Hello, I have a 2000 Chevy Tracker that my daughter loves and I’m in the process of replacing a lot of worn parts including the timing chain components. Since the valve cover comes off as part of that, I went ahead and took a look at the pistons via a borescope. I’m not really sure what to look for and whether I should consider getting the head and block machined and rebuilt. It’s got 130k miles and I’d like it to go 200k.

Thoughts on these photos? Piston 4 looks oily and the PVC was definitely clogged when I pulled it.

The rest look like they’re covered in quite a bit of carbon. I could walnut blast those as I do that for my BMW intake ports and valves every 30k miles. I could also run Seafoam through it.

The cylinder walls still show good signs of cross hatching but I can see vertical wear marks too. But could be normal for this mileage, I just don’t know.

Thoughts from any mechanics with experience in this area?



Spark plug port cylinder 1

2

3

4

Cams

Piston 1 at TDC.

Piston 2 at bottom. Shiny part on the top left looks like carbon removed??

Closeup of 2 center.

Closeup of shiny part on piston 2 with cylinder wall. You can see the cross hatching and vertical scoring.

Different angle on 2

Piston 3

Closeup of 3

Edge and wall of 3

4 is TDC as well and pretty greasy too.

 

>> I’m not really sure what to look for

A borescope won't tell you much about the condition of the engine. At a minimum you should do a compression check and then a "wet" compression check. If you have a compressor, Harbor Freight has an $85 leak-down tester. If you're worried about the condition of the head gasket, Harbor Freight also has a $34 products of combustion detection kit. These are all non-invasive tests and will tell you much more about the engine internals than a borescope.

 

Thanks for the input. At this point, I'm saving money by not having to buy a newer car and I'd like this one to last as long as possible. I'm going to go ahead and pull the head and engine block and have them machined and rebuilt. She'll love it when it's done!