Low compression 71 521 pickup

[CarlBrownPhoenix]

L16

 

Okay so I've checked the compression on my engine and it's not even close to what it needs to be. I am using a compression tester. I've pulled the head **valve cover** (getting ahead of myself haha) and the timing chain is in tact, the cam lobes are good.

 

I adjusted all the intake and exhaust valves except 4 I can't get it to where it needs to be for some reason. But after adjusting everything I have no compression on 4 barely any on 1 and proper compression readings on 2 and 3.

 

The engine was rebuilt about 2 or 3 years ago. But it has had some major timing problems over the last year. Thanks for all the help guys it is super appreciated.

[jefe de jefes]

Okay so I've checked the compression on my engine and it's not even close to what it needs to be. I am using a compression tester. I've pulled the head and the timing chain is in tact, the cam lobes are good. I don't know what's wrong. Any general suspicions before I pull the head? Thanks

adjust valves?

[MicroMachinery]

adjust valves?

 

x2

 

When you are performing this test, do you have the throttle opened up all the way? If not, try that.

[ppeters914]

Okay so I've checked the compression on my engine and it's not even close to what it needs to be. I am using a compression tester.

What engine? Yeah, probably an L16, but better that we know exactly. What are the compression numbers you're getting?

 

I've pulled the head and the timing chain is in tact, the cam lobes are good. I don't know what's wrong. Any general suspicions before I pull the head? Thanks

Ummmm...either you've pulled the head or you haven't. Perhaps you mean you pulled the valve cover?

[banzai510(hainz)]

what I do as a quick test is ck the rockers with the cam lobe pointing up. If rocker wiggles then the valve is closed. if not then adjust that rocker arm. if you adjust rocker arm pivot post down as far as it goes where its bottoming on the 17mm Jam nut. Means the valve seat is wearing and the valve is sinking into the head.

One way to cheat this is get cam tower shims or a reground cam so to raise the 14mm pivo ball on the rocker.But EZ er to get another head.

 

Go to the next rocker/lobe so on and so on and hit the starter to turn the engine (of coarse pull the coil wire so it dont run and spray oil everywhere.

[datzenmike]

Do a compression test on a warm motor. Leave all the plugs out when testing. Record your findings. Add 4 or 5 squirt of clean engine oil to each cylinder and re test. Record the findings. If the compression goes up significantly the rings are 'tired' and should be replaced.

 

BTW if contemplating a head removal do NOT remove the cam sprocket until you know about and how to lock the chain in place. If done incorrectly the chain tensioner will fall out and will require 2-3 hr$ of extra work and more tools.

[racerx]

yes compression check should be done when engine is warm...the other thing is how old is that engine? any smoke coming out? Also before you adjust the valves, take the 14mm open end and sand it down with a power sander. Since you need a slim open end. It just makes it easier cuz you also to use a 17 mm.