Need Advice/Timing-chain 86buick LeSabre 3.8 V6
Gene Gardner
My 86 Buick Lesabre (3.8 V-6) just died. Buick dealer tells me that
it will cost $900 if no valve/pushrod damage, and $1800 if there is.
This is a second car, and I have done a fair amount of serious
mechanical work on older cars (i.e. so-called shade tree mechanic).
Timing chain (or gear?) has jumped.
Can anyone tell me for certain whether this model does have
valve/piston interference, and even if it does...how likely is it that
valve push-rod damage has occured?
If I gamble that no other damage has occured, how difficult is it
to replace the timing-chain/gear, where no removal of heads is involved?
Thanks for any advice or suggestions...I am retired and have more
time available to undertake the project.
--
Internet, BITNET: ge...@csl.uiuc.edu
William H. Bowen
Gene,
The price the dealer quoted you for the work is within the normal
range for this work.
What happens on the Buick V-6s is the plastic gear teeth on the cam
drive gear wear out and the chain jumps. Had it happen on my 1987 Olds
98 at 85K miles.
As far as I can determine, the 86-87 Code "3" and "B" engines (look
at the 8th character of the VIN number) are not interference - these 2
engines are basically the same - the "3" has a roller lifter camshaft,
the "B" does not.
To change the gear/chain combo you'll need to strip the entire
"front" (passenger side) of the engine AND drop the pan (so you can
remove the timing case cover). Therefore, you WILL need to raise the
front end of the car.
There are a lot of detail items in this project, so I'd STRONGLY
recommend you get ahold of the GM factory manual for your car or 86/87
Olds 88/98 or Pontiac Bonneville (same basic body and engine as your
car). A good alternative is the Haynes manual for that car (Haynes #
19020).
Parts should cost about $85 (crankshaft gear, cam gear, chain and
chain tensioner, plus gaskets). I would also recommend you replace the
camshaft end play button (this item with a spring behind it mounts in
the center of the camshaft gear) and the crankshaft oil seal while
you're at it.
This is a project that can be tackled by an experienced "shade tree
mechanic" if you have the tools and the time.
Regards,
Bill Bowen
bow...@best.com
Daly City, CA
Uncle Dodo
>at the 8th character of the VIN number) are not interference - these 2
>engines are basically the same - the "3" has a roller lifter camshaft,
>the "B" does not.
The vin numbers are "3" up to 87, and "C" 88 and up.
The 87 and prior are technically interference engines. They can bend valves.
Sometimes they don't. The "C" almost never goes because they got rid of the
stupid nylon coating that caused the whole problem. Two steel gears last a
long, long time.
William H. Bowen
The "C" code engine is NOT the same as the "B" or "3" code engines.
The "C" engine is a 3800 Series 1 - different block, heads, manifolds,
etc. Also, the "C" engine has a balance shaft that the "B" and "3"
engines do not have.
The "B" and "3" engines where both used in 1986/87 (and the "3"
engine was also used on some 1988 models, but, according to the info I
have from GM, not on the "C" body cars).
Regards,
Bill Bowen
bow...@best.com
Daly City, CA
uncl...@aol.com (Uncle Dodo) wrote:
>> As far as I can determine, the 86-87 Code "3" and "B" engines (look
>>at the 8th character of the VIN number) are not interference - these 2
>>engines are basically the same - the "3" has a roller lifter camshaft,
>>the "B" does not.
>
Uncle Dodo
>
> The "C" code engine is NOT the same as the "B" or "3" code engines.
>The "C" engine is a 3800 Series 1 - different block, heads, manifolds,
>etc. Also, the "C" engine has a balance shaft that the "B" and "3"
>engines do not have.
>
> The "B" and "3" engines where both used in 1986/87 (and the "3"
>engine was also used on some 1988 models, but, according to the info I
>have from GM, not on the "C" body cars).
>
>Regards,
> Bill Bowen
> bow...@best.com
> Daly City, CA
Please watch who you quote...
The following quote you referred to.....
>>>>>>> As far as I can determine, the 86-87 Code "3" and "B" engines (look
>>>at the 8th character of the VIN number) are not interference - these 2
>>>engines are basically the same - the "3" has a roller lifter camshaft,
>>>the "B" does not.>>>>>
....that refers to the B and 3 being the same wasn't written by Uncledodo.
>>>>>>The vin numbers are "3" up to 87, and "C" 88 and up.
>>The 87 and prior are technically interference engines. They can bend
>valves.
>>Sometimes they don't. The "C" almost never goes because they got rid of the
>>stupid nylon coating that caused the whole problem. Two steel gears last a
>>long, long time.
The above was written by Uncledodo.
It says nothing about B codes at all.
The original post wanted to know if his 86 LeSabre would have bent valves if
the chain "blew"
I bet his 8th VIN in a 3. MAybe I'm wrong.
Either way, he will be VERY LUCKY if he has no valve damage.
People usually try to start it too much after it is gone and do extra damage if
it wasn't there to begin with.
The "3"s cam gear usually goes about 150K-165K . The "C" can and sometimes
will run "forever".
I have seen many 230K +
William H. Bowen
>>Uncle Dodo,
>>
>> The "C" code engine is NOT the same as the "B" or "3" code engines.
>>The "C" engine is a 3800 Series 1 - different block, heads, manifolds,
>>etc. Also, the "C" engine has a balance shaft that the "B" and "3"
>>engines do not have.
>>
>> The "B" and "3" engines where both used in 1986/87 (and the "3"
>>engine was also used on some 1988 models, but, according to the info I
>>have from GM, not on the "C" body cars).
>>
>>Regards,
>> Bill Bowen
>> bow...@best.com
>> Daly City, CA
>
>Please watch who you quote...
>The following quote you referred to.....
>
>>>>>>>> As far as I can determine, the 86-87 Code "3" and "B" engines (look
>>>>at the 8th character of the VIN number) are not interference - these 2
>>>>engines are basically the same - the "3" has a roller lifter camshaft,
>>>>the "B" does not.>>>>>
>
>....that refers to the B and 3 being the same wasn't written by Uncledodo.
I did NOT say that is was written by you, did I?
>
>>>>>>>The vin numbers are "3" up to 87, and "C" 88 and up.
Yes, you did write that part and it is INCORRECT! The 1986 LeSabre
could have either a code "B" (non-roller cam) or code "3" (roller cam)
version of the old-version 3.8L engine. It would NOT have a code "C"
engine. That was my point in the followup.
>>>The 87 and prior are technically interference engines. They can bend
>>valves.
>>>Sometimes they don't.
I've only run across ONE that did, and on that engine the gear failed
while the car was running a freeway speed.
>The "C" almost never goes because they got rid of the
>>>stupid nylon coating that caused the whole problem. Two steel gears last a
>>>long, long time.
>
>The above was written by Uncledodo.
>It says nothing about B codes at all.
>The original post wanted to know if his 86 LeSabre would have bent valves if
>the chain "blew"
>I bet his 8th VIN in a 3. MAybe I'm wrong
As I said, it could be either a "3" or a "C" - the VIN number tells
the story..
>Either way, he will be VERY LUCKY if he has no valve damage.
>People usually try to start it too much after it is gone and do extra damage if
>it wasn't there to begin with.
>The "3"s cam gear usually goes about 150K-165K .
I'e seen them go as early as 60K, and know a few "3" code (roller cam)
engines that still have the original gears at 200K+. I've not be able
to nail it down to a particular cause (some long time ones have gone
long periods between oil changes, some short time ones have had oil
changes every 3K, for instance).
Also, this problem is not confined to the 3.8: I've changed so many of
the gear sets in 50/60/70 vintage Pontiac V-8s I could do the job in
my sleep!
>The "C" can and sometimes
>will run "forever".
>I have seen many 230K +
Yep, the all-steel cam drive train should last longer than the
nylon-coated gears.