My 22r developed a strange engine rattling sound the other day and it has me baffled. It seems to be coming from the front of the engine. The sound only happens when the engine is warm and only at low RPM's like from idle to maybe 1500. I thought it could be the timing chain or guides so I pulled the valve cover but everything looked brand new and the chain seemed to have good tension. It was replaced about 50,000 miles ago. Otherwise the truck runs and drives fine. Anyone have any ideas? Thanks for any input!

Did you check the fan clutch and the water pump output shaft for play? Also idler pulleys on any of the belts (power steering or A/C if present)?

I checked all of the pullys and they seem to be fine but the water pump was the next thing I was going to look at. There is also a high pitch sqeeking sound at around 1500 RMP. There isn't any coolant dripping though. The fan clutch seems fine from what I can tell. How would I check the water pump output shaft? Would it be loose? Thanks again!

Grab it and give it a tug. Fan clutch bolts to the pump.

Squeal may be an idler pulley bearing (if you have any - none on the water pump/alternator belt).

I took a pretty close look at the water pump today and it sounds like the sound is definitely coming from it. The fan clutch and shaft feel good and tight, there is small wiggle that's barely detectible so I think this might be normal? It only wiggles when I try to tilt the fan back or forth and it's a very small amount. The rattle only appears when the engine is warm and seems to get worse the more coolant is being pumped and disappears above 2000 rpm. I'm pretty baffled at this point. It seems like if it were a bearing it would not be temperature dependent but I could be wrong. Also, I let the engine warm up to the point where the fan kicked in and still rattles so I don't think it is the clutch.

auto zone sells water pumps for $20 lifetime gaurantee.... cheap insurance if you ask me. there should be zero play in that pump. like 4 crawler said it could be a dry bearing in one of your pulleys, an overtightened or loose belt also.

Well if there should be zero play maybe I'll just replace it anyway. I've been through enough cheap lifetime warranty parts on this truck I'll prolly just get the real thing. Thanks for the input.

What I do is this.

Remove ALL belts, start motor. If noise is still there, bummer. If noise is gone, replace each belt one by one until the noise returns. Troubleshoot from there.

I blew a rad hose on a drive a few years ago and ended up filling the rad with (clean) river water to make it to the next town. After that, the seal in the water pump started squealing for months, but eventually went away. I figured it was due to lack of lubrication from no antifreeze.

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