I just bought a 2002 Thundercloud Sport Edition with 145K miles. I owned a 2002 limited and the engine was pretty quiet. This Sport has a roaring sound whenever I step on the pedal. It also seems to lose power going up hills at highway speeds. It seems like the tranny doesn't downshift if I give it a good push on the gas pedal. It drops down hard only if I push the pedal to the floor, but it doesn't have much power even then, but it sure makes a loud roar. ANy body know what is going on here? It seems to have decent power off the line, but the roar is very loud. The roar is very loud when it downshifts as I put the pedal to the floor, but doesn't make any power. Thanks for your help.

JR

What has the maintenance been like before you got it? A few things come to mind that can cause those symptoms. Fuel filter, timing, spark plugs, wires, all maintenance items really.

The plugs and wires are brand new. The timing belt was done but I don't know how good the mechanic was. I am not sure of the PO's maintenance. It's strange that one engine was so quiet and powerful and this one seems so doggy at highway speeds. It's hard to use the cruise because it kicks the tranny down twice to try and keep up on hills but still doesn't have much power in the lower gears. Thanks for your help.

Check your air filter. I know that seems sorta silly, but my sister had a vehicle that did that same thing. Lots of noise but no power. Turns out the air filter was clogged and not letting air in. Also had bad mileage.

After that do the normal maintenance stuff like suggested. A good thorough tune-up goes a long way.

Sounds like a seized fan clutch.

Ditto on the fan clutch.

Yep, probably the fan clutch as said before.

Yes what they said about the fan clutch.

With the engine off, can you spin the fan freely? or is it tight or maybe not move at all??

Went through 3 on my Tacoma before I got a good one..

With the engine cold the fan turns with just a slight bit of resistance. This was first thing before the truck was started.

Is the A/C on? or is the climate system set to defrost?

Having that on will kill some power and make the fan semi lock into position. To move more air through the condenser..

that is most likely the problem. both the sound, and lack of power.

Should it turn freely or not? I could feel a little resistance when I tried to spin it. Thanks for your help.

there should be a bit of resistance. but, unless you are able to spin it several 1000 rpms, that's not going to tell you much.

take it off, then do a quick test drive. you will find out right away. you can go several minutes without fear of overheating, assuming you are starting with a cold engine.