Chirp, Chirp...Bad water pump? Pulley?

Hey all,

I noticed the other morning that there is a chirping sound coming from around the water pump area (at least it sounds to be there or power steering area...front driverside of engine bay is a good way of putting it). I know this is usually indicative of a bad water pump, but the chirp goes away after a few moments of driving.

The chirp does get faster with your foot on the skinny pedal. You cant really hear it if youre in the cab though (unless youre just idling). I dont see/feel any weepage from the water pump (which is also ~4 months old). Any help into what it could be would be great. Thanks! :eeks1:

Link to video of the chirp:

http://s1008.photobucket.com/albums...B-8B0F-A6CF00F4D058-2792-000000A735ABF46B.mp4

I can't hear a chirp!? But...what year is your Jeep.

I'd look at the idler pulley first (if the belt is tightened already). Replacing that is cheap and easy.

Remove the belt and turn each pulley to see if there is any roughness, binding etc. on any of the components. Does it get worse with A/C on? Cold? Hot?

Its a 98 model, 4.0 engine. The "chirp" sounds somewhat like a tick when played back (its probably lost some of its sound due to internet compression). Its a very solid chirp/tick thats about two per second at idle on the video.

It doesnt seem to change the sound if I have the AC or heat on or off. It does it when the jeep is cold. After I run it for a few mins (for example, I was running an errand this morning when I took that video). I went about a 1.5 to my first stop and the chirp was gone. My wife drove it yesterday to take it in for an alignment (new lift kit!) and thats when I heard the chirp. By the time she had gotten to the shop (about 3mi), the chirp was gone.

I have never heard a water pump make a "Chirp".

As far as the sound goes, it is happening at a regular rate. Could simply be a slipping belt.

If you just replaced the water pump (and belt also I hope), you may not have tightened the belt enough. Those serpentine's need to be much tighter than the old 1/2" deflection rule; they need to be very taunt because there is no grip except the surface. If you didn't replace the belt, do it now.

WB9YZU said:

I have never heard a water pump make a "Chirp".

As far as the sound goes, it is happening at a regular rate. Could simply be a slipping belt.

If you just replaced the water pump (and belt also I hope), you may not have tightened the belt enough. Those serpentine's need to be much tighter than the old 1/2" deflection rule; they need to be very taunt because there is no grip except the surface. If you didn't replace the belt, do it now.

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The PO had the radiator, t-stat, and water pump replaced just before he sold it. I am not sure if he replaced the belt or not. I am presuming that he didnt, as he seemed to do everything as cheaply as he could. I have looked at the belt and it seems fine. I want to replace it anyway with a Gates (the current brand is unknown). Is there a spec that the belt should be tightened to? I use the 1/2" rule, as Ive always been told to not undertighten or overtighten the belt...

Btw, Ive heard that water pumps will squeak/chirp when the bearing inside goes bad. I have no idea if thats true or not, Ive been fortunate enough to never have had one go bad on me.

The spec is pretty darn tight

Just checked mine, and its ~1/4 to 3/8 beteen the ac comp and the wp

Keep adding tension until the ac comp wont slip the belt when it cycles on

The 1/2" deflection rule works for V-Belts because the sides of the belt grip the inside of the pulley groove.

You can't use it on a serpentine belt. Tighten it until you can play a tune on it. Forget the bearings, they won't be affected.

WB9YZU said:

The 1/2" deflection rule works for V-Belts because the sides of the belt grip the inside of the pulley groove.

You can't use it on a serpentine belt. Tighten it until you can play a tune on it. Forget the bearings, they won't be affected.

Click to expand...

I have only owed v-belt yj's up till this xj, so I just used the 1/2" method. I'll look up how to tighten the belt and set it to 3/8-1/4 and see if that fixes it. If not, I'll be testing the pulleys while changing the belt...I was just wondering where to start.

I had a less than 2 year old (was new, not rebuilt) water pump give an early warning "chirp" not long ago. The thrust bearing was worn out, and the impeller was rubbing on the pump housing. Has been pretty common with cheap water pumps from China lately based on posts I read here this year.

Engine off, try and wobble the water pump pulley with your hands.

WB9YZU said:

I have never heard a water pump make a "Chirp".

As far as the sound goes, it is happening at a regular rate. Could simply be a slipping belt.

If you just replaced the water pump (and belt also I hope), you may not have tightened the belt enough. Those serpentine's need to be much tighter than the old 1/2" deflection rule; they need to be very taunt because there is no grip except the surface. If you didn't replace the belt, do it now.

Click to expand...

I chased a chirp on mine for a bit. Thought it was the old weathered belt, replaced and still there. Then thought was the idler pulley, replaced and still there.

Turned out it was actually my harmonic balancer going bad and walking itself back into the timing cover. The contact on the cover made a chirp just like a belt squeal. Replaced and been fine ever since.

So make sure you check everything. Could be coming from a few different places.

JHumphrey, My '98/4.0 has been doing the same thing. Only when it's less than 60*F outside. I've been chasing it since last year on and off. New belt, new idler pulley, no difference. As stated above, the belt has to be a lot tighter than you'd think.

My XJ likes to do this, usually when cold, I think it's actually the AC compressor when it's at idle (AC not on), however it could also be the idler, that happened on my last XJ, I spent a fair amount of time chasing that one down, finally found it when I took the belt off, and started spinning pulleys and found the idler was feeling gritty/not turning well.

The idler is the cheapest and easiest parts to replace in order... $7 at autozone, next is the alternator (might want to put an HO alternator in while you're at it), fan clutch (yes, had this go bad, and worth checking), waterpump, harmonic balancer (these are always a PITA), power steering pump, and finally the most expensive and PITA of all, the AC compressor.

I'm going to be doing the ABS delete today, so I'm going to do the idler while I'm at it (already have the part).

Just an FYI, the telltale sign that the waterpump is going is leaking from the weep hole at the bottom. If you have any questions about the WP, climb underneath and usually you can see the weep hole on the bottom of the pump... look for any buildup around there, if you see some oxidation or dried coolant around the hole, buy the pump and schedule a few hours to do it, as it will probably start gushing fluid in about 2-3 weeks.

Ecomike said:

Has been pretty common with cheap water pumps from China lately based on posts I read here this year...

Engine off, try and wobble the water pump pulley with your hands.

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Mike, this, and finding a big green river under your Jeep, is the only tried and true method of finding out whether the water pump has an issue.

Hell, we can suggest replacing all sorts of stuff. But, the only sure way of locating the noise is with a stethoscope, close observation, and some patience.

If we are going to go by experience, this noise means squat. I remember when every single 70's GM SB sounded exactly like that sound track at a stop sign. It didn't mean anything was going to fail, it just meant that stuff made noise.

I ordered a belt tension gauge today (no NAPA in my area and none of my local parts stores had one in stock). When I get it, Im going to check the tension. If the tension is good, Im going to pull the belt (I want to put a Gates belt on anyway) and test the pulleys by hand while the belts off.

Side note, Ive been under the jeep off and on recently. Ive been keeping an eye on the weep hole and havent seen anything that makes me think its the WP. I do have a stethoscope and when I put it on the alt, the WP, and PS pump, I dont hear any squeal. Im also going to try the "mist on the belt" technique and see if that changes anything.

The past couple of mornings have been cool (less than 60*). So, my issue sounds like the same one that Reverend is experiencing.

Could be alternator with worn out brushes or case bearing, just replaced one like this myself that made a "chirp chirp chirp" noise until the truck warmed up to operating temp. Take the belt off and spin everything by hand and you'll probably get a good idea what the problem is.

NotMatt said:

Could be alternator with worn out brushes or case bearing, just replaced one like this myself that made a "chirp chirp chirp" noise until the truck warmed up to operating temp. Take the belt off and spin everything by hand and you'll probably get a good idea what the problem is.

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Was yours a case bearing or alt? Where is the case bearing and where is it located?

Here's my "chirp chirp" thread;
http://www.naxja.org/forum/showthread.php?t=921771&highlight=chirp&page=3

It ended up being a bad harmonic balancer after most of the other things were replaced.

Good luck,
Mike

Jhumphrey said:

Was yours a case bearing or alt? Where is the case bearing and where is it located?

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Mine was probably a little of both, the alternator itself has a sealed bearing in it that was bad (which is what I'm referring to as the "case bearing" since I don't know what other technical term it would be called). I went ahead and replaced the whole alternator, since the bearing itself was not something I could find and I wanted piece of mind that the alternator was new. The brushes being worn was probably a side-effect of the bad bearing. The alternator was still charging within specs, but the output was fairly low even with no accessories or lights on. I took the belt off and spun everything and the alternator was the obvious culprit, making the squeak squeak noise as I rotated it.

I've also replaced the harmonic balancer on this rig, but in my case it did not make any strange noises when it failed, it just shredded two serpentine belts in a matter of days because the rubber in the balancer had worn out enough that the outer part of the balancer had walked forward causing the belt to not be aligned right.

Before you go replacing the alternator or digging too deep into it though, just put a new idler pulley on (the one that is right next to the A/C compressor). It's cheap, easy to replace (just loosen the belt with the adjusters at the PS pump, unbolt and bolt the new one in, and tighten everything back up) and they do have a tendency to go bad and make noise. Plus if you let it go too long after it starts making noise, it can seize up and do some big damage to your serpentine belt. It may very well be your culprit.

My gauge arrived today! Looking at the gauge, its under 100lbs (it took a youtube video for me to verify that I was reading the gauge right...first time). It looks like Ill have to pull the e-fan to get to the idler pulley bolt. Speaking of, is the e-fan just two small bolts and it comes out? I also may have my hands full with the idler bolt, it looks like its somewhat rounded off. Its to tight of a space for me to get a wrench and my hands in to try to turn it...

The e-fan has two 8mm bolts at the top, and two tabs on the bottom that lock into place. After you remove the two bolts, just wiggle it from side to side when pulling upward on it and it will come right out. Just be sure to disconnect the plug first.