Hi all, have 06 TB 4.2L with 183,000 miles. oil full and clean, no codes but oil pressure gauge drops while idling when engine warm! Go's to normal 40-43 when given gas and has shut off (sometimes). Changed oil pressure switch but the problem still exist.
Will change oil because didn't do it when purchased TB due to full and clean but weight unknown! Different forums suggest possible oil pickup tub clogged, sludge buildup, bad cluster, ( if cluster bad it won't shut off). Any suggestions or fixes, thanks for all comments!!

 

How low does it go and at what RPM please? It's normal to drop pressure at idle, especially when hot. But not too much!

 

drops to 0, idles just under 1000

 

Ouch! Need to get a real test gauge put in place of the sending unit to verify if oil pressure reading is real. Then you will know if it is mechanical problem or just the gauge. I'm surprised no one has suggested this to you before.

If gauge is OK, then it's probably worn bearings that are not long for this world causing a loss in oil pressure. Is engine knocking or ticking or clacking when thoroughly warmed up?

 

Hi, thanks for comments. Will get gauged for actual oil pressure reading. Yes does tick sometimes than it goes away, was thinking sludge buildup in ports! Any thoughts?

 

Low oil pressure can allow lifters to bleed down and then they make noise. Sludge buildup is unlikely cause. Worn bearings likely.

 

Hi Les, sat watching the oil pressure gauge 5 minutes in the driveway after driving a few miles to get the engine warm. Noticed needle fluctuates down to 0 back to 40 to 20, to 10, to 0, etc without giving it any gas, just idling. Gave gas back to 40 then slowly fluctuates again. Engine sounds the same when this happens (quite) no variation, no sputtering, no shaking, no ticking. possible cluster problems. Scheduled oil pressure test with a shop! Thoughts: driveway is sloped, doesn't flutter till I'm in the driveway! Your thoughts or anyone else's are welcome..

 

I know you're wishing its not an engine problem. Let's just wait for the pressure test. Then there is more basis for determining the actual problem.