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Oil Pressure light?

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kodanja

kodanja

Obi Wan
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When im driving on the highway then get off my oil pressure light comes on and the pressure goes down to about 25. The idle seem fine about 900 rpm's.
When I take off the pressure comes back up... /ubbthreads/images/graemlins/crazyeyes.gif
I checked the oil level, it's right up there, no leaks /ubbthreads/images/graemlins/crazyeyes.gif

any thoughts? /ubbthreads/images/graemlins/england.gif /ubbthreads/images/graemlins/grouphug.gif /ubbthreads/images/graemlins/england.gif
 
Cheapest and easiest test is to replace the sending unit, which helps control the light. It may have a tiny piece of dirt inside. Depending on the circumstances, 25Lbs PSI is not that bad. Could be the viscosity of the oil that you're using over another weight. Just my first gut reactions to your question.
 
I changed the oil sending unit just recently maybe its defective. I'm using 10/40w oil, should I just remove the bulb.....lol
 
There may be nothing wrong at all. When exiting the highway the rpm's will naturally fall and with it the oil pressure. Most likely all is well.
 
Dave, you are correct, but what about the "idiot" light?
 
[ QUOTE ]
[ QUOTE ]
... I'm using 10/40w oil....

[/ QUOTE ]At least in summer heat, you might want to go to a 20W/50, which is the recommended weight.

[/ QUOTE ]

Bingo!

Andy hit the jackpot there. Especially as hot as it's been lately. I'd use 20W50 all the time except in the dead of winter in sub-freezing temps. Even then, a blend of a couple quarts of 10W40 with a couple of 20W50 might be appropriate if the engine has some miles on it, unless you are in the Yukon and talking about sub-zero temps.

/ubbthreads/images/graemlins/cheers.gif
 
Paul,

The oil idiot light will flicker when the rpm's are very low. Usually, the only time you should see the light flicker is when the car is started. Of course, when the key is turned to the "on" position the oil light should light and then extinguish itself as soon as the rpm's come up.
 
I wish I had a definitive answer for that. Have you tried pulling the bulb from behind the rpm gauge and checking to see if there's any crud in the socket?
 
[ QUOTE ]
So then how do I get it to stop [flickering]?

[/ QUOTE ]I suspect that the 20W/50 will help here. I seem to remember that the idiot light senders are supposed to extinguish the bulb around 7lbs. pressure. It makes sense that, after a sustained run on hot days, the pressure might ever so briefly drop that low...faster than the mechanical gauge can react.

Basically, if it is only a flicker on a hot day after a long run, and pressure is fine (as indicated by the gauge) the rest of the time (and the oil level is correct!), things should be fine. I haven't yet seen the oil light flicker on my Herald, but I have noticed that the pressure drops significantly at a very hot idle (as indicated by a supplementary Smiths gauge) after a hot run, but not enough to fret about! Oh, and I'm using 20W/50.
 
thanx for the insight, i'll do the oil change (20w/50) before I do anything drastic

thanx again! : /ubbthreads/images/graemlins/driving.gif /ubbthreads/images/graemlins/england.gif
 
As an aside to this thread. I had an interesting experience one very hot summer in my TR6 about 10 years ago.

I went to a Rocky Mountain Triumph Club meeting in Denver and the air temp at 6pm was still hovering around the century mark. Even with fresh 20W50 I watched my oil pressure creep down during the drive to Denver.

That evening I took an alternate route home through Golden, to Boulder, Longmont etc... When driving through the rolling foothills I could watch my oil pressure change. As I would drop into the cooler air in a trough, the pressure would go up and as I would climb back to the warmer air at the crest the pressure would drop. I could personally feel the air temp change as well. It wasn't just the car feeling the difference.

What amazed me was how rapid the effect was and how quickly the guage reflected it.

After that I ordered an oil cooler. /ubbthreads/images/graemlins/thumbsup.gif

/ubbthreads/images/graemlins/cheers.gif
 
Good choice Shawn. I didn't go the cooler route, but improved my oil pressure (hot on a 85-90 degree day after driving hard) from 15lbs to 25lbs psi at idle by the following three items:

Spin on oil filter adapter (using Fram filter now but will switch to K&N on next change)
New oil pressure relief kit (TRF)
Added external oil feed kit from switch to back of cylinder head (and replaced 3-prong switch at the same time)

I do run 20/50W oil all year round, but never drive in winter so no matter.

I don't know which contributed the most because I did all three at the same time. My oil pressure under acceleration is up to 75lbs psi as soon as I hit the throttle. Of course I only have 54K miles and have changed the oil and filter a zillion times, so that does help.
 
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