Swaping in a used engine, what should I do before I put it in.

Ok some of you have seen my threads on my old engine thats coming out.

Oil still not getting to the rockers.

So I have another engine out of my parts XJ, same engine same year. 1988 4.0, except this one was taken care of at least over the last year of its running life as I have reciepts from oil changes he did. The problem is its been sitting without running for about 2-3 years now.

Its been sitting full of oil and coolent.

I want to get my jeep back on the road so bad I'm tempted to just slap it in (only vehical, Canadian winter coming up fast) but I figure while its out I should inpect it and change some seals.

I was thinking of getting a full gasket kit and timing chain set. Tear down and inspect then just reassemble with the new parts. Then start running it on full synthetic and high quality filters so what happens to my last engine never happens to this one.

Any thoughts?

Oh and as much as it sucks pouring money I don't really have into my jeep the one thing this whole situation has done is taught me alot about the oiling system in engines and that I should always have a bit of money saved up for vehicle emergencies, so I guess thats a silver lining.

i'd rebuild it. new gaskets and have the cylinders honed and get a rebuild kit. thats what i am doing for my mj right now. i just like the idea of a motor that is basically new.

I don't have the time nor money to do a full on rebuild.

I wish I did but it would be off the road for quite a while then.

Change the oil and filter. Check for past leaks and fix them. Look especially at the rear main seal and valve cover gasket. Check the vibration damper for wear - probably be a good idea to replace it if it is the original. Consider replacing the water pump. Timing chain and gears might be a good idea depending on the miles the engine has. Would be a very good idea if you already have the damper off. New plugs, wires, distributor cap and rotor. Maybe a new CPS. Check over all vacuum hoses and probably replace those. New radiator and heater hoses and belts for sure. New thermostat also. Do a good coolant flush and replace with new coolent. New motor mounts. Consider rotating the oil filter adapter for cleaner oil changes. Look at the injector seals for leaks and replace if there is any question.

Make sure the engine starts before you pull it from the donor. Will make troubleshooting a lot easier if you know it ran to begin with.

Good luck. I'm sure I'm forgetting some things.

Spudboy

Replace seals/gaskets that would be a royal pain of the engine was in the XJ. Rear seal quiclky comes to mind!!

If the engine is already out, take a look at the top end and then drop the pan and see what it looks like down there. No need going through the same mess again.

Good luck
chris

Remembered some more on the drive home. If this is a manual tranny, new clutch, throwout bearing and slave cylinder. Depending on the miles on the donor engine and how noisy it is when you start it (still in the donor vehicle), I might be inclined to not worry about opening things up just to inspect them. You know more about the history of the donor than any of us though.

My take on it - the gasket set is one of the most expensive components of a basic rebuild. If you are going to spend the money on that, might as well do the rings and bearings too. In my shadiest shade tree days, I would do that with only a cylinder honing with ridge ream, and polish the crank journals with maybe a .001 undersize set of bearings. It's a slippery slope once you open up the engine so choose wisely

Spudboy

Prime the oil pump before starting it!

My engine actually looked worse than yours did when I pulled the cover. I bought it for a few hundred bucks but it actually came with a spare engine in the back to install.

Spudboy said:

My take on it - the gasket set is one of the most expensive components of a basic rebuild. If you are going to spend the money on that, might as well do the rings and bearings too. In my shadiest shade tree days, I would do that with only a cylinder honing with ridge ream, and polish the crank journals with maybe a .001 undersize set of bearings. It's a slippery slope once you open up the engine so choose wisely

Click to expand...

This is the route I am currently taking with the spare engine, cleaning the dirty engine and slowly building the stroker as time and finds allow.

The engine has about 200,000 on it. Its already on the engine stand in my dads garage. I drove the doner jeep around doing some light 4x4ing before I stopped driving it and started using it for parts. Its going in an auto XJ.

Spudboy.

I was talking about changing all the gaskets and seals so that would include new oil, filter and coolent.

My present engine has a nine month old water pump and cap/wire/rotor/plugs so I'll use those.

I'll check the hoses and belt.

And I've thought about rotating the oil filter and chaning it to the newer style for easier oil filter buying.

The gasket set is going to cost me about $125 Adding bearings and rings to that cost seems to be at least another $180 or so. Plus the timing kit is another $80 or so.

Thats just getting too expensive right now. If I want to rebuild a new fresh engine I'll using the sludged up block and take my time.

I figure if I was happy with an engine with 200,000 on it then I would still be happy with the same but with a good internal inspection and new seals.

One easy thing to do while it's out, replace all the freeze plugs including the one on the back of the block. I would pull the pan and do the seals, cleaning it out while I had the pan off.

We bought an engine out of a YJ to put in my dad's CJ about 3 years ago. It had been sitting on the floor of a garage and the guy new it ran when pulled. We took it home and put new gaskets (valve cover, timing, oil pan, etc.) and new front and rear seals.
We bolted it in, primed the pump, and it started in about 10 seconds. We left the valve cover off until we were sure oil was getting up there. Its been his daily driver for 3 years now.