Mechanics

NO COMPRESSION

2000 Cadillac Escalade

Engine Mechanical problem
2000 Cadillac Escalade V8 Four Wheel Drive Automatic 118000 miles

I HAVE JUST DONE HEAD GASKETS ON THIS VEHICLE AND I PUT IT ALL TOGETHER AND I FIND OUT THAT I HAVE NO COMPRESSION ON ALL CYLINDERS I HAVE TRIED TO DO THE VALVE ADJUSTMENT TWO SEPERATE TIMES ONCE WITH A FULL TURN AND ONCE WITH A 1/4 TURN I BELIVE I FOLLOWED ALL INSTRUCTIONS BUT AFTER ALL THIS I STILL HAVE NO COMPRESSION AND THIS IS DRIVING ME CRAZY IM STARTING TO THINK SOMETHING WAS DONE WRONG DURING ASSEMBLY BUT IM SURE THERE WASN'T IF SOMEONE COULD HELP ME THAT WOULD BE GREAT! THANKS TO ANY ONE THAT REPLYS IN ADVANCE
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Asetech1
October 26, 2009.



Hi
Try this back off rockers so your sure valves are seated. Is there compression? If so instead of adjusting At tdc and do ext so and so then int, so so. Start at TDC cyl 1 then rotate as to firing order. Tighten while rotating push rod with finges when there is resistence add 1/2 more turn.
Let me know
Thanks for donate

Docfixit
Oct 26, 2009.
Please explain alittle different please didn't understand copmletely more so about adjusting the valves while going through the firing order dont mean to sound stupid just sounds confusing thanks for your help.

Tiny
Asetech1
Oct 26, 2009.
What I would do first is set them all at zero lash when valves are closed, and check a cylinder to see if it has compression. The procedure calls for one full turn after zero, but we want to know if zero lash gives you some squeeze. If you still don't have compression at zero lash, were the heads serviced? At that point you would want to consider a cylinder leakdown test to find out where your air leak is. I included the GM procedure, but it would not be the first time that service info was incorrect.

Here is the gm procedure: Valve Clearance Adjustment

Turn the valve rocker arm nuts clockwise until all of the valve lash is removed.
Turn the crankshaft clockwise until the alignment mark on the crankshaft balancer is aligned with the notch in the engine front cover tab.
Look at the number 1 cylinder valves as the crankshaft balancer alignment mark approaches the notch in the engine front cover tab. If a valve moves as the alignment mark moves into position, the engine is in the number 6 firing position. If this happens, turn the crankshaft clockwise 1 revolution in order to reach the number 1 cylinder firing position.

With the engine in the number 1 firing position, adjust the exhaust valves for cylinders number 1, 3, 4, and 8 and the intake valves for cylinders number 1, 2, 5, and 7.
4.1. Turn the valve rocker arm nut counter clockwise until the valve lash is felt in the valve pushrod.

4.2. Turn the valve rocker arm nut clockwise until all the valve lash is removed.

Zero valve lash can be felt by moving the valve pushrod up and down between your thumb and forefinger until there is no more up and down movement of the valve push rod.

4.3. When all the valve lash is removed, then turn the valve rocker arm nut clockwise 1 additional turn (360 degrees).

Turn the crankshaft clockwise 1 revolution until the alignment mark on the crankshaft balancer is aligned with the notch in the engine front cover tab.

With the engine in the number 6 firing position, adjust the exhaust valves for cylinders number 2, 5, 6, and 7 and the intake valves for cylinders number 3, 4, 6, and 8.
6.1. Turn the valve rocker arm nut counter clockwise until the valve lash is felt in the valve pushrod.

6.2. Turn the valve rocker arm nut clockwise until all the valve lash is removed.

Zero valve lash can be felt by moving the valve pushrod up and down between your thumb and forefinger until there is no more up and down movement of the valve push rod.

6.3. When all the valve lash is removed, then turn the valve rocker arm nut clockwise 1 additional turn (360 degrees).

Factoryjack
Oct 26, 2009.
Thank you for your help. I have done what you suggested. I set all the valves at zero lash and I have a 100 psi on all cylinders. Then I proceeded to make the additional adjustment with one full turn past zero and I lost all compression on all cylinders. Compression went from 100 psi to zero and I started the procedure over twice, once with a half turn past zero and once with a quarter turn past zero. What do you suggest that I do now.

Tiny
Asetech1
Oct 27, 2009.
When you consider what you are trying to do by turning it past zero lash, putting the lifter in the center of it's travel, it makes no sense why it is holding valves open. Theoretically, higher than normal oil pressure, would create this condition. I am assuming that both the half turn, and quarter turn results in no compression as well? Are you sure you are adjusting them with the valve in a closed position as described in the procedure?

Factoryjack
Oct 27, 2009.
YEAH I UNDERSTAND WHAT YOU ARE SAYING BUT I DID FOLLOW THE PROCEDURE STEP BY STEP AND I JUST DONT UNDERSTAND WHAT IM DOING WRONG I KNOW YOU SAID SOMTHING ABOUT OIL PRESSURE BUT MY OIL PRESSURE IS PERFECT DONT KNOW WHAT ELSE TO DO I KNOW IT'S HARDTO FIX A VECHILE WHEN IT'S NOT IN FRONT OF YOU BUT WHAT YOU ARE DOING IS HELPING I HAVEN'T DONE A VALVE ADJUSTMENT IN 12YRS. COULD IT BE THAT ZERO LASH IS ENOUGH WITH NO ADDITIONAL TURNS IF NOT I AM OPEN TO WHAT EVER GOOD SUGGESTIONS YOU HAVE. THANKS

Tiny
Asetech1
Oct 28, 2009.
Is there anyone that can give me some advise on what to do next still loosing compression after valve adjustment is done not trying to put pressure on anyone just trying to deliver this vehicle

Tiny
Asetech1
Oct 29, 2009.
Set them at zero lash and run it, see if there is any noise. If you can run it with the covers removed, you can make fine adjustments to diminish the rockers from clicking.

Factoryjack
Oct 31, 2009.