Help! My daughter has an 03 Trailblazer with few hours on it. A few weeks ago, it started idling poorly and became hard to start to the point that she could barely get it to run. I did a compression check, which showed only 90 psi. I figured it just needed a new top end so I picked up a new +.020 Wiseco piston/rings/gaskets/etc had the cylinder bored put it all together and it still wont run. Compression is still only about 90 psi. Any one have any suggestions?[img]i/expressions/face-icon-small-confused.gif[/img]

 

You could have the head shaved .20 to bump the compression up.

 

That would bump up comression, but there must be something else wrong.
I wouldnt go shaving the head yet.

 

this is an obvious question, but did you check the air filter? It wont run worth $h!t if the air filter is clogged/dirty.

 

Yes, I did check/clean the airfilter and put in a new plug. I've been told that it may be one of the main shaft seals where the crank penetrates the case, but that sounds a little 'iffy' to me. Possible?

 

Get a good compresion gauge and do a bleed down test to see if you have a leak in the motor(like the seals)