Misfire, Noise, Problems...... - Page 2 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 03-19-2007, 07:48 PM   #11
Senior Member
Posts like a Corvette
Thread Starter
 
Join Date: Jun 2005
Location: Berkeley, IL
Posts: 1,596
Thanks: 0
Thanked 0 Times in 0 Posts
DarkShadow is on a distinguished road
Default

well i fired off an email to intense, ill wait and see what they say

in the meantime, i pulled the rear cover and found that the bolt for the #4 cylinder rocker unscrewed itself, i mean i was able to take it off by hand by the like 3 threads that were screwed in. I know we torqued the bolts right and we double checked them before putting everything back together.

so it looks like the rocker, pushrod, and valvespring retainer are damaged, and maybe the top of the valve stem, it has a couple marks on it.
DarkShadow is offline   Reply With Quote
Old 03-19-2007, 08:16 PM   #12
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

Did you reuse the bolts? They are torque to yield and "supposedly" each bolt of that nature should not be reused.
BillBoost37 is offline   Reply With Quote
Old 03-19-2007, 08:40 PM   #13
PopaDopaDo
True Car Nut
 
popatim's Avatar
 
Join Date: Jan 2005
Location: NY
Posts: 4,957
Thanks: 0
Thanked 0 Times in 0 Posts
popatim is on a distinguished road
Default

Quote:
Originally Posted by willwren
Unburnt fuel from the #4 went right to the O2. Straight shot. O2 said:

Quote:
Holy COW, this engine is running RICH!
Then Mr. PCM was told by the O2 what was going on, and leaned out all the injectors. Front manifold was glowing red from a lean condition.
Ok, something doesn't register with me brain. If the rocker was that loose then one of the valves wasn't opening; correct?

If it was the intake valve then the plug wouldn't get wet, the o2 wouldn't see anything from that cylinder and then what? Rich, Lean, or Normal. I would guess 'normal' since I don't see why 2 or 6 would be running rich. Fuel would begin to pool in the runner. Is the intake stroke cylinder vaccum enough to suck in fuel? I would think not unless you were in need of head work.

If it was the exhaust valve then the intake valve would open, air and fuel would enter, then fire. The exhaust would find no way out until the intake valve opened again and then what? BANG - you get a nice backfire?

So I don't see why fuel would be reaching the o2 sensor unless the injectors are the wrong.

Someone help me think right.
popatim is offline   Reply With Quote
Old 03-19-2007, 08:43 PM   #14
Senior Member
Posts like a Corvette
Thread Starter
 
Join Date: Jun 2005
Location: Berkeley, IL
Posts: 1,596
Thanks: 0
Thanked 0 Times in 0 Posts
DarkShadow is on a distinguished road
Default

Quote:
Originally Posted by BillBoost37
Did you reuse the bolts? They are torque to yield and "supposedly" each bolt of that nature should not be reused.
they were brand new from the dealer bolts, and the old ones were discarded.

honestly i have no clue why it came undone
DarkShadow is offline   Reply With Quote
Old 03-19-2007, 08:43 PM   #15
Senior Member
True Car Nut
 
Join Date: Aug 2003
Location: Salina, KS
Posts: 5,246
Thanks: 0
Thanked 0 Times in 0 Posts
TrueWildMan is on a distinguished road
Default

Quote:
Originally Posted by popatim
Quote:
Originally Posted by willwren
Unburnt fuel from the #4 went right to the O2. Straight shot. O2 said:

Quote:
Holy COW, this engine is running RICH!
Then Mr. PCM was told by the O2 what was going on, and leaned out all the injectors. Front manifold was glowing red from a lean condition.
Ok, something doesn't register with me brain. If the rocker was that loose then one of the valves wasn't opening; correct?

If it was the intake valve then the plug wouldn't get wet, the o2 wouldn't see anything from that cylinder and then what? Rich, Lean, or Normal. I would guess 'normal' since I don't see why 2 or 6 would be running rich. Fuel would begin to pool in the runner. Is the intake stroke cylinder vaccum enough to suck in fuel? I would think not unless you were in need of head work.

If it was the exhaust valve then the intake valve would open, air and fuel would enter, then fire. The exhaust would find no way out until the intake valve opened again and then what? BANG - you get a nice backfire?

So I don't see why fuel would be reaching the o2 sensor unless the injectors are the wrong.

Someone help me think right.
Was the rocker off enough to not open that valve at all? If it was somewhat still on there, the valve could still be opening a little bit.
TrueWildMan is offline   Reply With Quote
Old 03-19-2007, 08:48 PM   #16
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

From Intense'* site
"97 and earlier Series II 3800 engines should use CompCam Highload Valvsprings."
BillBoost37 is offline   Reply With Quote
Old 03-19-2007, 09:39 PM   #17
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

If the rocker comes off it'* pedestal, it can jam a valve slightly open, then take a beating. This would also make the bolt come loose, or appear looser than it would if it were installed on a good rocker arm. I've seen and experienced this personally with the HS rockers.

It came undone partly due to installation error, but complicated by the inaccessibility of the rear bank and the poor design of the pedestal.

Don't kick yourself. You're not the first. I just wish you'd posted BEFORE you installed them so we could warn you to be VERY careful. Shadd learned his lesson, and the replacement rocker is doing fine now.
willwren is offline   Reply With Quote
Old 03-19-2007, 09:55 PM   #18
Senior Member
Posts like a Corvette
Thread Starter
 
Join Date: Jun 2005
Location: Berkeley, IL
Posts: 1,596
Thanks: 0
Thanked 0 Times in 0 Posts
DarkShadow is on a distinguished road
Default

Hopefully intense still has some replacements, otherwise im screwed i guess...

I suppose the rocker is still useable but i would still prefer a replacement over using it

I would have posted before i put them on, but it was a spur of the moment thing, i was sleeping in bed and all of a sudden my buddies showed up and dragged me out of the house to install them
DarkShadow is offline   Reply With Quote
Old 03-19-2007, 10:01 PM   #19
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

Do NOT reinstall that rocker arm. Inspect the pedestal rail, the pedestal, and the rocker VERY carefully.
willwren is offline   Reply With Quote
Old 03-20-2007, 09:02 PM   #20
PopaDopaDo
True Car Nut
 
popatim's Avatar
 
Join Date: Jan 2005
Location: NY
Posts: 4,957
Thanks: 0
Thanked 0 Times in 0 Posts
popatim is on a distinguished road
Default

Thanks for clearing that up Will.
popatim is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
99 SLE misfire problems srirachasauce 1992-1999 3 08-22-2006 01:07 AM
Noise at specific speeds, sounds like tire noise but isn't? billha 1992-1999 13 04-25-2006 02:13 AM
Problems, Problems, Problems... swartlkk 2000-2005 2 11-04-2005 08:57 PM
Misfire problems only under heavy throttle 98SSE 1992-1999 4 07-07-2005 12:17 AM
problems, problems, problems big_boss2010 1992-1999 15 04-25-2004 09:05 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 06:22 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.