Chain rattle? Only does it at idle/cold/AC on. Audio Clip. | Ford Explorer Forums - Serious Explorations

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Chain rattle? Only does it at idle/cold/AC on. Audio Clip.

cross6

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Joined
February 26, 2008
Messages
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City, State
Baton Rouge, LA
Year, Model & Trim Level
2004 Mountaineer
https://soundcloud.com/humidbeing/my-recording-1

Trying to figure out if this is chain rattle or not.

2004 2WD 4.0 with 187k.


ONLY does this at idle when cold. If you raise rpm above idle it's silent. If it warms up it's silent. But turning on the AC will make the noise worsen hot or cold. Does not rattle/flair on startup.

Ran engine without belt and still did it when cold under 700 rpm.

Don't hear anything from compressor or engine when probing with stethoscope.

What do you think?

Shouldn't it rattle under load, too?

Will bad tensioners cause rattle at idle? I thought it was just startup?
 



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no belt eliminations

The rattle being present with the serpentine belt removed eliminates the compressor (as well as all other engine peripherals). Make sure the harmonic balancer is not failing: Harmonic balancer failure

Your rattle may be oil pressure related but pressure is usually higher when cold and lower at idle. Are you using full synthetic oil and a quality oil filter? What weight is your engine oil?
 






The rattle being present with the serpentine belt removed eliminates the compressor (as well as all other engine peripherals). Make sure the harmonic balancer is not failing: Harmonic balancer failure

Your rattle may be oil pressure related but pressure is usually higher when cold and lower at idle. Are you using full synthetic oil and a quality oil filter? What weight is your engine oil?


When the compressor is on, it gets about 2-3 times as loud.

I don't see any wobble in the harmonic balancer, but the belt tensioner does jump a lot. It's not weak, I replaced it once already with a new motorcraft unit.

However, it has a rough idle so I think the jumping might be from that?

Motorcraft oil filters and syn blend 5w-30 oil.
 






Try to find some non-ethanol gas and see if that helps. As much as I hate spending the money, I'm trying to keep regular unleaded (non-ethanol gas) in my '03.
 






Did you check your Iac valve? That could be causing a rough idle not a rattle though
 






load dependent?

Getting louder when the A/C compressor is engaged indicates it is load dependent. If that's the case, the rattle should also get louder when the transmission is in Drive vs Park. Have you tried listening for an exhaust manifold leak using a flexible tube?
 






If that's the case, the rattle should also get louder when the transmission is in Drive vs Park

Yes! It does!

You know, I do hear more drone in the cabin these days...

So would I stick the hose down by the headers? Between the runners?
 












Alright guys, I can't find any evidence of exhaust leaks, but I have found some things...

Water pump:

1. When leaning directly in front of the grill I can hear a groaning noise, only at the center of the grill.

2. Probing behind water pump pulley on pump housing /w stethoscope reveals a metal tapping and bearing drone/grinding noise.

3. The fan has some wobble at the ends.

4. The belt is walking back and forth about 1/16" an inch on the water pump pulley but not any other pulleys.

5. The belt skipping is causing a secondary problem: The belt tensioner is slapping around excessively and also chattering as found with a stethoscope.


This explains almost all my symptoms:

1. Why I'm slowly losing coolant. I assumed thermostat housing but it's probably coming out of weep hole. I do see wetness staining around top of crank pulley.

2. AC coming on loads belt and increases belt/tensioner chatter noise being caused by wobble in water pump.

3. In cabin there is a change in engine sound and you hear/feel whining/rumbling. Probably the water pump bearing and/or fan vibrations.

It doesn't explain why I still heard noise with belt off. But the noise was much, much quieter than what I hear with belt on.

NOW, it's possible I have a bad water pump bearing AND a bad primary chain tensioner, I do have almost 190K on this truck.

But this water pump is suspect, it's a Bosch reman cheapo with 100K on it...


So this is my plan for now:
I'm due for an oil change so I'm going to drain oil and drop lower pan. If no plastic I'm going to just do water pump / hydraulic tensioners (Already have them in my parts bin) / idlers or whatever belts items I find and hope that takes care of it.

This truck is in rough shape body wise (rusted out) so I'm not going to save it if chain guides are shot.


Thoughts?
 






Update:

Had a few minutes this morning and pulled the belt. Yep, I can wobble the whole darn fan clutch and water pump pulley up and down clunk clunk.

The clutch also wobbles when the pulley is held tight with the belt.

But I notice my alternator is covered in black belt dust...

So maybe the water pump pulley isn't the only source of alignment issues.

Ran engine again with belt off and probes with stethoscope, definitely hear the noise coming from bottom of engine near harmonic balancer. Loudest when I probe on the crank sensor bracket.

That would also contribute to the vibes/drone? Balancer also fits with bouncing tensioner and getting worse with ac on.

Looks like I'm in for a fan clutch/water pump/balancer. Don't know which went first or if coincidence.
 













Thanks. I have the old style. Going to replace it. I think the belt drive symptoms (black belt dust, belt skipping, tensioner jerking) warrant it before mine separates and eats through the AC line. Especially since I have a brand new compressor!

Going to hope it's the noise too. But I'll be surprised. Really sounds chain-ish to me. But we'll see. Going to fix that sloppy water pump and clutch while I got the belt drive off.
 






I pulled the balancer tonight.

My truck is a 2004, but I have a 2000-2003 balancer. It's definitely not the 2004-05 balancer shown in those threads.

Sticker on my engine says April 2003.

Can I still use the updated version with the different tone ring? Would I need to get a 04-05 crank position sensor?

edit:

Just looked up part numbers and seems crank sensor didn't change so I guess I'm good.

Haven't seen anyone else with an '04 have the pre 2003 balancer setup. Guess my truck must have been one of the first 04s to roll off the line and they had some old stock lol.
 






Going to replace balancer first to see if it was the noise before doing water pump/fan. Just so I can let 2000streetrod know he called it in post #2 ;)
 






Welp. Bad news.

Put on the new updated 594-236 balancer. It pressed on smoothly. Keyway on crank looked perfect still. Used new bolt torqued to 44ft-lbs + 90 degrees.

Fired it up with no belt and the wobble is just as bad maybe slightly worse. (Probably because old balancer had so much play in the rubber)

The noise is also unchanged.

Looks like I have a bent crank or extremely worn front bearing?

This started around same time as the chain rattle so I'm wondering if a tiny piece of chain guide got into an oil journal.
 






broken/bent crankshaft

In the 5 years I've been a forum member I only remember a couple instances of a bent or broken crankshaft on the SOHC V6. I think they were 3rd generation Explorers. Maybe the cause was a failed harmonic balancer.

The screen on the oil pickup prevents large fragments from entering the oil pump and the output of the pump goes thru the oil filter before flowing to the galleys and bearings. In my opinion the chances of a cassette or tensioner particle blocking a bearing oil passage are pretty slim.

I suggest a compression test before tearing the engine apart. It may not be worth replacing the crankshaft.
 






In the 5 years I've been a forum member I only remember a couple instances of a bent or broken crankshaft on the SOHC V6. I think they were 3rd generation Explorers. Maybe the cause was a failed harmonic balancer.

Yeah I've been searching the forum. The few cases I found seem to be broken snouts or broken at first bearing. But I pulled up and down, fore/aft, and tried to rotate the new balancer once it was torqued and I found no play to indicate a broken snout.

The diesel/rattle noise does come from the area by the side mirrors. I suppose it could be broken in the rear.

Could a bad flexplate cause the balancer to wobble? I know it can cause a similar noise from that area.

The screen on the oil pickup prevents large fragments from entering the oil pump and the output of the pump goes thru the oil filter before flowing to the galleys and bearings. In my opinion the chances of a cassette or tensioner particle blocking a bearing oil passage are pretty slim.

Right, right. Good thinking.

I suggest a compression test before tearing the engine apart. It may not be worth replacing the crankshaft.

Yeah I don't know what to do next. I can't handle pulling anything right now, going in for back surgery soon.

I'd bring it to the dealer for a diag but I doubt they will take it seriously. Will probably hear 4.0 explorer /w 187K and just say needs chains without doing any work.

I suppose I could have gotten a bad balancer. But I googled bad dorman balancer and it doesn't seem to be a common issue. The chevy guys had some dormans that wobbled but they were all using the wrong part #. This balancer was the right part by looks and how it felt pressing on.

One more piece of info: A few weeks ago, in idle, the truck made a violent bang that was loud and could feel. Like if an engine suddenly siezed. I immediately looked at the tach thinking it siezed but it was still running and never did it again...
 






other main bearings

Even if the flexplate were bad I don't see how it could cause a wobble at the front. The other main bearings should prevent crankshaft deflection.
MoreCrud.jpg

Is it possible to determine if the harmonic balancer retaining bolt wobbles?
How did you loosen the old balancer retaining bolt?
 






Even if the flexplate were bad I don't see how it could cause a wobble at the front. The other main bearings should prevent crankshaft deflection.
View attachment 78620
Is it possible to determine if the harmonic balancer retaining bolt wobbles?
How did you loosen the old balancer retaining bolt?

I made my own holding tool.

Piece of 1x4 hardwood long enough to go down and hit the pavement and extend about 5" past balancer. Bore a 1.5" hole for your 19mm socket to go through. Drill 2 3/8" holes off axis to prevent splitting and use your M8 x 100mm pullers bolts with some fender washers to bolt the 1x4 to the face of the balancer.

Takes 5 minutes to make with a cordless drill. I do this for most vehicles. Oak 1x4 usually can take around 250 ft-lbs in my experience if made correctly to avoid loading the same grain lines.

Not a fan of chain/strap wrenches b/c they put to much load on the outer part of the balancer/rubber.

This method lets you break loose/torque by fixing the inner part of the balancer.

How I got 44ft-lbs + 90 degrees so accurately.

You mean inspect the old bolt? I still have it.
 



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clever tool

I may make something similar for future use. My next question was going to be how did you torque the new retaining bolt but now I don't need to. With your method there is no possibility of breaking the bond between the inner and outer sections which could result in a wobble unless you tighten the M8 x 100 bolts too much pushing the outer section aft. By the way, a strap or chain wrench is supposed to be attached to the inner section (not the outer) in the green area identified below.
StrapIt.jpg

I purchased a chain wrench to try and use but in my opinion its worthless. Ford has a special tool similar to yours but made out of metal which I refuse to pay for.

I'm about out of ideas. I'll sleep on it and maybe think of something.

Edit: there should be enough washers/spacers between the board and the recessed inner section so the board does not push against the outer section when the M8 bolts are tightened.
 






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