Club 80-90 Forums

well i bit the bullet, bought the necessary from GSF and did the oil change, all went well - until i took it for a drive, got a flickering oil warning light then on permanent.

breakdown guy said the oil was way too thin and wasn't getting up to pressure. so today, drained it again as best i could without warming up the engine, then put in some 20W50 mineral oil i got. Again, all went well, until flickering light and then on permanent. Checked the oil, put a little more in and drove home without the light on, very occasional flicker if i had to speed up.

my last ditch plan is to warm it up this time, drain and put just 20W50 in, there must have been some of the "original" left in first time round. apart from this i'm stumped.

any other ideas?

Just put in 15/40 mineral and all should be well

Theclash wrote:Just put in 15/40 mineral and all should be well

15? nearly bought that, the haynes says 20w50, i figured thicker the better?

i always bow to greater knowledge as i'm just guessing, is the 20w too thick to get the pressure?

You need 20W50 or preferably 15W50 for air cooled motors.
Did you get the correct oil filter and did you fit the strainer gauze correctly (make sure is not blocking the oil pickup pipe)?
Otherwise you need to get the oil pressure checked.

bigherb wrote:You need 20W50 or preferably 15W50 for air cooled motors.
Did you get the correct oil filter and did you fit the strainer gauze correctly (make sure is not blocking the oil pickup pipe)?
Otherwise you need to get the oil pressure checked.

the choice was either 15w40 or 20w50, i plumped for the 20w50.

correct oil filter fitted

i only cleaned out the gauze etc, how would i fit it back incorrectly? could elaborate please.

how do iget the pressure checked?

cheers

You would take it to a garage or someone who has an oil pressure tester. Will be tested cold and hot. Garage will give you a psi or bar reading which you put on here for comment

Basically, they will screw the tester and guage into the location of the oil pressure switch (which could be faulty)

Also not uncommon for the wiring to fail...


Em
xx

monkeyboysee wrote: i only cleaned out the gauze etc, how would i fit it back incorrectly? could elaborate please.

Is the pick up pipe blocked by the strainer

I had a similar problem and, of course, stopped immediately. Not too far from home as it happened. I bit the bullet and drove the few yards home. It turned out that the oil pressure switch had failed. BUT it could be poor oil pressure so I wouldn't risk even the shortest journey until that had been checked.
I had a motorcycle engine let go at about 120 mph because of low oil pressure and the way I found out was because the middle rod had smashed a fist size hole in the crankcase; oil light flickered, came on then bang.

Someone else has suggested possibly an airlock?

Think I'm going to start over and change it all again, see if it makes a difference. Also going to order a switch, can't work out which one though.

Wish I hadn't bothered now, van has been running fine with the same oil for over 3 years!

This all seems very coincidental so chances are this is just a dodgy wire or switch rather than something more terminal like low oil pressure.
Stick with the 20W50 ...can I ask how much oil did you use?
I really wouldn't drop the oil again, draining the thinner oil and refilling with the 20W50 won't have left much of the thinner oil, certainly not enough to make a difference as far as this problem is concerned.
I would be suspicious of wiring to the oil pressure switch...maybe the switch itself although this would be a massive coincidence.
I guess another possible cause could be a stuck pressure relief valve caused by debris dislodged during the change...really difficult to say.

Measuring actual oil pressure (cold/hot) would certainly clarify whether this is 'actually' low pressure or a false negative (switch/wiring) obviously don't run the engine with the oil light on permanently.
Best of luck.

Martin

Update

finally got chance to have another look, first job replaced the sensor, no change at all, light lit permanatly!

next, i dropped the oil out, removed and drained the filter, got a good 3.5 litres out so pretty empty. refilled the filter, filled back up, light still on. after a bit of warming up the light went off. took it for a spin and started getting a flicker, very intermittent.

the thing is, the engine sounds right, performs right, i'm sure by now it would have seized as well!

tomorrow i'm going to put a new spade connector on the wiring to the sender, see if its that? another thought, i have had problems with the pcb strip, i have had to wire in separate dashboard lighting, it occurs to me that maybe there is a problem there? i think i will try and lash up a test light direct.

what a ballache, i'm thinking electrical fault at the mo, the engine just sounds right.

any thoughts?

The oil pressure warning light comes on when the circuit is grounded through the oil pressure switch, so a bad contact at eg the spade connector on the switch will keep the light off rather than putting it on. Try running engine with oil pressure switch disconnected, if light still flickers then it is a wiring problem. If flickering only when switch connected then it is either switch or low oil pressure.

out of interest, what would cause low oil pressure?

Worn mains, big ends, oil pump.
blockage in oilways.
relief valve failure.
wrong grade oil.
overheating.
oil foaming.
low oil.

kevtherev wrote:Worn mains, big ends, oil pump.
blockage in oilways.
relief valve failure.
wrong grade oil.
overheating.
oil foaming.
low oil.

well i can discard some of that list, its all strange as it runs fine and sounds "right" if you know what i mean. where is the oil pump, i haven't checked the electrical feed to it etc.