shadowraven

Hi, I'm having an issue that I just cant seem to pin point the cause of and was wondering if anyone had any ideas. I'm new and have been following the site for ages but haven't found anything similar, any ideas or a point to a thread I've missed would be greatly appreciated.

The issue:
I run the car (231, 2004) normally, let it warm up fully (20mins) and then attempt some 'spirited' driving, if I just run the revs high once or twice there's no problem, or doesn't seem to be. However if I push it for a little, 5 minutes or so, going above 5000rpm a few times, (dont have to be ragging the ***** off it) it feels really limited on power. This persists across the entire rev range and comes in intermittently.

Today I ran it high a few times with no problem, then when I hit 6000 rpm again it felt like I'd hit a wall, all power dropped off completely. I babied it for abit and it seemed ok. I then ran it high a few times with it feeling intermittently limited again, really badly on occasions with 60-70 taking 10secs, during this time if i pushed it above 5k it would sound far louder than usual, again only intermittently.

I've just replaced the coils, sparks, leads, battery, air filter, dry cleaned the mass airflow very carefully, cleaned the throttle body and had a full service and new CAT 2000 miles ago. It idles fine at 800rpm, doesn't missfire or anything. It starts fine from hot in 2 seconds or so easily, I really dont think it's compression as its so intermittent and starts fine, it feels more like its limiting itself for some reason however I'm not getting a CEL at all.

The only mods I have are a catback exhaust and ceramic coated headers which don't remove any sensors with the O2 sensor present in the collector so isn't limited to just one pipe.

I just can't think what it could be, any one have any ideas?

yokohamaboi

iTrader: (1)

Have you seafoamed? Or check if the actuators are stuck?

shadowraven

I seafoamed around 800 miles ago when it had a service. The actuators? For opening the SSV? No they're not, I can hear them cycle when I turn the car off and the problems also occurring across the entire rev range intermittently, not just above 6000k, although that may be a trigger, I'm not sure.

yokohamaboi

iTrader: (1)

Hmm this is a tricky one. Hmm i would check your ess and clean it. So you can rule that out of the way. Does it sou nd like a misfire?

shadowraven

Ok will do. Might pull the ssv at the weekend and clean it as well just in case but it is a large job. Going to try and get the codes pulled asap to check whether there are any issues there but as I said I can hear it cycle fine.

On the way to work today it did it again, more permanent this time, I ran to 7k fine, then as i dropped back down I had no power and this stayed the same until i got to work (about 10 mins). I also noticed a slight rattle but that might just be me hoping for a solution and focusing on ssv as a potential target.

Also, not sure if it's related but this morning before work I had the engine coolant low warning, checked the tank and it'd dropped by half? Bit worried about this as it is something I check weekly.

And sorry no it doesnt sound like a misfire, I just have no power after the first run to high rpm or so.

tza0001

iTrader: (2)

Your coolant dropping by half sounds like a lot of coolant missing. You see any leaks? Does your exhaust smells different (sweet kind of smell)? I would definitely keep an eye on the coolant. Hopefully coolant seals have not left the building.

shadowraven

Ok so I cleaned the ESS (it wasn't that dirty to begin with), and gave the SSV a jiggle as im actually able to reach it without removing anything, it doesn't feel like there is much resistance but i have no idea how much there is meant to be and it could still be jamming when hot. The car still doesn't feel right, I haven't had a chance to give it a proper run or reset the ECU yet but during the 15 min thrash I gave it (after warming up properly of course, lol) it still displayed the same issue. I phoned a specialist today and they said it might be SSV and if not the o-rings but I have no gunk in the oil (over 3/4 full)and the oil pressure seems to be normal. The fact that the oil pressure gauge isn't a true gauge doesn't help though.

There is no sign of any leaks, sputter or puddles, the exhaust is clear and smells normal all before running, during and after. I have also run the engine with the coolant cap off to check for bubbling and haven't seem anything, it all looks calm, I can see water being sucked up the left hand tube and there is no sign of an oil film in the coolant tank.

I was wondering as I recently removed the throttle body to clean it and removed the coolant lines from it to do so if air got in the system and was pushed around blowing out some coolant but it seems like rather alot to have lost by that means. The engine will have cooled down by the time I leave work so will check the level then and let you know how it is and how it is on the drive home. BTW after I topped up the coolant the warning light has remained on? Should this not turn off once it has been correctly filled and run a few times?

Thanks for all your help guys.

Cliffjumper126

The coolant light is a common issue. The fact it remained on makes me think that either you didn't top it off enough or that your sensor is failing. If that's the case you'll have to replace the coolant reservoir (there are threads about it). But if it is a failing sensor.... maybe it was never low in the first place?

tza0001

iTrader: (2)

There is a possibility that the coolant sensor is dirty or malfunctioning. It is a well-known issue with rx8's. As far as you are certain that coolant level is normal by visually checking it you should be ok. Just something that came up into my mind. Make sure that your ignition is installed correctly and all your wires and plugs are tight.

shadowraven

Cheers all. I've searched since posting and yeh your all right might just be the sensor, i'll give it a clean and if not try a replacement, sucks you need to buy an entire new reservoir though.
Sorry for bringing it up before looking into it properly.

It took a pint of water when I filled it up this morning and on checking before I left work it didn't look lower but it has only done 30miles today. I'll give it a full check at the weekend.

Back to the subject of power loss, I gave it a good run on the way home and although still present it felt slightly better, however the slight rattle and power loss is still present. I am noticing it at around the times the valves should kick in so I suspect it might just be them now and am feeling slightly calmer for it. I'll clean them out and run my remaining half can of seafoam through the intake and aux ports at the weekend and report back

Cheers again.

tza0001

iTrader: (2)

As far as your coolant sensor, before you buy a new tank you might want to try cleaning it. There is a DYI here I believe. The sensor gets dirty sometimes and it does not work properly.

roflcopter

iTrader: (2)

Your issue sounds somewhat similar to mine, which I haven't been able to solve yet. I see you have a scangauge, could you possibly watch sensor data from that(I honestly don't know if that will do it) and compare them to the logs I have pulled from my car?

My troubleshooting thread is here

FlashFire8

I have a similar issue as well, when i'm at WOT at around 7.5k+ i feel a sudden push in power and my intake noise gets louder as well, it happens around those rpms during heavy engine load. It feels like an ssv was stuck and suddenly loosened up but both my upper manifold butterfly's move freely and hold vacuum.

Good luck diagnosing your problem, have you checked your fuel pressure after driving for a while?

shadowraven

Hi Roflcopter, yeh I saw and read your post, unfortunately I dont have the ability to pull that quantity of data off my car, I dont have a scangauge. My issue doesn't seem to as regularly as yours though and is more similar to flashfire8's issue occuring under WOT the first time it happens, but then it occurs even at partial throttle. Backing off the throttle doesn't appear to resolve it temporarily like with your issue either. It comes and goes as it pleases and does so suddenly rather than creep up on me.

Flashfire8 I have no way of doing so atm but it did cross my mind. I think I'm going to pull the ssv and check that first as I'm growing more convinced it is that even though I can move it freely myself, it could also be the motor for the ssv thats going. Have you pulled yours and had a look at it? When I stripped my intake and throttle body it was pretty black and gummy so it does support what people have been saying. I'll post a picture of it once i get it out if i remember.
Might be worth pulling your throttle body to look at the state of it, if it is gunky especially around the edges the ssv might also be in a similar state, just a thought.

shadowraven

In the interest of completeness and helping others who may have had a similar issue- Over the last few days I have done 2x 250 mile trips. After about 150 miles on the way down I had the same issues again with intermittent slight juddering/ a feeling of missing and power dropping to the point I could barely accelerate at all, it would take 5 secs or so to gain 1mph. On the way back I had the same issue. I chucked in a can of injector cleaner and the issue started to get better, then 1/3rd of a tank later all appears to be corrected.