Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Driving with 20 year old oil

Hi-and thank you much for any input in advance.
I had recently purchased a 1994 Isuzu pickup with an unusual situation.
Apparently an older gentleman purchased this vehicle brand new and then barely ever drove it-from what I understand the poor gentleman had become ill (some kind of problems with his legs) and the truck had been kept in the family but never really used.
So I’ve recently purchased this vehicle with only 20,000 original miles on it (I know I was skeptical too) but the interior is as prestine as can be and there is no sign of wear and tear on the vehicle anywhere-except for the outside being weather beaten and a good amount of what I belive or rahter hope is just surface rust to the frame.
Anyway after putting just under two hundred miles on the vehicle I have it parked until I can change the oil and trans fluid-My question here is should I be worried about damaged I may have caused by driving it for that short time with the oil that was in it?
I was also wondering if anyone here could tell me where I could purchase some por15 or some other good rust inhibitor for the frame and if there is anything else on this vehicle I should be addressing due to it’s unusual situation.
Thank you so much again,

Been there done that. My uncle gave me an 86 chevy truck with 12k miles on it. Needless to say the oil need changing, tranny fluid. Greased everything. The big problem was the cooling. I replaced all hoses and belts. Then the radiator started leaking, replaced. Then the heater core leaked, replaced. That was the last weak point and it was then a good truck.

Beside the rubber I would replace the coolant, plugs, and the air and fuel filters. I was able to order POR-15 from Eastwood.

Good luck,


Thanks to both of yas!-sounds like good advice-I’m looking forward to it and it’s difficult to discipline myself not to drive until these things are done but sounds like it will be worth it

Replace the rubber parts ( brake hoses and the like), including the brake fluid, and change the main fluids (engine oil and trans fluid as you have mentioned. It wouldn’t be a bad idea to change the rear axle lube also.

cool-will do that

The tires too…20 year old tires can not be trusted…Change ALL the fluids…


My international rides on 38 year old tires and I’m ok with that. Of course it’s a riding mower :wink:

Include the brake fluid in your changout.

@‌oldlong haired dude
For rust coating on the frame, even if it has started to rust, just spray using a garden sprayer with a biodegradable motor oil (G oil) and paint areas with red grease you want to preserve. There is NO one time fix. It needs to be checked and coated every two to three years if it is exposed to moisture and that old. It works on all cars trucks.

Just something for consideration and without knowing the purchase price of this truck.

Low mileage is great but if someone is having to pay a shop to catch up all of the needs at what point does it become diminishing returns?
A DIY situation makes it more palatable.

It has an interference engine so that leads into the timing belt question among others that have been mentioned.

Just what isuzu truck is this?

Is it the Isuzu hombre . . . a rebadged S10, I believe

What engine?

In Minneapolis only Welle Auto parts carries Por15 on the shelf. Otherwise you have to order it. Just check the website for any local dealers but there aren’t many around, so you just pay shipping.

The good part about changing the oil now will be that oil technology has greatly improved since 1994. Oil was probably rated something like SE back then, and we up to at least SJ now.