Jack Adair

Hello fellow rotary enthusiasts. I drive a 2005 RX-8 with 133,000 miles on the engine. To my knowledge, the engine is still original, but I cannot be quite sure about that.

Anyways, since I bought the car about a year ago, performance has been great, the car handles well, the car is actually pretty practical, but it just has terrible gas mileage. So, yesterday, I completed the replacement of the entire ignition system. I had the ignition coils replaced, the wires replaced, and about a month before I had the spark plugs replaced.

Once the car was put back together and everything was replaced, I drove the car about 20 miles. I stopped and ate at a restaurant and when I went back to my car, the car hard started (the engine was still warm). I drove another twenty miles and the car still hard started once I started the engine again.

The next day, the engine is still hard starting, but the starting seems to be worse. Not only that, but I am hearing a really loud and noticeable, constant knocking sound coming from under the hood. I only hear it at idle. It is completely inaudible when driving. Upon closer inspection under the hood, the noise seems to be coming from the near the driver's side of the car.

You would think that replacing the entire ignition system would make the car start better. Do you guys have any ideas as to what could be the cause or how I can fix this? Iknow the knocking noise could be the engine mounts, the hard starting could be a bad starter, or the engine could simply be losing compression. But, hey, at least I am noticing better gas mileage visually. I have not checked mathematically yet.

*sorry about the long post. I thought that giving you more information would help you help me better.

Extra info:
- I use conventional oil
- I use premium gasoline
- I drive the car like a madman every once in a while
- I make sure the idle is normal before shutting off the engine to keep flooding from occurring
- I have stalled the engine at least 5-7 times now since I bought the car

Thanks for your help,

Jack Adair

Loki

iTrader: (1)

Are you sure the spark plug wires connect the right spark plugs to the right coils? Are you sure no spark plug or wire has come loose?

The knocking in particular makes me want to verify that.

Jack Adair

You have got a point. My friend and I made extra, extra sure that the wires were all in the correct spots. I am sure that the spark plugs are in tight. We marked the wires before taking them off. We first removed the coils, replaced them, and then replaced the wires one by one. Good system, right? Do the lengths of the wires have to match specifically with a certain coil and/or spark plug?

Loki

iTrader: (1)

No, but the lengths are sort of an indicator of which goes where. The trailing plug wires, for example, are shorter than the leading plugs wires, but you could still do something silly like connect a rotor 2 leading coil to rotor 1 trailing spark plug using a rotor 2 trailing wire. I only say this because we've had that - ehm - happen to users here.

Jack Adair

I will check out the the tightness of the spark plugs and see if the wires are on correctly. I am pretty sure that the knocking noise is just a bad motor mount. The noise, like Isaid, comes from the drivers side under the hood. I am just hoping that the hard starting is just the result of me screwing up in some stupid way and not the result of low compression.

Jack Adair

The car seems to start better when it is cold. There is not much of a difference though. The 8 still has plenty of power. Also, this morning, when I cold started the car, I did not here knocking coming from the engine. I do not think that the car is losing compression. I do think the starter is going bad and the motor mounts are bad.

Was there a recall on the motor mounts for an '05 RX8? The starter?

Jack Adair

I am sorry to say, but I think my RX-8 is losing compression. I am taking it to get a compression test done this weekend.

Jack Adair

I am sorry to say, but I think my RX-8 is losing compression. I am taking it to get a compression test done this weekend.

Jack Adair

Hey guys! Update: I had a compression test done on the 8 just this afternoon and I am proud to say that the 8 has very good compression for an 8 that has 133,200 miles onit, the engine being original. The cause of the hard starting was actually a wire that was not connected to a ccertain spark plug. I believe it was one of the leadings, which is not all that great. The spark plug and engine coil will be replaced. Currently I am driving like a madman to get that one spark plug clean again. The car is starting up well again and the knocking I was hearing is almost inaudible. Thanks to that one guy (sorry, I cannot see your name) who suggested that I did something wrong with myignition system.