110 V8 Engine Query.

Hi. Passing a garage this afternoon I had a quick look at a l/r for sale; it has a 3.5l carb V8. Seemed to drive ok (nice noise) but was a little concerned that a warning light showing a red oil can came on and stayed on when I parked with engine idling. If I revved the engine a bit it went out...

Should I worry about this suggested low oil pressure? I believe the engine has done about 70k and has been used very little during the last couple of months. I dipped the oil and it seemed nice and clean with no sign of water or gunge in it, but I wasn't really prepared for a more detailed investigation when I saw the vehicle.

(If I'd known I was going looking at l/rs today I'd have asked the group in advance what nightmares to look out for in 110s from the early 80's. Beyond the normal chassis and bulkhead rot is there anything else they are prone to??)

Many thanks,

M.

Reply to
McBad
Loading thread data ...

Is it low oil pressure or is the tickover too low ( I know it amounts to the same thing!) but is the engine/oil pump knackered or will an increase in idle sort it? Richard

Reply to
Richard

On or around Sun, 21 Sep 2003 23:31:31 +0100, "McBad" enlightened us thusly:

it's not at all uncommon on V8s. Nominal pressure is 30-40 psi at 2400 revs, but when hot (especially with the wrong oil and needing an oil change) they can drop down to about 10 or less at idle. The intermotor book says the switch closes at 5-10 psi, you can get light-at-idle. it should go out at fast-idle sort of speeds.

The engines should have 20W50 (or 15W50 is OK - the 50 part is relevant) unless fairly recent (not sure when, mind). If it's been filled with 15W40 or somesuch, then it'll have lower pressure anyway, and if the oil's due to be changed, it'll be lower as well.

dunno if they've changed anything on the engine other than the oil specification, though. The older books all say 20W50, the disco book says

15W40 it think.
Reply to
Austin Shackles

Correct value is 3-5psi, not a standard switch value for any other engine. Genuine switch is only £3ish from landrover. Get them to change the oil and filter for the correct grade and replace the switch with a genuine part, then have another look. Even if the light comes on at around 3-400 rpm (well below normal idle) there's a serious ammount of wear. Badger.

Reply to
Badger

On or around Tue, 23 Sep 2003 17:37:31 +0100, "Badger" enlightened us thusly:

well, the intermotor fitting is for all early V8s. Lists the 3.0-5.0 one for RR 3.5 1987-89, Defender 90/110 1988-on, Discos. Intermotor number

50611, whereas the other one (the 5-10 psi one) is 50600, and applied to earlier V8s in LR vehicles.

As to Rovers, it's listed for all the pre-SD1 variants, interestingly, the SD1 has a different one listed with 3 terminals (n.o./n.c.) and 2.0-8.0 psi.

Reply to
Austin Shackles

Yeah, but intermotor didn't design the engine or it's oil system! L/R now only supply the 3-5 switch as a replacement for all earlier type, due to known problems with the higher value switches. If switch operates at 9.9, say, and engine is a bit worn, then light could come on at idle even though the engine is within limits. Also remember that pre-SD1 engines have even less pumping ability due to the smaller pump rotors and you can see the problems that lie ahead. SD1 switch is linked to the fuel pump relay, hence the contacts that are open when pressure falls. If you crash and engine stalls, fuel pump is cut. Badger.

Reply to
Badger

On or around Wed, 24 Sep 2003 17:16:34 +0100, "Badger" enlightened us thusly:

aha. that's what it's for.

I was busily hatching a theory that the revised lower-pressure switch co-incided with the recommendations to use thinner oil :-)

which indeed they may; as the SD1 injection one is different, as above. Either that or too many people were complaining of oil lights coming on... personally, I'd rather one that comes on at idle; slightly more chance of it coming on soon enough to avoid destroying the engine if the pressure drops at speed.

Mine has a gauge, thobut. at it's normal idle speed of 900-1000 it shows about 15-20 hot, at in-gear idle speed of about 5-600 it drops to about 10. Idle speed set slightly high or it tends to stall if idling in gear for more than a few seconds. Also, it idles considerably slower when cold.

Reply to
Austin Shackles

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.