0 compression in 3 cylinders

[faulkner]

Okay just finished 6-bolt swap in my 1995 GS-T. 7-bolt head, 6-bolt block.
everything checked out, cas wired right, with new plugs and wires. timing set perfect. NO START! Got fuel and spark no codes thrown. So did a compression test and cylinder closest to the timing belt held 130psi, than all the rest held 0!
re torqued the head bolts to 100. top-line head-bolts and brand new head gasket.
Also did a leak-down test and couldn't really tell where it was coming from since the leak was so big. but it was coming out of the other cylinders. Also since all headbolts were just re torqued and the leakdown didnt spin the turbo or intake from what i heard could it still be valves?? need help asap! thank you.

 

[SICK SOCIETY DSM90]

I could be wrong but whenever we got a 0 compression the cylinder is dead and since its freshly rebuilt sounds like the piston rings are not sealing on those cylinders. If head is fresh also I doubt its a valve problem more of a ring issue. From my experiences with 0 compression readings that pretty much telling you there is nothing sealing at all. I would normally say burn piston rings but since its never been started since rebuild it probably just a piston rings not sealing in those cylinders. Just what my personal experiences so im curious to see what others opinions are also.

 

[Dsmkauai]

Have you checked timing again? What is the mileage of the motor and what did you do to it?

 

[SICK SOCIETY DSM90]

Ya I would re check timing before jumping into a tear down again but its something in that direction. Sucks if its something internal but weird stuff happends on rebuilds.

 

[faulkner]

Head is off my 7-bolt that got crankwalk, so bought my friends 6-bolt block
With 2g pistons and 1g big rods. It was out of his perfect running car. But
The head is from my gst. Timing is set 100% positive

 

[Rsawd95dsm]

What kind of head gasket are you running? Did you check the head and block for warping issues?

 

[faulkner]

How do I check for warping issues?
It was fine in my car like a week before the swap?
I think a composite headgasket. Metal

 

[95burgundyesi]

As a tip, when the engine is on the stand or out of the car, I like to crank it by hand 4 complete cycles like when checking timing marks, you would feel each compression cycle by hand. Removing spark plugs can let you focus on each cylinder. Works for me anyway for piece of mind.

 

[Dsmkauai]

If your using a mls headgasket and don't have perfect surfaces on the block and head. You could fight getting a complete seal. So its important to know which headgasket you used. With a oem gasket you can get away with alittle more but its a good idea to make sure your surfaces are within spec or perfectly flat.

 

[loogyz24]

What kind of head gasket are you running? Did you check the head and block for warping issues?

Yes very good point you have, when ever you take a head off I always check the head for warping. If you do not do this you will be walking home very quickly. It doesn't cost much to have the head resurfaced if it is warped.

 

[faulkner]

Set everything to tdc and pulled the head quick glance
Looks like valves aren't seated proper and moisture on the
Head gasket. Going to bed will update you guys in the am.
Please come back tomorrow to see what's up

The one I bought from extreme psi
OEM Composite Head Gasket : Mitsubishi Eclipse 90-99

 

[Dsmkauai]

Hmmm well what happen when your old motor finally walked? its usually not pretty. Could there have been damage to the valves and you just didn't realize it?

 

[boosted1stgen]

Yea anytime you get 0 compression is usually timing/valve related, cause ive seen motors that had a hole in a piston that would still build some kind of compression on that cylinder

 

[SICK SOCIETY DSM90]

Also do that leak down testing if possible to see if your piston rings are properly gapped and sealing the way there suppose to if not will also give you the 0 compression reading along with what was said above timming and valve issues.

And I agree with block and planning the head and block since the head is from a different motor gotta make sure its totally straight before putting them together or they will never seal if theres to much warping on either part it will make it difficult to seal the head gasket.

 

[thomcasey]

Did the lifters get bled properly? Could have some holding a valve open

 

[faulkner]

Just took the cams out, valves are bent ):

 

[Dsmkauai]

Dang bummers bro! But atleast now you know the problem and can fix it so that's a plus.

 

[BogusSVO]

But how did the valves get bent? Were they bent before install? Did they get bent installing the timing belt?

Also Just how bent are they?

 

[91mits]

u could get away with shimming the valves if its not too bad...my guess is you didnt bleed the lifters and it bent a valve upon initial start up...always bleed lifter...takes 15 mins but its a peace of mind...

 

[Dsmkauai]

My guess when his last motor crankwalked or upon initial startup.

 

[faulkner]

Yes my last motor crankwalked.
valves are not seating all the way to losing all compression. i took the cams off while the head was off and from under the valves you could stick a quarter in the gap on a few.

im going to go get a new cylinder head right now.
what steps do i take to install it properly and not have this happen again?
bleed lifters? and i just bought a new OEM composite head gasket and just had it on over night than took it off the next day tell me i dont need another new one??

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[BogusSVO]

A new Hg would be best.

There are many write ups on how to bleed the hlas.

Also when you install the cams in the new head, drop them in so the dowels are as close as possible to 12 O'colck

 

[faulkner]

okay cool i will try that. and a felpro headgasket a good choice?

 

[BogusSVO]

Felpro will be just fine, part # 9627 PT

 

[bryanwheat]

My guess when his last motor crankwalked or upon initial startup.

What about a thrust bearing out of spec is going to bend valves?