Had to replace valve stem seals on L27? - 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 04-12-2008, 12:54 PM   #1
Junior Member
Thread Starter
 
Join Date: Apr 2008
Location: McHenry, IL 60051
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
notagrampa is on a distinguished road
Default Had to replace valve stem seals on L27?

My Buick Park Ave has made a few little puffs of smoke on startup, and I have heard that the valve stem seals tend to go on these cars.

Has anyone done this in their garage, and can share their methods? How long does it take?

Thanks! Cheers!
notagrampa is offline   Reply With Quote
Old 04-12-2008, 01:23 PM   #2
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

Valve stem seals are not a common issue. Virtually unheard of, actually.

You'll need to remove the front and rear valve covers, then find a way to hold the valves up (stuff the cylinder with string or use an air fitting to hold them up) while you use a spring compressor to remove the springs (after rocker arm removal obviously).

You cannot re-use the rocker arm bolts. Buy new ones. You'll need a torque wrench for reassembly.
willwren is offline   Reply With Quote
Old 04-12-2008, 02:16 PM   #3
Senior Member
True Car Nut
 
Join Date: Aug 2004
Location: In your garage, swipin' da lug nutz
Posts: 3,067
Thanks: 0
Thanked 0 Times in 0 Posts
sandrock is on a distinguished road
Default

I remember Don telling me that the valve stem seals on the 94/95 motors weren't as good as prior years, and that they have been known to cause the *slight* puff of smoke on startup. My 94 does this too.

You can do the valve stem seals w/o head removal...just use compressed air to hold the valve in place when the keepers are out.
sandrock is offline   Reply With Quote
Old 04-12-2008, 02:18 PM   #4
Junior Member
 
Join Date: Apr 2006
Location: Purgatory
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
Bonneville92V688 is on a distinguished road
Default

Same here, I had a puff of smoke on cold starts on my '94.

No puffs or oil burning on the '92.
Bonneville92V688 is offline   Reply With Quote
Old 04-12-2008, 02:32 PM   #5
Junior Member
 
Join Date: May 2006
Location: BonnevilleHell
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
clm2112 is on a distinguished road
Default Re: Had to replace valve stem seals on L27?

GM valve stem seals are pretty much all alike. They can all get hard and brittle over the years and leak oil into the chamber...giving the little puff of blue on startup.

Easiest to do with the heads off the car, but can be done with the heads on.



Those are the valve seals. (green-blue rings around the the valve stems)

As willwren said, you'll need new rocker arm bolts and a torque wrench to tighten the rocker arms back down.

Other stuff: Valve Spring compressor (little type that fit over the springs and doesn't hold the valve..looks like a little gear puller) Small flat blade screwdiver, like a jewlers screwdriver, small rubber mallet, and a magnet. Compressor & compression guage set is really handy. (You don't need the guage, but the hose fitting that screws into the sparkplug hole usually fits a quick-disconnect air compressor hose too..allowing you to use the compressor to pump air into the cylinder through the spark plug hole.)

Bring each cylinder up to TDC firing. The rocker arms should be loose enough to wiggle them at this point, since the lifters are on the cam'* base circle. If you have a compressor, hook it up in place of the spark plug and presurize the cylinder to hold the valve against the seat. If you don't have the means to put air into the cylinder, you are not out of luck. Simply MAKE SURE the piston is at top dead center, the valve cannot drop all the way into the cylinder with the piston at the top. Exercise a bit of patience and use a magnet to lift up on the valve stem while you are putting the locks back in.

Remove the rocker are and use the spring compressor to remove the valve spring. Hint, when the spring is fully compressed, use the tiny screwdriver and magnet to remove the two locks that hold the valve in the hat of the valve spring. Years of cooked oil can make them stick in place, hence the screwdriver and magnet. You may also need to wiggle the compressed valve spring around to make enough room for one of the locks to come out...once one is out, the other stem lock will come right out.




Be carefull. Don't drop any parts down into the motor, or you WILL be taking the motor apart to retrieve it. (Pack a rag into the opening where the pushrods come up through as a little insurance.)

Remove the old seal, clean and lube the valve stem, and install the new seal. A deep socket is handy to use as a press to push the new seal down over the boss in the head.

Reinstall the spring, locks and remove the spring compressor. Lightly tap the end of the valve with a rubber mallet to make sure the locks are seated. Reinstall the pushrod and rocker with a new bolt. Then move on to the next valve.

About two hours later you will have all six done and can reinstall the valve covers.

By the way, since you have the rockers off, soak the pushrods in some solvent and blow out the tubes to make sure there'* nothing restricting oil flow up to the rockers. Check that they are straight by rolling them on a piece of glass. If the pushrods pass muster, put them back in. If not, replace them with new ones.
clm2112 is offline   Reply With Quote
Old 04-12-2008, 03:03 PM   #6
Senior Member
True Car Nut
 
Join Date: Aug 2004
Location: In your garage, swipin' da lug nutz
Posts: 3,067
Thanks: 0
Thanked 0 Times in 0 Posts
sandrock is on a distinguished road
Default

Study those pics carefully. Those pics are from a Series 2 (beehive springs give it away). S1 springs are the normal-looking type, and have a much bigger footprint for the spring compressor to hold onto. Not sure if it is mentioned, but since you are doing this on-engine, you might also want to look at a magnetic wand or something...AND something to block the oil drain holes with. Don't want to lose any keepers now, do we And what are those medical vice-grip thingies called? Those would come in handy too
sandrock is offline   Reply With Quote
Old 04-12-2008, 03:14 PM   #7
Junior Member
 
Join Date: Apr 2006
Location: Purgatory
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
Bonneville92V688 is on a distinguished road
Default

Quote:
Originally Posted by sandrock
And what are those medical vice-grip thingies called? Those would come in handy too.
Hemostats.
Bonneville92V688 is offline   Reply With Quote
Old 04-12-2008, 03:30 PM   #8
Junior Member
 
Join Date: May 2006
Location: BonnevilleHell
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
clm2112 is on a distinguished road
Default

Quote:
Originally Posted by sandrock
Study those pics carefully. Those pics are from a Series 2 (beehive springs give it away). S1 springs are the normal-looking type, and have a much bigger footprint for the spring compressor to hold onto.
Yes, I didn't have any pics of an S1 with a valve spring compressor on it...I could put up one of a SBC V8 head...but really, the valve spring/retainers/seal arrangement is the same across the entire GM line of OHV motors, even if there are varations on the size/shape of the individual parts.

I don't recommend using any kind of tools to grip the end of the valve stem. Yes, they are hard chromed and pretty resiliant, but I don't risk putting a scratch on them. A small magnet is all that is needed to hang onto the valves. That little scribe in the photo with a button magnet on the end works pretty well and available in any hardware store. It'* small enough to hang on to the tip of the valvestem without getting in the way of putting the locks in.
clm2112 is offline   Reply With Quote
Old 04-12-2008, 03:37 PM   #9
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

Many pics in this topic from last winter:
http://www.bonnevilleclub.com/forum/...ic.php?t=69358

Head removal isn't necessary. But you DO have to hold the valves up by either stuffing string into the cylinder through the spark plug hole or using compressed air.

If you drop a valve, you might not get it back up without pulling the heads.
willwren is offline   Reply With Quote
Old 04-12-2008, 03:47 PM   #10
Senior Member
True Car Nut
 
Join Date: Aug 2004
Location: In your garage, swipin' da lug nutz
Posts: 3,067
Thanks: 0
Thanked 0 Times in 0 Posts
sandrock is on a distinguished road
Default

Without looking at that topic, was it you or Curt that used zip ties to keep the valves in the heads? That'* a slick trick.
sandrock is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Tire air loss - valve stem, TPMS, prank? scottydl Buick 2 04-07-2015 02:17 PM
Replace a tire valve stem without special tools SignOfZeta General GM Chat 3 02-21-2014 06:49 AM
Needing some help on how to replace valve seals on on 89 Oldsmobile Delta 88 DeathDealer General GM Chat 0 10-31-2011 01:14 AM
where to find Valve seals maybe2fast 1987-1991 4 03-09-2006 03:11 PM
Valve stem seals? J Wikoff 1992-1999 1 09-17-2005 01:48 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 05:23 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.