Curious if anyone else has experienced anything like this...

I recently had my water pump and fan clutch replaced and now my truck sounds and feels different. It sounds a lot more "airy" or "vroomy," kinda almost like a dragster. It also feels a little less powerful. It feels like I'm giving it more gas but the rpms are just going up and there's not as much acceleration as there used to be. It used to run very smooth and pretty quiet but now its loud and weak. I think it may be affecting my gas mileage as well. Occasionally if I really punch it, it will get quiet like it used to be around 3rd gear.

Was curious if it could be a result of improper tension on the belt?? But would it be too much tension or not enough?

I read where one guy said his truck was revving up higher than normal before shifting after replacing the water pump and fan clutch but then he replaced the new fan clutch with the mopar original and the problem went away. The duralast water pump i bought recommended that I replace the fan clutch when replacing the water pump. Was this really necessary?? Should I try to reinstall the original fan clutch???

My truck is 2002 3.7 V6 with 150K, well maintained. Thanks for any help.

 

sounds like the fan clutch isn't disengaging... you should diagnose that first.

 

a used fan clutch must never be placed on its front/back.. always vertical . if it was placed down.. replace it.

I will add. my truck from new.. the fan clutch takes a mile or so to warm up from cold ...but it will unlock.. and sounds just like you describe .


replace the fan clutch.

 

He just had the fan clutch replaced from what I read in his OP... but it sounds like it's not working correctly.

 

Dont know about your fan clutch but... when it's engaged, you will hear a much louder engine sound because of the air it's pushing. This loudness will make you think your engine is revving much faster than it actualy is. So, maybe the noise you hear tricks you into thinking you are revving more and thus should have more power.

Neither the water pump nor the fan will effecvt your performance the way you describe, BUT the sound will certainly do wonders and trick you like I described.

My fan takes a bit to disengage as well. truck screams when I am barely moving down the road. people always look at me as if I am racing my truck.

 

If the clutch doesn't ever disengage then he'll see a slight decrease in MPG just b/c it's pushing additional rotational mass.... maybe like 1mpg loss at the absolute most...

 

I forgot that part.. YES the new fan clutch is not working correctly.

the Roar noise is the sound of the fan turning very fast.. as if the engine is starting to overheat. or working very hard.

in this case nether .

 

Double check the belt routing....?

 

Wow, Lots of good info here, thanks for all the replies.

How could I diagnose whether the fan clutch is disengaging or not??? Is that something I can verify visually???

I was wandering if the louder sound was playing tricks on my brain. Either way it is definitely annoying. I've had this truck for 10yrs and now it just "feels" different. I want it back the way it was.

 

Fan blades backwards.....just throwing things out there...im in a copy/paste mood tonight.

WARNING: BE SURE THAT THERE IS ADEQUATE FAN BLADE CLEARANCE BEFORE DRILLING.

1. Drill a 3.18-mm (1/8-in) diameter hole in the top center of the fan shroud.
2. Obtain a dial thermometer with an 8 inch stem (or equivalent). It should have a range of -18°-to-105°C (0°-to-220° F). Insert thermometer through the hole in the shroud. Be sure that there is adequate clearance from the fan blades.
3. Connect a tachometer and an engine ignition timing light. The timing light is to be used as a strobe light. This step cannot be used on the diesel engine.
4. Block the air flow through the radiator. Secure a sheet of plastic in front of the radiator. Use tape at the top to secure the plastic and be sure that the air flow is blocked.
5. Be sure that the air conditioner (if equipped) is turned off.

6. Start the engine and operate at 2400 rpm. Within ten minutes the air temperature (indicated on the dial thermometer) should be up to 88° C (190° F). Fan drive engagement should start to occur at/between:

7. 3.7L Automatic — 93° C - 99°C (200° F - 210° F)

• 3.7L Manual/4.7L Automatic/5.9L — 85° to 91° C (185° to 195° F)
• 4.7L Manual — 74° to 79° C (165° to 175° F)
• Engagement is distinguishable by a definite increase in fan flow noise (roaring). The timing light also will indicate an increase in the speed of the fan.

1. When viscous drive engagement is verified, remove the plastic sheet. Fan drive disengagement should start to occur at or between:
2. 3.7L Automatic — 76°C to 81°C (168° F to 178° F)

• 3.7L Manual/4.7L Auto/ 5.9L — 67°C to 73°C (153° F to 163° F)
• 4.7L Manual — 56°C to 62°C (133° F to 143° F)

A definite decrease of fan flow noise (roaring) should be noticed. If not, replace the defective viscous fan drive unit.





CAUTION: Some engines equipped with serpentine drive belts have reverse rotating fans and viscous fan drives. They are marked with the word REVERSE to designate their usage. Installation of the wrong fan or viscous fan drive can result in engine overheating.