No sense second guessing the situation, once you have results from cylinder leak down test...then you can go through the mental process of "what to do?" Until then...have a beer and enjoy the day.

 

I don't. I would like to pull it out, and swap it in a rust free truck down the road, and I am kickingyself for not putting fully rebuilt heads in when I did the head gaskets.

This one is too far gone to be a candidate for restoration or an engine rebuild.

I just don't have a hoist or engine stand. That could be remedied, but it's just bad timing. I am going to look into renting a hoist, may e hiring someone for a day to get it done safely.

I just wonder how much I can take off before towing it away. Our driveway is on a hill, and I will have to see if the emergency brake will stop it.

 

@CollieRover You can do valve seals with the heads in in place. There are tools that will hold the valve, and let you remove the spring and then valve seal. And install a new one.

In the dim old days we did by getting the cylinder to TDC to be safe.

 

Valve seals are just to prevent oil from entering the intake/exhaust ports around valves, which causes carbon build up on valves. The valve seat and valve itself are what keep/hold compression in cylinder. If the valve is not seating (sticking or bent) or is damaged (chipped)...the head has to come off.

 

Leaking valve seals don't give you zero compression.
I second The Deputy's suggestion -- wait until you've been able to do a leakdown test. If you have a borescope, maybe look through the spark plug hole to see if you can spot any internal damage. If it turns out to be a valve issue, that may not be too big of an issue to rectify. Even replacing a head isn't that big of a deal. It all depends on how much you want the truck to run properly.

 

I had to basically start at the top and work my way down on my 95 D1 3.9L engine. The clue for me was the Bank 1 Cylinder head was clean and shiny with marked head bolts vs Bank 2 which looked original to the engine. I would have done a compression test on all the cylinders, but that clue got me to thinking something was up on that side. I started by removing the Bank 1 head and sure enough within a few seconds Cylinder #5 was smiling back at me with broken rings, deep dents from what looked like the short valve cover bolt, and a crack right down the center of the piston itself (which once out the crack was about 85% thru the entire piston from living in there dead from 07 to when I tore it down in 2019....). Lucky for the 3.9L the sleeve itself was untouched from the carnage! I replaced the broken piston, slapped on some new rings, installed it, and then I tore the heads down and removed all the valves, inspected them, cleaned them, removed all the carbon build up, new valve seals, and I seated each valve. While I was that deep into it I went ahead and used some new Eurospare Lifters (very good quality units btw), and I put it back together. I wasn't able to be there when it fired up, but my friend sent me a video and the 3.9L was an extremely happy and great running engine.

 

Good advice.

 

The mechanic could not see any damage on the piston with his scope.

 

If there's no damage to the piston, then a lack of compression will either be a rod problem, a valve problem, a gasket problem, or a cylinder liner problem. The last one isn't likely (and the mechanic probably would have seen evidence of a crack if it was large enough to be causing zero compression) and the first would probably be causing significant noise, with loose pieces slopping about inside the crankcase. Which leaves two situations that should become evident if the head is pulled.