got me a 200k mile engine for $300 complete along with the instrument cluster. truck was inoperable so went ahead and swapped instrument cluster into my truck to verify mileage @ 209,952. Just did a compression test and all cylinders are at or near 300psi. this is a bone stock psd and wondering what the bottom line is for actual psi for a cylinder to mis fire/ Also should i install new injector o rings would there be a noticeable difference in compression psi? I've done cylinder o rings before and had not taken a before and after compression test. thankx!

 

Is the engine in your truck now? If so did you do the compression test on the engine while hot and with all 8 glow plugs removed? The compression on a cold engine will be higher than it actually is.

 

trans and starter were already sold, so a cold compression test with gp's in has been performed after purchase. This is a complete motor sothe purchase was mainly for the fuel bowl, turbo, oil cooler and potential for rebuild on the block at a later date

 

I hear ya! I just picked up a '95 7.3 out of an ambulance. Plan on a rebuild on it someday, maybe just to sell.

 

Bill why would it be higher when cold? I thought it would be just the opposite

 

oil has more viscosity and thins when warmed up from operation. The gp's are removed to make it a little easier to turn the motor over for the testing process