one piston is lower than others why?

[kr.k]

I have head off of my 95 talon engine and one of the pistons doesnt rise as high as others. Thats what the mechanic told me over he phone - I havent seen it for myself but it sounds strange. What could it be? I have been told its a sign of crankwalk... is it?

 

[DrZiplok]

It suggests that you might have mismatched pistons/rods.

There's only one "symptom" of crankwalk your mechanic should be checking; crank end travel. Tell them to measure it properly.

 

[turbofanatic]

is the mechanic or who ever is working on it rotating the crank after they took the head off? if so that is not good at all from what i have read. and all of the pistons should raise up to the same height, if not the compression ratio wouldn't be the same i wouldn't think. but any how it doesn't sound like either thing is good

 

[germain101]

could be a bent rod...was the engine making a loud rattling noise before the head was pulled???

 

[kr.k]

I started loosing a lot of coolant water and there was a lot of whiteish smoke coming out of exhaust.. that's why the head was taken off!

The head was examined/pressurised and found to be ok! Now how could the water enter cylinder? there is no water in the engine oil...

sorry DrZiplok but could you explain me what is crank end travel and how it is measured?
thanks for everybody's input!

 

[Jason's TSI]

Sounds like a bent rod, I fixed a 2g turbo eclipse that had the same symptoms, but it had a hole in the head and 2 bent rods.

 

[germain101]

sounds like you had a blown head gasket....one of the cylinders could have gotten enough water in it to create a lot of compression and bend the rod...you can measure the end play on the crank with a dial indicator...preferably one with a magnetic base...


ps, is the top of the piston, that is lower than the others, also cleaner than the tops of the other pistons???

 

[candela]

Yep... I agree with Germain

 

[kr.k]

Originally posted by germain101
sounds like you had a blown head gasket....one of the cylinders could have gotten enough water in it to create a lot of compression and bend the rod...you can measure the end play on the crank with a dial indicator...preferably one with a magnetic base...


ps, is the top of the piston, that is lower than the others, also cleaner than the tops of the other pistons???

That is the same theory my mechanic told me...
and no he told me they all look the same but it might be because I drove just one day with sprying water all around
he still hasent got time to get the bottom off of the car so I need to wait...

 

[DrZiplok]

Originally posted by kr.k

sorry DrZiplok but could you explain me what is crank end travel and how it is measured?
thanks for everybody's input!

End travel or end play refers to how much the crank can be moved along the axis of its rotation. You can measure it a variety of ways; your mechanic probably has the tools for the job.

See the crankwalk FAQ for a variety of ways of checking; the simplest one involves using a prybar to pull the crank pulley away from the engine.

 

[kr.k]

Yes, it is a bent rod!

I know I should replace all the rods to the forged ones but I don`t have the money to do it right now

So - if anyone of you would like to help out an fellow DSM`er in Europe then please send me your used but good 2G stock rod and to show you my gratitude I would send you back some very sweet Russian Vodka!

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P.S. where could I find specs for crank? pref. in metric scale...