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93 S-10 Blazer V6 4.3 Vin W Rocker arm issues Please Help!!


Renegadez
08-25-2007, 05:05 PM
93 S-10 Blazer V6 4.3 Vin W Rocker arm issues Please Help!!

Ok I have pulled this engine and put in a new crankshaft and bearing kit all new gaskets seals and new oil pump new timing chain and gears. Now with that said i did not touch the hydraulic lifters at all. I put back in the same rockers and push rods. this is were my issue is the heads have the rocker arm bolt that is partially threaded then come down to a shoulder. but I cannot get the nut tightened down to there the compression goes away and the moter will die I have tried to adjust them with the moter running and tightning them completely down with the motor off. The rocker arm studs ARE NOT completely threaded so you can opnly adjust them so far and it seems they bottom out on the shoulder so the nuts cannot get tight. If I tighten them completely the engine wont turn over. I have had several mechanics look at it they all walk away scatching their heads saying how wierd it is. Any help would be greatly apppeciated. Thanks!

RenZ

ericn1300
08-25-2007, 07:21 PM
from the repair manual: For the 4.3L (VIN W) engine and any 1993 4.3L (VIN Z) engines which are equipped with screw-in type rocker arm studs with positive stop shoulders, tighten the rocker arm adjusting nuts against the stop shoulders to 20 ft. lbs. (27 Nm). No further adjustment is necessary, or possible. complete instructions here: http://www.autozone.com/az/cds/en_us/0900823d/80/12/a6/58/0900823d8012a658/repairInfoPages.htm

Renegadez
08-26-2007, 01:52 AM
First off let me say Thank You for your excellent help and speedy reply!!

Now, This is exactly what I thought and did.

(For the 4.3L (VIN W) engine and any 1993 4.3L (VIN Z) engines which are equipped with screw-in type rocker arm studs with positive stop shoulders, tighten the rocker arm adjusting nuts against the stop shoulders to 20 ft. lbs. (27 Nm). No further adjustment is necessary, or possible.)

But after I did this then the engine would not start, its like theres no compression it doesnt even really turn over it just clunks. But when I back then nuts way off then the engine can start. But ofcoarse then it really clatters alot. There has been much debate among several freinds I have asked about this many specuclations from a collapased or plugged lifter to a flat place on the cam shaft. We are all stumped as to why we cannot run the nuts all the way down to the stop shoulder with out killing the engine.

Also on another note should not the push rods be basicly spaying oil out alot? To me it doe not seem to be pushing very much oil out the rods.

MT-2500
08-26-2007, 11:07 AM
Something is strange there.
Does you heads have the bolt in rocker arm studs?
Are you sure it has stock hydraulic lifters and cam?
Have the heads been reworked or changed?
With engine off not running find No 1 cylinder TDC compression stroke.

Then with right side valve cover off check for valves rocking on no 4 cylinder.
Valve rock is one valve closing and one valve opening as engine rools over no 1 TDC compression.
If not the timing chain is out of time.
If so at TDC no 1 compression.
Back off rocker arm adjusting nut on no 1 cylinder untill you have slack in push rod.
Then bring the adjusting nuts down untill the slack is gone.
With slack gone in rocker arm you should be able to still spin push rod with your finger.

Now tighten the adjusting nut down not over 3 turns.
If the non adjustable type rocker arms with screw in rocker studs the nut should bottom out before 3 turns and torque down.
And you should be able to still spin push rod.
If push rod wll not spin with fingers you have a problem with the valve adjustment being to tight.

Never tighten a lifter adjusting nut down over 3 turns down after slack is removed.
The correct adjustment on a lifter is half of the turns it takes to bottom out lifter or how many turn a lifter is.
MT

Renegadez
08-26-2007, 01:41 PM
Ok I wil go do exactly what you said and report back by the way the Rocker Arms are the kind with stop shoulders so there is no real adjustment from what i read on the auto zone site which was posted courteous of Eric. Several people have said this is indeed strange. Thanks for the help. I will get bacvk to you asap!

RenZ

93gmcjimmy
08-26-2007, 03:41 PM
I am curious, why did you have to replace the crankshaft? I would recommend you go ahead and try replacing the hydrolic lifters. The don't cost that much and over time won't pump much oil because the little pistons inside them tend to seize. When you do don't forget to prime the lifters before putting them in and cranking the motor.

MT-2500
08-26-2007, 05:53 PM
Ok I wil go do exactly what you said and report back by the way the Rocker Arms are the kind with stop shoulders so there is no real adjustment from what i read on the auto zone site which was posted courteous of Eric. Several people have said this is indeed strange. Thanks for the help. I will get bacvk to you asap!

RenZ


Are they the press in the head type or the bolt in the head type?

Renegadez
08-26-2007, 06:53 PM
Mt,
they are the screw-in type rocker arm studs with positive stop shoulders also the chain looks to br sry correctly I still cannot get the nut screwed down to te shoulder with out it choking the engine off I assume its taking away all the compression I know this is very strange.

93gmcjimmy,
I think you may be correct that I need to replace the hydraulic lifters. It is not shooting oil out of the rods like someone told me it should be spraying like crazt I am not sure if this could cause my rocker issue or not?

Thanks for all the help guys

RenZ

ericn1300
08-26-2007, 09:16 PM
since no adjustment is possible on the top end go back to the new parts and the bottom end. was the new crankshaft stock or performance? performance cranks often require new push rods, or it could be an out of spec or incomplete grind on the crank. what brand did you get? also the timing chain and gears replacement bothers me. loosening up the rocker arms changes the timing of the valves and might be compensating for a bad timing chain replacement, go back and tweak that first.

Renegadez
08-26-2007, 10:29 PM
the crankshaft I bought at advance auto in a camshaft and bearings kit I am not exactly sure what the brand is. I guess if I half to go back and take the timing chain cover off I should explore the idea of doing new lifters and cam while I already have it all apart again?

RenZ

Renegadez
08-30-2007, 07:06 PM
Changed the lifters and Bam its working Wo0Ho0!!! Thanks for all the help you guys ROCK!!

RenZ

MT-2500
08-31-2007, 09:40 AM
You are welcome.
Good Deal.
And Thanks for posting back how it went.
Glad all is well and working right.
MT

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