Copyright by Goodheart-Willcox Co., Inc.
342 Auto Engine Repair
Figure 16-21. A—Check the level and condition of the
intercooler coolant. B—Pressure testing the intercooler system.
A
B
Warning: Never open an intercooler system
that is under pressure. The operating
temperature of intercooler coolant is hot
enough to cause severe burns. Remove the inter-
cooler radiator cap slowly to verify that the system is
not under pressure.
If the intercooler coolant is low, there may be a
system leak. Pressure test the system as you would the
engine cooling system, Figure 16-21B. Refer to Chapter 12
for more information. A special adapter may be needed to
install the pressure tester on the intercooler reservoir. Do
not exceed the pressure rating given on the reservoir cap. If
the pressure is exceeded, the intercooler, intercooler radia-
tor, or intercooler coolant lines may be damaged.
With the intercooler system pressurized, check for
leaks at the lines or hoses, pump, intercooler radiator, and
intake manifold. If the pressure gauge “bleeds down” and
the engine misses or white smoke comes out of the tail-
pipe, the intercooler unit is the likely source of the leak.
The coolant is leaking into the intake manifold and being
burned in the cylinders. In this case, the intercooler must
be removed and repaired or replaced. Intercooler replace-
ment is covered later in this chapter.
Supercharger Oil Service
To service the oil in the supercharger, remove the oil
plug or dipstick, Figure 16-22A. With the vehicle level,
the oil should be even with the threaded hole in the oil
reservoir or the correct level on the dipstick, depending on
the design. See Figure 16-22B. Refer to the service manual
for the proper procedure for checking the oil level. If needed,
use a flashlight to illuminate inside the hole. A small length
of wire can also be used as a dipstick.
To replace the supercharger oil, use a hand pump as
shown in Figure 16-22C to remove the existing oil. Fill the
reservoir with the factory recommended oil. Then, replace
the oil plug, Figure 16-22D.
Supercharger Belt Replacement
To replace a supercharger belt, first remove the belt
cover, Figure 16-23. Usually, two or three small bolts
secure the belt cover. To avoid injury, disconnect the
battery to prevent accidental engine cranking.
A long wrench or special service tool is often needed
to compress the tension spring so that the belt can be
slid off of the supercharger drive pulley. This is shown
in Figure 16-24A. With the belt off, you can rotate the
supercharger pulley by hand to check for dry bearings,
rotor-to-housing contact, or supercharger timing gear
failure. See Figure 16-24B. Any roughness or binding
when you turn the supercharger pulley by hand indicates
mechanical problems.
Supercharger Clutch Service
Some superchargers are equipped with an elec-
tromagnetic clutch for engaging and disengaging the
supercharger. See Figure 16-25. This clutch works just like
an air conditioning compressor clutch. When current is
sent to the clutch coil, the clutch plates are pulled together
to lock the inner and outer hubs. The engine belt drives the
outer hub. The inner hub is connected to the turbocharger
shaft. In this way, the supercharger is engaged only when
high boost is needed to increase engine power.
If the electromagnetic clutch fails to engage, first
check for a bad clutch coil. Disconnect the clutch wir-
ing harness and apply battery voltage to the coil using
jumper wires. This should engage the clutch. A loud
click should be heard as the clutch engages. You can
also use a multimeter to check for an open in the coil
windings. The coil should have a low resistance. Infinite
resistance indicates an open in the windings. If the clutch
engages when jumpered, check for the proper signal
from the ECM.