Oil light flickering - fresh rebuild

[fordperson]

I have a bmw I6 engine right after a fresh rebuild everything is fine up until I get it to operating temperature where if i rev the engine and it goes back to idle the oil light flickers... it doesnt happen when the engine is cold tho.

my main question is, if there is a possibility the main/rod bearnigs clearances might cause such a behavior.

Tom

[MagicRat]

Oil lights should be banished to the deepest realms of Mordor.

Get a good quality oil pressure gauge. A mechanical one that uses a plastic pressure tube and a 270 degree needle sweep would be great, then you can see what the pressure really is.

Sometimes an oil light sender can be inaccurate and give you a false reading.

Otherwise, lets assume you do have low oil pressure. Warm oil is thinner. It can leak past loose (excessive clearance) bearings. If your oil pump is worn, thinner oil may not develop sufficient pressure.

Of course, pressure is lower at idle because the pump is spinning more slowly.

There are countless leak points for oil in a system. Your bearings may be okay, but you have a faulty oil pressure control valve. Or you may have an internal oil leak because an oil-related fitting was installed incorrectly.

It's possible they re-used the old oil pump (a big no-no)

Realistically, you sould bring this to the attention of the people who rebuilt the engine, because there could be an internal problem.

If that is not possible, verify the oil problem with the pressure gauge as stated.

The only sure way to correct this is to remove the engine, remove the pan and start checking bearing clearances, check the valve gear etc. If there is no warranty repair is available such expense for you really is not required. You shoudl be able to get many years of use from this engine if the pressure is managed properly

You can do this by using a synthetic oil with a wide viscosity range, such as 10W-40 or 10W-50, and see how that helps. Such oils will thin out less at operating temps. Again, get that oil pressure gauge hooked up; otherwise you have no way of determining how much of an improvement you get.

[LeSabre97mint]

Originally Posted by fordperson

I have a bmw I6 engine right after a fresh rebuild everything is fine up until I get it to operating temperature where if i rev the engine and it goes back to idle the oil light flickers... it doesnt happen when the engine is cold tho.

my main question is, if there is a possibility the main/rod bearnigs clearances might cause such a behavior.

Tom

Tom

What do you call a "fresh rebuild"? Were the cyliners bored out with new pistons, rod/main/cam bearings? Was the clearence of the bearings checked? Why was the engine rebuilt?

I agree with the second post....warning lights are for the birds!

Yes get a gauage and check what psi you're getting!

Regards

Dan

[jimmy[the]gent]

put a flat cardboard box underneath your car after its been driven then rev the motor if you see oil fall then you have a leak if you pull the cardboard and no oil fell then its your oil pump ........i wouldnt ignore the light man

your either loosing pressure by a leak or your oil pump isnt providing pressure