on a cold compression test I have 3 at 300, 1 at 320 and 1 at 325. guess that explains the bucking bronco affect when it starts under 40*.

Another thing I have going on is when the chip is installed it has a lopey idle when you tap the throttle, like at stop lights, drivethroughs or backing up to a trailer. It smooths out after a second or two but kinda annouying to me. Guess I will share my numbers with Bill and see if he can retune to better match my warn engine. Its gonig to be a while before I can afford to swap it out.

 

Disagree here. 320 is a dud. Joe, are we going to butt heads now? I was unhappy with my lows of 380s at Swamps which they said was low. Now since you swing there, what say you? They are wrong?

 

I dont "swing" anywhere...


320 will run fine. I have seen them run at less then that but the blow by issues become bad.

Why would we butt heads? you have your opinion (wrong) and I have mine... (right)

 

I am so confused . So are these compression numbers showing me why I am having issues or do I keep looking? I only have 148k on the truck.

 

Do the leak down test. I doubt you have a motor issue, but you may have a head issue. Be it a cracked head or heads, or injector cups or something. That would be REALLY low miles to have a motor toasted with what mods you have.

 

I would do the leakdown test with the rockers on. . .and physically bring each cylinder up to top dead center on compression. . . this will give you the most accurate results and all parts will be in the positions they are in while the engine is running. The miles really don't matter to the wear of the engine. Every engine is run and maintained differently. For example. . . I have just over 100K on my engine(owned since 66K) and I have compression issues as well. Not as bad as yours but I have one or two cold down near 360. I havn't done a leakdown test yet but my oil analysis tells me its the rings and cylinder walls that are showing the most wear. This tells me that the previous owner(a bank) didn't maintain the engine or run it properly.
On another note, I will replace the word leakdown with differential compression test. You can build or buy a differential compression tester(mostly used in aviation, check Aircraft Spruce Specialty). THey consist of inbound air to a pressure gauge, through a specifically sized orifice, through another pressure gauge, to a valve, to outbound air which simply hooks up to your adapter that goes in the glowplug hole. Set the pressure at 80 PSI before opening the valve and then open the valve. The second gauge will tell you your differential number. For example. . . 60 psi would be 60 over 80( 60/80). That would be a cylinder at 75%. THis also gives you the ability to hear where the air is leaking. This is a very detailed test and give you the most information about the condition of your engine. Combined with an oil analysis to confirm your results, you really can figure out what is going on. A worn engine will show most cylinders in the same %. A damaged engine will show irregular %'s. a damaged or blocked valve seat, bent valve or some other valve train related issue will also show irregular %'s and you'll be able to hear those issues through the intake, exhaust or crankcase. Damn that was long winded again, Sorry
Timmy

 

My last post tonight/this morning, good one Joe. Oh, you're wrong though. Those #s are not good for a diesel.