New to Nissan & the 240sx, help

[Silvia_pass]

Hello everybody, first time Nissan owner here. Bought a nice looking '95 240sx last night & can't get any sleep!! Excited to get this thing running and looking A1

First off the previous owner was cool & pretty much gave me full disclosure about the car before driving 2 hours out to look at it. Not much wrong with it really, just a few quirks.

The PO said there was an issue with the temperature gauge needle reading (HOT) then dropping ridiculously fast after a few seconds. Temp cyclically rises when stopped & idiling but will always drop just when you think it's going to over-heat.

( he said he swapped out the water pump / thermostat / hoses & the problem persists )

Soooo....

I visually inspected for leaks and checked on the reservoir fluid level.

No leaks, just no fluid in the reservoir. The reservoir itself has a cap and an extra hole punched out in it for whatever reason ( that hole is near the top, above the max fill line probably blew out from steam, I'll get a picture lol ) it probably has been drawing air in especially with the reservoir being empty. It won't matter when I fill & bleed though right? Or is that cap supposed to keep it pressurized? The hose comes into the reservoir from the bottom soo... Don't know. PO owner said he'd driven it like that for awhile and didn't really have a problem with it ( fluctuating temp) & chalked it up to a "sticky thermo" lol


So before leaving I filled it up ( the reservoir ) & drove the car 2 hours back home.

I hadn't even left the neighborhood before the factory temp. gauge spiked & dropped just as fast. With the car moving temp stayed halfway on the gauge.

I stopped for gas & just after leaving at the next light it predictably did it again. I hit the freeway & temp stayed halfway the whole ride.

Okay you know the rest, haha I've been home now & will be hitting up Nissan for OEM thermo & rad cap.

But most importantly getting rid of the trapped air in the coolant system. Don't really think it's a bad head gasket but I'll report back after a proper attempt to bleed it.

I know, the bleeder screw open & the heater on re-circulate while filling rad & watching for a steady stream from the bleeder valve.

Sorry for the long story, just pumped to fix this ASAP! Would I be better off getting a Nismo thermostat & cap?

Pretty much stock ka24de in the car now so not sure if I should use the lower temp stat - higher pressure cap lol

Would yall recommend a Koyo rad or Mishi? Maybe a better radiator than either one of those, don't mind spending money on quality stuff, pretty sure the po said car sat for awhile so getting a new rad might help keep things cool if there are any blockages in the rad now.


Thanks, I'll be back to update & post some pics.

[lunchmeat]

My temp gauge would jump around. Ended up being a bad temp sensor for the gauge. There's two temp sensors, one for the gauge, the other for the ecu.

[jedi03]

i have koyo, works great...I think mishimoto are pretty good too

[s13silvia123]

there's griffin, greddy, blitz, hks, base on your budget. KOYO has two types, the copper core or aluminum core. adding to the koyo there's also a 3 to 2 core as well.

[Silvia_pass]

Sorry guys, I can't get a picture to upload under 500 KB for now. Will try & play with my camera settings to get a smaller file size and show ya what I see.

Drivers side strut looks like it's canted & the spring doesn't seem to be sitting right. Car has 350z wheels so they're 18" but it's just that side that looks funny to me.

[Just Alex]

Maybe a bad temp sensor or some bad grounds? I personally run a Mishimoto and have had no problens, but have also heard good things about the Koyo. Either way you can't go wrong. Anyhow, hope you figure out the temp gauge problem!

[KAT-PWR]

Sounds like a fan issue if temp rises while stopped and drops while moving

[Crazyced]

Yeah change the sensor 1st, there are cheap. Make sure you change the gauge sensor, not the ECU sensor.

[Nissan2nr22]

Few things you should do:

Get a aftermarket temp gauge or radiator cap with temp measurement that way you can see if your car is actually overheating

Bleed the car properly using the bleeder, jack the car up angled, funnel and squeeze all the heater hoses and radiator hoses youll see crazy bubbles come up

Change temp sensor

If none of that fixes it its probably a bad cluster my silvias temp gauge jumped up and down and when i flicked it or knocked on it it would go back to normal (cluster bad)

[Silvia_pass]

I attempted to bleed the coolant through the screw and was getting good results ( air & then mostly coolant ) but I kinda panicked as I heard a fan kick on and some coolant started to billow out of the fller neck ( coolant doesn't seem to be flowing well although it did drop before billowing ).

I now know that the fan clutch might be bad. A friend of mine was dumb enough to shove his whole hand into the fan and stop it.

The rubber hose between the fuel hard-line and filter also ruptured when I first started her up this morning ( 4 inch piece of hose). Got that replaced... I took the car back out after kinda messing up the bleed / fill process and the temperature gauge still read hot - it came back down some but not dramatically like last night.

So far I'm convinced I need a radiator, oem clutch fan bearing? & a new oem thermostat... Any body in Ga can point me to a shop that can help button up this 240? I'm 30 min. N of Atlanta

[travon47]

Instead of just buying the most expensive and harder parts to replace, replace the temp sensor that the gauge runs off of. Also check how the wire on it is attached to the sensor because its only clipped on with a spade terminal and often becomes loose. You cannot just go to napa or where ever to get it because they only stock one (s13) but they say its for both, but it is not. an s13 sensor will put the needle way past the H when in an s14. Then rebleed . Also if the clutch fan was broke it would would raise in rpm when you rev the engine up and sound like an airplane taking off.

Originally Posted by Silvia_pass

I attempted to bleed the coolant through the screw and was getting good results ( air & then mostly coolant ) but I kinda panicked as I heard a fan kick on and some coolant started to billow out of the fller neck ( coolant doesn't seem to be flowing well although it did drop before billowing ).

I now know that the fan clutch might be bad. A friend of mine was dumb enough to shove his whole hand into the fan and stop it.

The rubber hose between the fuel hard-line and filter also ruptured when I first started her up this morning ( 4 inch piece of hose). Got that replaced... I took the car back out after kinda messing up the bleed / fill process and the temperature gauge still read hot - it came back down some but not dramatically like last night.

So far I'm convinced I need a radiator, oem clutch fan bearing? & a new oem thermostat... Any body in Ga can point me to a shop that can help button up this 240? I'm 30 min. N of Atlanta

[Silvia_pass]

I believe I got it, just re-did the bleed & capped it right after it stopped bubbling ( there was a lot of small bubbles that just kind of foamed out ) & finally topped it off again.

The rad billowed some but I made sure to top it off and massage the hose one last time before capping it. Car idles halfway even after running around.

Having late lunch now haha thx guys. Still going to go over the coolant system but she's running good ( got me & passengers to the taco shop )

Starting to like this thing, will try & get pics up by tonight.

[Silvia_pass]

So back to square one, somehow there is still air in the coolant. Might just have to do a compression test. I noticed the reservoir was bubbling up but not boiling over.

I'll ask again, will a hole at the top of the reservoir draw air into the coolant?

Will check oil level & coolant tomorrow morning.

[mechanicalmoron]

Originally Posted by Silvia_pass

So back to square one, somehow there is still air in the coolant. Might just have to do a compression test. I noticed the reservoir was bubbling up but not boiling over.

I'll ask again, will a hole at the top of the reservoir draw air into the coolant?

Will check oil level & coolant tomorrow morning.

No, there's a vent in the top stock, actually. You can silicone any shit you want over it if there's a part busted out, though.

Don't buy a radiator until you know what's wrong. Otherwise you complicate, not simplify. Don't buy any parts for your car without a clear idea of what will change and why when you install it. If it might fix a problem, that means you don't know what's wrong, so it won't fix anything, only break things.

When the motor's totally cold, if you bled it right the day before, when you take the rad cap off the level will be exactly up to it's bottom, with no bubbles and minimal fluid disturbance when you remove the cap.

It can help to hold the upper hose down, so it can't hold air above the level of the bleeder, as you bleed it. And like bleeding any car, a massaging both the upper hose and the throttle as you bleed it will give you much better and much faster results, and help you gauge how much of what's still in there.

Make sure you have a good radiator cap that can pass a visual AND pressure test - a common cause of coolant boiling into your overflow and that missing coolant eventually causing an overheat condition is a cap that can't hold the pressure that cooling system was designed for. Also, check the mating area under the cap and be sure that both the outer lip that seals the cap to the rad, and the lower lip, that seals the cap pressure valve, are clean and free of corrosion or knicks/damage. You can polish them with a scotchbrite, if they're crusty.

And, make sure your heater's on and car's up to temp when bleeding.

*edit* don't worry about a nissan cap.... unless you like spending more money on functionally identical parts that are only designed to last a season anyway.... Just get a quality replacement, they're all the same. The nissan of today isn't even the nissan that built this car, it's a generic part that nissan never made anyway. Go to NAPA, they'll have cap and thermo in stock, and the RTV you need for the thermo. (ultra grey/silver's good, cleans off well next time, and can be immediately fully torqued, though not filled for a while. skip the paper gasket. Also, it's good to have the tube, the grey stuff is the right and the best for most things on this car (or, any car), just keep in mind that it's 24hrs to cure).

Your head gasket is totally fine - don't go break everything because of poor diagnosis and superstition.

[mechanicalmoron]

Originally Posted by travon47

Instead of just buying the most expensive and harder parts to replace, replace the temp sensor that the gauge runs off of. Also check how the wire on it is attached to the sensor because its only clipped on with a spade terminal and often becomes loose. You cannot just go to napa or where ever to get it because they only stock one (s13) but they say its for both, but it is not. an s13 sensor will put the needle way past the H when in an s14. Then rebleed . Also if the clutch fan was broke it would would raise in rpm when you rev the engine up and sound like an airplane taking off.

Don't do this shit.

Check the sensor, because you should be familiar with it, but the wire coming off would make it read nothing, not high, it's simply got the signal or it doesn't. If you had the wrong sensor, it would not heat up and cool down, it would simply read consistently wrong.

There's no reason to suspect a sender from your symptoms - don't replace parts out of hope, that's stupid and makes your car worse and harder to diagnose.

[Crazyced]

You need to get one of these ASAP.




That will allow you to properly bleed your system. And if it still bubbles up like crazy after a while and the engine is up to temp then you can start thinking headgasket.

[5280VertDET]

Originally Posted by Crazyced

You need to get one of these ASAP.


That will allow you to properly bleed your system. And if it still bubbles up like crazy after a while and the engine is up to temp then you can start thinking headgasket.

I don't think they sell it at napa anymore, but:



https://www.amazon.com/EPAuto-Spill-...GHFCQS101NNH2C

[Silvia_pass]

Thx for all of the suggestions, day 2.

I checked the oil this morning and it's fine, the coolant was still at rad neck height. The reservoir was a little low though.

I bled the coolant on a cold start and had a geyser of coolant & air rush out out of the bleeder valve, took my gf to work ( not far away ) & still have fluctuating temp. I stopped by a friends shop & he said to try swapping out the fan clutch.

How many fans should this thing have? It has AC so there's a condenser in front of the rad but I can't see a fan on it. I haven't tried to use the AC, just the heat which blows hot as hell.

*I'm at a radiator shop now, going to have it looked over.

[KAT-PWR]

Jack the front of the car up and bleed via radiator cap.

[Trap Star]

I'll second the aftermarket temp gauge suggestion. Definitely a worthwhile investment. You out in Gwinnett?

[Silvia_pass]

OK, some light on the situation. The radiator shop I went to did a pressure test and it checked out fine so no leaks. Next they checked for combustion gasses in the coolant with the detector kit. The chemical pretty much stayed the same color although it was a bit lighter. Tech said it was probably not the head gasket. ( car doesn't smoke, no watery oil etc..)

Sooo I am for sure going to get a Nissan OEM temp thermostat and see how that goes. The tech at the radiator shop said the hose going into the thermostat housing was cold to the touch. The one on there now ( the thermostat ) was picked up from an auto parts store by the previous owner around the same time he said he did the water pump.

& for the poster who asked if I'm out in Gwinnett, yea.

Know of a good shop or person to give me a hand?

[Silvia_pass]

A friend of mine gave me a hand and we swapped in an OEM thermostat.

We also swapped a shredded alternator belt ( there used to be a 3 rib on there for a gates correct 4 rib belt ).

We bled the coolant via the radiator cap, ran the car for a bit & then closed it to let pressure build. After letting the car cool off some we topped off the radiator ( using straight up tap water at this point ) & repeated this process. We still have an over-heating issue at idle.

The fan clutch is shot? It's not engaging when the temperature climbs. Is it controlled by any sensor or just supposed to engage at idle when temps get high? I'll re-read the thread because some one did post something about a spade connection on one of the coolant sensors. Is it OK to swap both of these sensors with an auto parts store part or should I head back to Nissan? I asked Nissan for one of them & it was over $30 & a special order part so... Idk clutch fan is $50 at auto parts store & $180 at Nissan

In any case....

I don't want to rule out a bad head gasket yet, will be doing a compression test before swapping out the fan clutch.

I mean, the block test was inconclusive so if the compression test doesn't show even psi across the board we're going to do a leak down test. Any advice for doing the head gasket if it comes to it. How's the cometic & ARP kit? Any suggestions welcome.

[Silvia_pass]

OK, hate to leave things unanswered so here it goes.

After countless times trying to bleed the damn thing nothing worked except taking the thermostat back out.

It's just too damn hard to get all the air out. When I replace the fan clutch I'll throw the thermostat back in and fill the lower radiator hose before putting it back on the thermostat housing.

Me & a friend checked the coolant temp sensor with a multimeter & it's working fine so if I ever do run hot at idle it will be more than likely be because of the fan clutch ( it never engages even when hot but the AC fan does ).

Just glad I can finally drive without worrying it'll really blow the head gasket, I was pretty much 2 steps away from ordering the KA specific ARP head studs & a Tomei head gasket.

I'll get it sorted, thanks for all of the suggestions though really helped a noob out.

[Alpod]

Really shouldn't be that hard to bleed the car. As a daily driver (and even as a track car) I wouldn't recommend running without a thermostat as can prevent the engine from reaching operating temperature.

Get that spill free funnel that has been posted if you haven't already, makes bleeding a breeze. Just jack the car up as high as possible, run the engine, give the radiator hoses a good number of squeezes, make sure heater is on full blast if you have one, and rev the engine a couple of times.

Sounds like you still have air in the system along with the fan not cooling enough at idle.

[Silvia_pass]

Temp gauge hardly climbs at all now, my friend hooked up his obd2 scanner & cleared all the codes ( temp sensor came up because we unplugged it to test for continuity & volts. It read 4.75 V iirc we tested both sensors ).

We also pulled an egr code & cleared it but I'm pretty sure it tripped the cel again, oh well.

The only other thing we did was unhook the iacv & it helped with idle dropping when coming to a stop. We left it plugged back in and will try cleaning it later.

& I believe my mistake was not topping off the lower radiator hose "OEM" thermostat or not a huge ass air pocket is not your friend. Pulling the thermostat might help any poor soul stuck for the time being so there it is.

I'll update this thread anyways with a final solution ( will reattach thermostat once I get the fan clutch / & fill that lower hose before attaching it it to the thermostat housing ).

* the dead giveaway after all my unsuccessful attempts at bleeding was a super cold lower radiator hose no matter how bad I was over heating. The radiator wasn't clogged either, water came down and out the rad drain cock cleanly & swiftly.

BTW running straight water now lol no signs of rust in the system but will go back to a 50/50 mix in a bit.

[Kingtal0n]

Ive never had an issue with air in the cooling system on a 240sx. Ive never jacked up the car, I never used a funnel, I never did anything except remove the bleeder screw (on the sr20 there is a bleed bolt, on the KA I am not sure) and fill the thing with distilled water, carelessly, spilling it all over the place while pouring it in, and squeeze the hoses a bunch of times, and then keep spilling water all over the place, over and over squeeze and spill. Then run the engine and do it again with the cap off the entire time while it warms up. You can see the water flow through the radiator and little bubbles or w/e will come out bit by bit, you just keep on pouring water in carelessly (DISTILLED WATER) until it won't take anymore and the water gets too hot to touch. Then put the cap on and its done.

You need an OEM thermostat if you care about the engine. Proper coolant (water) temp is essential to longevity. I Would keep using 100% distilled water until you are sure the cooling issue is finished, fixed. THEN you can add coolant bit by bit and spill out some of the distilled water from the radiator hose. Using distilled helps because you can spill it and drink it, and do that anywhere you want and nobody can complain, you can just pull off the radiator hose or whatever and fool around with the system and nobody will complain about the green glowing fluid.

never use tap water in anything you care about, not even your body. Tap water contains ions which will conduct electricity (distilled water does not conduct) which will corrode the cooling system components by action of electrolysis.