Bad?

[Turtle]

Look at this picture here. Even after hours of hard driving the needle won't go any higher than this. No overheating what so ever. The coolant in the reservoir does bubble though. My radiator is plastic and I heard that one day when they went drifting the top of the radiator blew off of an s14 it was plastic...

The previous owner of the car put, new water pump, thermostat, flushed the radiator, new hoses. Basically changed all that stuff.

I don't want to drive my car if my reading on the gauge is wrong.

http://i35.photobucket.com/albums/d175/oscarzzzzzz/DSC02676.jpg

[Turtle]

Also, when my car reaches about 5,400 RPM it backfires. It idles at 1,900 RPM thats way too high don't know how to fix that, only on my old dirtbike .:loco:

[NemeGuero]

yah thats not good. I don't know why it would do that unless your thermostat is opening too early and never closes. Replace that.

The FSM details the procedure for adjusting your IACV.

and the back fire is cuz you need to replace your O2 sensors.

[180sx_Drifter]

change your gauge cluster and see if that works.

[SINxSELEKTAH]

it's probably just the sending unit not reading the right temp. if that is the actual temp of the engine, the only thing bad that would happen is poor fuel economy from running rich and you won't pass an emissions test

[Turtle]

Could it be a bad CTS?

[SINxSELEKTAH]

Could it be a bad CTS?

couldn't tell you that for sure. use your best judgement. warm up the car, pop the hood and check with your hand (don't put it directly on the engine). most car's normal operating temperature is usually around 190-210.

[tt99ol]

thats what i was thinking the cts might be bad, when its fully warmed up does the heater blow hot or is it just a little warm?

[Turtle]

My car doesn't have enough gas right now to tell about the heater but, the AC throws out warm air... =/ When I open my hood after driving and I open my bros hood also, 240sx my engine bay feels about the same temp. I changed the 02 sensor about 2-300 miles ago. It was a universal one.

[HS13KLS]

deff sounds like i believe there is an IAC valve.. maybe that. (idle air control) or best luck with the thermostat

hope that helps a little

[PoorMans180SX]

If he got some cheapo autozone thermo, then you should change it out for a dealer-sourced one anyway.

[The Chad]

+1 for a bad sending unit. My sending unit was bad on my old S14 and always read way too high or way too low. Replaced it and good to go :) . Now it's starting to happen on my current S14, but i know better now haha. :)
---I will add that it sounds like you have a few other problems on your hands as far as the backfiring and poor idle. Some good advice above as far as the 02 Sensors and such,...well good luck man!

[Dream240]

You're idle can be adjusted by turning the small screw attached to the IACV.

The IACV is located on the intake side of the engine, below the EGR, up near the firewall. Get a flashlight and peek down there, you should see a silver screw facing you. You can get to it with a short hand flat head screwdriver. Wish I had a pic of it but you should be able to find it.

To make sure you got the right screw, start car and proceed to tighten the screw, you're idle should drop. Don't tighten it too much!! It's a sensitive part and you can break the screw off in the IACV, then you're eff'ed. Loosening the screw will raise idle obviously.

As far as the temp problem, can you get access to a temp probe? if so, just warm up your car and check the temp of the hoses, you should have about 165 C on your top hose for the OEM thermostat. If so then it's either your sending unit, temp sensor, or gauge.

The temp. sending unit you can get here:

http://shop.nissanpartstore.com/buy.php?make_text=nissan&model_text=240sx&ml=240-sx-002&year=1991&part_name=water_temperature_sender&brand_name=nippon_thermostat&r=1&make_code=NI

The temp. sensor is here:

http://shop.nissanpartstore.com/buy.php?make_text=nissan&model_text=240sx&ml=240-sx-002&year=1991&part_name=water_temp-dot-_sensor&brand_name=nippon_thermostat&r=1&make_code=NI

GL

[JRas]

my car idles high until it's warmed up

your car should idle at 650rpm I believe

[Timeattack]

Definantly change your thermostat if that doesnt help, here is an old trick i learned that is very helpful------- After you have driven you car for a few minutes and you are sure it is at operating temp, let it idle for a minute or two then put a few drops of water on the block or head (if you can find a good spot) if the water sizzles and boils right off, your engine is 200+degrees, if it just sits their, your engine is less than 200degrees. I havent tried this on a 240 engine but it works on machines i work on that dont have temp gauges. hope this helps

[LA_phantom_240]

High idle, backfires, overheating (coolant boiling)... sounds like it may be a combination of timing and check to make sure the throttle isn't being kept open by your Cruise control cable and throttle cable. Also, make sure everything in the cooling system is in check.

[Turtle]

Well, I lowered my idle to around 700 RPM now there is an annoying rattle coming from what seems to be the front of the engine. My car doesn't have cruise control. I need to get a timing light to see how to do the timing right, but I did it by hearing it only and the rattle got a little less noticeable. But not when ever I switch gear it backfires it didn't do that before I lowered the idle. The car is at normal operating temp well, don't know about normal but, the way it usually operates.

[LA_phantom_240]

Well, I lowered my idle to around 700 RPM now there is an annoying rattle coming from what seems to be the front of the engine. My car doesn't have cruise control. I need to get a timing light to see how to do the timing right, but I did it by hearing it only and the rattle got a little less noticeable. But not when ever I switch gear it backfires it didn't do that before I lowered the idle. The car is at normal operating temp well, don't know about normal but, the way it usually operates.

Rattling from the front of the engine? Timing chain.
Before I go any further, search 'timing chain rattle'. :ughd: