Compression tester needed
- Thread starter Redbowties88
- Start date
What test though?
The truck would run smooth at idle but the balance rates in number 5 would be in the 10 range and number one was usually in the 5-6 range and the rest fairly normal.
Soon as you gave it a smidgen of throttle just enough to set the balance rates to 0 but not pick up any rpm the truck would run very rough.
And then some days the rates were fine and she was smooth as can be
The truck would run smooth at idle but the balance rates in number 5 would be in the 10 range and number one was usually in the 5-6 range and the rest fairly normal.
Soon as you gave it a smidgen of throttle just enough to set the balance rates to 0 but not pick up any rpm the truck would run very rough.
And then some days the rates were fine and she was smooth as can be
Turning the injectors off will give you a true cylinder psi reading. You don't want to just add raw fuel in to the cylinders increasing psi with every other stroke.
Ok then yes there's no fuel. I figured some would of shot out and made a mess if they were on.
Going to check the cylinders for coolant now
Going to check the cylinders for coolant now
so the cylinders that are down on psi are 1 and 5? cuz if they are right beside each other could be a bad gasket thats leaking into the next cylinder
With a cylinder between the two "bad" ones showing great numbers would concern me it may be something else besides a head gasket since they are not leaking into each other. Redue the test making sure your injectors arent firing and see what you get. If the results are the same percentage wise and the cooling system held pressure testing it also you might want to turn the power down.
yes numbers 1 and 5.... i don't think its a bent rod because those cylinders have had iffy balance rates for a few months now and i always chalked it up to injectors being out of spec.. ive been beating the piss out if it since then and it hasn't gotten any worse i would think if i had a bent rod it would of let go by now...
im going to try and hunt down the external coolant leak in a little while to see what it shows
im going to try and hunt down the external coolant leak in a little while to see what it shows
so talked to a friend and he gave me some ideas i hadn't thought of,
#1 my passenger side valve train has always been a bit noise... perhaps thats to blame for the down compression in 2 cylinder?
#2 leak down test...anyone ever done one on a duramax before?
#1 my passenger side valve train has always been a bit noise... perhaps thats to blame for the down compression in 2 cylinder?
#2 leak down test...anyone ever done one on a duramax before?
Merry Christmas!
well couldn't rig up anything to work as a leak down test so i just put the plugs back in it and drove it....
not building any pressure yet but the balance rates are still wacky...i did some logging so ill post up
there should be 3 logs in this folder..one after a cold start, one after a short drive and one after driving for 20 minutes or so
please let me know what you think
well couldn't rig up anything to work as a leak down test so i just put the plugs back in it and drove it....
not building any pressure yet but the balance rates are still wacky...i did some logging so ill post up
there should be 3 logs in this folder..one after a cold start, one after a short drive and one after driving for 20 minutes or so
please let me know what you think
where do u get a cooleqnt pressure tester i have one for the old style caps but not for these new style caps