Compression Test Results
- Thread starter spongerx
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shootmymime
New member
make sure you pull the EFI relay to cut fuel to the system, then hold the pedal at WOT then crank, crank until reading does not increase any more and record numbers.
I would say you numbers are low for the miles. factory i believe are 220 psi, a good used numbers are like 180-190.
to see if any cylinders are bad, none should be below 10% (i think it was 10%) of the avg readings.
nevada
Senior Member
did you do them in that order as well? im assuming yes.
did you have a charger hooked to the battery?
the numbers dropping towards the ends could just be due to the battery being a little weaker, and not cranking the engine over as fast.
that said, none of those numbers stand out as a problem. if its running/driving good, id run it and not think twice about it.
did you have a charger hooked to the battery?
the numbers dropping towards the ends could just be due to the battery being a little weaker, and not cranking the engine over as fast.
that said, none of those numbers stand out as a problem. if its running/driving good, id run it and not think twice about it.
LittleCaesar
New member
5 is the low cylinder for me.
The numbers look fine. Spend more time posting more good DIY repairs.
The numbers look fine. Spend more time posting more good DIY repairs.
spongerx
Member
Yep. Had it hooked up to a charger. And it is running really well. I'm just doing a tune up today and thought I would check the compression for curiosities sake.
Thanks everyone for your comments. I think I'll not worry about it and just continue with the tune up and beer drinking. Thanks. :cheers:
Singtoe
New member
Since you have a compression tester and your went through the tear down to get to the spark plugs.
Do another compression test following the same procedure that you did initially. (Don't add any oil to the cylinders). Write down the results, finish your tune up.
Then do a Seafoam treatment. Do the oil, the gas tank and the PVC Valve. Let it clean the motor for one tank of gas. Then do another compression test and see what the results are...
Do another compression test following the same procedure that you did initially. (Don't add any oil to the cylinders). Write down the results, finish your tune up.
Then do a Seafoam treatment. Do the oil, the gas tank and the PVC Valve. Let it clean the motor for one tank of gas. Then do another compression test and see what the results are...
slapdappy
Banned
The FSM says:
Compression pressure:
1,200 kPa (12.2 kgf/cm2, 174 psi) or more
Minimum pressure: 1,000 kPa (10.2 kgf/cm2, 145 psi)
Difference between each cylinder:
100 kPa (1.0 kgf/cm2, 15 psi) or less
Sorry to bring this from the grave...will the seafoam really help compression? I'm getting 145-155psi all around.
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shootmymime
New member
What the sea foam does is loosen the piston rings and let them seal the cylinder walls, thus giving you higher compression.
jgue467
Senior Member
Makes sense - i guess that is why seafoam and startron type products say they'll clean carbon and improve efficiency/fuel mileage (and make starts easier). I've used startron for almost 100k on my runner, does start easy and mileage may have improved about a half an mpg over time but that could be due to lots of things like fluid changes, good air pressure, tires. The stuff makes my small engines fire up instantly even after sitting a few weeks. :cowboy:
limitedvan8
New member
did a test today, battery on a charger, 6 cranks for each, did each cylinder twice to make sure i was getting consistent results
1 - 200
2 - 187-190
3 - 187-190
4 - 192
5 - 200
6 - 200
pretty happy with the results...i know some guys say 5 cranks but i generally go until there's not major bump in the needle
i'm pretty confident i'm "burning" coolant, white smoke on startup so i think i need to do a leak down test to check my headgaskets
1 - 200
2 - 187-190
3 - 187-190
4 - 192
5 - 200
6 - 200
pretty happy with the results...i know some guys say 5 cranks but i generally go until there's not major bump in the needle
i'm pretty confident i'm "burning" coolant, white smoke on startup so i think i need to do a leak down test to check my headgaskets
gamefreakgc
Elite Member
Our vehicles spew condensation like there's no tomorrow at startup. Are you sure it's coolant? If it does that at every startup you should have an empty coolant reservoir and a dropping level in the radiator.
limitedvan8
New member
it smells "sweet", my understanding this is a common sign that it's coolant
my res bottle is empty...
I'm watching the rad level now....truck hasn't been driven in a while and i never really noticed when i bought the truck at the end of last summer....terrible i know but it's not driven much as is
my res bottle is empty...
I'm watching the rad level now....truck hasn't been driven in a while and i never really noticed when i bought the truck at the end of last summer....terrible i know but it's not driven much as is
gamefreakgc
Elite Member
it smells "sweet", my understanding this is a common sign that it's coolant
my res bottle is empty...
I'm watching the rad level now....truck hasn't been driven in a while and i never really noticed when i bought the truck at the end of last summer....terrible i know but it's not driven much as is
I would refill both the radiator and the reservoir. Then after driving it a few times to purge air, use a sharpie and mark the coolant level when it's cold so you know for sure. No sense in trying to diagnose a problem that you're not even sure is there.
Mine when I got it smelled sweet as well at startup. Thought it was coolant until I found out it's just normal. Now it smells like rotten eggs, my cat is failing...
JayRolla
New member
it smells "sweet", my understanding this is a common sign that it's coolant
my res bottle is empty...
I'm watching the rad level now....truck hasn't been driven in a while and i never really noticed when i bought the truck at the end of last summer....terrible i know but it's not driven much as is
Pressure test the coolant system. Are you blowing white smoke? Misfire? Poor performance?
limitedvan8
New member
will do once i get it all back together. doing my injectors next weekend and i'm going to flush and refill with oem coolant. green stuff in there now.
limitedvan8
New member
yes on start up, don't think so under load, but tough to look behind me.
yes misfire, i'm swaping injectors this weekend as i know i have a bad one and only want to this this full removal once. i'd say yes for poor performance but then again these aren't exactly the most powerful trucks lol
i think before i do the flush i'll try to pressure test it. just need to find a tester i can borrow
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JayRolla
New member
If smoke only on startup, no oil in coolant and you have a bad injector than thats most likely your issue. Have you pulled plugs to see if any look wet?