M103 oil pump longevity (loud valvetrain on startup)
 

Our 89 300TE (190K miles, Mobil 1 since 60K, original valvetrain) gives me pause on startup. Oil pressure gauge goes to 1 bar, and then it's 2-3 seconds until it reaches 3 bar on fast idle. You can hear the valvetrain clicking until oil pressure gets above 1 bar. Runs perfectly after that.

This is my first vehicle with this kind of mileage - any thoughts/experience on longevity of oil pump or other causes of this?

THANKS

Brian

Make sure you use the correct Bosch or other quality replacement oil filter with a built in anti-drainback valve. Filters without them will fit, but the oil can drain out, even overnight, and it will take a few seconds for the oil pump to refill them and achieve full oil pressure.

Duke

The first thing to check is the sending unit, which is not only the likely problem, but also cheap compared to everything else it could be.

Possible noises:

Lifters that have bled down.

Timing chain tensioner that needs pressure.

Timing chain itself.

You may need some top end work, or simply a new timing chain and tensioner. If never done, I'd bet the chain and tensioner are done.

Mine just had timing gear replaced and it has a similar problem. after a few seconds, it quiets down. How would one know if the oil sender is not working?