95 Disco 1 - 5 speed.

Driving home from a semi long road trip yesterday - climbing a hill - downshift to 4th and feel a bump/thud/snap type of sound. Then all of a sudden I hear my engine fan sound very loud.

This sound increases in pitch and speed when the RPM's increase. Mostly notice in gears 1-4 - not gear 5, but that might be due to road noise / lower RPM's when in 5th gear.

Drove the remaining 1 1/2 hours home (it was night and cold out) and made it home no problem.

When at idle - the engine fan is spinning just fine.

I need idea's as to what might have broke - what to check to verify that it broke - then I will be back to ask how to fix it.

Please use language like "thingy" "****" & "do hicky" as I am not a mechanic.

Thanks in advance.

 

Are you sure the sound is coming from the engine and not from the exhaust somewhere? With the sound not being as loud at the lower rpm's in 5th gear I would be looking at the exhaust system.

I am not a mechanic but if everything else seems fine with the fan, no coolant leaks and your temperature gauge is not up in the "hot" zone, then that's where I would start looking.

 

More than likely the fan clutch crapped out on you. See if the fan will turn with the engin off & cold. Depending on how cold it is there, it will geel like it has thick peanut butter in it. Start it, let it warm up, shut the truck off & try it again, should spin easier than when it was cold. If not, time for a fan clutch. I've see some posts on here telling of success replacing the original fan clutch with chevy parts I think, but I replaced mine with a LRish replacement part from Atlantic British. Not that great of a mechanic myself, so I thought direct replacement would save me in the long run

 

Sounds like your fan viscous clutch thingy crapped out. Fortunately it sounds like it crapped out in such a way that your fan is continuously spinning vs where your fan never spins and your truck overheats.
There are three different Chevy fan clutch thingies that will work. Regular, Heavy, and Severe Duty. I would go with regular duty unless you really like the sound you're hearing now.
Or you can just get a OEM replacement.

 

Regular duty would be for a Chevy 2000 express van, 4.3 lter, without AC. $50 - $60. You will need to enlarge bolt holes in existing fan as Chevy is made for a different size bolt. On the engine side it is same size/thread as Rover, and same reverse direction, 6 inch, etc. The fan, if making this roaring noise, will likely be making enough air flow at idle to spin the elctric fan blades on the AC condenser (very front radiator) slightly. The noise can be confirmed by removing the fan belt, and cranking truck back up. It can be run for a minute for testing without issue.

 

The Chevy clutch on the fan side has a different thread size. So, in addition to enlarging the holes in the fan, you will need 4 new bolts, if you go this route. I think they were 3/8-16 by 1/2"... thingy, doohickies

 

New kink to throw in here. The fan appears to be working fine. No overheating at all. Could it still be the fan and not be overheating? It hasn't changed 1 degree from normal.

Another clue: If I turn my radio up really loud, my Rover drives just like it always has. I would not know anything is wrong with it.

 

Muskrat -

Not too long before you posted your problem, I posted one about my cooling fan running in cold weather. Those who repsonded pointed to my fan cluth / viscous fan.

Testing the viscous / fan cluth, I have found out that this is the problem. It still spins but it does not spin fast enough due to not functioning properly and I do not have any overheating showing on the temp. gauge.

Checking the viscous / fan cluth in the morning, when the vehicle is as cold as it can be, for resistance would be the first step.

See my thread for more details.

I would also again look around for an exhaust leak that may be causing the loud noise you described.

Good Luck

 

My clutch fan seized up. No problem with cooling since it was locked up all the time. It did sound impressive coming up behind pedestrians though but it's not good for gas mileage. ;^)

 

Again, it sounds like your fan clutch failed in such a manner that it is always spinning. It is better it fail this way. Your gas mileage will suck and it sounds annoying but it will save your engine. If the clutch fails in a way that it never spins, then you'll have overheating issues.