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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
i'll try to make this as clear as possible, cause i wanna drive my dam car.
it's a 1989 caprice classic, so it has the reverse rotation pulley system
i've gone through two waterpumps in the last two weeks. the original waterpump came off my 305, and it's been in use since i bought the car. i recently got the motor swapped, and i had about 8 days of fun with no issues.
i floored the car a few times, and put about 200 miles on the engine. it was mechanically sound, so, on the last day it ran, i drove it to work, and floored it when i got there. the car acted like the belt snapped, but it turns out my waterpump snapped off the block, leaving the mounts attached, destroying my rad, hood, fan, fan shroud. okay - the waterpump snapped like a hershey bar. it was just cheap, right? replaced everything yesterday, filled the coolant, got it to temp, revved it up, and cut it off. about an hour later, i started it back up. the idle seemed very high, so i tapped the pedal, and upon doing that, the new pump exploded, sending my pulley, clutch, and fan into my rad and simultaneously out of my engine bay, through my neighbors fence, into their yard.
i'm looking for opinions/facts here, and can share more info if needed. i just need to know what to change before i throw a third cooling system in.
is it the belt tension? i didn't use a tool to get the belt on, just my hands, though it did seem a little tight when the tensioner dropped on it.
is it the waterpumps being cheap? the original waterpump is a mystery, and the new pump was listed as new on oreilly's, so it shouldn't have been faulty.
i didn't change anything besides my motor oil after the swap, so i'm not sure why the car is doing this now.
Last edited by 3000iphones; 08-05-2022 at 11:34 PM.
I would start by checking the factory service manual for specification on belt tension and bolt torque.
I would check the alignment of the belt and all accessories, use a laser or something very exact so you are sure.
Then make sure you are using a high quality name brand pump from say rockauto.com, buy a top notch brand.
Tightness, torque, alignment, good parts. It should be the simplest thing on the engine to not explode. Very strange. Sorry for your trouble.
I'm suspicious that your pulley might be out of round, or wobbling or something. When I got my replacement water pump (reman), there were some leverage marks that deformed the mating surface of the pulley to the pump that I took a file to flatten out. I guess that could have happened to you but I'd think you'd notice it being really wrong for such a violent reaction.
I'm suspicious that your pulley might be out of round, or wobbling or something. When I got my replacement water pump (reman), there were some leverage marks that deformed the mating surface of the pulley to the pump that I took a file to flatten out. I guess that could have happened to you but I'd think you'd notice it being really wrong for such a violent reaction.
i should mention that before this new pump went in, i installed the same brand pump only to notice the hub on the pump was off, causing the pulley to wobble. obviously, i didn't crank it, and got a replacement. after installing the replacement there was no more wobble. the pulley and fan were spinning straight by hand. the initial start after the newest pump was installed was smooth, no wobbles. i'm confident in that, because i was feeling the upper rad hose when the fan was spinning, so i think i would've noticed any wobbles.
i'm not an expert, so i could probably do a more scientific test including the pulley, but it seems flawless.
Are you using bolts or studs for the WP pulley?
If they are too long and contact the WP casting at the back side of the hub, bad things can happen.
I suspect that the bolts/studs have just enough clearance when cold, but when the engine heats up, that clearance goes to zero and BOOM!
I would love to see a video of the explosion. If you have 3000 iphones - I'm sure you can sacrifice one of them.
The only thing that comes to my mind is, could one of your other belt driven devices (PS pump, Alternator, etc) be becoming stuck/jammed when you rev it, and be putting MAD tension on the belt, causing the weakest thing to snap?
Oh, and, even though it ain't a third gen F body, this is freakin weird enough that I don't mind the off topic, like No Emissions said I'd LOVE to see a video of it going "BANG!" just to satisfy my primal motorhead urges....
Are you using bolts or studs for the WP pulley?
If they are too long and contact the WP casting at the back side of the hub, bad things can happen.
I suspect that the bolts/studs have just enough clearance when cold, but when the engine heats up, that clearance goes to zero and BOOM!
I would love to see a video of the explosion. If you have 3000 iphones - I'm sure you can sacrifice one of them.
when i got the car the fan clutch and pulley were held on with two bolts and two studs. since i only had the two bolts when the first pump went, i went and replaced the studs, using teflon tape to make sure they didn't get too far in. the only way i could imagine the studs or bolts hitting is if the hub was seriously off track. looking at the broken off housing, it isn't scored at all, and the hub is still attached to the pulley and clutch. the bolts and studs aren't deep at all.
and, sorry for off topic. this issue is so strange to me, as the car went from running fine to doing this without being changed in any way. the pullies visually spin straight and freely, and the tensioner doesn't have any flat spots and has a smooth operation when being raised and lowered. i can imagine something stopping the system in it's tracks when i rev, but i wouldn't know how i'd figure which one is doing it.
The only thing that comes to my mind is, could one of your other belt driven devices (PS pump, Alternator, etc) be becoming stuck/jammed when you rev it, and be putting MAD tension on the belt, causing the weakest thing to snap?
Oh, and, even though it ain't a third gen F body, this is freakin weird enough that I don't mind the off topic, like No Emissions said I'd LOVE to see a video of it going "BANG!" just to satisfy my primal motorhead urges....
the pump that came with the car had two studs and two bolts holding the fan clutch on, so i replaced the two studs and used teflon tape when doing the new install. the waterpump housing isn't scored, and none of the bolts and studs moved in the hub. the bolts don't stick out, but the studs just slightly stick out.
as for the pulleys and accessories, all of the pullies look to be in good shape, and spin freely. the tensioner doesn't have any flat spots, and has a smooth operation when raised and lowered. i can imagine the belt being stopped in it's tracks, but i'm not sure how to figure which accessory it is.
sorry for the off topic, i just thought to post where a few people could see my problem. the explosion was very violent the second time around, so i'm sure it would've been a good video. the first explosion ripped my hood open above the fan
the pump that came with the car had two studs and two bolts holding the fan clutch on, so i replaced the two studs and used teflon tape when doing the new install. the waterpump housing isn't scored, and none of the bolts and studs moved in the hub. the bolts don't stick out, but the studs just slightly stick out.
as for the pulleys and accessories, all of the pullies look to be in good shape, and spin freely. the tensioner doesn't have any flat spots, and has a smooth operation when raised and lowered. i can imagine the belt being stopped in it's tracks, but i'm not sure how to figure which accessory it is.
sorry for the off topic, i just thought to post where a few people could see my problem. the explosion was very violent the second time around, so i'm sure it would've been a good video. the first explosion ripped my hood open above the fan
Just so you know, I do feel sorry for you with the repeated damage, I'm sure it sucks and I wasn't making a joke out of your situation
And, as to the off topic, like I said I don't have a problem with it. I've been a mechanic of cars, trucks, boats, and airplanes for over 50 years and I've never once seen a water pump literally disintegrate, let alone twice, so yeah I'm curious as Hell about what's causing such a dramatic failure. Back in the 1970s I had a starter on my Cadillac literally explode on a 5 degree January morning, of course I had no cellphone with a camera back then and there are still people who flat out don't and won't believe me that it happened without pics, but it's true, that poor starter turned into shrapnel with a bang that sounded like a shotgun
Please post up your finding when you arrive at a solution
i certainly haven't. does it make sense that a bad clutch could cause this?
i really want to drive the car, so i'm taking all suggestions. people have called the pumps themselves cheap, but what if i toss a $60+ pump in and get the same result?
it makes so much sense in my mind that maybe the belt is putting too much tension or downward force on the wooder pump pulley, causing either the shaft or housing to break, but it being a seemingly perfect tensioner, i'm afraid to only replace that and hope it all works. from what i remember, for my car/pulley system, the police package belt is like two inches longer, so i'm not sure if i could go with a larger belt or not. i could possibly try to find one that's like half an inch longer to create more slack?
i didn't try the "90 degrees" trick, and the belt seemed damn tight, but still possible to get it on by hand. would the pump really break before the belt? i'm so confused and curious over this.
edit: the clutch is perfect from a visual perspective, and allows the fan to keep the car very cool. the temps were doing great.
Last edited by 3000iphones; 08-07-2022 at 03:26 AM.
i just read a BMW forum post of a similar situation, and someone there said a failed bearing can be and is most likely the cause for a pump to grenade. i'm so afraid to replace only the tensioner and pump.. i might throw a spare waterpump my friend has in without a rad in case it explodes again.. if anyone has any additional advice or wisdom, i'd like to hear it.
longer belt?
new tensioner, pump, and pray?
i don't want to get the motor too hot, and i'll need at least two starts before anything happens
the final start only gave me about 5 seconds before it exploded. i couldn't even get out of the car in time to get hit by the flying pulley and fan
It's not my project, and it's not even an F-body. But if it were, I would be tempted to NOT install the the radiator fan shroud, and also use collars or spacers to eliminate the entire fan, then test run the engine without either installed. It should be able to run at least five minutes from a cold start without reaching any dangerous temperature. The heater could also be used to to cool the engine to extend that run time if needed, but five minutes should probably be long enough to observe the water pump and accessory drive system for any operational problems.
I had a power steering pump grenade in dramatic fashion once, culprit ended up being the unit had locked up so when the belt tried to spin it just pulled the whole pump apart and sent guts flying
I would try a slightly longer belt. That is the only item that is putting lateral force on the pump, so I would think it'd be worth a try?
It's not my project, and it's not even an F-body. But if it were, I would be tempted to NOT install the the radiator fan shroud, and also use collars or spacers to eliminate the entire fan, then test run the engine without either installed. It should be able to run at least five minutes from a cold start without reaching any dangerous temperature. The heater could also be used to to cool the engine to extend that run time if needed, but five minutes should probably be long enough to observe the water pump and accessory drive system for any operational problems.
not running the fan is a good idea, but if i do this, i either won't run the rad or i'll need to find a shield for it, because i have two banana shaped rads from this issue. i read that MAX 30 second run time is safe for a dry engine, so i don't think that'll help much. this issue is so stupid. i could do an electric pump and fans, but i wish i could just put that money towards my drivetrain
Personally I'd replace all the broken parts, and install a new water pump but no fan. Spin all the pulleys by hand, make sure they're happy. Fill it up with water so you get some cooling. I just can't see a water pump exploding due to belt tension alone, the fan and fan clutch are also suspicious components to me.
Personally I'd replace all the broken parts, and install a new water pump but no fan. Spin all the pulleys by hand, make sure they're happy. Fill it up with water so you get some cooling. I just can't see a water pump exploding due to belt tension alone, the fan and fan clutch are also suspicious components to me.
gonna make a few changes based on some advice from this forum and get it running. i threw "accident coverage" on the rad in case it gets turned into a banana, but i'm gonna hope it was as simple as it should've been from the start. gonna make sure all pulleys are spinning straight and lined up. there are multiple ways to run my serp belt, apparently, from google searching it, but i have a picture of my shroud's routing sticker, so i'll make sure it's the stock route. there shouldn't be any issues.
possible bigger belt if my belt seems too tight, new tensioner, no fan, no shroud, no wobbly pulleys, water in rad and run it
alright yall, thanks for helping my bbody havin ***. this should be my last post on this thread.
i was gonna just grab a junkyard fan and a relay kit cause i'm scared to death of a fan and clutch now, but since i already have a new fan coming in, i'm going to get a new clutch. the only thing coming off the old fan setup will be the spacer if i need it. does anyone think a fan clutch spacer is dangerous in any way for a waterpump?
i started it up a few times and the pump is still in tact. the pump is purple, so my engine is halloween themed for now
08-05-2022, 11:12 PM
