25 dollars at autozone. You take spark plugs out one at a time and screw compression tester in there and unplug coil to make sure it does not start then crank engine and write down compression results. make sure you do all cylinders and report back with the results.

 

They can use a scope to look at the cylinder and piston face through the spark plug hole...much like a doctor looks up your nose.
Both my Vortecs have a slight tapping sound on startup worse on a cold ambient condition, but I was always told it was nothing to worry about. I didn't worry about it and they are still running strong with no problems.

 

The problem is that I hear the tapping sound even after driving across town. And I'm not very good at not worring about something that could lead to costly repairs out of my pocket.

 

hmm i never knew about the scope thing....never heard of it or seen it before. I'll have to try it out one of these days.

Whatever the problem may be, I don't blame you for being worried about it. A vehicle is an expensive investment. Just don't let the dealer give you the run around.

 

i have one of those video scopes also, it is excellent for going through spark plug holes, checking disc and drum brakes, you can even hook it up to a TV, but as far as the ticking goes, you may have to get mean with your dealer, no techs like work that is covered under warranty and the service managers hate to give that work to them so they will try the cheapest easiest thing first, show them your angry face

 

I'd think they would take any work they can get right now. The service dept was pretty dead when I was there.

 

Well, just got off the phone with service mgr. What the actually put in the tank was BG44K. He says he didn't hear the sound himself, but said the motor was pretty warmed up by when they asked him to listen.

Anyway, he's going to get more info from the tech as to what he heard and thought it was.

 

Well....getting near the end of GM used cert warranty and powertrain warrant a month later in mid June so I took the truck to dealer again. I swear the knock/tick was getting worse. In fact is even worse after driving the highway for even a short trip.

The thought of it being worse wasn't just me. Mgr said it's very noticeable now. Dealer is doing a tear down and thinks the issue is coming from the cam or lifter(s). I noticed the sound is twice as prevalant from under the truck so cam area probably makes sense.

I'm a little nervous on the course of action they will take after tear down. I worry it won't go back together as it came apart.

 

i am actually still in high school and we have a scope that we stick in cylinders to check out the conditions, its a snake like scope with a mini camera and light on the end and they do work very well for looking inside a cylinder, but i doubt its carbon buildup. how many miles are on your truck?

 

just under 50k.