Oil pressure problems

[abscate]

I was thinking the same thing, which is why I haven't changed the oil pump yet. But the list is getting shorter, and the only thing on the list after this are main, rod and cam bearings.

I typically use Mobil 1. This time I think it was 0w30. I don't think I want to go thicker because of the turbo.

It's not a steady, constant drop in oil pressure... there's a cadence to it. That's what's baffling.

The only other thing that changes when the oil warms up is the oil cooler thermostat. But for it to pulse like that would seem very unlikely.

I think that is too thin oil for your motor - the user manuals are on line so I would go with recommendation there.

The turbos on these things never blow, they are bullet proof.

[as400jockey]

I believe you are making an error with the units. Hz is cycles per second, not cycles per minute. 59 pulses in 13 seconds is 4.54 cycles per second or 4.53 Hz.
volvolugnut

I stand corrected... I did mean to equate the two.. so cpm would have been the correct unit of measure. That's a bad sign... four years of mechanical engineering (back in the days of punch card computing) and I screwed that up.... losing some brain cells...

[as400jockey]

[/quote]
I think that is too thin oil for your motor - the user manuals are on line so I would go with recommendation there.
The turbos on these things never blow, they are bullet proof.
[/quote]

Interesting... the official recommendation is 10w30. I'm using 0w30.

So we'll see what happens after the replacement oil pump arrives. I'll be curious to see if the bouncing pressure needle changes, and if the issue remains I may change the oil again to something thicker.

[volvolugnut]

That's a bad sign... four years of mechanical engineering (back in the days of punch card computing) and I screwed that up.... losing some brain cells...

I understand all too well. I took an online class recently and had a lot of trouble with matching units and scientific notation. We share some background.
volvolugnut

[volvolugnut]

It was my OPINION that this oil (0W30) is maybe too thin. Even if it is the official Volvo recommendation for oil weight, all those miles can make bearing clearances larger.
volvolugnut

[June]

Every Volvo I have owned called for 5W30 oil. The turbo white blocks called for 10W30 when the stable temperature was above 86°F. 0W30 definitely sounds light for a 300K engine. Just curious to see what fixes the problem. June

[abscate]

I believe you are making an error with the units. Hz is cycles per second, not cycles per minute. 59 pulses in 13 seconds is 4.54 cycles per second or 4.53 Hz.
volvolugnut

I stand corrected... I did mean to equate the two.. so cpm would have been the correct unit of measure. That's a bad sign... four years of mechanical engineering (back in the days of punch card computing) and I screwed that up.... losing some brain cells...

Omg , another punch card jockey. These kids today with their compilers and SDKs....amateurs.

Smartest thing I ever did was attract attention of a female engineering student in the 1970s. Her card jobs always ran with a stickie note from the attendant ...”I fixed your stop card problem for you.”

Mine came back with the fatal error report.

I also went to a college with the punch card machines and job desk in separate buildings. On separate campuses.

WTF?

[as400jockey]

Actually in high school we first had a teletype connected by dialup and then got a minicomputer of some kind that booted off paper tape.

As for undergrad - 1979 was the last freshman class to use cards. In 1981 my girlfriend was bemoaning the long lines to get a terminal, so I took her to the basement and pulled a cover off a Hollerith machine. She said "WOW! This is GREAT! No lines!"

YABBA DABBA DOO!!

My son studied Mechanical Engineering at NC State. They're still teaching Fortran.

[hausmeister]

About oil...
10w30 instead of 0w30 only means that it will be thicker on lower temperatures, at operating temp they would both be 30weight.
I think it would only make sense if you recommend 10w40 or 10w50 or similar.

[amblerman]

About oil...
10w30 instead of 0w30 only means that it will be thicker on lower temperatures, at operating temp they would both be 30weight.
I think it would only make sense if you recommend 10w40 or 10w50 or similar.

I was going to reply with same thing about xw-30s all being approximately the same at once at operating temperature.

Another option is there are lots of easy to find 5/0w-40s here. 10w40 is getting harder to find and I'm not sure I've ever seen a 10w50 in stores here in the US. I have seen 10w60 but that is a special Castrol oil.

If the OP wanted to try a heavier weight oil, I suspect there will be plenty of choices in the 0/5w-40 range in auto parts or big box stores up in the greater Boston area. Including a couple of options from Mobil1 if he wanted to stay with that brand.

Off the top of my head, I know you can easily find 5/0w40s from Castrol, Mobil1, or Rotella in most major stores.

-A