Engine Noise--New Theory

[Guest]

I have been listening to every square inch of my running engine from top to bottom to try and figure where the heck that awful thumping noise is coming from. I have the mechanic's stethoscope jammed so far in my ear that I have an earache. Everything is normal sounding, everything, that is, except my AutoZone Delco-style alternator. Man, every part of that sucker screams with the scope, I mean loud, grinding, thumping noise. Especially at the rear bearing. Is it possible this thing is fixing to go out? I was thinking of running the engine for a few moments without a fan belt, or seconds actually, to see if this is the alternator is the culprit. Question, on a warm engine, how long can I run it without a belt, and thus without a water pump? I am at the point that I would just warm her up, turn it off, and cut the belt off to get an instant reaction. Sounds doable?

 

[DNK]

Just take it to Auto Zone and have them spin it up.
also Water pump ??

 

[Got_All_4]

Taking it to AZ is the best solution. However for an emergency repair to get me home, I once ran my TR3 when the fan belt broke by taking a knee high panty hose from my wife and some duct tape and mad a fan belt to only go around the crank pulley and the water pump. My point is that it does not take much to turn that water pump and you may be able to come up with something to run the pump. Than you would have all the time you would need to diagnose the problem.

 

[Brosky]

You could buy one of the link style emergency belts and just run it from water pump to crank and by pass the alternator.

 

[PeterK]

Moss sells a link belt that can be adjusted by removing links. For emergency/temporary use only (and alt testing).

My table saw uses a link belt that is used to reduce blade vibration. I wonder if they're one and the same i.e. can I used a table saw link belt on my TR?

btw - My totally remanufactured CarQuest alternator had me chasing a problem for a year which turned out to be the worn out alternator bearings. Not quite totally remanufactured. I used it as a core and purchased one (from a different rebuilder) with a lifetime warranty this time.

 

[DrEntropy]

Faen 'ell. Remove th' belt an' chime it up. You'll know INSTANTLY if it's quieter or not. If it quiets down, the alternator or th' water pump are the guilty party.... and if you hear "screaming" with a 'scope from the alternator it's a "lead pipe sinch" THAT's yer culprit.

 

[Got_All_4]

I case you don't know your alternator will free spin until the voltage regulator calls for more juice. The the regulator sends voltage to the exciter wire and then there is a load on the bearings as the engine turns the shaft.

 

[MGTF1250Dave]

I agree with the Doctor. You will have some natural circulation even with out the water pump turning. Some pre WWII era cars did not have water pumps and relied on thermal natural circulation to keep the engine coolant moving. I expect you can run the engine for several minutes with out over heating, even longer if you have an electric fan installed.

 

[Guest]

I case you don't know your alternator will free spin until the voltage regulator calls for more juice. The the regulator sends voltage to the exciter wire and then there is a load on the bearings as the engine turns the shaft.

Huh? There is no alternator clutch on these cars. The thing turns all the time. Aren't you referring to something similar to an air conditioner compressor? Just curious.

 

[TheSearcherMan]

For pete's sake, just run it without the alternator belt for a minute and see if you don't have the noise. You guys would starve to death if you worked on cars for a living.

 

[Mickey Richaud]

For pete's sake, just run it without the alternator belt for a minute and see if you don't have the noise. You guys would starve to death if you worked on cars for a living.

Not really, if they charge by the hour! :wink:

 

[angelfj1]

Alternator clutch???
Just disconnect the wires going to the alternator, which will un-load it. Do this several time and listen closely to hear any change related to loading and unloading the alternator.

 

[Tinkerman]

Searcher, I got a hearty chuckle out of your comment. Thats what we would have done when I used to work on cars many years ago. Our stethoscope was a long screw driver, worked quite well as I recall.
I find myself over engineering as I work on my TR3. I suspect it's because we are doing it for ourselves and not for a living that we are so cautious. Your right we would starve to death if we did this for a living. But we aren't. Its a hobby for us. Recently I had the help of a vacationing professional mechanic with my car. We got quite a bit done. He just plowed ahead not considering all the useless angles that I consider. I ask questions on the forum, that, years ago I would have never asked. I knew the answer then, still do in most cases now, but now I want confirmation. Besides there is always someone out there that knows more than I do, so quite often its a learning experience.

Regards, Tinkerman

 

[DougF]

I'd have to agree with the Doc. Over time I've gone all over the engine with the stethoscope, and all I've ever heard from the alternator is the brushes making contact.

 

[TR6oldtimer]

I use to test engines in junk yards and ran them without water, no problem. Just remove the belt, run it for a minute or so and you will know if it is the pump or alternator.

 

[swift6]

Wow, I'm agreeing with Searcher. Take the belt off and run it. You'll know if its the culprit in far less time than it would take to damage the engine or drain the bettery.

Also agree with Doc, if your hearin' screaming/groaning/thumping from the alternator already. You've found the culprit.

 

[Guest]

Nope, it wasn't the alternator. Dang.

 

[Tinster]

Nope, it wasn't the alternator. Dang.

<span style="color: #660000">Hey Bill !!

Maybe it's your water pump.
My brand new water pump makes a high pitched
squeel. Always did- right out of the box.

d </span>

 

[Brosky]

What does the timing chain cover sound like? Any thumping there?

 

[TheSearcherMan]

For pete's sake, just run it without the alternator belt for a minute and see if you don't have the noise. You guys would starve to death if you worked on cars for a living.

Not really, if they charge by the hour! :wink:

Well, they charge somewhat by the hours, not actual hours. HOWEVER, they pay mechanics on commission at dealerships. The auto manufactures have their own books that tell how much time they are willing to pay to fix their problems... This is why I don't do auto repair for a living. The ONLY way to make any money at dealerships, as a mechanic, is to steal it, in other words, sell, sell, sell, if they need it or not. If you don't do that, you will starve. Same is true for HVAC repairs, if you are not a thief, you are "not a team player". You, being decribed in Timothy as an "overseer", are well aware of the state of the world these days, as described in 11 Timothy, 3:2 Cheers