car sat awhile and it seems to smoke on start up wondering if there is a way to test these and if they can be changed on the car if needed?

thanks

 

They're straight forward to change. Remove the valve covers, remove the rockers, remove the valve springs (one cylinder at a time, making sure the cylinder is at TDC or injecting compressed air through the spark plug hole to keep the valves from dropping), then remove the seals. Of course, you'll need to reset the valve lash when done. Here's a link to that process:

http://shbox.com/1/4th_gen_tech2.html#adjust_valves

 

check them?

 

Smoking on start up is either valve stem seals or piston rings. The only way to find out is to replace the valve stem seals and see if it goes away.

 

How many miles are on the car? If you're at or, near 100K and want to keep everything in great shape, it's probably time to replace the valve stem seals. This would also be a good time to install fresh valve springs, as they fatigue with age. LT4 springs are cheep and perform well.

Other than a puff of smoke at start-up (after setting), there isn't any real method to determine if the seals are bad. Again, age and miles are a major factor.

 

I forgot, it could also be valve guides, but the cheapest thing to check/replace is still the valve stem seals.

 

this motor was built about 2k ago with LE heads