Hi Folks, I got this 1995 le sabre that just started having small then
large anti freeze puddles under it when idleing.
I took a flashlight and peered under the hood to see a coolant leak way up
under the shroud covering the plug wires somewhere. Seeing as it's -17
degrees out I didn't want to start to take anything apart yet.
I guess my question is - is this a common problem at about 103,000 mi? Is
it a big problem for the snowbank mec. that I am or is this a job for the
big boys with the adding machine on their desk. In other words an involved
job or a common easy problem. OR one for the local shop. Any advice would
be appericated, Thanks, Tom
Do some google research on GM plenum problems and GM intake manifold gasket
problems. You'll find everything you ever wanted to know. The repair is
about a 4-5 hour repair for the home or shop mechanic, if you've done one
before but is more like 8 hours if you've never done one. It's not a bad
job as things go, but I sure would not do it out by the snowbank.
On mine, the best local independent mechanic quoted $250 on this. I think
the plenum itself
cost $150. The dealership ate some of the cost and actually did the work
for $300 and change.
Base on the price from the independent, the job cannot be more than two
hours. (Normal shop
rates here are $60 per hour)
That could only be for replacing the upper plenum. I've done
a couple of these over the last few weeks, and to not replace
the lower intake gaskets at the same time would be a mistake.
To replace the lower gaskets and the upper plenum is about
4.5 hrs labour. Every one that I've had apart shows signs
of coolant getting into the engine not only thru the upper
plenum, but thru degradation of the lower intake gasket (same
basic material/design as the infamous 3.1/3.4 engine).
Hey Ian - you mentioned (a while ago) that you don't pull the rear valve
cover to replace the gaskets. How do you do this without cutting the
gasket? Has to be magic, man. If you can get away with cutting it to get
it around the pushrods, why not do it on the front gasket as well? I've
always pulled both front and rear, but I'm always up for new ideas as well.
Mike, that would be for the 3.1/3.4 style engine, not the 3800 intake
manifold gasket replacement. No magic...and no cutting of the
gasket. At least not the rear valve cover gasket. You still have to
remove all of the push rods and you can accomplish that in two ways,
wrench the rocker arm bolts out, which is hard, but do-able with
the rear valve cover in place, or (the method I use) just pry up
the rocker arms with a suitable tool (I use an 11mm brake line
wrench, Craftsman to be exact) and remove the push rods that way.
You do need to be careful and use common sense, sometimes the
engine will be in a position where you will be pushing the valve against
the piston. In this case, either turn the motor by hand until you can
push the rocker arm without interfering with the piston, or simply
wrench that rocker arm until it's loose enough to remove the push rod.
Here, a picture is worth a thousand words:
I have a number of "gearwrench" wrenches....I love these things, everybody
who works on cars ought to have a set, they aren't even that expensive and
you will be amazed at how well they work. I use them all the time on this
type of job and many others.
That works too...as long as everyone is aware of the risks.
I no longer try to actively sell the GM lower manifold as
the customer ends up paying an enormous amount of money
for a new manifold that has a different size EGR tube. I
usually ask how long they plan to keep the vehicle, if it's only
for a few years, just replacing the upper plenum and the
lower gasket will suffice.
I'd get the pipe kits, but because we are a dealership and
because of the mindset of our management, we won't install
aftermarket type kits. Mainly to do with liability and warranty
Are you talking about the pipe kits you epoxy into the system, made in
I found those on the net, but they are not widely available in the
We will buy a new car soon, and - if anything - wont have to worry about the
issue anymore. We may find that we only move on to new areas of vexation;>)
Yes, there are kits that come with a new plenum with a steel
sleeve installed in the plastic plenum and the smaller size pipe
that you install into the old lower manifold. If it was my own
vehicle I'd use this method.
Little story.....one of the salesman in our dealership had his
3800 ingest antifreeze recently. He had it towed to the shop,
and it was pronounced dead by the shop foreman. He was
in the process of getting a new engine ordered for it when
I happened to be talking with him. He told me what was
going on, and I pulled him aside and mentioned that replacing
the plenum only would probably be all he had to do.
I did it for him one Saturday down at the shop. New upper
plenum, new lower gasket, new plugs, cranked the coolant
out of the cylinders, changed the oil and it ran like a charm.
He was very happy! Most of these engines, even when
they've ingested enough coolant to hydrolock, are fine when
the above is done. Every now and then, yeah...you bend
a rod. But I haven't seen many of those.
By the way, our dealership has no problems with any of the
techs working on an employee of the dealerships cars in
the shop if they make their own arrangement. Just don't want
anyone thinking that I steal work from my own employer. I
do not do that!
Yes...and if the person wants to just have the job done thru
the shop, they only charge them 1/2 the door rate for
labour, and they can go pay for the parts over the counter
at 10 percent over cost...so even that is a pretty good
Is that also true of the Series I 3800s? If my memory serves, the
1995 LeSabres and Regals had Series I (VIN Code "L") engines, whereas
the Riv and Park Avenues had Series II (VIN Code "K") engines.
On the VIN Code "L" engines you don't have the issue with the EGR
system roasting the upper plenum since the EGR feed is introduced into
the plenum behind the throttle body.
While there doesnt seem to be as much of a problem with the Series I, I
a medium mileage one out of a junker a couple of years ago to rebuild for my
The engine had fine compression as it was, but I wanted a really fresh
I tore it down, I was surprised at the condition of the intake gasket. It
but looked like it should have been. It was just looked BAD.
I too would like to hear what Ian has to say about the Series I.
Yes, the Series I did not have the same problems as the Series II.
Probably the biggest problem that it had was the camshaft sprocket
had the plastic teeth which would eventually shear off, jump the
timing chain, and bend valves.
The Series I (as you mention) introduced the EGR gases into
the top of the plastic plenum where it seemed to do no harm.
Thanks for the replys guys, I don't think that is beyond my capabilities.
Seeing as I have more time that money. I guess I will wait for some warmer
weather and do it to it.
I got a Dodge 4X4 to drive in the meantime though it's a bit thirsty 8-10
Mpg. Oh Well.
thanks again, Tom
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