get your oil pressure back up when you start the engine after an oil change. I have never had a problem with the oil pump loosing it's prime, but if it happens, you would know pretty quickly, the first indication would be some serious valve noise from lack of lubrication. - Axel | ||
| Rick Clarke (Tugcap) New Member Username: Tugcap Post Number: 36 Registered: 02-2002 |
The term 'prime' refers to a pump. losing prime means losing suction, or suction pressure. A pump that loses prime usually tries to pump air, which immediately replaces the liquid that isnt there. A positive displacement pump will pump the air, creating a suction, and 'pull' more liquid into the suction (if there is liquid). A non-positive displacement pump, wont pump air, wont renew its liquid prime,and get airbound. Either way an airbound pump designed to pump liquids will fail relatively quickly unless reprimed. | ||
| Tbow (Tbow) Member Username: Tbow Post Number: 166 Registered: 12-2002 |
Priming the pump is more an issue when your rebuilding the eingine or replacing the front cover/oil pump. With a new engine and/or new front pump assembly you have to make sure that the pump gears are heavily coated with oil. Otherwise the pump gears will not have a good seal to pump oil from the pickup. On an oil change if possible it's always a good idea (but not necessary) to fill the oil filter with fresh oil this way you shorten the length of time the engine runs without oil while filling the oil filter. The way your doing it is just fine. | ||
| Matt Anderson (Disco01) Member Username: Disco01 Post Number: 100 Registered: 10-2003 |
How about using a K&N oil filter--less changes--would this mean less wear over time? | ||
| ron morgan (Rpm2429) New Member Username: Rpm2429 Post Number: 15 Registered: 08-2003 |
I have changed alot of oil on autos and aircraft and never had to drain, fill, then replace filter, fill with new oil before hand etc. The only way to purge the air out is to leave your oil filter loose, start the engine and when oil starts to squit out tighten it down. The oil pump is a positive displacement type pump, as long as there is fluid at the pick-up, it is pumping. Just drain and refill and put on a new filter, if the oil pressure light does'nt go out in a sec. or two then your pump is toast. just my 2 cents. ron | ||
| Geoff 93 RRC (Geoff) Member Username: Geoff Post Number: 191 Registered: 11-2002 |
Losing prime is a worry for the 3.9L with external oil pump. Drain old oil from sump, replace oil, fill new filter with oil, replace filter. If you lose prime, remove the pump and pack it with petroleum jelly. Most serpentine belt US Discos have the oil pump built into the front engine cover which isn't as susceptable to loss of prime.. With most engines oil flows through the oil filter first before the engine gets any lubrication. Filling the filter with oil never hurts IMHO. | ||
| Trevino (Trevinorungbull) New Member Username: Trevinorungbull Post Number: 10 Registered: 12-2003 |
way thank you kindly, fellow rovers, for your input |
