On Thu, 17 Apr 2008 17:10:45 -0400, Todd Leonard wrote:
>The subject line just about says it all. This car has about 40,000
>miles on it.
>I'm an old VW D.O.Y. of moderate ability, with little to no experience
>with water cooled cars -- aside from once replacing a water pump in an
>early '80s Chevy.
>But when I got the estimate of $600 at a dubious local shop, I figure
>it's time to learn.
>I'm in northeastern North Carolina, about 60 miles north or Raleigh,
>should anyone have a more reliable and less expensive mechanic to
>The guy who looked at it charged my wife $50 and told her he couldn't
>determine for sure whether the manifold was the problem, and to bring
>it back in for further investigation -- yeah, sure.
>S'long for now,
As always a lot of variables here, so I can understand why the mechanic
would want to verify everything.
If the upper manifold plenum is leaking, you would probably smell burning antifreeze.
A coolent system pressure test would show up the leak.
Check for coolant in the oil... look for sludge. Maybe pull a plug
or two and look at the condition. If there is coolant in the oil or
buildup on the plugs, the problem is more complex... perhaps the lower
intake is going also.
Replacing the Upper Plenum is pretty easy.... a quick check at
1996 Buick LeSabre Upper Manifold
shows the part to be about 150.00. ALLDATA shows the book labor to
be 1.6 hours for an experienced mechanic. Don't forget gaskets, injector "o"
Other posters have recommended replacing the lower
intake manifold gasket at the same time.... add another 2.6 hours labor.
So, did the shop quote you for both upper and lower intake manifold gaskets ???
If they quoted you for both.... $600.00 is a pretty darned good price.
Did they quote you just for just the upper one ?? If so... figure about 350.00
Again... doable for a DIY'r with medium experience... piece of cake if you've
done it once or twice before.... if this is your first time... figure on spending
a day or so....to get everything right.
(disclaimer..... I work on these things for fun... not for a living... however
the last 3800 upper plenum is still chugging along really well).
Here's a informative posting from aarcuda69062 back around march 2005
give aarcuda the credit for this one....
_____________pasted information from aarcuda69062....March 2005 _____________
Here is a picture of the bottom of the upper plenum, throttle
The larger round hole is where the EGR pipe extends up into the
upper plenum, the two smaller holes are coolant passages.
Here is a picture of the throttle body end of the upper plenum:
There are three oblong shaped holes visible between the two lower
studs, the two outside oval holes are adjacent to the EGR hole in
the first picture. The two outer oblong holes connect to the two
smaller round (coolant) holes in the first picture. Probe from
either to the other ( EGR to coolant passage) with a small
screwdriver or awl, you'll find soft spots and/or outright holes.
Gone on long enough, the whole lower part of the throttle body
end around where the o-ring fits around the coolant passages will
be soft and crumbly.
> I hope I'm not pushing my luck - I'm DIY'er whose still learning...
I always do the lower intake gaskets when I find a leaking upper,
I have yet to pull one apart where the lower gaskets aren't
disintegrating also. Your picture shows fluid pooled in the
lower intake, I can't tell if it is oil or coolant. If you DIDN'T
find raw coolant laying in the lower manifold when you removed
the upper, then I'd suspect that the lower gaskets are leaking
and that this is where you coolant loss is. If it is oil pooled,
the lower manifold bolt threads weren't/aren't sealed. Use thread
sealer/locker on the lower bolts and pay close attention to the
torque specs for the UPPER plenum bolts. You HAVE to use an inch
pound torque wrench because the values are quite low, otherwise
you'll crush the new upper plenum.
Pay close attention to the O-rings in the PCV cavity, if you
forget the O-ring around the base of the PCV valve, you'll set
MAP sensor codes.
Watch the connections to the purge solenoid, if you reverse them,
you'll set EVAP codes. Connect them exactly as shown on the
underhood vacuum diagram.
If you decide to do the lower intake gaskets, you'll also want to
replace the plastic elbow that connects between the right side of
the lower to the alternator bracket, hell, I'd do the lower just
to replace this elbow since they too are a weak point and prone
to failure. >> Stay informed about: 96 Buick LeSabre Intake manifold leak-how much $ or how to..