LionZoo

Sadly I'm only using the dummy temp gauge, so no I don't notice a difference. However I'm waiting on what Charles is going to say with baited breath.

LionZoo

Nope, every once in a blue moon I get the sound of one grain of sand at high rpms, but it's very quiet and very infrequent.

Charles R. Hill

iTrader: (7)

It's not anything of monumental proportions, really, just that when the Mazmart pump came out and people immediately bought it and installed it on their engines a few people noted that the engine seemed to warm up quicker. They took this to mean that the cooloing effectiveness was not as great with the Mazmart as with the factory pump, at low rpms. This posed a conundrum in the minds of many; worse cooling at low speeds versus cavitation at high speeds. However, that is not the case. The pump works fine and I recently asked others to note, rather than the shape of the fins, the shape if the center cone on the impeller.

Zephyrzone

Is that what this sound is? Cavitation at high speeds? I thought it was determined to be air in the coolant rushing through the heater core. And why doesn't everyone have this problem if it' a 'flawed' pump design?

My dealer is stumped. They claim to be working with Mazda to determine the source of the issue and I have to bring the car in next week again. My guess is they'll just flush the system or won't do anything. Looks like I'm getting closer to the Mazmart pump purchase...

zoom44

oh heheh i just told ozzygirl and railton to have their cars checked for trapped air. i hadnt been watching this thread for some time. good to see LZ has some relief

Charles R. Hill

iTrader: (7)

"Air in the coolant"=cavitation.

zoom44

yes yes

Charles R. Hill

iTrader: (7)

I brought this up a few weeks ago, and nobody seemed as intruigued by it as I was, but I'll ask others to again take a look not at the fins but the center cone of the Mazmart pump. This is a less-obvious aspect in the superior design of the Mazmart pump. The fins are a great upgrade but the center cone is equally responsible for the elimination/reduction in the likelihood of cavitation.

LionZoo

Well I still get very little marbles every once in awhile, but it's much improved and I feel the Mazmart pump was sure worth the money.

By the way, could coolant warming up quicker after installing the pump be due to the higher efficiency of the pump? After all it's the block that produces the heat; the coolant is merely a medium for heat transfer. A more efficient transfer device would mean that heat is transferred quicker (and in theory expelled quicker) and this could be why people are seeing faster warm up.

I'm also thinking about opening up the vents behind the oil cooler into the wheel well. Can anyone come up with a reason why I shouldn't? This is probably the wrong thread...

boanjangnararmine

i think you are describing the sound from the exhaust, not the glovebox area..

i have the same sound at around 4k rpm as well.. only after installed the rp supercat and hks legamax

Charles R. Hill

iTrader: (7)

LZ, Paul and I were discussing the very issue you mentioned; quicker warm-up times with the Mazmart pump. The theory is that the more efficient pump is eliminating hot spots that the Renesis may have. The rear rotor housing seems to run a bit hotter than the front and the thought is that the two housings may now be more equal in temperature. Quicker warm-ups times are better if that is, indeed, what is happening. For sure, equalized temps between the two housings is better.

Zephyrzone

This may very well be my own ignorance... but since the system is closed, and assuming there is no trapped air, I was under the impression that cavitation could not occur, regardless of which pump is in use. If I have a Mazmart pump or OEM, there shouldn't be any cavitation as long as there is no air in the system to begin with, right? I mean, neither pump can create air pockets in a system that is completely closed???

I'm very interested in this, seeing as how my car suffers from the issue. Thanks guys...

EDIT: I'm still a bit baffled as to why if the OEM unit is indeed flawed and causing this issue, why every owner isn't experiencing a problem. It seems to me that the OEM pump should either be inadequate therefore causing problems for everyone all the time...or it's something else.

Charles R. Hill

iTrader: (7)

Let me rephrase that, then; cavitation=the absence of fluid in certain spots.

zoom44

some peoples hearing is different. i have had noisy heater cores on several cars before- '89 honda accord and '65 mustang come to mind , those were loud an annoying. while i occasionally do hear some trapped air/cavitation in my 8 it isnt nearly as often or annoying as in those other 2 cars. is that different than other 8s? i believe some owners have more noise than others but i also believe its owners perception to a good degree.

muythaibxr

I have a bit of heater core noise on my rx8. It only happens when I first rev it up to about 3000-4000 the first time I start the car in the morning.

I figured it was pretty normal, and have had other cars that are the same.

Ken

CnnmnSchnpps

iTrader: (1)

Not air. Water vapor. The water pump creates localized low pressure zones where the water boils.

--edit--

Here's an interesting quote from Wikipedia (emphasis mine):

Zephyrzone

Again, I don't understand why all 8's don't have this. Unless I have some kind of super bat hearing and they all DO have this, I'm just one of the few that can hear it. Seriously though, sometimes it is awfully loud. The tech who went with me didn't want to go for a ride because he said "I can never hear that stuff." But he did hear it.

How difficult is the water pump to install? I saw a semi-DIY it looked relatively complicated. How many hours are we looking at?

CnnmnSchnpps

iTrader: (1)

All jokes put aside, I can actually hear bats as they chirp on by

Not sure why not everone gets this.. Coolant mixture? Variations from engine too engine? Not sure...

LionZoo

It's two hours to install and a relatively simple procedure. My own misgiving is that the sound is coming from behind the glovebox, but the water pump is on the front side of the block far away from the glovebox.

Design1stCode2nd

Mine still does it anytime over 6k rpm. It loudest first thing in the morning. Its been doing it ever since I bought the car. I wish Mazda would put out a TSB for it already and get it fixed.

6speed8

At 52K miles my car just developed that 'marbles in a blender' sound. On my car though, the sound is best heard by the passenger side rear tire well. It sounds like something is rolling around inside the exhaust pipe. Inside the car it sounds like it is coming from the glovebox area, but outside it is best heard by the right rear tire. Apparently is is quite noticeable from a distance too.

I am wondering if the catalytic might be fragmenting or a baffle in the muffler might have come loose. The noise can be reproduced in nuetral with the clutch in or out, and on my car is most noticable when first taking off (like the motion starts the 'marble' rolling'.

I remember reading a thread awhile back where someone's catalytic looked like it chunked up. I guess I will have to take the exhaust system down to verify.

F22C1

deng it my 06 at 6500 miles just developed 'teh sound'. It's starting to get colder now and was 40F when I just now noticed it.

It's exactly like everybody says, marbles in blender (or sandy road) sound from what is likely behind the passenger glove box area.

At first I thought it was maybe low gas since it was also when my gas light was on. Nope fill up didn't solve it.

I also noticed it only comes on at 7k to redline and progressively gets audible the higher up you go and same when revving down till 7. Can also pull this off in neutral to hear it longer if desired.

Never had it before. Now how do I get rid of it?? And are you sure it's the heater core and not the S-DAIS like some suspect? (and if it was stuck valves would that throw a CEL?).

MazdaManiac

iTrader: (3)

You folks still insisting that this noise is coming from the cooling system?

LionZoo

Considering before one afternoon it's there and the next afternoon it isn't and the only thing that I changed during the time was coolant mixture and my waterpump, yes I am apt to believe that it is my cooling system. Before I would get the noise quite often. Now the only time I get even a little bit of the noise is if I run my car hard less than 30 seconds after starting it up. Don't worry, the engine and everything is already warm, I just pulled over to admire the view.

rollerbldes

I had this, got cold air intake, now gone. Hope that helps.