low compression

Reply Subscribe

Thread Tools

Search this Thread

Mar 6, 2018 | 02:02 PM

#31

RightSaid fred

Account Disabled

Joined: Mar 2013

Posts: 714

Likes: 22

From: in a garage

Quote:

Originally Posted by deylag

If there are any vacuum leaks on the intake manifold then that would cause less air to go into the cylinder when you crank.

Your statement makes no sense at all.

Quote:

Originally Posted by 2006EvoIXer

Check intake cam lobes for cylinder 2 to make sure it is making full contact with rocker arms. If it does make tight contact, try to compress HLA under those two rocker arms. If they compress, HLA is probably leaking and not holding rocker arms fully up and allowing valvesprings to not fully open. This can also be the source of your lifter ticks.

It's not going to affect compression, if anything it'll go up due to the intake valve closing sooner

Quote:

Originally Posted by nor11384

Well, got a compression tester from autozone and all cylinders showed 153 except that one which showed 90 - 100. Poured a cup of oil and and it jumped to 120. :sigh:?

That test says it's a broken piston.

Last edited by RightSaid fred; Mar 6, 2018 at 02:10 PM.

Mar 6, 2018 | 02:12 PM

#32

2006EvoIXer

Evolved Member

iTrader: (1)

Joined: Jul 2012

Posts: 3,294

Likes: 197

From: California

Quote:

Originally Posted by RightSaid fred

It's not going to affect compression, if anything it'll go up due to the intake valve closing sooner

That test says it's a broken piston.

You're right. A bad lifter will slam the valves shut. He better start saving up.
Has your buddy removed his cams recently and reinstalled without bleeding the lifters?

Last edited by 2006EvoIXer; Mar 6, 2018 at 02:43 PM.

Mar 6, 2018 | 03:07 PM

#33

nor11384

Thread Starter

Evolved Member

iTrader: (1)

Joined: Jan 2009

Posts: 1,131

Likes: 34

From: tampa, fl

Not that I know of but always had bad lifter tick...

Mar 6, 2018 | 03:19 PM

#34

2006EvoIXer

Evolved Member

iTrader: (1)

Joined: Jul 2012

Posts: 3,294

Likes: 197

From: California

Quote:

Originally Posted by nor11384

Not that I know of but always had bad lifter tick...

then it's likely not the lifters.

Mar 6, 2018 | 03:40 PM

#35

nor11384

Thread Starter

Evolved Member

iTrader: (1)

Joined: Jan 2009

Posts: 1,131

Likes: 34

From: tampa, fl

Why? Never took a compression test...could have been like this for a while...

Mar 6, 2018 | 03:43 PM

#36

RightSaid fred

Account Disabled

Joined: Mar 2013

Posts: 714

Likes: 22

From: in a garage

Or multiple problems with multiple bad mods.

Mar 6, 2018 | 03:58 PM

#37

2006EvoIXer

Evolved Member

iTrader: (1)

Joined: Jul 2012

Posts: 3,294

Likes: 197

From: California

Quote:

Originally Posted by nor11384

Why? Never took a compression test...could have been like this for a while...

only way I can think of caused by lifters is if someon swaps out cams and didn't bleed the lifters. As they reinstall the cams they could compress some accidentally when installing new cams. Then lifters would rest high and under pressure, holding valves open.

Mar 6, 2018 | 04:15 PM

#38

nor11384

Thread Starter

Evolved Member

iTrader: (1)

Joined: Jan 2009

Posts: 1,131

Likes: 34

From: tampa, fl

Well, lets see...i plan on pulling the head and see if i can see anything...may have machine shop test it and see if valves were closing as they should...maybe it was carbon build up or something?

Mar 6, 2018 | 04:33 PM

#39

2006EvoIXer

Evolved Member

iTrader: (1)

Joined: Jul 2012

Posts: 3,294

Likes: 197

From: California

Quote:

Originally Posted by nor11384

Well, lets see...i plan on pulling the head and see if i can see anything...may have machine shop test it and see if valves were closing as they should...maybe it was carbon build up or something?

use an othoscope and look inside through spark plug hole. They're so cheap and I think it's about $30 on Amazon.

Mar 6, 2018 | 04:44 PM

#40

nor11384

Thread Starter

Evolved Member

iTrader: (1)

Joined: Jan 2009

Posts: 1,131

Likes: 34

From: tampa, fl

Yeah i could try that and see if something sticks out...

Mar 6, 2018 | 04:50 PM

#41

2006EvoIXer

Evolved Member

iTrader: (1)

Joined: Jul 2012

Posts: 3,294

Likes: 197

From: California

Quote:

Originally Posted by nor11384

Yeah i could try that and see if something sticks out...

that's the easieat thing to do. Also check cylinder 2 walls for signs of wear. I can see cross-hatches when I last looked in my cylinders.

Mar 7, 2018 | 04:39 AM

#42

nor11384

Thread Starter

Evolved Member

iTrader: (1)

Joined: Jan 2009

Posts: 1,131

Likes: 34

From: tampa, fl

Yeah I have a buddy that has one. Going to try that and see. Well he actually has one of those cheap wires from wish that you hook up to your phone but that’ll work. I think you can take screenshots so if I can do that I’ll post pics here.