Rocker arm came loose

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Geo - 08 Mar 2007 13:28 GMT

My '04 Pontiac Montana just spent three days in the shop getting a
loose rocker arm fixed that also caused a bent push rod. The tech
tells me this is very rare, in fact he's never seen it and has no idea
how it happened.

It should be noted that at about 10K the head gasket blew and this
same shop did the work. Do the techs need to mess with the rocker arm
when repairing a head gasket? If so, I believe I have found my
culprit.

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HLS@nospam.nix - 08 Mar 2007 13:39 GMT

> My '04 Pontiac Montana just spent three days in the shop getting a
> loose rocker arm fixed that also caused a bent push rod. The tech
[quoted text clipped - 5 lines]
> when repairing a head gasket? If so, I believe I have found my
> culprit.

You dont say what kind of engine you have in the Montana (I dont even
know what is available in it), but if you change a head gasket, you have to
remove
the head, and that entails the valve train.

What do you think happened?

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Geo - 08 Mar 2007 14:09 GMT

On Mar 8, 8:39 am, <H...@nospam.nix> wrote:

> > My '04 Pontiac Montana just spent three days in the shop getting a
> > loose rocker arm fixed that also caused a bent push rod. The tech
[quoted text clipped - 12 lines]
>
> What do you think happened?

I think when the techs were in repairing the head gasket they did not
properly re-attach or tighten one of the rocker arms. Between that
time and now the arm worked itself loose and cause the damage. They
were the last people to touch the part that failed.

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Mike Romain - 08 Mar 2007 14:34 GMT

> On Mar 8, 8:39 am, <H...@nospam.nix> wrote:
>>
[quoted text clipped - 17 lines]
> time and now the arm worked itself loose and cause the damage. They
> were the last people to touch the part that failed.

You would be correct likely.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
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Ray - 08 Mar 2007 23:10 GMT

Is it on the same head that had the new gasket? If so, either they
bunged something up during reassembly, or when the headgasket failed
(assuming you ended up with coolant+oil milkshake) you could have lost
lubrication and thus are suffering collateral damage from the first
incident.

Probably an error during reassembly of the valvetrain.

A quick google found this pic of a Chevy smallblock valvetrain - the V6
in your van is pretty similar.
http://images.google.ca/imgres?imgurl=http://hotrod.com/techarticles/p167282_ima
ge_small.jpg&imgrefurl=http://www.hotrod.com/techarticles/89518/&h=127&w=190&sz=
6&hl=en&sig2=tViNFWGs4Shk-P8Fc3qfMg&start=20&tbnid=EZGNoCnQTnP4sM:&tbnh=69&tbnw=
103&ei=bZfwRczWJ6GurgPH9c3yCQ&prev=/images%3Fq%3Dsmall%2Bblock%2Bvalvetrain%26sv
num%3D10%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%
3DN

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Steve - 08 Mar 2007 23:39 GMT

> You dont say what kind of engine you have in the Montana (I dont even
> know what is available in it), but if you change a head gasket, you have to
> remove
> the head, and that entails the valve train.
>
> What do you think happened?

I'll take a swag and say its a one of the 2.8/3.1/3.4 purhrod v6 family,
which I'm pretty sure has conventional Chevy-style ball-stud rockers.
Pushrod Chevies have always occasionally popped a rocker stud out of the
head, which is one of the many weakness of the ball-stud rocker arm
design. An overheat can contribute to loosening a stud in the head, too.

Others may well be right in saying that the guys that fixed the
headgasket didn't assemble the rocker correctly, but its ENTIRELY
possible that they did everything right and the stud still popped out
with no warning and no way for them to have predicted it.

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Geo - 09 Mar 2007 16:51 GMT

On Mar 8, 8:39 am, <H...@nospam.nix> wrote:

Everyone, thanks for all the advice. The repair shop didn't charge us
for the repair. They didn't admit fault, but in reality that's
exactly what they did as they didn't argue the bill at all. Once they
went back and discovered that they worked on the head gasket it was
pretty much over at that point. Thanks again all.

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aarcuda69062 - 08 Mar 2007 23:42 GMT

In article
<1173360538.798802.39180@s48g2000cws.googlegroups.com>,

> My '04 Pontiac Montana just spent three days in the shop getting a
> loose rocker arm fixed that also caused a bent push rod. The tech
> tells me this is very rare, in fact he's never seen it and has no idea
> how it happened.

It's not unheard of for the rocker stud to pull out of the
cylinder head. Small block Chevys have been known to do this for
decades, your Montana van has aluminum heads making it -that-
much more possible.
I've seen Chevy 3.1 V-6s (sister engine to your 3.4) with the
entire roof of the intake port pulled off.

> It should be noted that at about 10K the head gasket blew and this
> same shop did the work.

The mileage when the rocker failure occurred is?

>Do the techs need to mess with the rocker arm
> when repairing a head gasket?

Not necessarily. There are tools and techniques that make it
possible to remove the push rods without having to loosen the
rocker arms on this engine family.

> If so, I believe I have found my
> culprit.

Proving so will be difficult given this engines' history WRT
chronic failure.

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HLS@nospam.nix - 08 Mar 2007 23:48 GMT

"aarcuda69062" <nonelson@sbcglobal.net> wrote in message news:nonelson-

> It's not unheard of for the rocker stud to pull out of the
> cylinder head.

This happened a LOT in earlier versions. You had to go in and pin the
stud within the tower to stop it.

Typical GM bullshit.

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