Just wondering, im buying a p5 this week and I want to clean the engine first of all.
I tried searching for a complete how-to seafoam of our car, but without success
would I be better off with the seafoam or the engine flush OR both? (shrug)
Neither?
Engine "flushes" often do more harm than good, just use a good quality oil and change it frequently. I change mine roughly every 4-5K Km, but that's because I don't drive too much and do mostly city driving.
I don't think seafoaming your engine can do any harm, but I don't believe it'll do much good either. Unless the throttle body looks gummed-up I wouldn't bother. I did it just for kicks and didn't notice any difference, the white smoke was certainly entertaining but I wouldn't do it again. Most people do it by pouring the seafoam into the brake booster vacuum line while holding the throttle open a bit to prevent the car from stalling. Read the instructions on the can, the procedure is pretty straightforward.
Find out if the car still has the original ignition system, if not I'd recommend replacing the ignition coils, the spark plugs and the spark plug wires as preventative maintenance (perhaps you can use this as a bargaining chip). If any of those components starts to fail the engine will run rough (and even stall) and eventually failure to replace these parts will result in rapid deterioration of the primary catalytic converter which is a b**** to replace and is pretty expensive.
Also, if the engine has a rough idle which isn't related to a faulty ignition system the EGR valve might be stuck open/closed. These cars are notorious for going through EGR valves, especially in our climate. Mazda has a revised valve which is supposed to last much longer, often referred to as the "Canadian EGR".
Other than that these cars are pretty good (if you can deal with the rust), good luck on your purchase.
