igropemotoko

One day I suddenly noticed a total and complete lack of power from about 3,500 RPMs. It stayed sluggish right until 6,500 RPMs where I got a huge kick in power from the auxiliary ports opening but still not the pull that should've been there.

I instantly assumed it was the SSV not opening properly. A code eventually came up. I babied the car for a week or so until I could set aside some time to check the solenoid and remove/clean the SSV if need be. During that time, I got another code for the ACV solenoid. I noticed that the SSV would ONLY stick after driving for a while. Every time the car cooled down, the valve functioned properly and I had all the power I should. After 15min to a half hour I'd go through the revs and there was just no power there. Just like a switch. Figuring I'd kill two birds with one stone with the solenoids, I went to work.

I first reached down to the SSV actuator and flipped it by hand. It seemed very smooth and opened with little effort. After seeing my ACV solenoid code, I figured perhaps the connections were bad on both solenoids so I removed the UIM and all three of the solenoids. I put 12v to each of the solenoids to check that they were working and that flow was directed the correct way. They all seemed perfectly fine. I cleaned the contacts on each solenoid, checked the wire harness for breaks or weak joints at the connectors and cleaned those harness connectors as well.

I put everything back together and took a test drive. SSV was working fine. I could feel gobs of power like I should. I drove for about 30 min and suddenly no power. I still feel the 6,500 RPM kick but there is nothing between 3,500 and 6,500. The ACV, however, code cleared itself.

I go back under the hood making sure all the vacuum lines are good. The actuators seem to hold vacuum well and the vacuum accumulator on the back of the oil neck had plenty of vacuum when I removed the check valve to make sure it was working. I made sure the check valve was on correctly and working properly.

I finally decided to dig down deep into the SSV. Once I pulled it out, it seemed only slightly varnished (the Mazda tech who did my warranty engine replacement had cleaned it, the VDI and the Aux Sleeves like I had asked.) I cleaned it and the LIM anyway just to make sure. Put everything back together. No SSV chatter. Once the car was warmed, I gave it hell and everything was working fine. After about 30 min of driving the power was gone again, only between 3,500 and 6,500.

The only thing I can figure is heat buildup is causing a problem somewhere. Perhaps the actuator diaphragm is loosing vacuum once hot? Is a solenoid gummed up once the temps get high under the hood?

What do you all think?

Just wanted some feedback on this before I did anything else. Engine has 6,000 miles.

Brettus

iTrader: (2)

next time it happens , pull over to the side of the road and get yr passenger to turn off the engine while you watch the ssv actuator .
It should do an open/close cycle if operating correctly . If it doesn't then check if vacuum is doing an on/off after pulling the hose off .

igropemotoko

Awesome. I'll do that next.

TeamRX8

iTrader: (25)

the actuator arm should move freely by hand as well

j9fd3s

i don't have a lot of experience with the Rx8, but on an FD, the check valve would be suspect. especially if the SSV moves freely and the diaphragm holds vacuum when hot.

mike

nycgps

iTrader: (1)

reason why they said that is because the SSV on Rx-8 is known to get stuck so bad that u can't even turn it by hand. at least the original version. Mazda came up with a newer one to fight this problem.

igropemotoko

I can always move it by hand very easily. I still haven't had a chance to have anyone ride with me so I can watch the shut down but when it stopped working, I jumped out, popped the hood and reached down and was able to move it no problem at all. Hop back in the car and it's still nothing. I parked it. 2 hours later full power for 20 min then suddenly, no power between 3,500 and 6,500.

Once I have someone ride with me when it happens and I can watch the valve during shut down, I'll let you all know what happens. I have a feeling the diaphragm is leaking at a certain temp or the solenoid is jamming at high temp.

nycgps

iTrader: (1)

I would say the easiest is u just go out and drive the **** out of the car and keep going on and off between those rpm. it will keep cycling the valve and usually will unstuck itself.

igropemotoko

Had to do some running around today. Car lost power eventually. Once it had been that way for a while, I hopped out and popped my vacuum pump onto it. The SSV fully opened at 7 inches of mercury. I pumped it to 10 inches of mercury and left it for five minutes. It didn't loose any vacuum. It must be the solenoid. I suppose I'm going to tackle replacing it tomorrow.

TeamRX8

iTrader: (25)

if it move easily even right after you notice the issue (hot-hot-hot, be sure to wear gloves) then

the solenoid could be failing or have a wiring connector issue

the actuator could be failing (you already checked this)

there could be a vacuum system issue though this would also affect the VDI since it, the air pump exhaust valve, and the vapor purge system all work off the same vacuum storage reserve system. A vacuum gauge, a tee fitting, and a long piece of tubing will let you check the vacuum holding capacity of that system while driving

it could be something else

.

igropemotoko

I'm swapping with a new solenoid now. I pulled the oil neck/vacuum accumulator off and put it on the bench. I hooked up a vacuum pump to the check valve end and had the solenoids plugged into the vacuum accumulator. Held 20"Hg no problem. I put 12v to the ACV solenoid and it pulled fine. Same with the new SSV solenoid. VDI port has a small restricting pin hole which causes a very slow pull. (I'm assuming it's supposed to be this way. It appears that there is a molded plastic restrictor in the grommet with a perfect pinhole in the center. Tested them all several times. About to put everything back together.

igropemotoko

So, it seems the solenoid was the problem. Out of curiosity, I hooked up an unused good solenoid and the "bad" solenoid to a 12v source and left them for an hour. The bad one was REALLY hot and would not return to the open position after you put 12v back to it. It was simply stuck. The other one was slightly warm but worked fine. This is why the bad one checked out okay on the bench but as it got used and stayed on longer and longer (plus engine bay heat) it would quit working hence why I had full power for about 20 to 30 min.

Thanks for the help, everyone.

nycgps

iTrader: (1)

I'm so happy to see someone like you who will actually go out and fix a problem instead of just sit and cry and bitch.

nice job man

Brettus

iTrader: (2)

/\ what he said but nicer ...

Coldwound

iTrader: (1)

I had a very similar problem with my 8 heating up after about 20-30 minutes and losing power, it felt like my torque was gone.

I noticed my center console you could cook breakfast in when I lost all my power. I took it to have a different cat. put in and the problems gone.

igropemotoko

Haha. Thanks, ya'll.

Well, I sure as hell can't afford to let the dealership do it (thankfully, I have an awesome one when I do need them). Labor prices are insane and after removing most of this stuff once, it becomes almost second nature anyway.

I mastered the art of the UIM removal now. lol

nycgps

iTrader: (1)

it really takes maybe 1/2 hr to remove it, that's when I'm taking my sweet time. lol

why ppl afraid of doing this ... I dunno

shazy

^because they look at the how to and then are flabbergasted by the amount of steps to take lol like me.
I just looked at it myself and use some logic and realized it was really easy to take off hahaha.

maffatato15

this seems similar to the problem i am having. Did the car get a little louder while loosing power? Seems like a valve is not functioning properly after about 20-30 mins of driving, especially on hotter days. I took the ssv out and cleaned it thoroughly back in march. Taking the upper intake manifold off would be no problem for me to get to the solenoids.

TeamRX8

iTrader: (25)

Bump

Can the oil neck/accumulator tank be removed without pulling the UIM off? Guess i had always assummed that it couldn't.

igropemotoko

I'm trying to run through it in my head. The neck can be unbolted from the metal oil fill tube without removing the UIM for sure. And it can be unbolted from where it meets the UIM but you can't pull it out from the firewall side. You'd have to move some wires and remove the alternator at the very least to slide it from the front and even then I think the accumulator tanks hang low at the firewall side and would probably be next to impossible to pull out. Once you master removal of the SOB bolt at the back of the UIM next to the firewall, the rest is cake.

TeamRX8

iTrader: (25)

I'll just remove the UIM. Never have any problem getting it off.

Trying to help a local guy out. SSV is clanking, some power/acceleration issues. If it didn't start so easy and idle so well I'd think the engine is on the way out. Going to try a solenoid swap next which is why I asked.

houstonrx8er

iTrader: (8)

bump for a rare find.....quality thread!!!

Zandorr

/\ Bump/\
Described my problem perfecty and I'm gonna tear into my UIM next weekend, thanks!

skc

Ordered new solenoids hoping it will resolve my high rpm power loss