does that car have vvt or whatever they called variable valve timing back then? If so I would stick to the recommended viscosity as changing to heavier weight oil in my sons Envoy eventually caused the cam actuator to spit out codes which then meant it would not pass inspection. I am curious what other comments on this thread will be tho'

 

I normally run the 5w20 reg. Oil.
unless you are in the arctic where temps are ALWAYS below zero -
that is the WRONG weight oil - you should be using 5W30 -

But I thought I might go with a 15w40 instead.
15W40 is never called for -
not even if ALL of your driving was limited to Death Valley - during the summer -

On start up I get a little pinging sound then goes away after few minutes.
that has nothing to do with oil -
probably carbon knock -

Im talking regular oil here not synthetic.
makes no difference -

 

does that car have vvt
NO -

 

On start up I get a little pinging sound then goes away after few minutes.

not likely oil related. "few minutes" or few seconds? Please, please, please, let's not have another oil war.

 

Please, please, please, let's not have another oil war.
aw - come on - you're no fun -
it's been WEEKS since the last one -

 

alrighty. My brother-in-law's 2nd cousins aunts grandfather suggested I should use a 50/50 mixture of 20W50 Castrol and Bardahl. whatya think?

 

If you want to go to a heavier weight oil, use 10W30 (that's what I use), but 15W40 might be pushing it a bit.

 

At 68,000 miles that roller cam engine has not completed break-in.

As recommended by GM and in the owner's manual, use a good brand of 5W-30 engine oil. Reset the OLM at each oil/filter change. I happen to like a WIX 51522 filter.

15W-40 is good for HD diesel and construction engine use. We used it in the (4) twin-turbo Cummins V-12 diesels in the research ship I used to skipper. 20 gallons per engine.

Google "cadillac forums northstar cold carbon rap". Study this - all of it. https://www.cadillacforums.com/cadillac-tech.html

 

on cold start up 15-40 will sit in ur oil pan and maybe think about circulating for a few seconds before it does, crank & rod bearings will be the first to go

 

hi, houg! haven't seen you around in a while.

 

Deliverance

 

You forgot the Marvel Mystery Oil

 

Anyone who does not have at least a pint bottle of MMO on the shelf cannot qualify as a gearhead or wrencher.

 

Wow, I've not seen one of those cans since I was young buck. Daddy should have been on the billboards.....lol But was told not to use it in late model stuff as it degrades the O2 sensors. Dont know if its true, just going on dipstick talk.

 

Any petroleum or solvent product can degrade the O2 sensors - if used to excess. An ounce or so of MMO to 6 gallons of gasoline is perfectly OK. Problem is, many fixit pundits go by the adage "If a little is good, more must be better!".

Remember - gasoline contains all sorts of additives and cleaners as-is. If you use a TopTier fuel there's no need for adding other "cleaning" snake oils. If a tad of MMO makes you feel all warm and fuzzy, go for it. In my long lineup of gasoline engines since 1954 I have probably burned enough of the stuff to float a battleship - can't say whether it ever helped or hurt anything.

 

Well, that sounds like great advise to me. I'll just have to stop and get me a bottle just I can feel "warm and fuzzy"...lol Thanks Sub.