compression test on my 7bolt

[dsm3000]

I did a compression test on my 7bolt , c.#1 is 120/ c.#2 is 130/ c.#3 is 30/ c.#4 is 150. Why is it doing this? I'm also boost spiking. I have checked the w/g,b/c, and the BOV.

 

[VETTE_50_TH]

That motor is toast. Time for a new one. Cylinder number three is done. I would like to see what your cylinder walls and piston looks like after you take you head off.

James

 

[dsm3000]

Ill post pic's later. I have a balt motor to put in, should i do it now or later?

 

[kiwidog]

I'd replace it as soon as you possibly can before something really breaks and fails and either leaves you stranded or with more things broken than just the engine.

 

[VETTE_50_TH]

That thing should be a toaster by now. Pull that out of there, and put in your other one.

James

 

[dsm3000]

The motor is not smoking?

 

[bane3d]

Your compression is horrible. You could do a leak down test and determine where the issue is but if you have a motor already to be dropped in, do it. There is the possibility that you could lose pieces of piston rings out your exhaust and the damage to your turbo could be bad. You willing to take the change and cause more harm or just get it done. Heck, I'd love to watch since I'm in St Peters and about to pull mine and ship it.

d

 

[dsm3000]

I'm taking the motor to Terry's machine shop to check it out.

 

[dsm3000]

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[STM tuned]

valves all bent and broken?

ouch

factory compression *should* be 178ish accross the board without more than a varience of 14psi between cylinders.

 

[DJYoshaBYD]

Just swap your motor in, and take the other out before you do even more damage to it, and it renders the block and and crank useless.. If you take it out now, you can have it machined and rebuilt over a period of time, and make it into a race motor.. Or sell the block to someone who wasnt as lucky as you to have another motor, so they drove their's until a rod peeked out the side of the block and said "hello"...

 

[eclipsetech]

pull the head and see the extent of the damage to the cylinder wals if its good hone all the cylinders and get new rings if not dont bother boring it, just get a 6bolt.

 

[1AWD90]

Agreed just swap motors but i would still do a leak down test on our 7bolt. Could be simple as bad valves seats ect. A leak down test will tell you for sure why the low compression. If it sounds like air is coming out of the intake or exhaust its valves. If it sounds like its comming out of the fill hole or the dipstick its rings or worn cylinder wall.

 

[dsm3000]

I have a drag motor getting put together now. so she will be drag only, not less i get called out...