e99 f350 Compression Test

[riverboy460]

Ok heres the deal. I have been looking up how to compression test this truck. I already bought the diesel compression tester kit from harbor freight and modified it with a 9 inch grease gun whip hose and put the quick detachment fitting on the end of that. the harbor freight kit includes the glow plug test fitting.

so now all I need to know is how to properly perform the test. I know I need to let the engine warm up first. shut it off and remove glow plugs. but what I am unclear on is what to disconnect. do I just undo the connector to the valve cover gasket on both sides and perform the test. cant really find a write up that explains everything that needs to be disconnected to do it right so I don't damage the engine. thanks for the help.

reason why im wanting to check the compression is because I have a few issues going on right now. I bought this truck with 72,000 miles on it and it now has 85,000. I fried my pcm with the chip my fault replaced it. truck ran good for awhile and I had a hpop leak fixed that and resealed the fuel bowl as well. new oem ipr in the pump when I installed the adrenaline. I have developed a idle surge when warm now. no codes on my ae related to this. however I did have the truck die on me once 3 months ago. casued a p0340 I think it is for the cps. been fine since.

I noticed I have been loosing power at least feels like it to me. fails number 8 for a cct test on ae. but I have been told its because of the grey cps. compression test will rule this out. I also recently noticed I have what looks like black oil droplets in my coolant resovoir and also looks like some build up on the side walls of it as well. i am suspecting bad injector orings and cups maybe. not sure if its fuel or oil. injectors all buzz good. no coolant in oil looks normal on dipstick. I consume maybe a quart of oil every 3,000 miles. I change my oil every 3k in the truck since I have owned it.

I just purchased full force diesel stage 1.5 180/30cc single shot injectors. bought a riff raff frx. and ccv mod. also ordered 8 new injector cups from clay along with his rental tool and 620 locktite along with a oil cooler reseal kit. I am trying to build this truck to be reliable and pull my 5th wheel and boat. so far its been a money pit so im trying to work it out. I don't need a hot rod. I originally ordered stage 2 injectors but after talking to Pat at ffd I realized that it was over kill so dialed it back to the 1.5's.

current mods are a S&b cold air intake, trans boost and pyro gauges, adrenaline hpop, 4 inch turbo back mbrp exhust and a php hydra tuner.

thanks for any and all advice. im mechanically inclined for automotive and just learning the diesel side since I bought this truck.

can cracked injector cups allow exhaust gases in the coolant tank? truck dose not run hot at all always runs normal.

 

[mandkole]

What I do ;
-cold motor (clearances are looser)
-remove all glowplugs to reduce the work on the starter
-install gauge on cyl
-With remote starter switch, roll the motor 5 times.
-as the motor rolls the first few times gauge value will increase
-on 5th gauge spike, record the value

 

[OBS-Addiction97]

What I do ;
-cold motor (clearances are looser)
-remove all glowplugs to reduce the work on the starter
-install gauge on cyl
-With remote starter switch, roll the motor 5 times.
-as the motor rolls the first few times gauge value will increase
-on 5th gauge spike, record the value

You don't have to disconnect the fuel pump wiring? I've kinda always wonderd how to do this myself.

 

[Arisley]

Nope, when you disconnect the 42 pin connector, the injectors cannot fire. If they don't fire, no fuel will be injected into the motor.

 

[ju015dd]

Yep , pull all glow plugs, 42 pin connecstor . bump engine over to clear cylinders . install test tool on which ever cylinder you wish to start. Bump engine over 5 revolutions and record reading. Repeat for the remaining 7.

 

[riverboy460]

Thanks guys. Can u tell me where the 42 pin connector is i am assuming its the one on drivers side in front of engine? Its a square looking one right?

 

[Arisley]

Correct. Top of the driver side valve cover.

 

[7.3toreador]

What was the verdict with the test?

 

[m j]

you dont even turn the ignition on so no fuel pump etc will run , jump the starter solenoid to spin it

 

[riverboy460]

I didnt do it i had bad luck and dropped the harbor frieght glow plug adapter down the lifter galley and spent a while fishing it out. Ended up removing the last rocker arm on #8. I was only going to do it because i have a very slight rpm miss at idle only. I just did all 8 injector cups and put in full force stage 1.5 reman injectors. They are 180/30. Im anput to add a frx which is in my garage and do the ccv mod both from riff raff diesel. I was skeptical on doing all this work if engine needed work but i jut figured i would go back in another day to do the test after the bad luck. I found a piece of fuel hose in my garage so next time should go smoother to install the tool. Thanks for the replies. Ill update what they are when i do them this weekend maybe.