First off, sometimes, not always, it has a rough idle. It'll bog down to almost 500rpm and almost stall out, after stepping on the accelerator and bringing up the idle over 1000rpm, it rarely bogs back down.

Secondly, if I idle for a few minutes, there's a somewhat intermitent knocking noise. It'll knock for a few seconds, then go away, possibly come back, doesnt seem to be affected by raising RPM at idle, but goes away (as far as I can tell) when I start to drive.

Third, my temperature gauge is down @ 1/4 while driving on the highway or at constant speeds, and goes to about 3/4 when idling. It also had a lot of difficulty warming up this past winter. Granted, driving in near-freezing/sub-freezing temperatures makes it hard to warm up, but even when it was above freezing it still had a tough time warming up. I'm coming up on replacing my timing belt, so I'm going to be replacing my waterpump and thermostat, but I was wondering if there was anything else that might cause the heating/cooling problem. The antifreeze in my system is good down to about -30ºF according to one of those syphen-gauge tools.

Lastly, my AC was making a whining noise earlier this summer while I was on the highway, took me a good while to figure out what was causing it (a lot of other noises on the highway kept me from figuring out that it was my AC), but when I found out it was my AC, I turned it off. Then when I got near my destination, I was sitting at a light, and turned my AC back on and it stalled my car. I've tried it a few times since then, and it doesnt stall my car anymore, but it does still make that whining noise. I never turn it on for more than a second, but I'm thinking that I'm out of coolant or my compressor has died. The clutch on the compressor has become almost pale-white, and looks like it might be a bit rusted. It didnt look like that before, used to be black-ish. Any ideas/comments?

Thanks.

 

Well, if your engine is knocking, that is definitely not a good situation. Your engine is basically destroying itself when you hear it knocking. You need to either retard your ignition timing or go with a higher octane fuel.

The cold start problem could probably be attributed to a bad air regulator. It's extremely common on the 2nd gens. I wouldn't worry about it unless it really bothers you.

As for your hard starts I'd check your ECU and make sure all of your sensors are good. If your sensors check out okay, then you might just need a tune up. I'd also check the fuel pressure to make sure enough fuel is getting to the engine, check for air leaks or clogged filters, and check your exhaust and make sure nothing is clogging up.

As for the A/C, it might have just been the belt that was whining. The white stuff is probably just normal rust and corrosion. As long as it's putting out cold air, the compressor should be fine. They rarely fail on these cars.

As for the engine cooling problem, as long as you're not overheating or losing coolant, everything should be alright. While the needle going up 3/4 gauge is a little high, it's techinically considered normal especially when idling. Also, you have to remember that the radiator and water pump aren't functioning like brand new parts, especially if they're original equipment. You can't expect them to work at peak efficiency after 15 years. As long as there aren't any leaks, the pressure is high enough, the coolant is in good condition, and both of your fans work, I wouldn't worry about it. I'd do a radiator flush immediately before you replace the waterpump and thermostat so you don't have to run that old, dirty coolant through your new parts.

-C-