New Motor

I’ve got a truck with a new motor and tranny it got less than 20 miles on it but as been sitting for about 3 years how should i go about starting it for the first time in so long

With a new motor? And sat for three years?

Here’s what I would do. Buy the cheapest five gallon bucket of motor oil you can find. Dump as much oil into the engine as it can hold. Let the engine sit for two weeks with this oil to pickle all the internal rotating components.

During this two weeks, check out the fuel system. Smell the gas in the gas tank. if it smells OK you might be good to go. If doesn’t smell very good, you’ve got a fuel system problem.

After the two weeks pass, drain all the oil out of the engine. Install a new oil filter and fill the the crankcase with the proper oil.

Crank the engine over, and cross your fingers!

Tester

Good suggestion. I would add to that, pull the spark plugs and give each cylinder a splash of Marvel Mystery Oil (making sure to keep track of which spark plug wires go to which cylinders.) Loosely thread the spark plugs back in to the heads and let it sit as Tester suggested. Then, when you get ready to crank it over, pull the plugs back out and turn the motor over for a few seconds. This will do a couple of things: it’ll spin the rotating assembly with no compression, which means no load on the piston rings, wrist pins, connecting rod bearings, or main bearings. Also, it’ll expel any fluid that might be sitting in the cylinders. The oil will hopefully keep the rings from sticking. After you have cranked it for a little bit, put the plugs back in, and follow the rest of Tester’s suggestions.

Remember to be nice to the motor for the first 100 miles or so, no full throttle jaunts, no towing, etc. Also, you’re going to want to probably change the oil again at 250 miles or so, because you will be still breaking in the new bearing surfaces.

And only twenty miles on it? Geez! You also have to break in the cam! If you haven’t done it.

If you get this thing running, before you drive it, you have to allow the engine to idle at 1800-2000 RPM’s for at least twenty minutes to get the cam to break in.

Tell us the history of this vehicle. Twenty miles on a new engine that sat for three years?

Tester

Sometimes the starter motor cannot even turn the engine over initially if the piston rings are sticking badly. Years ago I tood a trip abroad for 4 months and left my car with a relative in a humid, hot East Coast town. Coming back in September, the engine would not turn over, the mechanic had to attach a lever to the front of the crankshaft and turn it over a few time. After that with the help of some of the potions listed above, we got the car going.

Good luck.

Yeah, my thinking was, hopefully soaking the cylinders with Marvel would help reduce the chance of anything being completely stuck when he went to turn it over.

Why not turn the engine over with a power bar and socket by hand while the plugs are out?

The truck belonged to my grandparents they bought it new in 85 they bought a new truck in 97 and turned the old one into a farm truck that didnt see much work about 8 years ago i tried to buy it but grandma said no 3 years ago the motor blew the body is still in great shape so she took it to the chevy dealer and told them to put a new motor in drove it home parked it in the barn and there it still sits, now shes wants to get rid of some stuff around the farm and said i could come get it. What was wrong with the tranny i have no idea.