GM 3800 Engines, Slight Mods That Help a Lot
General Motors 3800 Series Engines.
In many GM sedans, the 3800 engine resides inside in one
form or fashion. Hundreds of thousands of these cars have been produced. The
3800 engine can be found in normally aspirated, supercharged, aftermarket
turbocharged, bored out, heavily modified and bone stock. With some small
modifications, they can last a long time. GM used some inferior components that
tend to fail. Replacing these can make your car last a long time with minimal
maintenance. One common issue with them all is the use of the orange Dex-Cool
coolant.
General Motors sold many vehicles with orange Dex-Cool as
the coolant medium, only to have these vehicles leak coolant and/or oil in a
short period of time. This coolant has an acidic property that tends to eat
away at the cheap gaskets used in these engines. A class action lawsuit
resulted in payouts by GM, however they still use this coolant. The intake
manifold gasket became another problem and many recalls have been made for
this. Eventually, after all current stock was used up, GM improved this gasket.
The acidic coolant will eventually blow out the intake manifold, and/or the
head gaskets. Then fluid leakage occurs. Coolant leaks can cause the car to
catastrophically overheat. Oil leaks can rob the vehicle of its life blood and
result in a blown engine as well. At one point these cars were sold as not
needing a coolant flush until they reached 100,000 miles. Well in reality, they
do not make it this far.
In the case of this car, I removed the Dex-Cool at about
24,000 miles. Glycol based green coolant allowed me to drive over 150,000 miles
before the gaskets began to leak. However, several recalls have been announced
for this car. One was for the front head gasket leaking oil onto the exhaust
manifold. In this car, the exhaust is right in front, just behind the radiator
fan. The foil like heat shield can be seen. If oil leaks onto the exhaust,
during hard braking for example, a fire can result. GM says to park the car
outside so that the car burns and does not take the house with it.
The way this happens is, often times the coolant eats the
intake manifold gasket and then pools up in between the heads, which then eats
the head gaskets. This gives you two opportunities to have your car blow its
engine and leave you stranded somewhere.
Spark plug wires are routed right over the metal intake
manifold. No protection is provided for the wires. The spark plugs have heat
shields for the boots where they enter into the car engines head. In my
picture, metal foil bubble wrap insulation is added to give some protection to
the spark plug wires going over the intake manifold. Some versions of this
engine have a plastic intake manifold. This will crack over time, and cause
leakage of coolant. This engine is a 3800 Series III, or Third Generation,
where they at least decided to use an aluminum manifold. However, aluminum
transfers heat more easily than plastic. I recommend the addition of foil
bubble wrap to protect the spark plug wires. There are other areas GM went
cheap on this engine.
GM left the front and rear strut tower brace off many of
their cars toward the end of their sales life. Pontiac, Buick and Oldsmobile
sedans had these at one time. However, the Pontiac and Oldsmobile cars lost
this feature when those divisions of the company were being shut down.
Aftermarket parts with "Pontiac" emblazed in red are available, as
are hot red and chrome variants. All of these cost several hundred dollars. The
stock Buick strut braces in black are available and will bolt on fairly easily
into the cars. The black brace shown in my picture here bolted right onto the
front tower braces. Bolts were already in place for this part. $35 cost savings
per car, times several hundred thousand cars add up. The addition of these
braces stiffens the suspension and makes the car ride a lock tighter. It also
transfers more forces to the sub frame for aggressive driving. You never know
when you may need to enter a corner at high speed or when maneuverability is
needed. This particular car came with a free flowing exhaust, but many have a
very restrictive intake.
The air intake is a large black box, that cuts off free flow
of air. K&N intakes are worth the price of more fuel economy and
horsepower. You may have a cavitation sound though, which may be a good thing
for some. It is louder, some may like this, and the car sounds like it is out
of tune under acceleration. In reality though, the car runs quite well. The
increase in horsepower is about 5-15 and if you do not punch the accelerator
too much, fuel economy does increase. These cars often get 25-30 miles per
gallon. For a 3600-pound car, this is not too bad. On the highway, they have
done better yet. This is all with about 220 horsepower in a normally aspirated
car. So with a few modifications, you can have a long running GM product and
save all that extra cash for other things.
