Proper Procedure for Compression Test : 2.7L V6

I'm considering doing a compression test on my 2001 2.7L V6.

I haven't done one of these since I owned a '68 Pontiac Parisienne 2+ 2
w/327, and a slew of bikes. My old comp tester needs to be replaced.

Before I proceed, is there anything "new" in the generally accepted
method for doing a compression test ? Anything special about doing the
test with 2.7L V6 ? Any electronics that should be disconnected during
the procedure ?

Many thanks....Phil

 

I'm no expert, so someone else will have to chime in. The 2.7L plug
holes are recessed several inches, so the compression tester needs to be
able to reach (do they make exensions since several engines are like
that these days?). Something else (and again I'm no expert - just
something I observed about 10 years ago) - it came into vogue to,
instead of doing a compression test, to do what's called a "cylinder
balance" test. That's where you disable one cylinder at a time at idle
and record the rpm drop - a weak cylinder was indicated by not much of a
drop compared to the others. But I'm sure you can still buy compression
gages.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Thanks Bill. Yes they make extensions for the compression testers. They
generally come with a 15" hose.

Since I wrote the original question I've been thinking that I'll have
all the plugs out during the test (good, since I have to change them
anyway), I'll have to disconnect the LV wiring to each of coils so I
don't damage those, and I'll have to prevent fuel from being pumped into
the injectors while turning the engine over. I'm not sure yet how to do
that part.

Besides curiosity, the purpose of this is see if running a couple of
Auto-Rx treatments makes any real difference to the compression; it has
for many users.

Phil

 

On the LH cars, lookng at my '99 FSM, it's real simple - PDC Fuse S (20
amp) supplies power to the coils and the injectors and nothing else.
Just pull that fuse. You didn't say what vehicle this is on, but I
suspect they used the same power distribution philosophy on all other
late model vehicles.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Thanks Bill. It's a 2001 Intrepid.

I'll check the legend in the cover of my PDC to see if the same fuse
will kill fuel and coil power in mine. If so, that makes life a lot easier.

Thanks again...Phil

 

You're welcome.

I also have a 2002 FSM - I just checked and it shows the exact same
thing (fuse 'S' for coils and injectors), so you're pretty safe to
assume that's how your '01 is. With very few exceptions, the power
distribution stayed the same thru the 2nd gen. LH car run.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

betcha the chains jumped

 

Huh?? I don't recall him saying that there's any problem - he's just
curious about compression after using an additive.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

his first post came up expired could not see it had to google to see
his first one