Engine Fan

[Trail Blazin96]

Hey guys,

My blazer just started this, I was driving along and it was fine normal driving, the i went in to the store and got what I needed and when i left i could hear the engine fan real loud and now it makes that noise when regular driving, will not sound loud unless i apply more pressure on the gas! Please help Anyone, the sound is annoying! 96 blazer LS 4 door.

[86TATpi]

Sounds like the fan clutch is bad. With the engine off, grab the fan blades and try to turn it. If it's hard to turn or doesn't at all the fan clutch is bad.

[Trail Blazin96]

How hard is it to change, how much does the fan clutch cost???

[Trail Blazin96]

I went and tryed to turn it and at first it had a bit of tenchion, but it still moves and that is just the blade do I need to move the whole thing? I dont know but only the blade is spinning, nothing else.

[Trail Blazin96]

Please help milkado14 or Blazer Lt

[86TATpi]

The blades should turn with a little resistance. When it's running do the blades move slower than the engine? When the engine warms up the thermostat in the clutch causes the viscous fluid to move out of the reservoir and spin the fan with engine speed. Check the condition of the fan blades as well. A new clutch can run up around $50 (with a/c). Your best bet would run the Blazer and watch the fan. The sound you described sounds like the fan engaged which could be a failing clutch or the vehicle is just getting that warm. Shouldn't be hard to change either.

[Mikado14]

Ok, here goes. What the others have said is all good. If you can turn the fan blades only, with the shaft staying stationary, it is more than likely good. If it is hard to turn then it is more than likely questionable. Secondly, does the fan have any side to side wobble? If it does, change without any hesitation.

From what you describe, it sounds like it is locking up too early.

If you decide to change it, you will need to remove the top half of your fan shroud. After removing, you will have good access to your fan. I believe it is a 10mm wrench to remove the four nuts holding the assembly on. When you remove the four nuts, be careful you don't let the blades hit the radiator and remove the assembly out. Exchange your fan to the new clutch and reverse the procedure.

I would recommend going to the dealer. I have found that for the '93 there are eight different fan clutches for that year, or so I was told by the GM dealer. If you go to an aftermarket, there should be a few variations for your driving conditions. Select accordingly.

So I bought a clutch for $94 from GM, jobbers price and installed it. That was eight months ago and now the fan has a wobble. Go figure.

[Trail Blazin96]

The Fan I guess you could say turns with the motor all the time! Or that is how it sounds, it has been getting colder now but I don't remember it making the noise last Feb, it was still cold. I had made a 280 mile trip and and the day after we got back it started! Could that have been why it is doing what it is doing? 96 BLAZER LS

[BlazerLT]

Mine does this sometimes.

It will activate until 2000rpms and then will disengage.

This is normal. Only if it doesn't disengage will it need to be changed.

[recurve]

Genius! Genius! Genius! You guys are the best. I have this same symptom with our '97 Blazer — loud engine roar, all the time but especially when you hit the gas pedal.

BlazerLT, you're great (a savior really) but you confused me a little. What is magic about 2000 rpms? I can see if you are driving at highway speeds there will be enough air without the fan to cool things down… but what if you are towing a boat up-hill in low gear? Maybe you're doing 3000 or more rpms but physically your truck is moving slowly up the hill, shouldn't the fan then spin as fast as it can go - engine speed?

Thanks,
-- recurve

[wolfox]

If your engine temp is elevated, the fan will engage and turn at engine speed. The idea behind the viscous clutch is that it will stay engaged or "sticky" in high temprature situations, or low RPM conditions. If your engine is hot from pulling a heavy load, or just getting off of the highway, it will roar a bit at take-off, and may keep roaring until it has drawn enough air to cool itself and the radiator off. Once the load is removed, and the temps returning to normal - a bit of roar at take-off is normal, but as BlazerLT says, calm down after 2000+ RPM's. No big deal.

[BlazerLT]

Mine does not roar all the time but only some mornings when I pull away and accelerating.

At 2000rpms it will disengage and I won't hear it anymore. And after that one time I usually don't hear it at all for sometime.

If it is roaring all the time, you need to change the clutch.

[recurve]

I drive like an old lady most of the time. I purposely try to keep my rpms less than 2000 all the time. During the first 5 minutes of driving in the morning, I try to keep less than 1500 rpms. Even when I'm on the highway I'm usually at about 2000 rpms going 65 mph.

In our '95 Blazer LS, it is always pretty darned quiet. Slow speeds, highway speeds, it feels like a "luxury" car as far as being quiet.

Our '97 Blazer LT is the one that probably has the broken fan clutch. It is always roaring. I haven't had a chance to inspect it yet though.

Again, thanks a million guys,
-- recurve

[BlazerLT]

If it is roaring, the clutch is gone and wow, does it put a drag on the motor.

You sure it is the fan roaring?

[Trail Blazin96]

Originally Posted by BlazerLT

Mine does not roar all the time but only some mornings when I pull away and accelerating.

At 2000rpms it will disengage and I won't hear it anymore. And after that one time I usually don't hear it at all for sometime.

If it is roaring all the time, you need to change the clutch.

That is how my truck was doing, first thing in the morning, but now it is a constant thing going all the time. So you think it might be stuck, it spins engine speed all the time!

I guess this was a good topic, all though it took a while to get the information i needed I got it and also helped out a fello owner