2002 Oldsmobile Silhouette silhoutte GL van

TINALEWIS72

MEMBER
2002 OLDSMOBILE SILHOUETTE
3.4L
6 CYL
AWD
AUTOMATIC
137,703 MILES

My alternator went out we replaced it and then van started overheating I changed thermostat and it still overheating, its not losing water in coolant or radiator but there is now a hissing noise in the area of thermostat. When I put heater on its hot for 5 minutes then blows cold air. Could my belt be placed on wrong to make the overheating? Is there a hose that connects to thermostat to radiator behind the engine?

1 Reply

CARADIODOC

MECHANIC
33,910 POSTS

There's other, more common causes of overheating, but given the recent service, it is indeed likely the belt is wrapped the wrong way around the water pump pulley. You can't physically do that on most engines but you can on some. One potential clue is the ribs on one side of the belt will always ride on ribbed pulleys. If you find the smooth side riding on a grooved pulley, or the grooved side riding on a smooth pulley, it's wrong.

As a side note, GM has had a really big problem with their generators since they redesigned them for the '87 model year, and they have no desire to fix them. They develop huge voltage spikes that can damage their internal diodes and voltage regulator, and interfere with computer sensor signals. The battery is the main thing that dampens and absorbs those spikes. Repeat generator failures are real common. In fact, it's not unheard of to go through six replacement generators in the life of the vehicle. To reduce that number of failures, replace the battery at the same time unless it is less than about two years old. As they age, they lose their ability to dampen those harmful voltage spikes. The old battery will work fine in a 1986 or older model.