• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Best overall diesel engine oil winter vs summer

dbrannon79

dbrannon79

I'm getting there!
Messages
6,163
Reaction score
13,284
Location
Seguin, TX
Hey guys, I know this has probably been discussed many times before, but I wanted to get an opinion for motor oils on a fairly worn engine. my last change I did about 500 miles ago I added a quart of lucas oil stabilizer to mobil delvac 15-40 due to guessing at the possible noise my engine was making. adding it didn't change anything, so for the noise I still believe it's in the valve train or fuel system.

but anyway now that winter temps are setting in (morning low temps in the 40's), I have been noticing on morning startups my oil pressure doesn't climb up to 40 like it normally does. it takes a second longer gradually getting there. I am wondering if I should drain it and refill with fresh 15-40 or even go to something like a 5-40 oil. one morning when I cranked it up, I heard the clatter I would normally hear at first startup after changing the oil, lifter tap... tapity tap tap for like 2 seconds before oil pressure started rising.

as far as the 5-40 oil, I have read online that it is a good weight to run year round. during the summer on my truck my oil pressure will stay at 40 on the road and drop to around 25 at idle running mobil delvac 15-40 (non synthetic) but not so much in the winter it stays around 40 all the time. So I know the mains and or the cam bearings do have enough wear that effects oil pressure as with any high mileage engine would.

What's y'all's recommendation? the current oil only has about 500 miles on it along with the filter. should I just drain the oil and replace leaving the filter on for the next change? and should I switch to something like a 5-40?
 
I went to the 5-40 Rotella T-6 and the engine cranks a lot faster in cold temperatures.
Last time The truck was due for an oil change, all I could find, was at walmart, was T-5 15-40. Parts stores didnt have T-6 too. So I went back to WM and bought both jugs of the T-5 15-40 that they had on the shelf.
Getting close for another oil change and I am going to do some online searching, see if I can find the 5-40 T-6 and order that in. I can use the 15-40 for next summer.
When I went to the T-6 The engine cranks faster in extreme cold temps, but, I did notice a slight drop in OP, maybe a couple or three pounds of pressure. It picks up the oil a lot quicker so I can live with that.
The ODO says the truck has 260,000+ miles on it. I know nothing about this engine, if it has at one time been replaced, I know Knott and, the PO knew nothing about the truck too.
 
from what I have found online, Amalie makes the fram oil. bit not positive on this... can't be any worse that WM supertech oil !!

additivehelp.com

Fram Now Makes Oil! Or So They Would Have You Believe... - AdditiveHelp.com

If you've been to a Carquest or Advanced Auto recently, you may have noticed something much different about their oil section. More specifically, the part of
additivehelp.com additivehelp.com
 
I do have a full 5 qt bottle of supertech 15-40 laying in the bed of the truck I had bought for top off oil a while back when we went on our vacation trip. but I have always been leery of using it. I could give the fram synthetic 5-40 a try since it's available here. it does seem promising more so that that article I linked about the supertech. the article does say it's not for performance. That makes me think ST oil just meets the bare minimum specs to get by on a budget.
 
The 6.2L diesel (and same design the punched out 6.2 known as a 6.5L 6.5TD) is one of the most studied and published engines for cold oil flow around. Your Taxpayer money at work for the military.

https://www.thetruckstop.us/forum/t...bility-in-a-6-2-internal-oil-flow-info.41477/

What oil filter are you running? Your symptoms suggest the oil filter has a bad anti-drain back valve.

IMO in Texas I suggest the 15W-40. Just not cold enough for the 5W and these dirty engines are hard enough on oil as it is. Diesel oil is hard to find at this time esp. T6. AMSOIL will still drop Diesel oil on your doorstep. - However their oil filters are having trouble being "in stock" at this time like everything else.
 
Just went oil shopping in town. Advance closed. O’riellys nothing on shelves. Stopped at the most dreaded store around, Autozone! Only thing they had was Mobile 1 5-40 So I sucked up on their prices at a little over $80 for two gallons and a filter and went for it. How much longer over 3k miles can I get on this stuff? I’m old school and not too intune with synthetics.

28F430F3-CFB3-438D-BFB4-E83380A69531.jpeg
 
You should spend some time looking up oil filters. The ACDelco Ecore is a sad cheap filter anymore on par with a FRAM OCOD. They had to redesign ECores once due to filter failures taking out engines. They have the cheapest antidrainback valve known to harden and not work over time.

Best you can do is get a filter with a silicone anti-drain back valve.

Good luck trying to avoid FRAM, who via Champ labs makes ACDelco filters, and Purolator that now can hide in a Wix filter can because both are owned by Mann-Hummel ... Not many oil filters left untouched by these two cost cutting clowns.
 
Sadly it’s a fram I have on there’s now. I was in a hurry when I changed it before but in my defense it’s the better crappy one. I figured since going to this expensive stuff and since parts and oil is getting hard to come by other than ordering online I’d get the Delco one they had this time around

Photo oh what’s in the truck now
7895BC9C-C7E7-4683-A4CA-96AADF82A6CF.png
 
I was always partial to Baldwin filters. We had a distributorship 9 miles away since the 1970's. FS bought it and closed it down. Now we have no good place to buy filters.

When I switched to Amsoil with the 1989 - Amsoil Tech recommended the 5w30 heavy duty diesel engine oil. I ran it in all the 6.5s. Never got less than 300,000 miles on any engine.

I also ran a bypass filter. Either FS2500 or Amsoil. I prefer the FS2500s
 
You must log in or register to reply here.
Back
Top