Hey guys,

1350km now, since 1100km, I've started to up the RPM's and redlined several times. I use Shell V-power 91 only since I bought the car. I've added half a bottle of Castrol 5W-20 already to top up the oil. I'm now starting to get the "sand in a blender" sound. It's not as loud as marbles, but like fine sand. It happens from 5800pm and up all the way to Redline. I have the MS CAI. There is no power loss at any range.

I've done my research on the forum here and read up on all the issues related to marbles/sand in a blender. Yes it sounds like it comes from the glovebox side, passenger well lower area. I've heard it's related to some heater core issue getting air bubbles in there from the coolant?

Have you guys in GTA experienced that at all and do you guys have a solution?

 

I have that problem too. Although I'm not sure I'd classify it as a problem. A lot of people have that and if it was a real problem, it'd be TSB'ed by now. (Of course I don't keep track of TSBs, so maybe its already out!) Anyway, sometimes I get it, sometimes not. I rarely get it if I use Shell and if the car is warmed up for at least 1/2 hour. I find a lot of problems here aren't really problems until you start looking for it.

 

Engine was warmed up for at least 20 minutes of city driving before taking it up to higher RPM's....

I just hope it's not doing anything damaging to the engine.

 

Do you have a sound clip of it?

does it sounds like this?
https://www.rx8club.com/showpost.php...&postcount=120

 

I've seen that clip, that one sounds a lot harsher than mine. Mine is quieter, like sand or rustling, or cell phone static... yeah cell phone static.. at first I thought it was creating some EM interference with my FM radio, but when I turned that off.. then I turned the A/C off.. and then I turned the ventilation system entirely off (outside circulation maintained)... it's still there.

Then I searched here, and found some guy posted a youtube video of it

http://www.youtube.com/watch?v=bm3NcgTnmRk

Sounds more like this... This car is new too. Only 1350 km!

 

Hi footman, I have the same problem, kind of a crackling noise from the glove compartment, once in a while, usually when I start driving. Its annoying..

 

I have have that problem too. My car is a 2007 GT Velocity Red, almost exactly like yours Frontman!

I don't know why or how it happens but it sounds exactly like that video you posted. Between 6-9k RPM's. It comes from the passenger side glovebox area. I'm suspect of the heater core thing, it sounds to me like something is rattling, but I removed everything from the glovebox. I'm taking it into the dealer for them to diagnose but I doubt they'll do anything about it. It is SOOOOOOOOOOO annoying. I love revving the car but when I hear that noise it makes my car sound terrible.

I was using Lucas Upper Cylinder Head lubricant for a while and I think the sound went away. I don't think it has anything to do with the motor except with the lubricant it ran a bit smoother so it never hit the harsh frequency that makes the noise. Just a theory though. Ug, my car is new and I love it, but it is by far the noisiest car I've ever owned! Rattles, vibrations, road noise. Grrrrr

 

Let me know what the dealer says to you. and by the way, who is your dealer? where ar eyou located?

 

I had that sand in the blender sound. Usually happened when I revved the car. I switched up and only used Shell and it went away. Go figure. No idea why, no idea why it really went away.
________
Hero Cbz

 

I have the exact same problem. If you ask me, it's sounds like a gurgling in the fuel pump as it tries to keep up to the fuel consumption.

Now I'm just guessing, but based on when the sound occurs (high revs) and also based on track day experiences of myself and two other club members, the fuel pump can't keep up to the high revs when you are going around a corner sharply, because the engine will choke from fuel strain. The problem exists when you drive around a track hard (the fuel chokes on you because of the G-forces) I'm willing to bet (This is IMHO of course) there is good reason to investigate this further.

Now that you mention it, I notice this with some brands as well. For example, I get this gurgling sound when ever I go to Petro Can..... Odd. But Esso and Shell, I don't get that gurgling sand noise. That's my experiences anyways.
A friend of mine combined two fuel pumps feeding from both ends of the tank into one fish bone line into the fuel injector. This fixed the fuel choke... not sure about the gurgling sand noise. (I bet you he doesn't hear it).

 

Willing to bet.... the fuel pump in the RX8 is not up to par. I don't have the knowledge or skill to check this hunch, and I don't even care to argue.

But I'm willing to bet a better fuel pump replacement (Under the rear seat behind the driver seat) would be the answer. I was planning on that upgrade anyways, since our club tech promoted it. (What the heck I'm going to do it anyways... can't hurt right?)

 

I'm near Washington DC. Maybe my car is choking on all of the hot air that gets expelled from the city...

I tried Water Wetter per LionZoo's suggestion and for 2 days the problem went away. At the same time, however, I had just filled up my tank with "trusted" gas. The week prior I went to some shady place that was using a 10% ethanol mixture.

Today the marbles came back, and because I'm out of Lucas UCL and my Idemitsu isn't here yet, I was running without any premix. I filled up again and put in some 2 stroke full synthetic mix (4 oz per 12 gallons) and added some more water wetter. If this doesn't fix the problem, nothing I can do will. I go to the dealer on Tuesday.

 

UPDATE:

I'm running 7.5oz of premix and 1 bottle of Water Wetter. The marble/sand sound is still there.

I just dropped the car off at the dealer today to have a headlight replaced and asked the tech to go for a ride along to diagnose the marbles. It wasn't very noisy today but it WAS there and he heard it which is good. He is working with other tech's to try and solve the problem. We shall see. Hopefully I'll be posting some good news in another few hours.

 

keep us posted!

 

Everyone interested or posting in this thread should jump over it this one instead:

https://www.rx8club.com/series-i-tech-garage-22/more-marbles-can-observations-93836/page11/

It's a bit more comprehensive and active and addresses the same issue.

 

UPDATE:

I''m going to post on the other thread, but just in case anyone is still subscribed to this one...

I've been off the board for a while (traveling a lot), but am back and active again. The shop called Mazda of North America about the sound. They're official line was that "it's normal" (I hate that answer) and it was indeed air rushing past the heater core. They said it can't be fixed but should go away with time. Uhhh, ok. That doesn't sound right to me. However, for no identifiable reason what-so-ever, it has been gone for quite some time. I've been using the same gas now but I don't know how or why that would make a difference.

 

I've had the sound since day 1, it doesn't bother me, because it's NOT always present.