Yay! My first problems!

[altralosix]

Now I realize why people buy new cars...

I just bought this '93 240 HB last week. 142,000 miles, 5sp.

The first problem is that my car sometimes likes to idle tooo much. It usually happens after I've been driving at a constant speed for a while, like 60mph down a highway for 5-10 minutes. I'll push in the clutch when getting off the highway or coming to a stop, and the tach will drop to idle but keep going down to 300-400RPM. The engine will "stumble", the oil light will flash on for a split second, and then it will come back to life and get up to 700-900RPM. Usually once I drive it around town through a couple of stoplights it goes back to normal. Actually, what is the "normal" idle speed with the a/c off? Mine seems to vary a bit. Sometimes as low as 500, sometimes 800-900.

Second problem I discovered tonight. I was at a stoplight, 1AM, it was a loooong light. I have the clutch pushed in, transmission in 1st, right foot on brake, and I'm bored. I push down on the gas pedal a bit with my right foot just to listen to the engine roar, tach hits 3000 and I hear this awful screech from the engine. I tried it again, same thing about the same rpm. I was pretty freaked out and left it be and waited for the light. On the way home I want to try it out again, rolling down the street, I push in the clutch and let it idle and then rev it past 3000 and nothing happened. Nothing else happened on the way home.

Could it have been a belt slipping? It was rainy and wet. It sounded pretty low pitched for being a belt, but I don't have much experience with slipping belts either. nor do I have much experience with engines about to explode, so I'm a little worried.

Any ideas? The main reason I bought this car is because it was cheaper than my old one and I'm in college and can't afford much of a car payment anymore, don't tell me it's about to cost me a buttload of money in a shop.

[projeckDspdStar]

i've seen the idleing problem when u have the a/c on. my 89' idles around 800-900 with out a/c on.

[altralosix]

the idling problem actually doesn't happen when I have the a/c on. It appears that raises the idle enough that it won't go down too low.

[BoyWonder]

The KA is not usually considered the smoothest idling engine Nissan has ever made. I believe correct idle is right around 750-900ish on a good day, but going too far below that could be a problem. Someone else is going to have to jump in on how to sovle that one.

As far as the noise you're hearing; a belt screeching (in my expirience) is usually quite high pitched and most audiable at low RPMs. It could possibly be your fan, but you should pop the hood and have a friend rev your engine a little to see if you can replicate the noise and listen to see if you can get a general location it's coming from. I'm afraid that's the best I can offer.

[Silvia007]

First off, for a 1993 and it's all stock, try replace the ground cables. Hop on over to Checkers or something, pick up a few 4 gauge battery cables and connect directly from the negative of the battery to the the engine. If you look around, you'll see a few factory grounding points. You can get like 8 gauge for the grounding from the alternator to the chasis also. After that, if it still does it, I'd recommend a tune up, distributor cap, rotor, wire, and plugs. Check the fuel filter also it could be original. Lastly check for cracked or worn out vacuum hoses. These will be the cheapest route although the spark plug wires may be a little on the expensive side at about 50 bucks for a set. Everything else is dirt cheap.

For the Screeching problem, almost always it's your belts. See if they are cracked or too loose. Remember if they are loose, do not over tighen them, my buddy's sr20 right now whines like a whore because he over tighened the belts to the point where they were about to snap. If this is not the case, check your power steering fluid level. If everything is fine, well like boywonder said, open the hood and have a friend rev it trying to reproduce the same weather conditions.

All this should cost you around maybe 150 bucks or less for you to do.

[altralosix]

Great repsonse, thanks!

I'm going to track down the guy I bought it from today and get some maintenance history on it so maybe I can narrow down which parts are oldest.

Oh yeah, is there any way the screeching sound could have been clutch? The clutch in this car starts catching pretty much as soon as you start releasing the pedal. Is there any way something could be not lined up properly and that sound was the discs slightly rubbing?

[Doomed2Walk]

The idle thing may be plugs and wires? I recently got my 100K tune up and I got my plugs replaced, but since I went late on a Friday evening, all the stores were closed, so I couldn't get the wires. So I had to go a night with the old wires and everytime I had to stop, I'd have to keep giving it gas when idling or else the car would stall :[

[amolao]

Being summertime, I presumed that you had your AC on, the squeal (very loud and it sounds like your engine is about to blow up) is probably the compressor is going out, if the clutch (compressor AC) is about to go, it squeals like a pig...

Very expensive to repair, the compressor is close to 400 dollars unless you ebay that mofo. Im hoping is your belts, bro....lot cheaper...

[altralosix]

Drove it around quite a bit today, as well as removed the resonator box from the intake. I never heard that screeching even revving it the exact same way I did last night. So hopefully it was just a belt.

[altralosix]

, check your power steering fluid level.

Looking at the front of the car, where is the power steering fluid reservoir? Is it to the right of the brake fluid reservoir? Fairly small? It's way past the MAX line. Just noticed that today.

Also noticed the oil level is too high. could that be causing any problems?

edit: another question while I'm at it. The previous owner started using synthetic oil recently. I don't really want to risk the leaks and switch back to dino oil. Am I looking at any issues switching back? Should I run a synth/dino blend first?

[BoyWonder]

The power steering resevoir is a little bronze colored tank with a black cap, on the Driver's side on DOHC (91+) 240s and on the Passenger side on SOHC (89-90) 240s if I remember correctly.. could be reversed. Either way, easy to tell because it's the only resevoir that's has lines going to the steering rack.

The resevoir on the right of the brake master cylinder (if looking from the front of the car) is a the clutch master cylinder. It can often look overfilled but the cap actually fills a lot of the top space, so it's hard to close it right and still have it be overfilled.

[ricebike]

one of many low-idle-speed causes: carbon buildup @ the throttle body plate/valve.

remove the plastic/rubber intake boot & do a visual; most likely black w/ crud.

proceed to get a can of intake cleaner/ TB cleaner/ <in a pinch, carb cleaner> spray/wipe/old toothbrush

may/may not have starting problems after doing this; I just let the remaining cleaner fluid to evaporate before starting my engine up again...

[navysnail]

so your idle is just low when the ac is on?

there is a valve that regulates airflow into the engine, when you turn on the ac the valve should open up and bump up the idle

[altralosix]

so your idle is just low when the ac is on?

there is a valve that regulates airflow into the engine, when you turn on the ac the valve should open up and bump up the idle

No, it's the exact opposite. When the air is on it's fine. It only drops too low with the air off.