I got a weird one for you all and I am yet to come up with anyone else having this same issue.

06 Shinka - 93,000 Miles
Coils, plugs, leads, clutch all original. No mods. All OEM parts.
No CEL, no oil light, Coolant light on (bad sensor), TPMS on because its cold

Started up fine today and I knew I needed to take a long trip this weekend down a few states so I picked up some 5w-20 conventional like I always do and checked the oil in the parking lot. I noticed the dipstick was down to about 1/4 level so I topped her off just a little hair above the fill line (maybe 2-3 millimeters above). When I went to start her up again there was a noticeable vibration on the shifter when I put it into reverse and started to exit the parking spot. I did not think much of it because it almost felt like the car does when you don't give it enough gas at low gears, just like that chugging vibration if anyone knows what I am talking about. I then put the car in first gear and drove off only to feel the same vibration again at exactly 2000 RPM but this time it was stronger though the shifter and I could feel it on the wheel. Thinking that was odd I stopped in an empty section of the parking lot and tried again in first gear and got exactly what i was expecting, more vibration at exactly 2000 RPM. The strange thing is the car runs fine anywhere above that or below that. Idle is fine with the occasional vibration from the Low fuel pressure resistor kicking in and when I took it out on the backroads a few minutes later the car ran fine and red lined for me with no issues or CEL flashing. it climbs through the power band just fine but something around the 6000K mark sounds like the engine has a swore throat almost because the noise it was making was deeper and had a little more bass to it. if you shift any other gear and somehow pass 2000 RPM you instantly get vibration.

Here is the weird part... the car will still vibrate even it its not in gear and you hit 2000 RPM. I sat in my driveway and did a few test revs about 25 minutes ago and got the same results.

Never once has the CEL come on and all I feel is vibration at the 2000 RPM mark. The clutch hooks up fine and shifts are what they always feel like, but I am completely baffled at what suddenly caused this. My understanding is that overfilling the oil can cause some problems for you by going into the intake, but I know it did not overfill the pan to the point where its puking into my intake. I know, I checked.

Could it be engine mounts going bad suddenly and this is just a coincidence?

Any and all ideas would be welcome and I can check them later this weekend.

 

You verified that your maf sensor is clean? I'd check that.
It could very well be coincidence. Check your fluid levels, ignition components (using the proper testers) and motor mounts.

 

yes, I can confirm that the MAF is clean. I had a problem a while back where the MAF was shutting the car off a few seconds after ignition and this is nothing like that. At any rate, the MAF is as clean as I can get it. I will check fluid levels and report back soon.

 

***UPDATE***

ok, things just got weird and I am completely stumped. I am continuing my work and will update as I find things.

I decided to drive her down on the trip thinking nothing was catastrophically wrong with the car and I am happy to report she drove 600 Miles this weekend with no major problems. Engine temps, oil pressure, and everything else was fine except the shifter was vibrating a lot more then normal. I checked my oil frequently and noticed no major issues. My gas mileage during the trip was awful which saw me getting just under 200 miles on each tank (yes, I filled up three times this weekend). I had the cruse set to 75 MPH and the RPM was steady the entire way but the car was drinking way to much fuel for a highway trip. This past summer I drove 900 miles in her and filled up three times averaging 300 miles to a tank. (sorry no MPG conversion)

When I returned home on Sunday I took a look at the intake, inspected below the car, inspected the exhaust, inspected the oil pan, and checked the engine mounts but could find no apparent issues. I let her sit for a few hours to cool down and then I went for a drive down to the store. (here is where things get weird) during the trip, the car never once shook or vibrated once. the store is a short three minute drive down the road and the engine temp needle barley even moved so I know she was not warmed up. On my way back home as I was pulling into my driveway the vibration returned in full force in gear or out of gear. I tested the engine again with the car out of gear and the entire center column, shifter, and steering wheel all vibrated a good bit. I turned the car off, jacked it up, and inspected the bottom again and could find no issues again.

This morning I was leaving for work and started her up again. (something to keep in mind is this car is my daily and I currently have no other ride, I would not normally continue to drive the car but I can't miss work during this time of year) When I began my morning commute everything seemed fine. No vibration, no shaking, no nothing. I figured things would happen eventually and sure enough as soon as the engine warmed up the vibration returned in full force at 2000 RPM in or out of gear.

Something to note here: I am also feeling a HUGE lack of power through the power band. The engine just feels like its not pulling like it should. I have been driving this car for 3 years and autocrossing it for a year now, and I know what the power band should feel like and there is certainly a lack of power when the engine spins up.

Only thing I have not pulled is the coils. I know they are original to the car, but could bad coils or plugs cause the entire thing to vibrate like this? I'm not getting misfires or any CEL to show signs of misfire.

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I have determined the following:

- The car vibrates hard at 2000 RPM when warmed up
- Vibration occurs in or out of gear in the center console, wheel, and shifter
- Vibration is constant, no knocking.
- Clutch peddle is not vibrating and gear changes are normal
- Clutch hooks up fine (from what I can feel)
- Small vibrations can be felt above 4000 RPM
- Engine is not pulling or producing power in the high RPM anymore
- I am using 5w-20 Conventional oil and 93 gas

************************************************** **********

Possible causes?

- Bad plugs, coils. leads?
- Lose engine mounts that I can't see?
- Transmission going bad?
- Exhaust problems? loose exhaust?
- Bad engine? engine going bad?


************************************************** **********

Any and all ideas or recommendations are always helpful. I will update this thread as soon as I find more information.

 

So you coils and plugs have 93,000 miles on them? If so, I would start by replacing them. Then see if the problem persists. Plugs should be replaced every 25k miles or so. The manual says every 35k, but I think that's too much. The ignition coils are also a regular replacement item (if using stock coils). Some people change them every time they change the plugs. I do it every other time. Ignition wires should be replaced along with coils. After this, check the condition of the catalytic converter. Running with failing ignition might have damaged it.

 

What mechanical experience do you have? I'm just trying to get an idea of your abilities to troubleshoot correctly.

You need to verify with a certainty that the parts you're inspecting are damaged or not. Jacking up the car and shining a flashlight on it isn't gonna cut it...

 

@Jastreb: Will do, Coils have never been replaced on the car in the 40k miles I have driven it. I will order them tonight and replace this weekend.

@RX8Soldire: Fair question, I am not a professional by any stretch of means. I caught the car bug about 6 years ago and have learned as much as I can in that time. When I mentioned that I checked the intake I did not simply shine a light on it and call it a day, I disassembled the whole damn thing down to the lower intake to check intakes and valves, haha. I gave things under the car a good look for cracks and other points a failure. Once again, I am no professional and no expert but I do have the knowledge to tell if I see something wrong. I know a good bit about my 8 but nowhere near what I would like to know. Is it possible I missed something during my inspection? yep, but without a second set of eyes I would be hard for me to know for sure. I will post pics this weekend of the coils change and if you guys see anything please let me know.

 

Well if your coils have less than 40k miles on them, they could still be ok. Your previous post made it seem like you're way overdue to refresh your ignition, so even if it didn't fix the problem it's something you would need to do anyway. You could test the coils though to make sure 1 of them isn't dead though. Definitely replace the plugs if they have > 25k miles, and the ignition wires if they are still original.

 

Yeah get a tester from napa. It looks like a spark plug with a ground clamp. You can test coils and wires with them. Wires at least every 60k miles and plugs every 30 or so. At least pull them and see if they look good. Those could easily be the problem. If they are then your killing your cat. It and the engine can go in a few weeks if things are failing and your still driving it.

 

Just replace the coils, wires, and plugs as a starting point. My 2005 with 32,000 miles (just bought it) seemed a tad bit slow. Replaced the ignition components, cleaned the maf, changed the air filter, cleaned throttle body, and it runs better. Not a huge change, but smoother idle.

 

Hi
I also have this issue, I get vibration around 1900rpm in and out of gear.
Mine is also intermittent, I have noticed this vibration year around 2 years, in that time I have refreshed the ignition, replaced the maf and o2 sensor, engine mounts, catalytic converter, fuel pump and have checked and rechecked for vac leaks.

I run regular 95 unleaded and also premium 99 (I am in the UK). It makes no differences, one thing I have noticed when looking at the live obd2 info, is the ignition timing bounces around a lot, dropping into minus figures, then bouncing up to into positive figures.

I have also considered having the PPF reset, although mine as never been removed and loosened off.

Hope this helps.

Antony

 

Also my ssv actuator rattles sometimes under load.