Gretch

Well, witout looking at the patient I would say it is acting like a new water pump bearing. Does the tensioner roller spin about as freely?

BTW, you really need to be an exhaust sound freak to enjoy the movie.....I think there are about ten spoken lines in the whole thing. I also own a copy. Good for rainy saturdays when I have done all the wrenching but can't take Getch out vette huntin'................

SharkSkin

Oh yeah... This is why one must have a good sound system for movies.

geekapalooza

Gretch - Even the new / tighter tensioner roller spins more freely than the WP. I CAN spin the WP with 1 finger, but you definitely feel some resistance, and it will not coast at all, the way the tensioner roller will.

goliver

If you have access to a point and shoot thermometer it might be worthwhile to take temps when you start it and give it a go with the lower cover off to see if a bearing is heating up rapidly.

I feel for you man. This kinda thing is pretty scary. Wishing you a cure!

Regards,

Garth S

The water pump impeller immersed in water = a brake: and if cast iron vs plastic, there's an inertia to overcome before it would enjoy coasting. Again, a key feature to look for is absolute silky smoothness in the bearing - and no lateral or axial play: the tension roller does have some play in these directionas - but they all do.

T_MaX

Water Pump: as long as you don't feel any rough spots, or spots that are tighter then others it should be ok. The WP should feel tight and tighter than just a sealed bearing. A sealed bearing only has to hold the grease in, where the WP has to not only hold the bearing grease in, but keep water from passing the shaft assy.

When you spin the new WP, your looking for a nice tight, but smooth turn. You should be able to spin it about 1/4 to a 1/2 turn (If you try real, real hard, you might able to spin it 3/4 of a turn).

geekapalooza

Great descriptions on how the WP Pulley should act / feel guys. I can almost say for sure that the WP is fine after reading your posts. The descriptions match up perfectly.

That being said, not much more I can do until the parts get here tomorrow afternoon. I guess Saturday is D-Day, and in this case I hope D doesn't stand for "Disaster".

Invitations are still open for anybody in the Houston area that wants to drop by, and offer a hands-on opinion. Besides, I'd like to see the neighbors reactions when they see multiple sharks invading the neighborhood!

Thanks again.

Gretch

Wish I could be there........I thrive on technical challenges and I have a very soft spot in my heart for an ailing shark.....It does sound like both WP and tensioner roller are functioning properly.

I have some questions........Did you test the tension on the belt after it had the moaning incident? Are the cam gears attached tightly to the cams? How do the teeth look on the cam gears and the crankshaft? You sure you have the right belt (re shape of "teeth" wise)? What does the underside of the belt look like? what do the edges of the belt look like? Are there any scuff marke anywhere on the block or cam covers where the belt travels? If you have the pump off, how does the impeller look? is there any scuff marks on the inside of the block portion of the impeller housing? That about covers it.....

Gregg K

Gretch, I feel the same way about mechanical challenges. Too bad we can't be there to observe the operation.

I have to second all that Gretch said- Those all went through my mind, as well. And I couldn't think of anything else. Let the mystery be unveiled.

geekapalooza

Ok – First off, sorry for posting an update so late. Saturday evening didn’t go well, and really just needed to totally walk away from it on Sunday and today, to recharge the batteries and keep the family happy!

Let’s see, er.. ummm…what are the lyrics of that Talking Heads song – “Same as it ever was”. Yeah - that’s it, or how about another Talking Heads song – “We’re on the road to nowhere”.

Yep - That fits the bill perfectly…

Hrer’s a recap of the install procedures:
1. Installed TB with old original (proven good) tensioner roller, new arm pivot bolt, new bushings, and new tensioner roller bolt and nut.
2. Left the center TB cover off for observation purposes.
3. Adjusted belt tension to perfection.

Results / Observations:
Upon cold start, belt was still-hunting fore and aft on the cam gears (not off to a good start). With the center TB cover off, you can actually see the gyration around the entire lap that the belt makes. Much more noticeable on the bigger cam gears though. The tensioner roller was steady and true, with the belt riding on it well. The front edge of the belt was just riding on the front edge of the tensioner roller.

The belt was a tad bit looser in the Kempf tool window after checking the tension when the engine was warm, thus the tensioner was apparently doing its job well.

The Water Pump pulley started to get extremely hot, very rapidly. It appears that the other gears (cams / oil) started heating up as the belt got heated up, and transferred the heat. The water pump touches the entire smooth side of the belt (no groove in pulley), and was much much hotter than all other gears, including the tensioner roller! Hence it apparently is the “conductor” of all of the heat in the belt. After 4 or so minutes of idling, heat and / or stress then induces the dreaded moaning noise. The improvised stethoscope (screwdriver) indicated the noise to be from the water pump. The WP pulley feels so hot you cannot touch it for more than about a second or so. This can’t be healthy for the belt?!

Ok – So the belt is getting cooked from the water pump apparently, and the pump apparently is the culprit in the moaning noise. BUT the pump pulley turns very smooth and true - so what would cause the hunting of the belt?? It never did this before. I did notice the belt rides on the very front of the water pump pulley with a gap in the back side of the pulley, if that has anything to do with it.

Also – What would cause the water pump to do this in the first place– it’s a brand new PCNA rebuilt. Could UPS have used the package as a football? Here’s a hypothetical – Let’s say there was an air pocket around the impeller, and it was dry. Would no coolant around the impeller cause the heating / moaning? Or does the WP not rely on coolant for cooling or lubrication? And yes, I filled the block with 50/50 dexcool coolant to the top via the upper radiator hose, then the radiator was filled via the lower rad hose. Filled the coolant overflow and burped it squeezing both radiator hoses. I did notice when filling the block that no water came out the lower hose fitting, I’m guessing that was due to the T-Stat being closed though?

The belt stayed good-looking, no scuffs, scrapes, etc. The WP pulley turned so true that it looked like it was sitting still – but it wasn’t.

When manually turning the crankshaft, the TB moves about 3/64ths of an inch fore and aft on the pass side cam gear – not much. No variance on the drivers side when manually turning the belt. You can definitely see the hunting on both cam gears when engine is running, more so on the pass side cam gear. It appeared to be much more variance on both when the engine was running – overall.

Where to from here?

Thanks

ErnestSw

Don't know, but a couple of observations.
You wouldn't be the first person to have a newly rebuilt water pump fail. The moaning noise is probably either from the water pump bearing, or the plastic impeller rubbing against the aluminum block. My guess is the bearing because of the heat issue. In any case you're going to have to remove the water pump, so it remains to be seen what the problem is. The uneven heating of the belt COULD somehow be involved in the runout that you're seeing.
We're all with you until it's done.

H2

Offhand, it doesn't seem apppropriate that the water pump pully would get so hot so quickly. What if you were really pushing the car with high revs? It might boil the coolant! Plus all that heat is going to lead to a premature failure of a couple of items. Sounds like you may have a bum water pump. Not good news, I know.

Harvey

Garth S

Yes, the pump must come off.
For what it may be worth, when my pump failed, the shaft tilted enough to make the TB track to the front of the pulley, to chew the front belt edge off, and to allow the inpeller to touch the block. Because the impeller was plastic, the press fit/keyway(?) failed , and the impeller jammed against the block. This led to a most rapid temp increase. If the impeller were cast iron, I doubt it would have become loose - rather it would have had an aluminum lunch from the block face.
It is unlikely that anything so severe is occurring on your car, but the beginnings may be there.

T_MaX

I don't blame you for walking away! It take a big person to take a walk and a deep breath. It sure saves on paint and glass work

Sounds like you did everything right! The walking belt issue should be left up to the pro's IMHO, maybe someone from DEVEK, 928 intl or 928sp will ring in there thoughts. But 3/64th sure doesn't sound that bad (again, JMHO).

As far as the WP, My thinking is the same as the others. I'm sure if you bought it from one of the big 3 they would be more than happy to provide a replacement!

Burping the air can be tricky and everyone has their own way. I loosen one of the Temp. sensors (till it's just sitting in the hole) that sits on either side of the upper rad hose while filling. When coolant comes out, I tighten it back up.

Gregg K

You found it.
There's no way that pump should get too hot to touch. And the lack of water would not be a problem. We don't know what is happening. But it's not a lab experiment. Yet. Do a swap, and see what the next pump does.
I was terrified that by not having the covers on, the belt might come completely off. Phew.
Out of curiousity, it might be interesting to compare pumps. Get the new one and old one side by side. Measure the overall distance from the inside of the flange to the outtermost impeller. And also see what the bearings feel like.
Weird.