Please help me identify this squealing noise coming from the front! Traveling repair

Hi, I’ve just gotten done replacing the 2 idler pulleys, tensioner and belt AND the alternator. This noise hasn’t gone away and I’m not sure what to do next. When I used a hose to my ear to try to pinpoint the source of the noise it seemed like it was coming from the fan area. Definitely center of the vehicle. Tested the fan clutch, it’s not locked up at all (and I couldn’t find any mention of them squealing when they fail) and I’ve heard it kick in within the last 2 weeks or so. Also my water pump has been replaced within the last 20k. Using the hose it did not seem to originate from there either.

The noise seems to come and go, but is definitely getting worse. I made it to San Diego so I could grab parts from Europarts.

Starting to get nervous...

https://streamable.com/xf28k


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What was the brand name of the replacement water pump?
Why was it replaced?

What was the brand of the replacement tensioner?

Was the noise there before you started replacing parts?

bill in tomahawk

I did not replace the pump, had it serviced at west coast sprinters (I believe?) in Salinas California. It was replaced because I was leaking coolant.

Tensioner was a Litens, idlers were INA brand.

Yes they were replaced because of the noise. I took a video of the sound before and after replacing, it sounds identical.



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Power steering fluid is at a good level, and I have been putting Lucas stop leak ps fluid in it for a while now due to a leak in the rack. Usually I associate power steering pumps with more of a groaning (when you turn the wheel) whereas this is constant (changing with rpm of course)


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OK, I did a bit more research. I think I ought to be more suspicious of the water pump. The sound seems to be originating from there. I had been ruling it out since I've had such little use out of it since it's been installed. However I have no idea how old the tensioner was, and the idler/tensioner bearings were all dry. Saw a post suggesting that worn tensioners can accelerate wear on other belt-driven components, so perhaps it was well overdue for pulley replacement but what I've been hearing is the failing pump. Going to figure out how to deal with it from here, but at least I have a next move to make.

Of course I can/should verify that it's actually belt related first by removing the belt and briefly running it to see if the noise goes away.

What gasket was used with the water pump? The thinner aftermarket paper gaskets can sometimes cause the impeller to rub on the housing. Though I am not sure if that would make that noise.

Wish I knew. The water pump and brake rotor/pad replacement has been only service I haven't done myself since getting my sprinter in '15. This all is encouraging me to deal with my own problems myself so that I know, and am capable of dealing with it next time it arises. At the time I was travelling, it seemed like a lot of stuff to rip out while on the road, not to mention trying to capture and deal with coolant (and how stranded do I get if I screw up!). Of course I just yesterday tore it down almost enough to deal with pump replacement; it wasn't the end of the world. I may call West Coast Sprinters on monday and find out.

On the bright side, it gives me a chance to replace those hoses which should have been done at the time.

I would think if it were a clearance issue it would've been there since the start. I'm not sure it sounds like a failing bearing -- though I can't speak from a ton of experience.

Ok, think it’s sorted out now! In case any one is curious:



I found this nice little pattern carved out. After replacing the pump, the noise went away AND the tensioner is no longer bouncing. I didn’t see any corresponding wear on the pump impeller but it’s steel, perhaps it doesn’t show. Anyone seen this before?

I also had to replace my alternator again with the old one (unrelated issue). Now I’m noticing the belt is walking around a bit. What would cause this? It does look like it’s gotta be moving at the alternator or water pump pulley, both look completely stationary. I took a video, please let me know if you have any insight or if this looks ok, I’ve never seen so much wobble on the belt.

https://streamable.com/xtgwm

Also note the problematic pump did have a metal gasket.

What brand of pump?

It looks like your idler pulley cockeyed. Or possibly the bearing is worn. You can see it wobble. The belt tracks with the wobble.

I just replaced the idler pulleys (ina) and did it with the radiator swiveled out, pretty sure it went on just fine- I did notice it can bind on the shoulder of the bolt but I did check to make sure It seated properly. I’ll look again tomorrow when I have light. The replacement pump is a Hepu from europarts-sd. The idler pulley hole came pre-threaded.

The failed pump was a Graf.