Engine Noise from Assessories

Maybe one of you can help me trouble shoot a noise.
It sounds like a noisy tappet, but its not.
4.7L motor in 2004 truck with 150k miles that gets drive about 6k per year..
I got a complete ASIN timing belt/water pump kit at 140k miles as preventative maintenance. No noises until the last month or so when I began to notice it.

• If I pull the serpentine belt the noise goes away, so I've isolated it to one of the driven components there.
• I've sprayed the serpentine belt with soap, WD40 etc. which has no impact, the belt was new with the water pump.
• I used the hose tool to listen to every accessory/idler bearing and thought it might be the top idler bearing, I replaced it, even though if felt fine - no effect on the noise.
• I've felt each bearing/shaft that are driven by the serp belt and checked axial play, they all feel very good.
• Tensioner idler and spring: While running, it's not jumping around more than you might expect. I've sprayed WD40 into the spring box - no effect. I've put pressure on the arm to load it either way - no effect. And the idler pully bearing feels just fine.
• Air Cond.: On/off - no effect.
• Next I've held a long screw driver against all kinds of parts while it's running, and the only place I feel a vibration that seems to correlate with the frequency of the noise is right on the water pump housing. But with the serp belt off, the water pump bearings etc. feels great. I push the shaft in or pull it out while turning it, and it feels fine, nothing rubbing in there that I can feel.
• Power Steering pump: The fluid looks clear/fine. I can feel a sight clicking when I turn the shaft, like the vanes are going past ports. But the bearings feel great, the steering functions fine. If I steer hard over to get fluid through the bypass vale has no effect, either direction. And I can't get any noises through the hose trick or vibrations through the screw driver.

So what seem like a very solvable problem has me baffled. What else can I try??

Thanks in advance.
Mike

 

Man, that's a toughy. Sounds like you've done everything I would have recommended. Is the noise coming from behind the timing belt cover?

 

Even quality new parts can be defective. Since you narrowed it down to serpentine belt/water pump related I would replace the belt and if it's still there the water pump.

 

Maybe post up a video of it to help us identify it. The last time I had a weird noise similar to this, it ended up being the AC belt tensioner assembly on my Tahoe. I would have guessed AC clutch at first on your truck. Did you cycle the defroster on/off?

 

You sprayed the pulleys but did you spray the AC with wd40? Does turning the steering wheel do anything? I'm wondering if it's the AC or power steering. You might be able to hit the alternator with a garden hose to see if it changes tone. Those three would be my next guesses.

 

I can't help but thank you for posting in a clear, concise format with bullet points.

 

Thanks all, some good suggestions here, especially flooding the components with water. The one thing t5hat I didn't check but will next, is the torque on the drive wheel off of the crankshaft. I'm wondering if I didn't get it torqued enough, and after 10k miles its rattling around down there.
I'll let you know what I find......yes, a 'toughy' as said here.
mk19

 

Keep us posted and good luck!

 

Update:

• Checked the torque on the Crank Shaft pully...……it was tight. I had wondered about that since I'd had some trouble torqueing it when I did the Cam Belt and worried that maybe it had worked loose in the 10k miles since - worried because if it was loose, it would be causing serious damage to the Crank (not good at all). But that was fine.
• Got in there with my water hose and spray nozzle and went from component to component, drenching all in including the serpentine belt. Not a single change in the "tappet like" noise throughout the whole thing.

What's next: I'm increasingly convinced that it's coming from within, and it sure feels like its the water pump. But that's a bit of a job, and it's not that loud. The water pump bearings/shaft play etc. feel fine as mentioned in my original post. So therefore I don't see much risk in just running it until either it dies or whatever. I've always tended toward the idea that sometimes its just better lo let the failure progress until its clear what it is...…..and in this case, I can live with it and think that's what I'll do.

If that changes, I'll update you. Thanks all, and let me know if anyone learns of water pump failures that lead to clicking (impeller contacting the housing? - I can't feel it).

Thanks, mk19

 

I think you are right about it being your water pump. I just went through the same thing with my wife's 2002 Camry. Developed a tick in the front of the engine. I replaced the belt even though it looked good. All the bearings and water pump felt good. Basically did everything you did. Decided to live with it. Roughly within 10K miles the water pump started leaking coolant. Put a new Toyota water pump on it and all my noise is gone.

I would do like you plan just live with it but keep an eye for it leaking. Might or might not be the same issue. Just thought I would share my experience.

 

Great input PCJ! Thanks.
Curious……….when you got the old pump out, could you see the cause of the ticking?

 

Curious……….when you got the old pump out, could you see the cause of the ticking?[/QUOTE]

No, I didn't see or feel anything definite in the old water pump. I gave it the usual look over as you do when you pull a part off and was totally surprised when I fired up the engine and it was quite as can be. I gave the pump a better look after that and still didn't see anything obvious. I figure just enough coolant was getting on the bearing to damage it and cause some noise but not create an obvious leak and then the seal just let go.

 

Thanks.
I'll update you all when I have more info.
mk19

 

Update:
I tried to get a warranty replacement water pump yesterday and the guy told me that the plastic impellers on the ASIN pumps can be cracked in shipping/handling and that might be the cause the noise. He said the aftermarket NAPA and Gates (same pump) among others had steel impellers that are better. Sounds plausible that a crack could have progressed over the 10k miles I've put on it, or even that part of a blade came off and is being banged on but the rotating impeller...…...it sort of sounds like that kind of tappet like clicking. In any case its 2.5 years old, so no love from the supplier. I don't think I'll go with another ASIN if/when I decide to pull it. Of course I wouldn't have inspected the new pump for such a flaw...………..lesson learned.
mk19k