Valve lifter noise 1995 M50TU

[Scott C]

Well, finally got a chance to measure my oil pressure as a means to identify why my lifters clatter so much at idle when oil is warm. At start, the oil pressure went up to 60psi. After it was up to temp, the oil pressure (idle) was under 20 and close to 15psi. Bentley says 7-28 psi is "normal"

This clatter is really prevalent when the car is hot and oil pressure below 30psi. I have tried several oils (ran mobil1 0-30 for a long time) and now run castrol dino 20w50 but no help on this situation. Yes, the oil level is correct. I suspect that the top end is not getting the oil flow it needs.

Next step is to remove the pan and check for obvious oil/sump issues. Does this sound like it is worth replacing the pump if I find no failed gaskets in pickup to pump connection?

Thanks,
Scott

[mzarifkar]

that is a huge oil pressure range for normal. let me know what you find, I have the same problem on the same engine

[Russell]

i also have a random "tick" when warm. It even comes and goes while idling. I suspect it is more of a sticking lifter due to wear or a piece of dirt/sludge. I just put marvel Mystery oil (MMO) in a attempt to clean teh engine. I have also noticed the tick is gone after I change the oil. It seems to come back after I have about 3,500 miles on an oil fill.

[Bill R.]

If you read all the TSB's on m50 ticking you'll notice that higher viscosity oils such as 20w50 tend to make the noise worse rather than better. I believe its related to how small the orifice size is on the HVA, the 0w30 and 0w40 synthetic oils that are approved seem to help more.
15 psi at a hot idle is acceptable.
I would be more likely to suspect a bad gasket at the oil pickup tube but when Phil and others had this problem in the past it tended to do it after a long drive when it was thoroughly warmed up

Well, finally got a chance to measure my oil pressure as a means to identify why my lifters clatter so much at idle when oil is warm. At start, the oil pressure went up to 60psi. After it was up to temp, the oil pressure (idle) was under 20 and close to 15psi. Bentley says 7-28 psi is "normal"

This clatter is really prevalent when the car is hot and oil pressure below 30psi. I have tried several oils (ran mobil1 0-30 for a long time) and now run castrol dino 20w50 but no help on this situation. Yes, the oil level is correct. I suspect that the top end is not getting the oil flow it needs.

Next step is to remove the pan and check for obvious oil/sump issues. Does this sound like it is worth replacing the pump if I find no failed gaskets in pickup to pump connection?

Thanks,
Scott

[Scott C]

If you read all the TSB's on m50 ticking you'll notice that higher viscosity oils such as 20w50 tend to make the noise worse rather than better. I believe its related to how small the orifice size is on the HVA, the 0w30 and 0w40 synthetic oils that are approved seem to help more.
15 psi at a hot idle is acceptable.
I would be more likely to suspect a bad gasket at the oil pickup tube but when Phil and others had this problem in the past it tended to do it after a long drive when it was thoroughly warmed up

Thanks Bill,

The pickup tube is the first check today... Can't wait to get that pan off - sigh...

Scott

[Scott C]

Thanks Bill,

The pickup tube is the first check today... Can't wait to get that pan off - sigh...

Scott

Vent - what a pain to remove those bolts on that pan....

[Scott C]

Vent - what a pain to remove those bolts on that pan....

And now it is actually loose... Hope to know today real problem. Some of those bolts are hard to find - realOEM helped much.

[Scott C]

And now it is actually loose... Hope to know today real problem. Some of those bolts are hard to find - realOEM helped much.

The pickup was tight, there was a gasket and it does not appear to have been leaking...

[Scott C]

The pickup was tight, there was a gasket and it does not appear to have been leaking...

Okay,

It has been a few weeks since I reported on this ticking issue. SO the short story is that the pickup gasket was fine. I replaced the inner parts of the oil pump for $35 from the dealer (yes, dealer) and now have good oil pressure at idle (17psi) with 10w40 vs 15psi with 20w50 that I had been using (all at operating temp and I don't know how accurate my gauge really is). What I can say is that it has been a wonderful 2+ weeks WITH NO VALVE CLATTER which is what I was trying to solve.

So, in my case - new pump innards - solved the terribly annoying valve train clatter (lifters not vanos).

Scott

PS - I never could get the oil pan out - I did it all the work with pan down as far as it would go and the engine jacked up about 1.5" on each side.

[Ross]

Are those the new parts in the pic? They look fine if the old stuff.