How do these pistons look? (Page 1/2)
Patrick's Dad SEP 24, 09:12 PM
These are, obviously, pictures of the borescope looking down into the 2.2L Ecotec of my son's 2005 Chevy Classic (Malibu). At just over 60K, the timing chain let go, and, this being an interference engine, I started to disassemble the top of the engine to take a look at the pistons to see if they'd been damaged. A friend loaned me the borescope. I have to say that I'm not experienced enough to know what I'm looking at in these video images. I see dings in the surface of the pistons and one even looks chipped, which I don't think is good. Am I wrong (about the dings, not about them not being good)? TIA
carnut122 SEP 24, 11:40 PM
I'm not seeing an issue. Have you run a compression check?
tesmith66 SEP 25, 08:06 AM
I'd worry more about bent valves than damaged pistons.

I think a leakdown test would be more appropriate, as you would need a timing belt to do a compression test. If the belt is cheap enough, it may be best to install it and then see what happens. It's a lot of work, but will be cheaper than removing the head and sending to a shop for inspection.

Good luck.
Patrick's Dad SEP 25, 10:23 PM
I could replace the belt without removing the head, but, I've got to take so much apart, I might as well pull the head and swap it with a rebuild ($625/ish, plus core). That would take care of the valves, as well, but, I figure, if the pistons were damaged, then it's a lot of time and effort for naught.

This is entirely a shade tree operation.
tebailey SEP 25, 10:25 PM
Almost every interference engine I've seen snap a belt has bent the valves. But there's always hope. Pull the old head off before you buy anything, that way you'll know what you have before you spend any$$$$

[This message has been edited by tebailey (edited 09-25-2015).]

Tstang429 SEP 26, 12:16 AM
Make sure you get the updated tensioner setup. My pistons have nice little knicks for 40k miles and 5 years. My cavalier took out the valves same situation same motor. I don't think id buy a rebuilt head either. I took mine up had a valve job done for around 200. that was new valves new seals new guides assembled and ready to drop back in.
tesmith66 SEP 26, 08:17 AM
My comment was based on my son's experience with a Chrysler Sebring. That was Chrysler's recommendation (and what their techs do) because the labor involved in pulling the head and all that would always exceed the value of the older car. He ended up selling the car for $400.
Patrick's Dad SEP 26, 09:33 PM

quote
Originally posted by tebailey:

Almost every interference engine I've seen snap a belt has bent the valves. But there's always hope. Pull the old head off before you buy anything, that way you'll know what you have before you spend any$$$$




Killing me. Going to have to get a torch or something to get the exhaust manifold off.

Thanks to all.
tebailey SEP 26, 09:44 PM
I feel your pain, that's the worst part of pulling a head. I've had to pull a lot of broken bolts out of heads in my 30+yrs of doing that. Just take your time, lots of penetrating oil and if necessary, fire wrench PS if you do break a bolt off, the machine shop can yank it out for ya, or get a reman head.

[This message has been edited by tebailey (edited 09-26-2015).]

tebailey SEP 27, 11:17 AM
There was an episode of All girls garage that did a head on one that snapped a belt.