I have an old 1986 Dodge Caravan with 150,000 and the #$%@ Mitsubishi engine. Would it be better to use new conventional oil or could I put my used Mobil 1 from the other vehicles in it to extend the life of the engine. It's not worth new M1. Also, the Mobil 1 I will put in it is generally 3-4 months old with about 1,000 miles on it. Essentially what I'm asking is if the additive package will be depleted/broken down sufficiently in the used M1 to where it's not as good as new dino oil. I love recycling . Any thoughts?

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1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley AFPR, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Ruger P95DC, hot wife, new oil filter, thick rubber floormats, no cats.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."

 

Jethro,

Lubrication seems to be a featured topic lately.

Personally, I wouldn't bother with direct recycling of the oil in an engine. IMO, used synthetic oil can be reused if it is cleaned up with finite filters and dehydrated. For engine oils, the pH of the oil also needs to be checked and corrected. Mineral oils break down and lose their polymers pretty quickly when heated, and it's the polymers that provide the necessary protection at higher temperatures. Mineral oils can be cleaned and refortified with fresh additive packages, but at that point you may have crossed the line of economic efficiency.

The synthetic oil is great for older engines unless they are leaking or so worn that consumption is high. If the engine is mechanically sound, the synthetic wouldn't harm anything, but used synthetic is just introducing more contaminants into the sump unless the oil is highly filtered and acid neutralized. In your case it is possible that the rings are being sealed partially by sludge. The synthetic would tend to clean those deposits away and allow more blowby and oil burning. If not, you can use it without fear of damage.

You could experiment by mixing a partial fill of synthetic with the next change, or using a synthetic blend. If bad things start to happen, discontinue use of the synthetic and wait for the sludge to reform.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

i use to reuse the mobil 1 from my kart engines in my lawn mowers and tractors. the kart engines only had a few hours on the oil at most and it looked "good as new" when i put it in the lawn mowers. i did run it through a coffee filter.

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

Thanks guys. I'll probably just keep using Havoline 10W-40 to keep the smoking down until I work on the head, but all this talk about lubrication over the last couple days got me cooking up some strange ideas. That coffee filter idea is pretty good, ede. I may try that just for the hell of it anyway, since I don't have much to lose.