348 water pump question

So, I pulled my engine to do the belt service and decided to put a new water pump in while apart. I noticed before I installed it a few differences from the original, one is now haunting me. First, the entire assembly is made out of aluminum, even the impeller. Looks better and higher quality, however when I turned the pully, I noticed that the back of the pully, closest to the housing was out of round by about 1/8". The shaft is not bent but when I rotated it, you could see, in reference to the housing that it seemed lobed. Like an idiot, I installed it without thinking. I am going to call the parts dealer this morning for advice but I am wandering if I should pull it off and get another one or try to straighten it a little better myself. Any thoughts??

 

I would say absolutely not. Since the timing belt rides on this pulley, its straightness is critical and I would not play with it. Ask for a replacement or, if you cannot get a replacement because you installed it, just forget it and buy another one.

 

Awesome, thats what I wanted to hear. Thank you

 

that seems awfully weird.

 

We have seen various quality issues with those aluminum with the vortex type impeller. The impeller is cast and some have had casting cracks, if that impeller lets lost a chunks and jams the water pump all sorts of horrific damage can ensure I have one, in the end I put my old pump back as it was a few years old and did not use the newer more efficient design version.

As far as straightening it your self that will never happen to a degree required. Ether way pull it off, I did the same thing, after thinking about the water pump I removed the belt and put the old one back on, but for a different reason than you.

 

1st, buy from quality place like Ricambi and that will reduce issues. WP rebuilds are easy but still the builder needs to have a brain. They can be screwed up easily. There are no new WP's as far as I know so everything is rebuilt. The most critical thing is for the impeller to not hit the housing. sounds obvious but you better check. I have had rejected pumps because of that. I put clay on the blades to measure the gap to the body. I'm looking for about 3/4 to 1mm of gap. If you don't check with clay at least install and spin to make sure it spins free. The impellers need to spin true while probably not a problem wobbly impellers increase cavitation potential. I'm not sure why there is so much trouble with 348 WP. I never have issues with any other pumps over all the cars and car models I have worked on even Maseratis but the 348 pump that is super critical because the timing belt runs on it has the lowest number of successful rebuilds and lowest quality of rebuild that I have ever seen in a WP. On more than 1 occasion the old WP I removed was better overall than the rebuild I have received. Anyone working on 348's really needs to look closely at these replacement pumps.

 

Daniel does not sell the after market water pump anymore due to the quality issues. You can buy a rebuild kit from him, or a brand new pump.

 

Funny you mention....my car (355) had one of these pumps on it when I bought it, had been installed by the PO during the major only a few hundred miles before. Driving down the road at low speed, the shaft snapped and the pulley went flying. Thank god no damage to anything, but almost had a heart attack at the sound of the serpentine belt whacking the undertray (sounded like the engine was grenading). Why did the shaft break? No idea. Belts weren't too tight.

 

The dealer I bought it from is shipping me another one. We will see how it works out

 

Again, better off rebuilding the old one.

 

Glad I kept my old one for the next go around...

sjd

 

Hi there, what did you end up doing? I'm at the point in my rebuild where i need one also?

 

Sorry raising old topic, but I’m in the middle of major and replacing water pump. I have bought spare Superformance water pump like 4-5y ago but after checking these threads I think I’ll leave it out due to possible quality issues. (Very happy to be corrected)

So there comes my question; as of 2025, would you only buy original water pump or is Capristo water pump as good alternative?

As I’m within EU, sourcing parts is pita nowadays as no part sellers inside EU. UK is still the only source for parts but duties etc have to be paid.

 

I installed a capristo water pump in a 355, and it didn't last the trip out of the shop for a road test. Maybe they have improved since, but that was the first and last one I ever installed.

 

How about this company: 348 TS / TB / GTS / GTB / Spider

 

Goon info, many thanks! And I forgot to mention that this for 348.

 

I've also been wondering about the quality of the 348 water pump which AW Italian sells...

 

It looks very much like Superformance one, I decided to buy original one so I will leave Superformance one for spare. Just by turning it its quality looks fine, but also changing water pump is a major project. And most likely I’ll try to rebuild old one for spare.

 

Now you guys messed up my mind... I just bought a water pump from Superformance when collecting parts for the major but do I dare to have it installed or should I call it a loss and order a new OEM pump instead? I would expect someone here to have a Superformance one in their 348 or Mondial, and I would also think there to be heated comments if someone has had their engine go bang due to a faulty pump.

Judging just by pictures the Ricambi and Superformance pumps look the same to me. AW Italian also looks practically identical but the outside is polished and the pulley color is different. Difficult to know for sure if these are from the same manufacturer because all are no-name aftermarket products.

Additionally Maranello classic parts is selling the Capristo pump and does not stock the OEM. Capristo has a similar metal impeller as the no-name pumps but the other details are different.

 

Mikko, I haven’t heard any broken Superformance ones, just that ”there has been some probs with aftermarket ones” So I decided write down money spent on new Superformance pump and bought (IMO very expensive) original one, changing it is just so much work. And as you mentioned, interesting piece is as well that Maranello parts only have Capristo one currently.

 

I have put 1100 miles on my Superformance pump in the last year. I put loctite on the impeller nut. I did try to remove the plastic impeller from the old pump, but it cracked in half. It was 8 years old.

 

Hello everybody
Need to replace the water pump in my GTB
The old pump was not replaced the last time (10yrs ago)
So it has been in there 20+ yrs
Having a major done in Feb
Somebody can give an input on how there pump is doing?

 

I’ve put another 1000 miles on mine without issue.