| Author | Message | ||
     Daniel McElroy (Danielm60660) New Member Username: Danielm60660 Post Number: 6 Registered: 05-2003 |
I have a mouse under my hood. It's a chirp/skeak, but not a belt. A neighbor, former auto mechanic, says it's my "fan clutch". Could this be the dreaded viscous unit? If so I have three questions. 1. How much for the part, average? 2. How difficult is it to replace, really? 3. If it is not this, what else could be the culprit?...I know I havn't given much to go on but I have NO other symptoms. It does go away when I rev the engine. A/C on or off makes no difference, gear makes no difference, does not happen when engine is cold, very intermittent in general. As always, thanks in advance. Daniel | ||
| Robert Sublett (Rubisco98) Senior Member Username: Rubisco98 Post Number: 895 Registered: 04-2002 |
I can't hear the sound from here, but it could also be the bearing in your idler pulley/tensioner. Mine made that same noise for awhile, I didn't know what it was. Driving down the interstate at 80mph and that thing seized up, belt wrapped around everything in the engine compartment. I am by no means an expert, that is what my mouse turned out to be though, and it went away with rev of the engine, wasn't there when the engine was cold, etc.. Good luck.. RS | ||
| Jim H. (Victor_mature) Member Username: Victor_mature Post Number: 55 Registered: 02-2003 |
Okay, don't do this until someone else on this board chides in to say that I'm either a genius or an idiot (either one is likely) but here's a way to stop your fan to determine if it is the culprit: Remove the top part of the fan shroud (on my D1 it's two buckle-clips, takes two seconds) Start the vehicle and then take a regular 4" paint brush and lightly allow the bristles to brush the fan as it rotates. Exert pressure incremently until the fan stops, then release it immediately. If your noise stops (or becomes constant)when the fan stops then your neighbor is right and it's the viscous unit. If the noise is uneffected then it's probably a bearing -check your belt tensioner first. This is probably a bad idea but I had reason to stop the fan to check something and this is how I did it. JH | ||
| Erik G. Burrows (Erik) Member Username: Erik Post Number: 219 Registered: 04-2002 |
Or you could just take the fan off, with the right tools it takes 2 minutes. | ||
| Matt Lipetska (Matt_lipetska) New Member Username: Matt_lipetska Post Number: 1 Registered: 02-2003 |
I have '95 Disco (103K mi.) and about to replace my fan and viscous unit. My shop manual calls fo the use of two "Land Rover" special tools. Are the tools really necessary and what are they? Has anyone replaced these items and how long did it take? Thanks | ||
| Jim H. (Victor_mature) Member Username: Victor_mature Post Number: 56 Registered: 02-2003 |
I just replaced the fan on my '94 and I used the time-proven method of swearing, bleeding and throwing wrenches. I don't have the special "LRT" tools so I used a grande crescent wrench (the coupler nut is 36mm) and a large screwdriver against the pulley bolts to block it from turning. The coupler nut is a standard thread rather than a right-handed thread (in other words, lefty-loosey). If Eric can do this in two minutes with the right tools than it may be worth purchasing those special tools because I found it to be kind of a bitch. JH | ||
| Erik G. Burrows (Erik) Member Username: Erik Post Number: 220 Registered: 04-2002 |
I tried the wrench/screwdriver/swearing method, but it didn't work for me, and I bled a lot. So, I called around for shops that sell/rent "fan wrench" sets. One near my house did, and rented it to me for nothing but a deposit. The kit I used had lots in there. They are just 3/16" thick sheet steel cut into the shape of a big wrench. This goes around the bolts on the fan pully to hold it steady, while you use another one on the big nut. With two of these long-handle, thin wrenches, it really is a two minute job, and no bleeding/swearing required. | ||
| Daniel McElroy (Danielm60660) New Member Username: Danielm60660 Post Number: 7 Registered: 05-2003 |
O.K. next question...Where can I find the idler pulley? Is it on the top or bottom of the engine. Does anyone have a diagram? Can this be adjusted to fix the noise? Also, this neighbor did hold the fan still while I started the engine. The chirping was constant the enitlre time and remained after he released it. I would like to try adjusting the idler pulley if possible to rule it out, but I do have 104k on my 98 just like Mr. Lipetska. Maybe he and I shoud get together for this...we'll have a good ole' nuckle bustin', curse work usin' time. | ||
| Daniel McElroy (Danielm60660) New Member Username: Danielm60660 Post Number: 10 Registered: 05-2003 |
Just bumping this up. Hate to be so impatient, but I will be pressed for time to deal with this after this weekend so any advice is much appreciated...of course if I need parts that will be a different thing all together. | ||
| Reed Cotton (Reedcotton) Member Username: Reedcotton Post Number: 132 Registered: 01-2003 |
Daniel- Last night I was going to answer this, but when I finished it sounded too sarcastic. The idler pully is the one attached to a spring loaded arm. All the other pullys are connected to machines such as the alternator, powerstearing pump, waterpump, engine crank, etc. On my '96 it is to the right and slightly above the water pump. -Reed | ||
| Daniel McElroy (Danielm60660) New Member Username: Danielm60660 Post Number: 11 Registered: 05-2003 |
Reed, Sarcasm is expected, appreciated in fact. I'm not very good at many things, so a sense of humor is a must. Is this "idler pulley" adjustable/how do I test it versus the fan clutch. Last of all, is the fan clutch the same as the viscous unit? Thanks, Daniel | ||
| Jim H. (Victor_mature) Member Username: Victor_mature Post Number: 57 Registered: 02-2003 |
Fan clutch is the same things as the viscous unit and if the noise didn't change when your neighbor held the fan (I like this guy) then I think you can rule out the viscous unit. There's no adjustment to the idler pulley (a.k.a. belt tensioner). The idler is basically a spring loaded arm with a steel wheel on it that keeps the serpentine belt tight. If that bearing starts to go it'll usually start with a squeak that will eventually become a growl, then a shriek, and when it goes it can get a little messy. Here's what you do: take off the top part of the fan shroud (the two quick-release buckles). Standing in front of your car looking at the motor, the idler pulley is just below your alternator and a little to the left. Using a 15mm socket and breaker bar (use an extension if you need to, to avoid putting any pressure against the plastic fan blades-they can break) slacken the tensioner by turning clockwise on the bolt that would be the "axle" of the idler 'wheel'. Slip the serpentine belt off the alternator pulley and push it out of the way (no need to remove it completely, just get it out of your way). Spin the idler pulley by hand, see if you can find your noise or if you can feel any excessive slop in it. If you have some dry lubricant, put a small amount into the bearing, you won't really be able to extend the life of it but if your noise goes away after lubing the idler bearing then at least you've found your problem. USE THE LUBRICANT SPARINGLY, you don't want it flying off and getting on the belt (and making it slip). If this doesn't work to identify the source of the squeak, then it's probably a different bearing going, maybe the alternator, PS, maybe water pump, or AC compressor. Get a mechanic's stethoscope and start listening. Good luck! Jim | ||
| Reed Cotton (Reedcotton) Member Username: Reedcotton Post Number: 138 Registered: 01-2003 |
Daniel- What Jim said. -Reed | ||
| Daniel McElroy (Danielm60660) New Member Username: Danielm60660 Post Number: 12 Registered: 05-2003 |
Thanks for the info. Once I do locate the bad bearing can I replace the bearing only or do I have to replace for example the entire alternator? -D | ||
| Jim H. (Victor_mature) Member Username: Victor_mature Post Number: 67 Registered: 02-2003 |
Alternators can be re-fitted with new bearings and brushes but I've always just replaced them because you'd always rebuild the alternator completely, checking output and condition of the diodes, voltage regulator, etc. Water pump bearings are part of the unit, same with AC and PS. From what I've read on this board, the idler bearing is pretty easily replaced though, and is a common bearing. If it is the idler I'd go that route. Is this squeak something that's totally obvious or is it something you have to strain your ears to hear? A squeak that's getting louder/worse is something you need to find. If it's just 'a noise you noticed' then I'd wait and see. Pulley/belt noise is (somewhat) normal. If you can't figure out what it is, just keep an ear out for it and monitor it. The problem will usually become more and more apparent until it becomes obvious. Jim | ||
| Daniel McElroy (Danielm60660) New Member Username: Danielm60660 Post Number: 13 Registered: 05-2003 |
Progress report: I pulled the belt and the alternator seems to spin very freely as does the idler pulley and other units (p/s and so on). The fan does have a bit of resistance and there is a sound when I turn it. I don't know if this is normal or not. I can't find anything that feels "sloppy" either. Jim H. This is a very obvious new whine that is constant. -Daniel | ||
| Daniel McElroy (Danielm60660) New Member Username: Danielm60660 Post Number: 14 Registered: 05-2003 |
O.K I just searched the old messages and found a couple mentions of the fan/viscous unit spinning freely when the enine is off and cold, but should be at least more difficult (or locked up completely)when teh engine is off and hot. Does this include removing the serpentine belt as I did earlier or does this also apply if I leave the belt in place. -Daniel | ||
| Reed Cotton (Reedcotton) Member Username: Reedcotton Post Number: 145 Registered: 01-2003 |
Daniel- With the serpentine belt OFF the fan should not only spin freely, but the pully (drives the water pump) behind it should also spin freely. With the serpentine belt on and the engine cold, as in sitting for a while, the fan may not spin freely as the oil in the viscous unit has all drained to the bottom and causes friction. Starting the engine you should hear the roar of the fan for maybe a minute while the centrifical force moves the oil to its "cold" position in one of the chambers inside the viscous coupling. Then it should spin more freely. When the engine is warm/hot (needing the fan) a bi-metalic coil changes shape and moves a valve into position to let the oil into another chamber creating friction and driving the fan. From what I have sumised the fan is never really free spinning, nor is it totally locked up. (In either case don't use the fingers to test it when it's running ;-) ) Anyone- I took mine off the other day and heated the coil up to where it moved, it turned maybe 45 degrees, I am not sure if this is all it needs to turn. Anybody know for sure? -Reed | ||
| Daniel McElroy (Danielm60660) New Member Username: Danielm60660 Post Number: 15 Registered: 05-2003 |
Reed, When I removed the belt a while back the fan did spin, but not nearly as freely as the alternator for example. There was some resistance and a clicking sensation very muffled feeling. I'll be ordering a new viscous unit I think just because I have read a few threads about it going at about my mileage. (104k) Now changing it is another story... | ||
| Reed Cotton (Reedcotton) Member Username: Reedcotton Post Number: 154 Registered: 01-2003 |
Do you get the clicking sensation with the belt on? If not you may want to examine your water pump a little more closely. As long as you have a tool, or wrench that can access the nut on the back of the VC, changing it should not be a problem. The fan is held on by four bolts that take a hex insert like an allen wrench. (If I remember right they are metric.) Should be no problem. -Reed | ||
| Daniel McElroy (Danielm60660) New Member Username: Danielm60660 Post Number: 18 Registered: 05-2003 |
Reed, Now the water pump is a whole other can of worms, right? Is this a different operation than changing the viscous unit? -D | ||
| Reed Cotton (Reedcotton) Member Username: Reedcotton Post Number: 155 Registered: 01-2003 |
Daniel- Yes it is a different can-of-worms, but it operates on a common shaft. The fan is connected to the VC, the VC is connected to the shaft that also runs the water pump. To get to the pump, you have to remove the fan, the VC, and the pulley. At that point you should have fairly easy access to the water pump. If a water pump goes bad, it is usually fairly obvious. Usually you'll notice some coolant leaking, and you won't think much about it. Between the initial leak, and the catestrophic failure of the pump bearing, you might hear a clicking sound. If the bearing is really toast, then you will be losing great quantities of coolant and you will probably also notice the serpentine belt won't stay on because the fan is sitting at an angle to the engine. (This is because the some or all of the ball bearings that hold up the shaft that all this other stuff is mounted on are missing from their proper place.) Should be easyt to check with the belt off. If the water pump is going south, you might actually feel a wobble in the water pump shaft. This might be a more logical place to look for that clicking sound. Check both out before changing either. -Reed |
