ok i have 2000 suburban with 5.3 cast iron block alum head 706.what going when i crank it up it blue smoke for few second's then stop's can let it run few more mins revve it up and it will roll some more blue smoke.and i've check the oil i dont use much but it does use oil because oil pan and valve cover gaskets.and i dont use any coolant alway stay the same.i looked at the oil look's fine still nice brown color.i've cleaned the pcv valve and egr both full of carbon.can anyone help??oh and i forgot it has 154k miles on i alway keep the oil changed

 

can someone plz help me??

 

Valve guides??

 

Don't mean to sound like a wiseass, but that's a pretty hard paragraph to read. Grammar and punctuation go a long way.

If you want to investigate before doing anything, pull your plugs. Are they all fouled, or just one or two?

Or, you could just replace your EGR valve, since that's a common cause (especially if all the plugs look about the same).

If one or two plugs is particularly bad, you're looking at having to replace valve stem seals or piston rings - both big jobs.

 

Ok thank you.i've pulled 1 of the plug's doesnt look fouled.just a tiny black ring around the bottom.ok my next question is.how do i do a compression test on this engine?

 

You will need a compression checking gauge (Harbor Fright)
You will need to remove the spark plug for each cylinder
you will need to disable the ignition, in this case just removing all of the spark plug wires will do the trick...
you can do them dry or you can do a couple squirts of oil in each cylinder but just do it the same way for all 8.
They will all be a little different but should all be in a similar range...

Given the age of the engine I would suspect valve stem seals and some ring wear...
if you have been good about oil changes the rings may be in good shape and you have worn/dried out valve stem seals...

 

Ok i know.i've kept on top of everything.but i can't speak before hand.i got when had 140k.
other then i've keep the oil change every 4000 mile's

 

also ( thanks Tech2 ) when checking the compression be sure to disable the fuel pump i.e. pull the fuse so you are not pumping fuel into the system....

 

Well thanks everyone.i will let you know the result's.when i get my gaugae in

 

Also when doing a compression test, the butterfly should be wide open. Not sure how you do that on a ECM controlled throttle.

You said it does use a little oil but then said something about pan and valve cover gaskets. My guesses are valve seals, valve guides, and/or rings.

If Chevy still uses the square O-ring valve seals, they are relatively easy to replace. You need an air compressor and valve spring compressor. The umbrella-type seals aren't that hard to replace either.