Best water pump for 3800 v6
- Thread starter easym
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Nothing wrong with the GMB water pump. GMB says to turn it by hand after filling the coolant before installing the belt and starting the car for the first time after installing it 
If you feel like spending the money, the OE GM water pump is still available.
Whatever water pump you get, don't use the gasket that comes with it. Get a Fel-Pro gasket. You should also replace the bolts. Dorman has a set of bolts for the WP.
To drain the coolant from the knock sensors like GM says, you will need an oxygen sensor socket like this. Make sure the engine is cold, like first thing in the morning cold, or else the knock sensors won't come off without damaging them. They use a tapered thread with some loctite on the threads.
Also this. Get aftermarket metal elbows, if they haven't already been replaced by now. The O-rings that come on the metal elbows suck, so you will have to swap them with OE O-rings.
If you feel like spending the money, the OE GM water pump is still available.
Whatever water pump you get, don't use the gasket that comes with it. Get a Fel-Pro gasket. You should also replace the bolts. Dorman has a set of bolts for the WP.
To drain the coolant from the knock sensors like GM says, you will need an oxygen sensor socket like this. Make sure the engine is cold, like first thing in the morning cold, or else the knock sensors won't come off without damaging them. They use a tapered thread with some loctite on the threads.
Also this. Get aftermarket metal elbows, if they haven't already been replaced by now. The O-rings that come on the metal elbows suck, so you will have to swap them with OE O-rings.
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- May 16, 2022
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All I know from me and all my friends that we all owned a 90's GM with that 3800. When putting that new water pump one back on ( or even taking it off , been so long I can't remember but you got that one long aluminum bolt and I hope you don't hear like me and and ALL my buddies got that "PLINK" sound as the long bolt snaps in half and then you get that terrible feeling ol crap what did I just do and what do I do now?
We all found out that GM will actually run fine minus that long bolt... LOL
We all found out that GM will actually run fine minus that long bolt... LOL
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- Feb 6, 2025
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- 654
I bought the genuine GM from RockAuto.
I second the GMP pumps as an excellent optionNothing wrong with the GMB water pump. GMB says to turn it by hand after filling the coolant before installing the belt and starting the car for the first time after installing it
If you feel like spending the money, the OE GM water pump is still available.
Whatever water pump you get, don't use the gasket that comes with it. Get a Fel-Pro gasket. You should also replace the bolts. Dorman has a set of bolts for the WP.
To drain the coolant from the knock sensors like GM says, you will need an oxygen sensor socket like this. Make sure the engine is cold, like first thing in the morning cold, or else the knock sensors won't come off without damaging them. They use a tapered thread with some loctite on the threads.
Also this. Get aftermarket metal elbows, if they haven't already been replaced by now. The O-rings that come on the metal elbows suck, so you will have to swap them with OE O-rings.
I had older gen II 3800's, but had no issues with whichever Duralast pumps that were sold at Autozone at the time. Granted I only put on a few tens of thousands of miles after that before getting rid of those vehicles.
I had no issues getting the bolts out, nor reusing them or using the included gasket. Don't recall using sealant either - but it's been a while, it's possible I did.
I had no issues getting the bolts out, nor reusing them or using the included gasket. Don't recall using sealant either - but it's been a while, it's possible I did.
It is pretty difficult to mess up manufacturing a water pump. When in doubt , you can't go wrong with an OEM pump if available.
Pretty hard to be mad about $22 free shipping on Amazon for the GMB..
https://www.amazon.com/GMB-130-1780-Replacement-Water-Gasket/dp/B000P4S8UA/ref=sr_1_1?crid=34MQ4SGNJV34C&dib=eyJ2IjoiMSJ9.nTk7RX4JlPtWgB7-NaOw7EFZ_-pSkwUzD17-Shm5QoH-6TkSDXrP3MH8ALo7ErSZI77dE2PaXiN_icV65Yzip_OfgKNmQo1bVNOA3uvJXp3-eTcDfEUSWrQtYp1kywM1tJOAmxuxzJ92PUFVF7XM3nqgFDZvbaR6lkek_bBDkk_1qg8Fm_Bc8cY1b6UBBLjNceYLyxanOyCMQ2cjUqYUexHT36doqeKPl2Wn69XG8kw.ubuv6-58n9T2DHI3guM8L_iKujvkyCpR_in2oiqwG-0&dib_tag=se&keywords=GMB+130-1780&qid=1773229878&sprefix=gmb+1301780,aps,455&sr=8-1
GM Genuine is $87
https://www.amazon.com/ACDelco-251-718-Original-Equipment-Gasket/dp/B0016IDG1A/ref=sr_1_1?crid=3GPSKUZDOLMJA&dib=eyJ2IjoiMSJ9.eAaMo93qa-n_CArVBBi5QDyGg_YQNWnGrANEnwYHbvlveGvKPbCo_zbFzmvr4qhKIipiecMjF5JLuezPmeBzmbYGDK10cqJshJNKc1UkL0TxtwEoVEcjvXcPylSVz3YBQT0m7_JAmzE6_wzYfgikWw.xHEG8Sf3IuB8pP6Lxdb4j3fA0hsuGg9nf-esmyqhWGU&dib_tag=se&keywords=251718&qid=1773229991&sprefix=251718,aps,330&sr=8-1
Interesting the OE comes with a metal gasket. When you search for just gaskets I guess they are different depending on whether or not the pump is stamped "metal gasket only"
https://www.amazon.com/GMB-130-1780-Replacement-Water-Gasket/dp/B000P4S8UA/ref=sr_1_1?crid=34MQ4SGNJV34C&dib=eyJ2IjoiMSJ9.nTk7RX4JlPtWgB7-NaOw7EFZ_-pSkwUzD17-Shm5QoH-6TkSDXrP3MH8ALo7ErSZI77dE2PaXiN_icV65Yzip_OfgKNmQo1bVNOA3uvJXp3-eTcDfEUSWrQtYp1kywM1tJOAmxuxzJ92PUFVF7XM3nqgFDZvbaR6lkek_bBDkk_1qg8Fm_Bc8cY1b6UBBLjNceYLyxanOyCMQ2cjUqYUexHT36doqeKPl2Wn69XG8kw.ubuv6-58n9T2DHI3guM8L_iKujvkyCpR_in2oiqwG-0&dib_tag=se&keywords=GMB+130-1780&qid=1773229878&sprefix=gmb+1301780,aps,455&sr=8-1
GM Genuine is $87
https://www.amazon.com/ACDelco-251-718-Original-Equipment-Gasket/dp/B0016IDG1A/ref=sr_1_1?crid=3GPSKUZDOLMJA&dib=eyJ2IjoiMSJ9.eAaMo93qa-n_CArVBBi5QDyGg_YQNWnGrANEnwYHbvlveGvKPbCo_zbFzmvr4qhKIipiecMjF5JLuezPmeBzmbYGDK10cqJshJNKc1UkL0TxtwEoVEcjvXcPylSVz3YBQT0m7_JAmzE6_wzYfgikWw.xHEG8Sf3IuB8pP6Lxdb4j3fA0hsuGg9nf-esmyqhWGU&dib_tag=se&keywords=251718&qid=1773229991&sprefix=251718,aps,330&sr=8-1
Interesting the OE comes with a metal gasket. When you search for just gaskets I guess they are different depending on whether or not the pump is stamped "metal gasket only"
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I've used GMB on many engines. So far, so good. They are built well IMO.
Looking at old Dodge Magnum applications (3.9/5.2/5.9) it looks like O'Reilly's house brand MasterPro is actually GMB.
Ironically I've had their "better" Murray leak profusely in under 8k miles, so in the future for quick availability I'll be at least handling the MasterPro stuff. In the application above the pics actually show "GMB" cast into the body
Useless trivia.....
Oem. Ac Delco
GM Genuine, sure. Basic AC Delco, no.
Anyway for shizzles & gizzles I called up the Masterpro pump for an '07 LaCrosse with 3.8. Here again looks like GMB. Retail $42, commercial $36. @GMBoy
I used a GMB about 9 years ago on my old 3.9l Dakota, I put about 70k miles on it and my buddy owns the truck now, still works fine.
I stay away from at all cost, Gates. Had to replace the last one on my kids Mazda Protégé in less than 6k miles. You have to remove the timing belt to replace it, never again. Such a pain