Oil Warning light comes on after a few hours?

[paulmack]

Hi All,

I have just returned from a couple of weeks in France with my '86 T25 High-Top (RHD Petrol 1.9 litre).

Before I left I had a mechanic check all the levels for me (oil, brake fluid etc) - it came back with a superb bill of health.

I have had it for 6 months with absolutely no issues - it runs like a dream.

Anyway, after driving for about 3-4 hours at around 70mph I noticed the oil warning light flash every now and again.
Over the next 20 minutes or so the flashing started going faster and I noticed that the van was struggling to reach the same speeds.
Performance was definitely affected and I was struggling to keep up a cruising speed of 50-55 mph.

Panicking I pulled over and checked the oil levels - all good.
I phoned the mechanic that checked the van out and he said that unless the van was overheating (it was not) or the engine was making noises (it was not) then I shoudn't worry and the red light was probably a red herring.

Anyway, still unconvinced I set off again and the 15 minute pit-stop seemed to have done the trick - she was off like a rocket with no red light and reaching a decent speed again.
However, after a further half hour or so the light started flashing and the van started slowing down again.

We made it safely and for the remainder of the trip the van went fine, although we didn't travel any great distances.

On the way back I kept the top speed limited to around 60-65 and she went fine, although the light started flashing slowly after around 4 hours driving.
No real performance issues.

I have searched the forums and the wiki and whilst there is plenty of info on oil levels and pressure I cannot see if anyone else has had the same issues.

Does anyone have an idea?
Was I just pushing her a bit too hard on the way down?
It was fairly hot - maybe she was just overheating.

I would be interested to hear from anyone who has had similar issues (specifically the slowing down once the oil light started flashing) and what they have done to fix it (if anything can be done!).

Thanks in advance,
Paul.

[syncrosimon]

I would initially try changing the oil to a slightly thicker grade, such as at least a 15-40 or 20-50 if you can find it. It maybe that as you were running at more or less full throttle that the oil was getting hotter than normal, reducing the viscosity, and allowing the oil light to flicker. The oil change should sort it out. Normal 10-40 oil is prob a bit thin for these engines.

[toomanytoys]

Oil cooler needed for extended periods of fast/loaded driving in hotter ambient temps.. plus the trick of thicker oil.. 20w50 will help..
but.. if you say it felt like it was slowing, then you may have done some damage and the problem will only get worse..

I have seen oil temps of 115+ (reliable temp stickers on oil filter) even with a standard type oil cooler..

[HarryMann]

Performance was definitely affected and I was struggling to keep up a cruising speed of 50-55 mph.

But what were the conditions??

Hot...? high load, light? Wind? Incline (slight but imperceptible) etc.. These are big heavy vans, with small engines, when everything is right they go OK but...

Once everything gets really hot, all engines will lose power and slow down, if only that the intake and cyl temps reduce volumetric effciency, it might even be detonating!
Then, if the big-ends were running themselves, ditto!

If an engine doesn't want to go at a certain speed, then that itself is a warning...

20-50 !

Lots of wiki and

[paulmack]

Thanks to all that replied.
I will try the oil change straight away - great advice thanks.

Harry - yes, there were 'all of the above' in play - I had a fairly heavy load (missus, surfboards, awning, baguettes etc!), there were high winds the whole journey, it was pretty warm etc etc

I think you are bang on the money - when all conditions are right these vans go great but if not then there could be issues.....

I also suspect that once that red light started flickering my paranoia took over - inclines become performance failures blah blah blah

I will send it back to the mechanic for another lookover and I will mention all of the additional info from your replies too.

Thanks again and god bless 80-90!

[Mr Bean]

Hi All,

I would be interested to hear from anyone who has had similar issues (specifically the slowing down once the oil light started flashing) and what they have done to fix it (if anything can be done!).

Thanks in advance,
Paul.

I had a dead ringer all but the slowing down. Mine is a 1988 Liesuredrive hightop waterboxer. Are you sure it wasn't the waterboxer equivilent of Twostroke Twitch? (explanation below) When I first got the van I marvelled at the low engine revs particularly in fifth. However when loaded up for a holiday in France and towing my boat I found myself wondering how the engine could cope with pulling such a weight which it did willingly at between 70 & 80 MPH. If pushed itwould occasonally give a flicker of the oil warning light and the light was prone to come on on tickover. As you probably know the oil pressure swith comes in three colour coded (presumably) ranges. Although at that time IO did not ownthe Bentley manual which may say which is which. However I did replace the pressure switch and Oil Pump which lessened the problem but did not cure it completely. Again without the manual I had no idea what the oil temp should be but felt that it was too hot. So I fitted an oil cooler from Kenlow. It cost over £100 but well worth it for peace of mind. I can get the light on if I slow the engine down by dragging the clutch in gear on tick over but am completely happy to set off again this year. The adapter fits under the oil filter and two swage ended flexible pipes run to the ccoler matrix. I have a pair of computer fans connected via a relay to the radiator fan. The matrix is installed just to the right of the rear number plate flap and the fans are set to suck air out of the engine bay. I am currently trying to work out how to upload pictures but if you are very keen I could send you some picks on conventional email.
Cheers
Ken
Two stroke Twitch: The involuntary pulling in of the clutch and closing the throttle when while flat out on an overtuned two stroke motorcyle of a certain vintage when a slight change of engine note is imagined. This is usually accompanied by an equally involuntary clenching of the bottom.

[Grun]

ken,
You said.........

I am currently trying to work out how to upload pictures

Have a look in the wiki Here

I can usually manage photobucket.... just

Mike

[Mr Bean]

ken,
You said.........

I am currently trying to work out how to upload pictures

Have a look in the wiki Here

I can usually manage photobucket.... just

Mike

Well I am having all sorts of trouble with my PC today and both Muchos and Photobucket crash when I click to upload. Plus those thick as poo's engineers from virgin have done all sorts of stuff to my broadband connection including fitting a new modem which is incompatible with my wireless router when all I need is a connection re-terminated in the loft. Now they want £40 off me for one of theirs. When my ready light blinks I have to go into the loft and agitate a simple straight connector which I keep on telling them. Bearded balloon nutter has sold all but 2% of it now so what does he care as if he ever did. Damn and blast! Spit and curse. Baah poo! I am going off to watch one of the many repeats that evn the BBC are putting on nowadays. Lucky it is Freeview as if you don't haveto pay for the licence!
Grumpy old Ken
Well moaned? Phone 0870 .....
Still fingers crossed the van is going OK now