Gonzy

'08 40th anniversary model, manual. Just recently purchased with 30K miles. Car feels as it's unable to keep a steady idle and starts to shake a bit. Please pardon the rudimentary explanation, I know nothing about cars, but want to learn. Any info would help. I already tried searching the forum for idle related problems and came up with nothing. Thank you.

CaymanRotary

Sounds like engine mounts to me. Easy to inspect.

Gonzy

Thank you.

Loki

iTrader: (1)

Engine mounts don't cause poor idling.
I'm surprised your search didn't turn up anything, this is not uncommon. How old are your ignition coils? Is the car modified? Do you have any obvious holes or cracks in the intake or vacuum lines?

Gonzy

It's not modified. Ignition coils were replaced at 10K. No modifications. Not sure about vacuum cracks, I'll look into it. Thank you.

Loki

iTrader: (1)

Can you make a video of exactly what it sounds like? Also where are you located? The fastest/easiest solution might be to find a rotary specialist in your area to see the car.

Gonzy

Loki I don't think it's noticible enough for video to catch, but I'll try. I'm trying to do what I can before I take it to a rotary specialist, I have one here in South Jersey. My lazy *** took the time to read through the stickys and here's what I found so far. My MAF looks clean, not sure if looks clean is enough, and the filter looks brand new, no oil or gunk. I thought this would be the problem as I'm pretty sure I overfilled the oil. My next step is to clean the ESS with some brake cleaner, if that fails, I'm going to seafoam, and install a new coil kit as well as spark plugs. I'm wondering if I "need" the BHR kit as I don't track, this is just my daily driver. Glad to hear your opinion on this. Again, thank you for your time.

Loki

iTrader: (1)

BHR's kit isn't really a performance upgrade, it's a longevity upgrade. My first and only set has 60k miles on it. I wouldn't trust a set of stock coils over 25k. So, while it's more expensive to start, if you plan to keep the car it's a net positive.

This might be a non-issue. Are you using air conditioning, and does it only shake/shake more when AC is on? The A/C compressor cycles on every minute or so, and will cause the idle to dip about 50rpm, increasing vibration. If that's all it is, and you have confidence in your engine compression and ignition health, and no other symptoms, then you can leave this alone.

One solution is to increase the idle speed via ECU tuning to 900 or so (from 800). This takes away the vibration.

CaymanRotary

He mentioned it shakes, that’s why I’m guessing engine mounts since they are easy to inspect. Video would help.

Gonzy

I just started using my A/C so I'm pretty sure you're right. Thanks again Loki.

Gonzy

Hey man I appreciate the effort non the less.

Loki

iTrader: (1)

Cayman isn't wrong about the vibration though. Given the low miles your mounts are probbbbably fine, but it's a common failure point.
May want to examine them for leaking/collapse regularly.