I have a 04 rx8 that over heated. The radiator completely cracked and lost fluid very quick and I didn't notice till there was a cloud of smoke. I changed the radiator and it starts. But it's a rough start. Chugs a little and the CEL flashes for about a minute. Then goes away. There is also a knocking sound coming from the engine. I can't really pin point it but it sounds more towards the passenger side. The car runs good when it is warm but the start up
Is bad. Any suggestions?

 

First things first. When the overheating occurred, was the car running hot for a long period after the coolant dump?
If yes, then I would think that a trip to the nearest rotary specialist would be in order to get a compression test to see if any internal damage occurred. Also, ask if he can pull up a list of recent codes from the ECU to see what the CEL has been trying to tell you. If all that checks out good, then a full ignition revamp (coils, wires and plugs) should be the next step to see if startup can be improved. While doing the ignition, you might as well clean the MAF and ESS, then do the NVRam reset followed by a startup and about 5 to 10 minutes easy idle to allow the ECU to reaquire fuel trims. Then, take it for a drive and see if there is any improvement.

Good luck!

 

It ran for a minute or two after the dump. Probably a minute too long. As for the codes I will try and get them this weekend. For the plugs and wires does any one have any recommendations on where to purchase these? My local auto store is very limited to parts for rx8s.

 

Depending on how spectacular the radiator blow was, cleaning the MAF and ESS might help. The air intake is above the radiator, a coolant coated MAF likely is not a happy MAF, ESS covered in coolant might be an issue as well. These are pretty easy to clean. Check the air box for coolant as well.

 

Where you purchase the ignition parts depends on a) your budget
b) how much driving you intend to do
c) your budget after repairs from the coolant dump
d) what sort of driving you plan on doing (ie racing)
e) your budget

I guess what I am really saying is that a lot of variables exist, the foremost of which is how much cash do you have left after fixing the cooling issue. Also high in consideration is what shape the engine is in.
If all is good cash and engine-wise, then if you plan on driving it a lot and/or hard, BHR (Black Halo Racing) ignition parts (there is a listing for them in the vendors forum here) and the correct NGK plugs. The coils/wires kit will set you back about +/- $500.. and the plugs usually retail for +/- $20. each. BHR does online ordering and the plugs *should* be available through most Big-name auto chains even if they have to order them for you. Being canadian, I can't guarantee this first-hand, but I have read on here that some chains like Autozone sometimes have package deals on OEM-equivalent coils/wires/plugs at a lesser price Howver, and this is most important to your wallet and peace of mind; use EXTREME caution if considering deals on Ebay. OEM, there, frequently isn't and the coils they sell cheap are often trash.

 

Yah the radiator cracked on the top right by the air box. There was definitely Coolant in the box. So I will clean the MAF sensor.
My car is just my daily driver. No racing. So i don't know if the bhr ignition set up would actually be worth it? Is it worth just changing plugs? Just to see if those just got damaged in the heat up? Or is it common for plugs and wires to fail together ?

 

Personally, I think coils fail before plugs and wires. I keep running through OEM coils, maybe getting a year or two out of a set. I keep saving for the BHR, just to not have to change coils, but I keep having other needs for the money. I just pulled plugs out of 2 cars that had the center electrode completely worn away and still functioned, not well, but you could measure the gap with a ruler. But, if a coil goes, even a good plug will not fire.

I would clean things up and get the car running, if you need coils, go OEM for now. Once it runs, consider upgrades. I just started saving from mine again.