Motor oil question: Delo Diesel 5W-40 synthetic in a gasoline car? - Page 2 - PeachParts Mercedes-Benz Forum

Idle · #1 09-12-2014, 12:42 PM

Quote:

Originally Posted by aklim

What exactly does "wore out" mean? How did the mechanic determine what was wrong? Was a teardown done?

I just pulled off the valve covers of my GM 350 L98 motor. The holes are pretty large (at least 3/8 inch if I am viewing it right)

Doesn't say much. Without a teardown, how would anyone know why it failed and how the oil helped?

Prior to my friend taking the car to a mechanic he asked me to listen to it since it had 'a noise'. I figured perhaps a water pump or harmonic balancer. Maybe a lifter.

Nope. It was pretty clear the crank bearings were hammered.

Like I said: I don't know much about Fords and don't really care to. I was only repeating what I was told.

aklim · #2 09-12-2014, 01:13 PM

Quote:

Originally Posted by Idle

Prior to my friend taking the car to a mechanic he asked me to listen to it since it had 'a noise'. I figured perhaps a water pump or harmonic balancer. Maybe a lifter.

Nope. It was pretty clear the crank bearings were hammered.

Like I said: I don't know much about Fords and don't really care to. I was only repeating what I was told.

I suspect what you were told was simply jumping to conclusions if there is no proper analysis done.

Zulfiqar · #3 09-12-2014, 01:09 PM

Quote:

Originally Posted by Idle

I knew a guy that wore out his Mustang motor in 72,000 miles. The mechanic told him he was using the wrong grade of oil.

According to the mechanic (and I don't know much about Fords so I am just repeating what I have been told) the oil return holes in the heads are too small for the higher weight oil to run though at a speed needed to supply the oil pump. Therefore oil tends to get trapped on top of the heads and is not getting back to the oil pan fast enough to be pumped in the correct volume.

He started using the correct grade of oil and after nine years he still has the same used engine that was installed to replace his original.

Isnt this more true of Nissan engines like the CA18 and RB25 - their oil drain holes were the size of pencils

INSIDIOUS · #4 09-13-2014, 09:52 PM

Quote:

Originally Posted by Idle

I knew a guy that wore out his Mustang motor in 72,000 miles. The mechanic told him he was using the wrong grade of oil.

According to the mechanic (and I don't know much about Fords so I am just repeating what I have been told) the oil return holes in the heads are too small for the higher weight oil to run though at a speed needed to supply the oil pump. Therefore oil tends to get trapped on top of the heads and is not getting back to the oil pan fast enough to be pumped in the correct volume.

He started using the correct grade of oil and after nine years he still has the same used engine that was installed to replace his original.

So then would too thick an oil show up as low pressure on the gauge (hot) and replacement with thin oils would increase hot temp pressure readings? edit, the reason I put that out here is the idea that perhaps in most cases of low oil pressure indication developing it is just that the old oil is gunking up, moisture or what not, and just needs changing and perhaps the viscosity was not the issue? Mechanical issues can be ruled out if a simple oil change rectifies the low pressure indications. Right?

Skippy · #5 09-11-2014, 04:59 PM

It should be fine. Oil analysis would prove it.

Simpler=Better · #6 09-12-2014, 10:14 AM

Not with that engine, but with a Ford 2.3 (timing belt drivbes the oil pump...) I run whatever is on sale. 5-20, 10-30, 15-40, straight 30, etc. 60k of doing this and no problems.

I tihnk changing it regularly is more important. FYI, the place that sells rock bottom ford parts has wix 51515 filters for something like $5.20/pc when you buy a 12 pack.