looks like my truck suffers from low compression. here are the numbers I got after I warmed it up
7=340 8=340
5=360 6=350
3=350 4=340
1=340 2=380

At this point I am not sure if fixing it or just replacing the entire motor with another is a better option. I am going to do a leakdown test to try to find out why were its going.

I have an early 99 so maybe replacing it with the later style would be a good idea. What is all involved in swapping up. I know that the turbo and the airbox is different. Anything else that I will have to concider? Are all the blocks the same?

 

I'm not an expert, but those numbers don't seem that bad to me, depending on miles. How many are on it?

 

Check out this thread. Your numbers are not good but it should still run for a long time with proper maintenance.
https://www.ford-trucks.com/forums/8...n-numbers.html

 

Torquing down the injectors & rockers are a very good idea, if it's never been done. Just for grins, I checked one of mine before I pulled the injectors out and it took about a 3/4 turn! Who knows what the rest were. The rockers were in pretty good shape -- some required a little more on them, but nothing like the one injector I checked. My new ones are all torqued down to spec now.

Rockers are 20 ft-lbs, injector hold-down bolts are 120 inch-lbs.

 

thanks for the tip on retorqueing. I will do that before I dig into any deeper. I did replace the injectors a couple thousand miles ago. I do hear a gurgling sometimes when doing the compression test. This might be pressure pushing back up the injectors.

I think I will pull each of them and check the copper washer and o-rings.

 

thanks, the truck runs but has some issues. I did follow the link above last summer.

 

Broke it all down and retorqued the rockers and both injector bolts. all the orings and copper washers looked good. also cleaned out the injector cubs with long q-tips to be sure there was no debris for the washer to sit on. Gave a coupe a boost but didn't get me out of the red.

7=350 8=340
5=360 6=380
3=380 4=340
1=355 2=400

decided to not worry about a leak down test until I have enough money to at least do a head job since this is my best case senerio at this point and do some research into what it takes to bring my early 99 to the later version.

 

Off topic.. butttttt..

I have an complete engine minus start that I wanna go look at.

Could I do a compression test on it by hooking the compression tester up and using a 3/4 in impact on the crank to spin the engine over? I doubt it would show that much pressure but since the impact puts out the same amount of torque each time couldn't I use that to see if all the cylinders are putting out similar pressures?

Thanks and good luck to the OP

 

Edit: Also I wouldn't want all the torque on the crank bolt

You might get away with that only if all glowplugs are out. But I doubt that will work very well. Same amount of torque as a starter but the starter is engaging a large gear. . . so the torque at the center of the crank is much higher.

Your compressions aren't horrible. It will smoke on startup. . . especially when cold. But I almost guarantee a leak down will show you its through the rings. With all of them being so close thats a good bet. Change the oil regularly, get a oil bypass kit. . . send out samples then you will really know the condition of every part in your motor.

 

You own a marginal engine. Checking the compression on a warm engine will also inflate the numbers so if that is the case it is even worse than a cold compression check with the same #s. Did you try adding oil to the cylinders to see if it helped the rings seal and boosted the numbers?

 

the latest numbers are from an at temp engine. The cold numbers are worse. I didn't put oil in the cylinders but there was oil from the glow plugs holes that I allowed to leak down.

I am guessing as well that its the rings. I don't know for sure what did it but I don't think that I will put a k&n air filter in another vehicle.

 

I am going to guess this isn't going to work out to well. like previously posted you don't want to hammer on that harmonic balancer bolt that much and I wouldn't guess that you could get the engine to spin fast enough to get real compression ratings.

Probably best to pull your starter out and throw it in that engine for a test. But from what I have been reading leakdown tests could provide you valuable information and no need to crank the engine.

 

Someone want to PM me about the leakdown test? Thanks all.. sorry for the hijack

 

Nothing WRONG with those numbers... Anything above 320 is a runner, maybe not great, but I dont see anything to call a rebuilder for...

 

my take is remove your rockers (so you don't have to figure out where top dead center is) put this tool onto a compression test adapter (minus the core) and charge the cylinder. Listen for the escaping pressure. Either out of the intake, exhaust or dip stick hole. This will give you an indicator of what has warn and by how fast it leaks how bad its warn.