valve stem seals?

Status
Not open for further replies.
Messages
373
Location
Port Colborne, ON
i have a 1989 chevrolet s10 2wd 4.3L V6 with 210,000 km on it. in the morning it smokes when you first start it and rev it cold. you know the deal. so is there anything that will fix this, or is it even a problem that i should worry about at all.
 
Messages
2,008
Location
North Carolina
The smoking is a design flaw that GM has in those 4.3's. It was a defective valve stem seal. Mine started smoking on my 93 Sonoma at 12K warranty replaced the seals and it was fine till I sold it with 128k on it. If Auto Rx stops the smoking on start up then Frank has gotten himself a gold mine for sure. (Even thought I think it is one anyway, RX is the Bomb, that stuff is just way ahead of its time and works like a charm. Thanks Frank!!!!!!!) My dad's 89 GMC S-15 smokes a ton on start up but that is it. Pulled his plugs and they looked great, no build up. So that means that the valve seals are the only problem. He also has the early model 4.3 that vibrates like crazy, before they corrected it with the balance shaft. For the longest time I thought it needed a tune up or the torque converter was going bad in it. [Big Grin]
 
Messages
7,775
Location
Oklahoma
Was it a design flaw or blessing???? This is what I've gathered: When parked, oil runs past the valve stems and then down through the pistons. Coats the pistons with oil. That's why it smokes at first when you start it. I have a 93 GMC and does that. Doesn't loose any oil, just smokes very little at start, that's it. Like I said, that could be a GOOD thing!! [Smile]
 
Messages
238
Location
Monterey Park, CA
Your valve guides are worn out. When cold the valve guide clearances are so great oil is being sucked into the combustion chamber on the downstroke. Then when your engine heats up the valve guides tighten up and you stop burning oil. Leo
 

Greg

Thread starter
Messages
373
Location
Port Colborne, ON
quote:
Originally posted by pedaltothemetal: Your valve guides are worn out. When cold the valve guide clearances are so great oil is being sucked into the combustion chamber on the downstroke. Then when your engine heats up the valve guides tighten up and you stop burning oil. Leo
thanks but i understand what the problem is [Smile]
 
Messages
2,008
Location
North Carolina
It is really noticeable at idle but under acceleration it goes away. I have to say one thing his 4.3 in that 89 would smoke my 93 4.3. I mean it will get up and go just about smoke the tires hard. Of course mine was a 5 sp his is the automatic. His has 104k on it and never uses a drop of oil between oil changes at 3k a change. He lucked out and gets it changed at the dealer he bought it at for free as long as he owns the truck. Now every 3k or 3 months is a killer deal for free. That dealer is loosing money on him. [Smile]
 
Messages
2,008
Location
North Carolina
It was a dealer thing back when he bought the truck. He takes it in at the 3k or three months with ever comes first. They even grease it for him and check all the other fluids with no charge. I told him that is the deal of a life time.
 

Greg

Thread starter
Messages
373
Location
Port Colborne, ON
quote:
Originally posted by Rat407: The smoking is a design flaw that GM has in those 4.3's. It was a defective valve stem seal. Mine started smoking on my 93 Sonoma at 12K warranty replaced the seals and it was fine till I sold it with 128k on it. If Auto Rx stops the smoking on start up then Frank has gotten himself a gold mine for sure. (Even thought I think it is one anyway, RX is the Bomb, that stuff is just way ahead of its time and works like a charm. Thanks Frank!!!!!!!) My dad's 89 GMC S-15 smokes a ton on start up but that is it. Pulled his plugs and they looked great, no build up. So that means that the valve seals are the only problem. He also has the early model 4.3 that vibrates like crazy, before they corrected it with the balance shaft. For the longest time I thought it needed a tune up or the torque converter was going bad in it. [Big Grin]
hey, when you say it vibrates, do you mean at idle or when you're accelerating or what? i've got vibrations on both accounts. [Thumbs Down!]
 
Messages
9,725
Location
Central Coast, Calif.
that's interesting. i've got an 88 s15 4.3 with 150,000 miles and it has no smoke at start up. it does use a bit of oil but it makes an 80 mile trip everyday at 70mph so some oil usage is expected. that truck has had no real mechanical problems during it's life. it's only needed minor tune up parts. you can tell it's an 80's GM vehicle though. the paint/clearcoat is peeled and the interior is falling apart.
 

CJH

Messages
489
Location
Pennsylvania
quote:
Originally posted by sprintman: Needs one or two Auto-Rx cleans (Maybe three if real bad) IMO. Frank will explain what it does for valve stem seals.
When the only tool you have is a hammer, every problem looks like a nail. [ June 30, 2003, 01:46 PM: Message edited by: CJH ]
 
Status
Not open for further replies.
Top