240sx hard idle/knocking

[tags]

First post, hate that I didnt get to dig around more before I had to come crawling, but a friend told me this place may be able to help me and here I am

So I've got a 92 convertible 240sx. I'll just walk you through what the last month or so has been.

The car started idling low and almost stalling out and shutting off at takeoff. My buddy adjusted the idle screw and it fixed it for about 24 hours, then once it got warmed up the next day it started doing it again.

Now

It started idling very hard recently. But it seemed like as long as I stayed on the gas it was perfect. Then it started getting to where it shook even during acceleration, and now knocks/ticks up to around 20 mph or so then evens out. This is where I am now, and when the car is sitting still idling it shakes violently. The oil level is fine... (Although I did make a 75 mile trip with it low the other day)

Once I get paid I plan to buy spark plugs (yes I'm too broke to buy them right now even tho they are cheap), and clean the MAF Filter/Sensor.

Another thing to note,I read in another thread that this wouldnt matter but im just going to throw all my info out there. My roomate said that my coolant resevoir shouldnt be full ALL the time and the water shouldnt be almost black and that I should check the hoses for clogs and flush my radiator... which I havent gotten around to yet.

I'm now seeing my 240 pay for my procrastination and I do love this car. Any and all insight into my idle/knocking problem would be greatly appreciated. Thanks!

[moso]

Sounds like you should start with oil and filter change then move on to a compression test. I believe you can rent one from one of those chain parts stores. The test is simple, remove all spark plugs and remove the fuel pump fuse. install the tester in the first cyl, hold open the throttle and crank the engine. all cylinders should show over 150psi with less than 15psi variance between cylinders.

[tags]

Sounds like you should start with oil and filter change then move on to a compression test. I believe you can rent one from one of those chain parts stores. The test is simple, remove all spark plugs and remove the fuel pump fuse. install the tester in the first cyl, hold open the throttle and crank the engine. all cylinders should show over 150psi with less than 15psi variance between cylinders.

What specifically am I asking to rent?

[moso]

compression tester.

[tags]

One more stupid question... Should I be using 10w-30 or 5w-30?

[moso]

meh, depends on what your driving conditions are and the time of year. either will keep your motor from exploding, nissan suggests 10w-30 and that is probably what is best for your daily driver.

[tags]

ok, oil changed and new spark plugs. The plugs were straight nasty. The compression test was iffy because the hose wasnt secure on the gauge so I'm not sure we got a good seal.

but the good news is after an oil change and spark plugs it's running fine again. still idling slightly hard but def not as sluggish