Sorry for this second post, but I think that my symptoms have changed from going through the process of fixing everything else. My previous post had to do with rough idle when cold. I change my spark plugs and wires, and ran Seafoam throughout (oil, gas, intake), and now that part of my engine is fine and smooth. Now that the rough idle has gone away, I hear a persistent knocking sound coming from my fan, I think. It is definitely in the middle front area of the engine. It's '98 5.0L V8 Explorer by the way. Could my fan clutch be making this noise? I've detached the shroud around the fan and the area is clean and free of debris between the radiator and fan clutch. When it's cold I can move the fan blades, but if I try to spin it, it moves about 1 blade before coming to a stop (a lot of resistance). Thanks for any suggestions.

 

Didn't see this post before I responded to your first one. I'm cutting and pasting my answer from the other post even though you've answered some of my questions in this one.

"Could be. With the engine off, see if there is any play on the fan shaft or the water pump shaft. Try moving the outer edge of the fan towards the rear and front and see if there is any movement on the shaft. There should be none. Also, see how easy it is to turn the fan. There should be some resistance. Lastly, if you're still not sure, with the engine running, take a rolled up newspaper and touch the outer edge of the moving fan with the opposite end of the paper from where it is being held. Obviously, be very careful about getting into the fan or belt(s), stay clear. If the fan stops turning when a paper is placed against it while the engine is running, the clutch is too weak. However, a bad clutch would typically result in an overheated engine, not really in a rough idle."

If it doesn't appear that the problem is the clutch, you might want to listen using a mechanics stethoscope or improvise with a long screw driver or scrape. If you have a long screw driver, you can place the tip at points on the engine and put your ear against the handle. Listen to areas around the timing cover. Your knocking could be a timing chain. It could also be other things. When the engine is running, look at the harmonic balacer to make sure you don't see any improper movement. When the engine is off, look at the harmonic balancer to make sure you don't see any rubber pieces sticking out. Also, check all of your pulleys along the belt path for any abnormal play with the engine off.

 

I'm bringing the comments from the other thread to this one. It makes it better for someone searching in the future, and easier for me now than switching between threads.

It shouldn't have that play. It could be the bearings are going. Still check the other pulleys, and if you can, use a real or improvised mechanics steathoscope to listen to the block.

 

It sounds like bearings that are going bad. Are there bearings in the clutch? Sorry for the stupid question, if it is?

 

Yes there are bearings. Not a stupid question. Only stupid one's are those that go unasked and therefore unanswered. The bearings are not replaceable, just get a new clutch.

 

Will do. Thanks JerrySimm and I'll let you know how it goes. Would it be really bad (harmful to the rest of the engine) if I drive it to the auto parts place and back (4 miles round trip)?

 

i vote that it is a bad water pump.

 

No. If it's only clicking and just has very slight play, it could last for a good long while. The clutches are pretty robust in design. Very often, folks don't notice theres a problem until the engine starts running hot.

 

Could be a water pump. I was working on the assumption that she observed the movement in the clutch.

 

Before you go buying parts do this first.. remove the serpentine belt and start the engine. If the noise is still present, you've got an engine problem. If the noise is gone it's either a pulley, waterpump, or fan clutch.

Don't run the engine more than a minute or so with the belt removed, as it may overheat. While I agree with the other posts that's it's probably a pump or clutch problem, it will save you a lot of hassle by doing this one simple diagnostic procedure just to be sure. Plus while the belt is off (after you shut off the engine) you can spin all the pulleys by hand and feel for a problem.

Good luck, let us know what you find.

 

Yes. The movement I observed was in the clutch. It's being delivered tomorrow.

 

before you take off the clutch do this:

take serpentine belt off, grasp the fan and rock it side to side, watch the pulley where the belt was, if it moves even a little bit, than it is the water pump bearing.

 

OK, I've got the fan and the fan clutch off, started it (warm) and it still is making the knocking sound in the same area. It's not as loud now, but still there.

 

if you have the serp. belt on it is the water pump.

 

Yep, serpentine belt was left on and it's a '98 5.0L V8. Thanks!