Footman

iTrader: (2)

install heater hose orifice Mine went away

Shamblerock

Footman, so you are saying it wasn't anything to do do with timing issues or a resulting fuel/air mixture burning to rich?

SauerKraut

It seems to be a little different for everyone, except the sound... we all seem to agree upon that.

Others have had it go away through replacing their CAI with the stock box, couple fixed with a coolant flush, others with the SSV valve I believe

Footman

iTrader: (2)

Shamblerock, I don't know what you are talking about, I never said anything about timing issues or fuel/air mixture ratio.

Shamblerock

Footman, sorry man, I saw a few guys mentioning here that the rattling sound could be related to the engine timing being thrown off by a cooling related issue which makes the car burn very rich as a result. In my case, it really does sound like all of a sudden as soon as I hit 5500-6000 RPM I get this rattling sound that seems like its poor detonation. With your fix for the rattle, it seems you never had a timing issue so I was kind of surprised that it was something totally different from what i think I have. So after much reading and with all my professional mechanic experience of 37 minutes of reading tops, I think I'll be able to solve this problem by replacing my ECT sensor.

Lord knows I've been chasing this problem for over a year..changed, plugs, wire, AEM air filter, ignition coils, rad flush twice. Problem still was there...went to mazda under my extended warranty and they changed my MAF sensor, the furl injectors, fuel damper, oil, rad flush again and still didn't fix it. So they replaced the engine. Got the engine brand new and fresh and guess what? Same rattling sound!!! So what left is the ECT and then intake and everything connected to it. If it was just a matter of living with a rattling noise, then I could do that really easy, but I am thinking i am causing damage in the high RPM range where I tend to drive in that range most of the time.

Footman, sorry for confusing you earlier, and sorry for confusing you again now, which i am sure I most certainly did!!

Shamblerock

Changed the ECT sensor in the hopes that it would send the correct temperature to the ECU so it doesn't burn too rich did not work, unfortunately. Still have that dam rattle starting @ 5500 which sounds like the timing is off but I really don't feel any lack of power during that time....maybe very little. This rattle is causing me serious frustration....sounds like its coming from driver's side front....

Footman

iTrader: (2)

Have you checked your exhaust header heat shields?

Footman

iTrader: (2)

and how many KM you have on your reman engine?

Shamblerock

I didn't personally check the heat shield but i had a mechanic do so and he told me its perfectly fine. I have about 20,000Km on the new engine. Mazda spent thousands repairing things and then replaced the engine. Same sound exactly before and after the new engine. If I floor it gradually over 4-5 seconds, then little chance of rattling. But if I floor it quickly before 5,000 RPM then almost for sure I'll get that dam rattle which sounds like pinging. Most people that drive in my car, including a mechanic who specialized in Mazda Miata/Mx5's, don't hear it or feel it. The mechanic drove it and didn't really hear the rattling but I know its there and hear it each time. I just don't want to damage the engine because of pinging or poor timing. Picked up a Scan Gauge II device and trying to see what's going on with the car. Noticed that the timing goes from -5 at idle to +20 during cruising and between 33 and 44 when under hard or full throttle.... I'm thinking of getting a cat delete and a program for the ECU to tell it that the emissions is perfect at all times (even when its not) so it doesn't advance and retard the timing constantly. Then you can pin down the issued because you established a constant key attribute that has a major effect on performance.

Karack

have you checked the top of the fuel tank pump unit for wetness Shamblerock?

it would be due to a lean condition not a rich condition, as i noted i have seen a handful of pumps crack at the outlet line off the pump body which causes a low fuel pressure issue and subsequent lean condition.

Shamblerock

No I did not. Wouldn't I get a little smell of fuel in the back seat? Also car burns fuel a brutally as it always has so I don't think I'm burning lean! LOL... Maybe I should check that to rule it out. Its under the passenger rear seat, right?

Karack

yep, just pull up on the front edge of the cushion to pop it out and then remove the 4 phillips screws holding the inspection cover on. it's worth checking out even if you can't smell fuel since it's less than a 5 minute check.

Shamblerock

Thanks. Will do tomorrow and report back. I'm looking for any sort of leak or something loose or out of place.... Thanks again.

Shamblerock

Finally got ti it. Took of the seat and the plate covering the tank. Couldn't see any thing wrong, no funny smells of gas. It looked bone dry. I wanted to take of that large white ring but my spidy sense told me "F&^% with it without using the right tool, then be prepared to buy a new ring and possibly new fuel pump, genius"...so i didn't remove the ring. later found out you do need a special O Ring tool.... Where can I get a new O ring tool? Mazda, the bunch of thieves?

Karack

it's best to use the proper tool but you can use a mallet and large blade flat tip screwdriver. you won't really see anything inside though, the sock is about the only other thing you could check in the area but is buried inside the pump module. that is about the last thing to check on your checklist and is still a possibility. if the top of the tank is dry then rule out the pump module/casing being faulty.

wcs

iTrader: (2)

Hey Shamblerock
Sorry for arriving late to the game here,
I may have missed it but I saw Footman recommend the orifice piece that goes in to the heater hose line. That has always been my understanding of what caused the MIAC thing.

However that particular sound comes right behind the glove box.

The ECT thing is interesting hadn't heard that before so quickly I have a few thoughts on that:
1) If the ECT was broken and always indicated low engine then you would not be able to rev over 5500 rpm. This is the same ECT sensor the limits the revs when the engine is cold.

2) The Ignition Tables for Cooling compensation only have a max range of Leading 1 degree at -40f and Trailing of -1 deg 40f that's only 2 degrees split, not alot really

In post 209 you mentioned your timing values.
-5 at idle is fine.



The other values are hard to say as you need the Calculated Load and RPM to lookup the cell value.



I have a spare Cobb AP .. version 2 I believe.

I've not actually used it yet so I'm assuming it works but I can bring it and we can hook it up to your car if you would like to collect some data logs.

wcs

iTrader: (2)

+1 on its best to use the tool.
Darkbrew and I had a hard enough time using that ... it can be tricky.

BTW I also have a spare fuel pump.
Don't have a spare fuel pressure gauge, and that's what you really need.

Prism11

iTrader: (1)

Was there a solution found to your problem Shamblerock? Im having the same issue, only after having driven long distances though. Right around 5500 to 6000 rpm there is a horrible rattling noise. I was thinking it had something to do with the intake and the VDI opening up but I dont believe it would cause such a noise if something was wrong.

Shamblerock

Negative...still own the rattle....I am thinking same a you that it has to be in the intake somewhere....Lord knows I checked everything else.......I'm miffed about it.....learning to just live with it...Maybe one day I'll get a decent mechanic to take off the intake and make sure all the stuff in there works properly.... There is a video on you tube that shows you how to remove the SSV, test etc...

Palkalocka

Doing a coolant flush solved the rattle for me. Seems like the same issue: long drives, usually warm temps, around 6000rpm. It didn't completely eliminate the loss of power though. I later gutted the CAT and did a SeaFoam treatment. It seems okay since, but it is starting to get warm out so I should find out soon.

DarkBrew

Shamblerock, Did anyone check the SSV as the source of your rattle? Some members have had this issue.

Footman

iTrader: (2)

Remember...

SSV 3750 rpm open
VFAD 5500 rpm open
APV 6000 rpm open
VDI 7250 rpm open

what RPM range is your rattle occurring at?

Prism11

iTrader: (1)

I think a coolant flush may solve some of the problem as my coolant light came on yesterday at higher rpms trying to pin point exactly went the rattle was starting. but there is also a loss of power which I am thinking is from either the VFAD or APV not operating properly because of the rpm range that the rattling occurs. Ill have to pull out those valves and check if they are stuck.

Mo287@hotmail.com

My care is just has no power and keeps turning off on me.

Eraserlfh

Well after reading all 9 pages of this topic, ive had simalier issues. I got my 2004 RX8 used with almost 68k miles, i have now almost 92k miles, the problem started around 91.3k miles. unknown if the engine had been replaced before. Heres what ive done so far. Replaced 2 coils which greatly improved the starting of the car. had 1 weak trailing and 1 weak leading coil. both new coils went on the leading. 2 new spark plugs in the leading. Spark plugs wires were replaced. No exhaust leaks or rattleing there. Castrol 5w20 oil wont put anything else in my car. MAF cleaned. K&N air filter, put it in when i got the car. Oil consuption isusally about a quart or so every 3k miles, normal? no premix. Oil preasure is between the halfway and 3/4 mark, normal? I usally run 89oct. Used B-12 Chemtool fuel system cleaner, Seafoam and octance booster, no change. Had my step brother in the car with me and the car was making a noise simalier to what a previous user posted, kinda like a cow mooing, idle is sorta rough, power loss in a varity of rpm ranges, cant get past 7.5k rpm in 3rd gear anymore, becomes gutless, 4th gear cant go past 5k rpm. When its first started sounds like it has an exhaust leak/growling but goes away. Will try a coolant flush. Did notice coolant was leaking out the overflow tube slightly. Daily driver.