Continuous Water Pump Issues, Really Need Help!
Burning Brakes
Joined: Feb 2022
Posts: 818
Likes: 235
From: Bakersfield, CA
@98CorvetteTas I am certain that our vehicles' water pump rotates in a counter clockwise position based on my research and some information found here on CF. But if you want to make sure, Google is your friend, plug in ...what is water pump rotation for 1998 corvette. There is also a write up on LS1Tech forum. Look up the parts numbers on Rock Auto and it will tell you the rotation as will other vendors' web sites. Good luck. Cheers!!!
@jim993 Ha you beat me to it my brother. Happy vetting cheers!!!
@jim993 Ha you beat me to it my brother. Happy vetting cheers!!!
Burning Brakes
Joined: Feb 2022
Posts: 818
Likes: 235
From: Bakersfield, CA
I forgot to mention that a forum member had posted a pdf file of corvette part number for various years which is a wealth of information. Some parts list not only the OEM number but also an AC Delco number where appropriate.
Edit: also if you want a copy of that file LMK itis a wealth of information
Edit: also if you want a copy of that file LMK itis a wealth of information
Last edited by snaitaz@aol.com; Sep 27, 2023 at 08:52 PM.
Burning Brakes
Joined: Feb 2022
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From: Bakersfield, CA
Thread Starter
Cruising
Joined: Sep 2023
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Thread Starter
Cruising
Joined: Sep 2023
Posts: 14
Likes: 2
@vette4fl @jim993 @snaitaz@aol.com I want to thank you guys for all of the helpful advice and information. You guys don't know just how much I appreciate it. The pump started making noise today so I'm now pretty much certain that it is indeed the issue. I'll be talking to the mechanics again in the coming days to hopefully iron out exactly which pump will be going on the car next and when it can be done. I'll keep you guys updated.
No Hostility Be Happy
Joined: Aug 2018
Posts: 10,082
Likes: 7,398
From: South Hill Wa
2022 C5 of the Year Finalist - Modified
2021 C5 of the Year Finalist - Modified
I'm just talking out of my butt here.
I can't say I've ever seen a standard rotation water pump in any factory serpentine accessory drive system in my life. Maybe there is a design out there somewhere, but in a C5 it turns opposite the crank.
There are over 2 dozen leak points for coolant in a c5 engine bay alone. I'm wondering if you have something else going on besides the water pump problems. Especially if you are constantly smelling coolant.
LS water pumps are known for being kind of junky, and NAPA is not the same company of years past. I have had very good luck with Autozone LS water pumps.
People often ask me why I have never changed the original factory water pump in my 97. Even after having the engine apart multiple times for mods and then an actual engine replacement I still have the stock original pump in there. Why? because it's not made in Chi NA, it doesn't leak, and it works.
I can't say I've ever seen a standard rotation water pump in any factory serpentine accessory drive system in my life. Maybe there is a design out there somewhere, but in a C5 it turns opposite the crank.
There are over 2 dozen leak points for coolant in a c5 engine bay alone. I'm wondering if you have something else going on besides the water pump problems. Especially if you are constantly smelling coolant.
LS water pumps are known for being kind of junky, and NAPA is not the same company of years past. I have had very good luck with Autozone LS water pumps.
People often ask me why I have never changed the original factory water pump in my 97. Even after having the engine apart multiple times for mods and then an actual engine replacement I still have the stock original pump in there. Why? because it's not made in Chi NA, it doesn't leak, and it works.
Le Mans Master
Joined: Feb 2021
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From: Florida
2025 Corvette of the Year Finalist - Unmodified
2024 C5 of the Year Winner- Unmodified
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The coolant reservoirs are known to sprout tiny cracks as they age and can seep fluid.
I’m about to change out my pump and hoses, just because they’re all original 2004, and also the reservoir because of that reputation.
I’m about to change out my pump and hoses, just because they’re all original 2004, and also the reservoir because of that reputation.
No Hostility Be Happy
Joined: Aug 2018
Posts: 10,082
Likes: 7,398
From: South Hill Wa
2022 C5 of the Year Finalist - Modified
2021 C5 of the Year Finalist - Modified
I agree V4fl. The tanks can be very problematic especially in cars with a high amount of heat cycles and age on them.
Thankfully water pumps are incredibly easy to change on these cars. For such a cramped engine bay it can be done in under an hour.
As replacement car parts quality have continued to decline in recent years we're going to see the preemptive and preventative parts replacers get bit in the butt by junk parts causing more problems than if the original parts had been left in place.
Thankfully water pumps are incredibly easy to change on these cars. For such a cramped engine bay it can be done in under an hour.
As replacement car parts quality have continued to decline in recent years we're going to see the preemptive and preventative parts replacers get bit in the butt by junk parts causing more problems than if the original parts had been left in place.
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Race Director
Joined: Oct 2004
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I believe heat cycles are as bad, or worse than, age alone. Even though I know they're not cheap, Edelbrock makes a great water pump for the LSx engines. I paid a bit over $300.00 for mine 9 years/50,000 miles ago. Absolutely no issues. They advertise them as having about 20% more low speed flow than OEM, with stock flow at high RPM. Plus, they're rebuildable. Just thought I'd throw this out there, FWIW...
Race Director
Joined: Oct 2004
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Remove both belts BEFORE spilling any coolant on them. Put them on the bench, wherever. If you spill enough coolant them, your belts will squeal like you wont believe. I ruined both of my under 15,000 mile belts by getting them soaked good with Dexcool. Tried brake cleaner, carb cleaner, even belt dressing. NOTHING helped. Car sounded like a flock of seagulls under the hood. Embarrassing big time, because everybody looks when you drive by, to see what the Hell is making all that noise!!!
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
Wow, talk about making things confusing. If this is indeed the case and they have been ordering parts that are substitutes for 251-744 it could explain all of my issues. Regardless of brand if they're spinning the wrong way they're going to be destroyed eventually. So you're 100% certain that my pump spins counter-clockwise from the factory? I'll make sure that they pay attention to that when ordering if that is the case.
Thread Starter
Cruising
Joined: Sep 2023
Posts: 14
Likes: 2
I agree V4fl. The tanks can be very problematic especially in cars with a high amount of heat cycles and age on them.
Thankfully water pumps are incredibly easy to change on these cars. For such a cramped engine bay it can be done in under an hour.
As replacement car parts quality have continued to decline in recent years we're going to see the preemptive and preventative parts replacers get bit in the butt by junk parts causing more problems than if the original parts had been left in place.
Thankfully water pumps are incredibly easy to change on these cars. For such a cramped engine bay it can be done in under an hour.
As replacement car parts quality have continued to decline in recent years we're going to see the preemptive and preventative parts replacers get bit in the butt by junk parts causing more problems than if the original parts had been left in place.
Thread Starter
Cruising
Joined: Sep 2023
Posts: 14
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One thing I recommend is buying a quality NEW pump, NOT a reman. Get either the pump I mentioned, Edelbrock, or a genuine GM pump. One IMPORTANT TIP:
Remove both belts BEFORE spilling any coolant on them. Put them on the bench, wherever. If you spill enough coolant them, your belts will squeal like you wont believe. I ruined both of my under 15,000 mile belts by getting them soaked good with Dexcool. Tried brake cleaner, carb cleaner, even belt dressing. NOTHING helped. Car sounded like a flock of seagulls under the hood. Embarrassing big time, because everybody looks when you drive by, to see what the Hell is making all that noise!!!
Remove both belts BEFORE spilling any coolant on them. Put them on the bench, wherever. If you spill enough coolant them, your belts will squeal like you wont believe. I ruined both of my under 15,000 mile belts by getting them soaked good with Dexcool. Tried brake cleaner, carb cleaner, even belt dressing. NOTHING helped. Car sounded like a flock of seagulls under the hood. Embarrassing big time, because everybody looks when you drive by, to see what the Hell is making all that noise!!!
Thread Starter
Cruising
Joined: Sep 2023
Posts: 14
Likes: 2
I believe heat cycles are as bad, or worse than, age alone. Even though I know they're not cheap, Edelbrock makes a great water pump for the LSx engines. I paid a bit over $300.00 for mine 9 years/50,000 miles ago. Absolutely no issues. They advertise them as having about 20% more low speed flow than OEM, with stock flow at high RPM. Plus, they're rebuildable. Just thought I'd throw this out there, FWIW...
Race Director
Joined: Oct 2004
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Last edited by grinder11; Sep 30, 2023 at 04:33 PM.
Instructor
Joined: Nov 2007
Posts: 167
Likes: 18
From: South East USA
Could it be over pressurizing ?
Maybe get reservoir cap tested/replaced...
I just replaced my reservoir and it came with a higher PSI rated cap. I opted to leave the original lower PSI cap on.
Just a thought.
Maybe get reservoir cap tested/replaced...
I just replaced my reservoir and it came with a higher PSI rated cap. I opted to leave the original lower PSI cap on.
Just a thought.
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
I'm almost certain that ADO-251-744 is the pump on my car right now which is not a remanufactured pump according to Delco. The NAPA pumps were not so surprising to see fail but the failure of this specific pump has me wondering of maybe there's something else causing their failure. The belts have always come off before any coolant gets released but unfortunately by then they're already ruined from driving with the pump pissing out fluid.