1994 bonneville serpentine belt water pump

bobs77vet

bobs77vet

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one of my DD a 94 bonneville 3.8l v6 has gotten noisy and investigation revealled that the serpentine belt has slipped....and there is some smell of antifreeze and no fluid in over flow tank......i put the belt back on properly but it immediately slipped off again and into riding on the engine side of the pulley like it did before.....is this a classic sign of a bad water pump? or does a damaged serpentine belt always ride off? thks bob
 
When there is no tension on the waterpump does the pulley seem like it's got play in it?

When you say "the serpentine belt has slipped" there should be a tensioner pulley to allow constant tension on the belt, I wonder how it's slipping, unless it has stretched over time.


If anything, if the belt is worn, try a new belt.


Along the firewall, does there seem to be a dry or wet spray of antifreeze to give an indication that the waterpump is starting to leak. The antifreeze will probably splash off of the power steering pump up against the rear firewall.
 
if it is like the 3.8 in my 97 camaro there are plastic elbows betwen water pump and intake that crack. the belt tensioner is expensive .. well if it is the buick 3.8
 
Maymyvetteliveforever said:
When there is no tension on the waterpump does the pulley seem like it's got play in it?

When you say "the serpentine belt has slipped" there should be a tensioner pulley to allow constant tension on the belt, I wonder how it's slipping, unless it has stretched over time.


If anything, if the belt is worn, try a new belt.


Along the firewall, does there seem to be a dry or wet spray of antifreeze to give an indication that the waterpump is starting to leak. The antifreeze will probably splash off of the power steering pump up against the rear firewall.
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yes their looks like a fine spray of fluid and the round pulley on the water pump that has no grooves in it seems wobbly. i dont know how the belt is slipping either but it seems to move off of the grooved pulley some how and rides back closer to the engine and starts rubbing on the engine and the side of the belt is distengrating. the belt is $33 and water pump is $32. the tensioner seems like it exerts the right amount of pressure


JeffP1167 said:
if it is like the 3.8 in my 97 camaro there are plastic elbows betwen water pump and intake that crack. the belt tensioner is expensive .. well if it is the buick 3.8
Click to expand...

i did replace the elbow with a metal one last year sometime
 
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bobs77vet said:
Maymyvetteliveforever said:
When there is no tension on the waterpump does the pulley seem like it's got play in it?

When you say "the serpentine belt has slipped" there should be a tensioner pulley to allow constant tension on the belt, I wonder how it's slipping, unless it has stretched over time.


If anything, if the belt is worn, try a new belt.


Along the firewall, does there seem to be a dry or wet spray of antifreeze to give an indication that the waterpump is starting to leak. The antifreeze will probably splash off of the power steering pump up against the rear firewall.
Click to expand...


yes their looks like a fine spray of fluid and the round pulley on the water pump that has no grooves in it seems wobbly. i dont know how the belt is slipping either but it seems to move off of the grooved pulley some how and rides back closer to the engine and starts rubbing on the engine and the side of the belt is distengrating. the belt is $33 and water pump is $32. the tensioner seems like it exerts the right amount of pressure


JeffP1167 said:
if it is like the 3.8 in my 97 camaro there are plastic elbows betwen water pump and intake that crack. the belt tensioner is expensive .. well if it is the buick 3.8
Click to expand...

i did replace the elbow with a metal one last year sometime
Click to expand...

there are 2 of them though
 
The antifreeze spray is usually and indication of a pending waterpump failure. If it's not a SSEi, meaning non S/C then they're not that difficult to change. If it's supercharged then add another 1.5 hrs to the swap, since there are more parts to remove.

If the waterpump needs to be changed than I would do so and recheck for belt slippage. If all pullies are inline then it shouldn't slip. Most of the pulleys have grooves in them anyway.
 
bobs77vet said:
well i guess i have some exploring to do tomorrow am[/QUOT[/I]

When I did the tension new on my 3.8 the old one was very weak and would hangup in certain positions. That is probably what your problem is, also change the idler pulley that is by the tensioner.
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well it was the water pump pulley bearing, the bearing was totally shot and the pulley was actually wobbling. its amazing that the water pump never started leaking wildy and had a castastrophic failure...... what a PITA to change .....had to take 1/2 of the motor mount out and loosen all of the motor mount. probably one of those jobs that if you had done it once before it would have been a piece of cake . probably took me 2.5- 3 hours of which 1/2 hour was putting it back in and finishing it up.
 
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bobs77vet said:
well it was the water pump pulley bearing, the bearing was totally shot and the pulley was actually wobbling. its amazing that the water pump never started leaking wildy and had a castastrophic failure...... what a PITA to change .....had to take 1/2 of the motor mount out and loosen all of the motor mount. probably one of those jobs that if you had done it once before it would have been a piece of cake . probably took me 2.5- 3 hours of which 1/2 hour was putting it back in and finishing it up.
Click to expand...

Is yours FWD? Mine looks very simple to replace.
 
JeffP1167 said:
bobs77vet said:
well it was the water pump pulley bearing, the bearing was totally shot and the pulley was actually wobbling. its amazing that the water pump never started leaking wildy and had a castastrophic failure...... what a PITA to change .....had to take 1/2 of the motor mount out and loosen all of the motor mount. probably one of those jobs that if you had done it once before it would have been a piece of cake . probably took me 2.5- 3 hours of which 1/2 hour was putting it back in and finishing it up.
Click to expand...

Is yours FWD? Mine looks very simple to replace.
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yes FWD

most of the time was trying to figure how to move the motor mount out of the way, it had a stupidly placed stud that prevented me from taking it out, i was only able to move it over to the side and then it would hang up on the radiator hose clamp.

there were two long water pump bolts that were buried in the motor mount housing and you couldn't take the bolts out with screwing with the motor mount.
 
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Maymyvetteliveforever said:
Glad to read it worked out Bob, is your Bonne S/C'd?
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not quite....a hand me down from my 89 yr old god mother....a couple of yrs ago with 59k on it. so i decided that my 16 yr old son and i would share that car and its been a DD ever since....the car has an invisible force field around it, no matter where i park it doesnt get any door dings. my son will drive it to work this summer and i will use another one of my cars for work. the goal with this car was to do all the maintenance on it ourselves and not spend a dime more then was necessary to keep it running, kind of a test to see if i still had it or if i had gotten to old and soft....i have to tell you its a dream to drive my 6 miles to work in it never going over 25 MPH.....its like being in your living room sitting on a couch, bumps what bumps...and when the kid needs a car in college it will go to him. i believe strongly that children get hand me down cars, and if they want a new one they can open up their wallet.
 
in a Fbody it's very simple to replace water pump and tensioner, lotsa room if it's RWD....

years ago I had a small leak on one of these stupid plastic ellbows and it took me a while to figure out why the belt kept flying off the pulleys ....

did you replace the pump and the tensioner ? might as well while you have access
 
I've owned Bonnevilles for over 20 years a 90 SSE and presently a 97 SSEi and I love them. With the exception of the intake manifold gasker problems which in my case I already replaced, I've found the 3.8 ltr a strong motor.


Mayyourbonneliveforever.
 
i agree the motor is strong this one consumes some oil, doesnt smoke or anything and doesnt leak just a half qt or so every 1000 miles, doesnt matter the grade or dino or synthetic, and i have receipts for oil changes every 3000 miles or annually which ever is less...the tensioner looks ok and has lots of tension on it what is a sign of it going bad? it didnt seem to have any wiggle or play in it. the tensioner has easy access and sits on top in plain view
 
When a tensier starts to go bad you will start to hear a sort of squeel or bearing type noise same as you would in an alternator. Sometimes if it's really bad it will start to shake since the bearings in side are moving around too much. I normally check them by using the stethescope.

Keep in mind the thread on the tensioner is reverse thread.
 
Maymyvetteliveforever said:
When a tensier starts to go bad you will start to hear a sort of squeel or bearing type noise same as you would in an alternator. Sometimes if it's really bad it will start to shake since the bearings in side are moving around too much. I normally check them by using the stethescope.

Keep in mind the thread on the tensioner is reverse thread.
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i dont know if i have enough balls to put my hands that close to those spinning belts.....its like the first time at 16 and using a timing light and you hit the fan....that makes you come alive fast....
 
the tensioner spring sometimes gets weak... or the bearing makes noise.... I would change it with the water pump and a new belt just for piece of mind knowing you won't have to work on this again anytime soon..... if i remember right the tensioner is like $40 .... in the past I've had to do stuff over again because of shortcuts, so now I got converted to a "do it right, do it once" guy...

one problem I had with the 3.8 V6 was the ignition module and the three coil packs: the supersmart GM engineers placed them where they get heat from the header underneath and water from the cowl above... :smash:
 
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