noisy lifters with high oil pressure

[ceevester]

Happy New Year, everyone. I have a 2000 Safari, 4.3 L, automatic, AWD, with 145,000 miles on it.

Lately, when the engine is first started, the lifters make a very loud clicking noise, and the oil pressure gauge reads up around 80psi if the accelerator is pressed at all.

The loud clicking lasts for about 5 or more minutes, and the same with the oil pressure. However, after 5 minutes or so, the lifters quiet down to "normal", and the oil pressure gauge reads as it always has, at right around a little over 40 psi, with no real fluctuations upon acceleration.

The oil level is in the operating range, however, about three weeks ago, when my son started the engine, I heard the loud lifters, and immediately told him to turn the engine off, as I thought the oil was too low. Sure enough, I checked it, and it was almost two quarts low, so I added oil to get it into the correct operating range....and chastised my son for not listening to the noises coming from the vehicle he is driving.

Anyway, ever since then, the engine has the loud lifters on start up, and for about 5 minutes, with the oil pressure spiking up around 80 psi for about the same length of time...

Could this be blocked oil passages?...maybe a failing oil pump?...since the symptoms return to normal after a short time, I am confused as to what it could be, and how to remedy it.

Thanks for any thoughts or suggestions anyone might have.

[MagicRat]

Assuming the gauge is accurate............ 80 psi is too high and might blow-off your oil filter.

I think the oil-pressure relief valve may be plugged with debris. Its located inside your oil pump, which is accessible if you drop the oil pan.

[ceevester]

Thanks for the reply, MagicRat...

I guess I can give that a try...but it's COLD today!!!! LOL

It just seems that the symptoms are so identical each time I start the engine, as far as the noise, and oil pressure...and the time it lasts before returning to normal, that I wonder if it really could be just random "gunk" blocking the relief valve each time?...

It's certainly worth looking at though.

[old_master]

Hi Dan, sorry for the delay. Just for grins & giggles, you might want to check the oil and make sure coolant isn't getting in there from a leaky intake gasket. Honestly though, I think Magic Rat hit the nail on the head with the relief valve! You can access the oil pressure relief valve quite easily. Remove the oil filter and the oil cooler line adapter block, the valve is right there, don't have to drop the oil pan.

[MagicRat]

After re-reading the OP's initial post, there may be some sludge and debris in the oil as well. It wouldn't hurt to run some engine flush through the system and change the oil, along with inspecting the pressure relief valve.