Oil light

[Matt Chapter]

I've noticed recently that at startup the oil light is a little slower to go out. Maybe a half second instead of a quarter second.  What would be a good starting point for troubleshooting?  Is the oil pump driven by the timing chain?  I've got the oil level at 3/4 dipstick and I'm using 20w50 for the Texas summer.

[montmil]

Matt, Have you recently changed to the 20W50 from a lighter oil? Austin is still relatively cool in the mornings and a slightly heavier 'summer weight' oil will move a wee bit slower in a cold engine... I'd guess about, oh, a quarter-second slower. Ride happy, amigo.

I'm more worried about these massive, expensive condo projects that are destroying the unique personality of South Lamar and SoCo. That's my mini-rant for you.

[Barry]

I guess you want some assurance that there isn't a leak bleeding off oil pressure. Short of actually measuring the pressure with a gauge I'd do a test. Ground the ignition leads and crank the engine on the starter as you might do when priming the system after an oil change.  The oil light should go out even at low cranking revs, always does for me anyway at least with cold oil. I've never tried it hot but a hot test would give you some reassurance that an oil pressure of something like 7.5 PSI  is being developed at the lowest possible revs.

If yours fails the cold test I'd say you have a problem that needs investigation. If it passes cold and fails hot I'll undertake to check mine hot to see if it's reasonable to assume the light should go out hot.

[Matt Chapter]

Matt, Have you recently changed to the 20W50 from a lighter oil?

Nope 20wFiddy no matter what Barry says!  I've seen this with the engine hot as well as cold, though.

I'll have to pay more attention and see if the light goes out during cranking.  I know that it will go out sometimes before I've managed to get it started.

Mostly I was wondering if it could be affected by the timing chain.  I think I'm hearing a whisper of grinding and recent posts about the timing chain have me nervous.  Also I think I've seen the oil light come on at idle when the engine was fully warmed, once.  It was out of the corner of my eye in rush hour traffic though.

[Justin B.]

If it is bugging you you can add in an oil pressure gauge so you can see exactly what is going on.  I had some oil pressure concerns with the Dawg and it helped me out with some peace of mind.  I have a Moto Meter 150 PSI gauge, steel braided line, and a "manifold" I machined to allow gauge and idiot light to coexist if you are interested - just PM me...

[Barry]

The oil pump is driven off the end of the camshaft so in away it's related to the timing chain but a bit of slack in the chain isn't going to affect oil pressure.

I would never recommend thinner than 20W50 for Texas - honest I wouldn't  

[Tony Smith]

I would never recommend thinner than 20W50 for Texas - honest I wouldn't  

Similar climate here and I run 20W60 in summer and 20W50 (Penrite oil) in winter.

If I am going touring in summer I have been known to use Penrite 60W and on one occasion Shell Aviation 50w single grade. Then I fitted a oil pressure gauge and got a major fright - no more mono grade oils for me.