oil light flickering at start up

[idosubaru]

This is a new one for me. IDoing a free t-belt job for a friend on his 240,000 mile 2003 Legacy EJ25 manual trans.

 

Driving the car home the oil light flickers when starting from a dead stop when you gas it good.

 

Drive normal, nothing. Give it some stank from a stop and it flickers every time just for a second or two then goes out.

 

Legit or bogus?

[subaru360]

Try another sensor if you have a spare. Measure the oil pressure with a mechanical gauge if that's not it. If the idle is really low the light could come on.

[ericem]

I guess its safe to assume there is oil? I wonder if a bad oil filter could cause this too.

[idosubaru]

If the idle is really low the light could come on.

funny you say that, it seems to do it when it "bucks" from a start so to speak. doesn't seem to run 100% so it might be a low idle thing only. probably nothing. good call.

[CNY_Dave]

Could be the oil level is a bit low.

 

Could be the pickup tube is sucking a bit of air.

 

Could be the oil pressure is a bit low (worn pump or large clearances) and just off idle the RPMs drop a tiny bit and it's just enough to lower the pressure and kick on the light.

 

Dave

[OB99W]

Gary, the oil pressure switch/sender should allow the warning light to be off with as little as about 3 psi. The spec is for the pump to produce greater than 13 psi at 800 rpm. If the cause isn't something obvious, then you should probably put a gauge on it before doing any work. That way you'll know whether the oil pump needs attention, or there are excessive clearances, etc., or if it's more likely that the switch/sender is the culprit.

[nipper]

Check the engine RPM, the oil level (change it if it hasnt been changed in a while), Alt output before you start chainging parts.

 

Next get a cheap mechainical oil pressure gauge for testing purposes. Make sure it can clearly read the lower range.

 

After that we can start looking at more hideous things.

 

How is the gas mileage?

[idosubaru]

I think it's related to the hydraulic clutch system, other threads i was posting about. The bucking and near stalling probably caused it.

 

Didn't ask him about gas mileage, i'll say something.

 

I'm replacing the timing belt and will probably reseal the oil pump though and check those rear backing plate screws.

[frag]

If you want to check the easiest first, have a look at the connection to the oil pressure sending unit (just below and behind the alt). I had the same flicker and it was the connector that was almost off. If it happens only at idle, it's maybe because the engine is vibrating more then.

Just in case.

Good luck!