xanex18

Hello,

To preface, the car is an 05 shinka with 68k miles on it. I have had it for about 5k miles. The previous owner stated that the ssv stuck after driving highway sometimes but I never experienced this when I drove the car 200 miles home. The coils, plugs, and wires were all replace 15k miles ago, with receipts. The car has progressively gotten worse with hot starting over the past 6 months to the point that if the car turns off after a hard drive, I have to wait a minimum of 15 minutes to start it. That being said, I can push start the car perfectly fine. I don't know if that means compression is bad as I would think with bad compression, even a push start wouldn't turn it over while hot. Also I don't want to say I have a rough idle, but it almost pulsates. It sits at about 850 but will drop down to 750, vibrate really bad for a couple seconds, jump up to 950 and then drop back to 850 for about 20 seconds before repeating the whole process.

I can pretty much guarantee the ssv valve has started to get worse over the past month though. I redline the car multiple times every time I drive it. The car feels gutted after 5k rpm right up until about 7.5k rpm where it roars back into life. If I drive at the same rpm for more than 5 minutes, the car will try and stall at a stop unless I stomp on the accelerator a couple of times. And just recently, around 6.5-9k rpm I will hear an intermittent metallic rattle. I can't say for certain it is coming from the passenger area as it isn't quite loud enough. Very rarely the sound will happen in the lower rpms if it is kept at a level rpm, ie 4k rpm for 30 seconds. Everything I've read indicates that this is most likely carbon buildup on the ssv causing all of these symptoms. The buildup causes fluttering which is the rattle noise i hear, causes the ssv to stick shut, the hesitation at 5-7k rpm, and stick open causing the stalling after a steady rpm is held for more than 5 minutes. The only thing stoping me from 100% faulting the ssv is I can very easily turn the actuator by hand. I would think if it was gummed up enough to cause issues that it wouldn't be that easy to turn.

I don't have a mightyvac at the moment to double check the acuator holds pressure, but since everything seems like it runs and drives fine around the town, and only gives an issue when driving in specific ways, than the parts themselves are fine and it's just gunked up. Is the ssv possibly responsible for the idle and starting issue also or is that pretty much compression related? The stealership wants $230 just for a compression check and they can't even tell me if they use a rotary compression tester or just pressure test the whole engine. I have an extended warranty for 3 years or 30k more miles and the warranty covers apex and side seals, so i'm not too worried about a new engine if that is the case. I'd prefer to rebuild, but warranty.

So am I right in assuming that the brunt of these issues are pointed at the ssv being gunked up? I will test the actuator and solenoid when i pull the ssv to clean it.

xanex18

Hmn so after a drive with my brother, we both agree that the sound is coming more from the center console area rather than the glove box area. Almost like a loose bolt wobbling behind the radio or something but more metallic.

JamesD31

Regarding the hot start, as long as your ignition is healthy (which it seems like it should be), the next step I would say is check the starter. Make sure it is the upgraded starter - if not go to AutoZone and pickup the starter for the 2007+ Mazda RX-8. It will fit on your 05 and should start right up - even when hot.

I just did this and it has worked magic.

Loki

iTrader: (1)

SSV issues sound consistent, except the hot start. Is Mazda quoting you $230? There is a book cost for a proper compression test, should be 120ish.

I'd get that done before you invest time in the SSV. That stuff will all be easier if the engine needs to come out. Have your catalytic converter checked also. Do you smell exhaust in the cabin? Does the cat glow red after a spirited drive?

xanex18

Yup, both mazda dealers in the area quoted me around 230 for the compression test and then they couldn't even confirm that they actually compression tested and got numbers back rather than pressure test and just say good or bad. I was thinking it might be a starter issue, but i recall there being 3 types of starters. The original, which was bad, and then a late 05 starter with one number and then a 2g starter with a different number. Both of the last 2 are supposed to be good and i have the later 05 model starter. I cant remember the actual starter number though. As for the catalytic, i forgot to mention the previous owner punched it so there is nothing to get clogged up. I just don't want to take the car in and pay in the neighborhood of 250 just for them to say it barely passed compression and send me on my way only to have to bring it back in a month when it blows up. What are the tolerances the mazda has to look at when they say bad engine? Is it generally before major issues present or does it litterally mean the car dies and is dead dead?

Loki

iTrader: (1)

Mazda looks for compression and vacuum numbers. How those numbers translate into symptoms is different in every case.

I doubt it's the starter. Unless the starter is turning suuuper slowly, you shouldn't need to wait 15 minutes. The reason hot starts are harder than cold starts is the clearances in the engine open up when the metal is warm, so it haas more leaks over the various sealing surfaces, so it can't build compression quite as well as cold. So if you have low compression to begin with, it's even harder to get started.

Is there a rotary specialist in your area who may charge less for a comp test?

Nisaja

You said the car shuts off after a hard drive. That could indicate a bad fuel pump. You can't start it back up until the pump cools down. Which is usually around 10-15 mins.

The RPM fluctuation might be because your AC was on. The RPM drops when the AC compressor kicks in. It can vibrate horribly at 750 RPM when your motor mounts are starting to fail. Try it with the AC off.

The starter was upgraded in 2007. Only 07+ models came with the upgraded starter. You can test your starter's cranking speed with a Bluetooth OBD2 scanner paired to your phone. Add the RPM screen, press the accelerator pedal to the floor (this cuts fuel to the engine, so you can keep cranking without starting the engine :P ) and crank. The RPM shown on screen is how fast your starter motor spins. Easy

I don't know about the SSV issue.

Good luck

JamesD31

I had my car die while sitting at a red light before and that turned out to be a dead engine. So it might not be fuel pump but worth a shot to get it checked out.

Obviously, the next step is compression testing.

xanex18

Ya, the car only makes you wait to crank after ******* the car. Like, if im just running errands, then it's harder to crank hut it will crank. If I've been ******* it then it won't start until 10 to 15 minutes so it cools down. Is there a test procedure for the fuel pump? I know some cars have a nozzle to test it in the engine bay. The car does the vibratimg regardless of the ac on or not. Its more noticeable with it on but it will do it regardless. As for the starter, there are 3 numbers. One is n3z1, n3h1, and n3h1 a. 2 are good and one is bad. I believe one is from late model 05s, one is early 05s and 04s, and one is the new updated starters. So i think mome was the late model 05 one, but i will double check the number and cranking numbers anyways.

xanex18

cranking rpm is 273 so I don't think the starter is the issue.

Jastreb

iTrader: (1)

Your fluctuating idle is indicative of a vacuum leak. Are there any stored codes other than the one for the catalytic converter? The metallic rattling could be detonation. There are several possible causes for this, but running hot and lean is one if them.

For the fuel pump, there's a quick disconnect fitting in the engine bay that you can hook a pressure gauge to through a t-fitting. I'll post the procedure from the workshop manual after I dig it up later today, unless some one else beats me too it. Good luck and please keep us posted on your progress.

xanex18

Alright I don't think I'm running lean as the car kind of smells like a lawn mower and burns gas like nobodys business, think i get about 150-170 a tank on 93 octane. No stored codes aside from the catalytic. I could be running hot, I think my bluetooth obd2 was reading 205 or 208 when i was ******* it and it cooled down to just under 200 when i cruised. Not sure if that's hot or not, I can't recall the numbers I read a while back to be wary of. And I'll do some searching for that procedure myself but if you find it feel free to post it, may help others anyways.

My obd2 sensor was saying that i had between 12-13 and up to 15 in/hg vaccuum when i was testing the cranking. I'm not sure where it pulled that number but it was at 16 when i shut it off. Now, something I just found when i was poking under the hood, is apparently the previous owner was afraid of his maf sensor falling off because he torqued the damn thing down and ripped the threads right out of the plastic. So I'm probably gonna pick up some self tappers in a slightly larger size and maybe a splash of epoxy. Just to make sure it grips well.

I'll look for videos of the detonation sound and see if it sounds similar because it really doesn't sound like MIAC that I've heard in my research. It's more like if you sit metal shavings in a coffee can on the hood of the car and slowly revved the engine. Just a slight metallic rattle but loud enough to be heard over the engine at 8k rpm. I appreciate all the input and I might see about a compression check here soon just to see what's what. cheers.

Loki

iTrader: (1)

Low vacuum, hard warm starts, poor fuel economy... All this points to low compression. Sorry chief. May want to verify that before investing time/money in other things.

xanex18

Will do captain I kinda figured it was on it's way out. The guy i bought it from was mild mannered and seemed kinda scared when i took it for a test drive and revved the hell out of it. So at about 70k miles i figured the seals were about done for.

Nisaja

Yes, if your car doesn't die on its own, then it can't be the fuel pump. But it's worth a shot just to rule it out. But before everything you need to do a compression test. Hard starts when hot is a classic case of low compression. You said you can't start at all when you've driven it aggressively. I guess what happened was the engine got hotter, and components expanded more. That means less compression. So you had to wait till it cooled down and everything contracted to start it back up.

You coolant temps are fine.

Cranking RPM is perfect. You have the updated starter.

The metallic rattle could be a lotta things. It really depends on how loud it is. If it's a slight, barely audible metallic rattle, a lotta people have said that's normal. You need to make a video of it and post it.

You can check for vacuum leaks by pulling up the MAF, AFR, STFT and LTFT gauges. Watch them for a while. Drive around a bit and get the readings while moving. Post them here

xanex18

alright well i'm an idiot. I went out for a drive to check those numbers and forgot to turn on logging so I didn't really get an idea of what it was as i was ******* it. BUT; What i did see was that the AFR stayed around 14.6-15.0 at idle, the stft was all of the place, when the car vibrated crazy bad it was at -5.7, the ltft seemed stable around 10.8 at idle, and the maf was fairly idle except if i blip the acclerator, it drops and fluctuates quite a bit before rounding off. After that it has a change of .2-.4 g/s every couple of seconds.

Loki

iTrader: (1)

That sounds normal except the 10.8 LTFT at idle. The car is asking for more fuel to maintain 14.6 AFR in closed loop, which means it's getting more air than the MAF says its getting. Which means you have a vacuum leak somewhere in the intake.

Nisaja

Yep. Vacuum leak. What was the MAF reading? Sure it's stable at idle but what was it :P

xanex18

Alright went out for a 30 minute drive and logged the data for the whole drive. I have it in spreadsheet form if y'all want to look at it, otherwise it looks like at idle the maf was reading around 5.8 g/s to 6.2 g/s , fluctuating a little here and there. The AFR stayed around 14.8 the whole time, jumping up to 15 for one second and then some decimal fluctuations but mostly stable. I left my phone in the car so i think it took reading while the car was off because the LTFT seems to have 3 numbers over the course of the drive; 10.93%, 7.8%, 8.5% and 5.8%. 10.9 seemed to be the standard when i was watching it though. The highest was 14.8% for 1second, and the lowest being -16. now like i said, I left it connected when i turned it on and off so those numbers might be off, but that's what i got. I can post the data log if y'all want the raw numbers

Loki

iTrader: (1)

Yeah post up the raw data.
But the 'normal' LTFT is 0. LTFT is basically a measure of how far outside of factory fuel/air calibration the engine has to go to maintain the intended AFR (14.8ish on a warm idle). There are good reasons it might not be 0 like atmospheric pressure and altitude, but unless you're writing to us from the bottom of the Atlantic ocean, that's probably not the case. So. Go back through the intake, check for loose connectors, cracked hoses, clamps that aren't tight or other types of holes.

xanex18

https://docs.google.com/spreadsheets...it?usp=sharing

Link to the log.

And ya, like i said, both the maf screws are borked to the point that the maf wobbles. So i can pretty much garuntee that there is a vacuum leak there, but i don't know if the maf is reading that air or not. I haven't been able to think of a good idea other than get slightly wider self tapping screws to solve the issue as I don't want to epoxy it or just melt plastic back into the holes.

xanex18

Oh and I'm pretty much at sea level, so atmospheric pressure wise I should be fine.

Loki

iTrader: (1)

Why not buy a used MAF tube and MAF somewhere?

xanex18

New air box is 100-150$. MAF mounts to airbox tube so that's kind of my only option. Didn't wanna throw 100$ at something a 5$ screw could fix and i probably will snag one because I'd like to have spares of things, just not right now.

Jastreb

iTrader: (1)

I'm actually a little offended Mazda chose to save a few dollars with such a cheap design for mounting such an important component. My suggested fix:

Parts list:
1. Screw-to-Expand Inserts
for Plastics, Brass, 6-32 Thread Size
McMaster-Carr

When I did the repair, I used the insert with the lip, but I think it would have been better to use the ones that mount flush.

2. #6-32 pan head phillips machine screw. I forget the exact length... I think it was 3/8, but you should check what fits best.

Procedure.
1. Use a 3/16" drill bit to drill out the hole down to a depth of 1/4". Be careful that you don't drill down too far and punch all the way through to the tube where the air flows.

2. Thread a #6-32 fastener into the top of the insert and gently tap the insert into the hole with a hammer. I found that if you don't have a fastener inserted, the soft brass insert deforms and makes it impossible to put in the screw afterwards.

3. Attach the MAF using this more secure and durable method then the stupid self-tapping screws.

While you're doing all this take the opportunity to clean the MAF and the ESS, and reset the NVRAM, if you have not done so already. This should help your car idle a little better.

Was your idle MAF reading taken with AC on or off? 5 g/s is considered normal for this car when fully warm and with the AC off. Regardless of whether you have a vacuum leak or not, it does not account for the hot start problems. I'm afraid a more serious issue is at play.