Mopar Action On-line – Tech Questions


Tech Question

marc lowman, noble, OK, 2001 dodge durango 360

My ’01 Durango runs about 20 lbs oil pressure hot at idle (360 engine, not a wannabe 4.7). I thought I remembered a tech article where you recommended a 15/40 or 15/50 Mobil 1 oil in a small block.Currently, it’s running 10/30 Castrol syntec. I’ve read alot of flack about how nothing but Amsoil is the only “real” synthetic oil, etc.. on the internet. In my old Mopars I wouldn’t hesitate to use 10/40 or even 20/50 in the summer to bring the pressure up to my liking. Since these new small blocks have roller cams and lifters I was wondering if a too thick oil would cause a top end oiling problem like it would on overhead cam tight tolerance “new generation” engines? It has 30,000 miles and is out of warrantee if that helps. My 00 Ram 318 holds about 35-40 lbs oil psi hot which makes me wonder if I have a problem or are the 360’s larger main bearing size contributing to this? Any thoughts or suggestions would be taken as gospel O’Great Ehrenberg (sorry the ass kissing came at the end).

Marc, there’s no question that some clearances in your engine are a bit larger than they should be, but the slow idle speed on the newer SMPI 360s makes the problem seem worse that it really is.

Mobil 1 is what I use, personally, now and for the last 25+ years. It’s a REAL synthetic. It’s what every Chrys. engineer I know uses. And, if I were in your shoes, as long as you aren’t talking about sub-freezing temps, I’d have 15w50 Mobil 1 in there in about 30 seconds!

I’m not saying that there’s anything wrong with Amsoil. But I believe that they are really just a distribution outfit, with no actual refining capacity, they just put their order out for contract bids as needed. From their website: ” AMSOIL INC. markets the most complete line of synthetic lubricants…” (Italics added by me). They also do this with Vitamins, fertilizer, etc. And their distribution system is designed specifically to maximize retailer profits and generate lots of word-of-mouth. Nothing wrong with that — if you’re the retailer. But with Wally-Mart selling M-1 for $20 / gallon, to me it’ a no-brainer!



Main Index | Current Issue | Tech Q & A | Tech Archive | Subscription | Advertisers Links | Contact Info