S14 Overheating Intermittently

[LA_phantom_240]

Okay guys, here's the situation. My S14 has started some intermittent overheating in the last week. It started last Saturday (the 6th) on my way back home from the beach with some friends. I was sitting at the last light before the open road, and happened to notice my temperature gauge was just a bit higher than usual. It was at exactly halfway in the normal operating range, which was about 1/6th higher than usual. I realize the stock gauge lies, so I keep an eye on it. Well, the light is long as hell, and the temp climbs slowly. I shut the A/C off to slow it down a bit, and roll down the windows only to find I can't hear my fans. The light changes in the nick of time, and I hit the highway and the temp plummets. I get to my friend's house to drop him off, and open the hood and notice the fan fuse is blistered and toasted. I couldn't see anything immediately wrong aside from that, replace the fuse, and head home.

Well, I haven't driven the car much this week because I had the flu. I didn't notice it overheating at all, and the fans worked fine. Today, however, I noticed at another traffic light that my temp was just a tiny bit higher than usual, so again I shut the A/C off, and it goes normal. Tonight, I was driving home with the A/C on again, and it was just fine cruising. At a light, it crept up... a bit faster this time, even after shutting the compressor off. As I turned into my neighborhood, it was close to reaching the top line of the normal range. I turn down my street, and it starts to touch that line, so I shut the car down and coast into my driveway. The fans are on like they should be, and so I cranked it up and let it circulate til it was cooled off.

Here's what I'm running
KA24DE
CX Racing Aluminum radiator (Yes, I cheaped out.)
Flex-a-Lite 220 fans
DIF fan controller, 1st fan set to 176*, 2nd at 190*. Both fans come on on a hot day with the A/C on.
1 Bottle Water Wetter
Just a little glycol
Distilled water

Here's what I'm thinking
Sticking thermostat - I haven't changed the thermostat in the motor, which I put in the car last August. Yeah, I should have while the motor was out, but whatever. I guess I wasn't thinking hahaha.

[Sileighty_85]

Yeah sounds like a sticking thermostat

[LA_phantom_240]

Good. Well, when I get less lazy I'll change it... lol. Still feelin a bit under the weather.

[0wn3r]

bleed your radiator, or make sure it's full at least. i had that prob with my KA and a flush n fill took care of it.

[gprb25]

Thermostat seems like a good bet.

If the problem still occurs, then I'd look at the water pump.

[Def]

Thermostat. I'd also check for a blown HG. Could have happened with the first overheating.

[LA_phantom_240]

Thermostat. I'd also check for a blown HG. Could have happened with the first overheating.

It's a possibility. A very small one, albeit.

[OBEEWON]

No leaks anywhere? Im in agreeance with sticky T-Stat since it goes down on the highway. But before you replace it do what 0wn3r said, make sure the heater is on full blast.

[Def]

It's a possibility. A very small one, albeit.

You'd be surprised. The easiest(only?) way to warp an aluminum head is to overheat it while it's torqued down to an iron block that doesn't expand at the same rate as it does. Aluminum/aluminum engines don't tend to have that problem.

[LA_phantom_240]

You'd be surprised. The easiest(only?) way to warp an aluminum head is to overheat it while it's torqued down to an iron block that doesn't expand at the same rate as it does. Aluminum/aluminum engines don't tend to have that problem.

True, true. But there's no oil in the coolant, and the oil doesn't look milky. Also, there's no white smoke, so hopefully I'm in the clear.

No leaks anywhere? Im in agreeance with sticky T-Stat since it goes down on the highway. But before you replace it do what 0wn3r said, make sure the heater is on full blast.

I don't think there are any leaks. I haven't smelled coolant, heard any hissing, or noticed any change in coolant level. I'll check it out though. About making sure the heater is on, I can't do that. The heater doesn't work; the valve that opens to let hot coolant in is frozen shut. It's been like that since I've had the car (two winters, lol). I gotta change that this winter though. I actually have a working blower now, so I'm gonna want heat this winter lol.


I got a thermostat from AutoZone, a gasket, some RTV, and went to town. The thermostat looked kinda grodey. The black rubber surrounding the plunger (for lack of better terms) was mostly gone, and it looks like the whole moving assembly is a little bit off center of the hole. Also, there's a strange wear pattern on the brass the spring surrounds; it's shiny and worn on one side, indicating it has been rubbing against other metal parts. This wear pattern only went roughly halfway up, which indicated to me that it could have only been opening halfway and getting stuck from off center movement, and binding up. I'm waiting on my RTV to cure before refilling the cooling system (drained the radiator and flushed the motor with the water hose) with 1 bottle water wetter, ~75% distilled water, ~25% Glycol antifreeze.

[LA_phantom_240]

UPDATE: Replaced the water pump as well. Had mega overheating. I forced water in the radiator with the bleeder open, closed everything up, and gave it a shot. Also, disconnected the cable that actuates the heater core so that I could open it up to help the bleeding process.

The temp gauge is now rock solid while standing still idling/revving. Both fans come on, and the lower radiator hose isn't hot to the touch. I'm wondering if maybe the radiator is cooling efficiently enough that it doesn't get the lower hose hot?

Then again, I could just be thinking with my ass.

[steve shadows]

Step1:

Do a radiator pressure test you can borrow the unit from a Kragen with a deposit

Step 2:

Do a compression test when the motor is cold and one when hot (make sure to pull fuel pump and ignitor chip and to keep throttle plate pinned open)

Step 3:

Is your coolant being drank?

Step 4: check to see if your cooland system is ever boiling over when the gauge goes crazy

If it is not boiling over and your compression is good changes are your gauge just sucks

Step 5: you may be getting a butt load of hot air in your system, these pockets are causing your problems. Make sure your sytem is in good shape, ie no radiator leaks

Step 6: Upgrade your radiator to a two pass, PWR makes the best one for th the money. Two pass radiators have less chance of getting air insystem due to design and use a high pressure cap.

Step 7: Most importantly all SR20 cars that are raced and are Swaps into american or different chassis shoudl be using

A. Nismo Thermostat
B. Swirl Pot (Or coolant surge tank)

Please search for Swirl Pot write up and buy one immediately, I will bet you if these isnt something damaged already then this will fix your issue if it's just an air in the system issue.

Step 8: Invest in Apexi or PE headgasket with Integrated Fire Ring around cyinder design. This lockd in cylinder pressure and will never allow blow through into cooling jacket especially when used with high torque yield studs like Mazworx or ARP studs

Step 9: do all of these things in order and add some colder heat range 8 spark plug and

and 10:

A. your car will never overheat no matter what
B. your car will make more HP because it will be more efficient and never leak in the cooling system
C. your motor will last much longer and bearings will have less scaring
D. your motor will be easier to drive and more pleasant and reliable

Enjoy!

[LA_phantom_240]

Step1:

Do a radiator pressure test you can borrow the unit from a Kragen with a deposit

I have a pressure tester here at my house, and it held just fine.


Step 2:

Do a compression test when the motor is cold and one when hot (make sure to pull fuel pump and ignitor chip and to keep throttle plate pinned open)

Pardon my being naive, but what will this accomplish, aside from bringing me to tears after finding out my KA is worn out?

Step 3:

Is your coolant being drank?

Nope. It's just chilling.

lol. Pun. If it were chilling, I wouldn't be having a problem here

Step 4: check to see if your cooland system is ever boiling over when the gauge goes crazy

If it is not boiling over and your compression is good changes are your gauge just sucks

It's not boiling over. I don't let it heat up to that point, because then I know something will get messed up.

Step 5: you may be getting a butt load of hot air in your system, these pockets are causing your problems. Make sure your sytem is in good shape, ie no radiator leaks

I know where there's an air pocket, which is likely the cause of my problem. The lower hose neck before the thermostat is holding air. Apparently, the jiggle valve isn't doing it's job, so I'm gonna go ahead and make a modification to the thermostat.

Step 6: Upgrade your radiator to a two pass, PWR makes the best one for th the money. Two pass radiators have less chance of getting air insystem due to design and use a high pressure cap.

Bah. The car's a DD, not a race car.


Step 7: Most importantly all SR20 cars that are raced and are Swaps into american or different chassis shoudl be using

A. Nismo Thermostat
B. Swirl Pot (Or coolant surge tank)

Please search for Swirl Pot write up and buy one immediately, I will bet you if these isnt something damaged already then this will fix your issue if it's just an air in the system issue.

It's a KA. Furthermore, I need the car daily, and can't wait on a thermostat to come in, and a swirl pot is overkill.

Step 8: Invest in Apexi or PE headgasket with Integrated Fire Ring around cyinder design. This lockd in cylinder pressure and will never allow blow through into cooling jacket especially when used with high torque yield studs like Mazworx or ARP studs

Maybe some day when i decide to build a KA for turbo.


Step 9: do all of these things in order and add some colder heat range 8 spark plug and

and 10:

A. your car will never overheat no matter what
B. your car will make more HP because it will be more efficient and never leak in the cooling system
C. your motor will last much longer and bearings will have less scaring
D. your motor will be easier to drive and more pleasant and reliable

Enjoy!

I couldn't have asked for a more reliable car so far. A cooling system problem isn't a biggie... except for it's a KA. I'm seeing now how hard it is to bleed them.

[0wn3r]

Honestly dude, you should have just bled it first.

i've got an SR and pretty sure i'm not rocking a nismo thermostat

[LA_phantom_240]

I've bled it. Multiple times. It doesn't overheat while idling/revving anymore, but as soon as I put a load on the motor, the temp shoots up. The last thing I have left to replace is the radiator cap, and continue bleeding. This go round, I did notice that the coolant did move to the overflow tank, though it never really bubbled like it was boiling. Maybe the radiator cap isn't holding pressure.

[Gnnr]

Go to the DEALER and get an OEM Nissan Thermostat and Radiator Cap.

Don't trust those cheap auto parts store made in china garbage replacement parts. They're always made of the cheapest metals on earth. Those two items are so cheap at the dealer anyways why bother with an auto store one? Since you have an aftermarket radiator I would get a name brand radiator cap since you may need a different pressure rating than OEM.

Check the car after its sat overnight and it is absolutely cold and check the radiator coolant level and the tank.

[LA_phantom_240]

Go to the DEALER and get an OEM Nissan Thermostat and Radiator Cap.

Don't trust those cheap auto parts store made in china garbage replacement parts. They're always made of the cheapest metals on earth. Those two items are so cheap at the dealer anyways why bother with an auto store one? Since you have an aftermarket radiator I would get a name brand radiator cap since you may need a different pressure rating than OEM.

Check the car after its sat overnight and it is absolutely cold and check the radiator coolant level and the tank.

Don't have a ton of money right now to go buy OEM shit, cause I've been sick and not at work.

Also, don't have time to let it sit overnight right now. If I can't get it right by the end of the night, yeah I'll check.

[Gnnr]

Fuck. I guess you don't care. Take it from someone who has a warped head and blown headgasket.

Thermostat $20.71
Radiator Cap $24.33

That's the prices at my local dealer and if you get it from one of the online dealers I bet it'll be cheaper.

[LA_phantom_240]

Fuck. I guess you don't care. Take it from someone who has a warped head and blown headgasket.

Thermostat $20.71
Radiator Cap $24.33

That's the prices at my local dealer and if you get it from one of the online dealers I bet it'll be cheaper.

Getting it from somewhere online like West Covina would be an excellent idea, except that this car can't spend time inoperable waiting for parts to come in. It's my only car.

If the radiator cap from my old radiator doesn't fix the problem, the thermostat is going bye-bye til winter comes around.

[Gnnr]

Well, run it without the spring then like this:

http://img337.imageshack.us/img337/4999/tstatrestrictortncl0.jpg

I had the same problem, would overheat with the thermostat so I left it without the spring. Ran it like that for almost 2 years but now the shit finally gave way and I'm going to have to redo the head.

[LA_phantom_240]

Well, run it without the spring then like this:

http://img337.imageshack.us/img337/4999/tstatrestrictortncl0.jpg

I had the same problem, would overheat with the thermostat so I left it without the spring. Ran it like that for almost 2 years but now the shit finally gave way and I'm going to have to redo the head.

You wouldn't happen to have a bigger picture, would you? I can't really tell what's going on there lol.

[Gnnr]

Cut out the spring components and just leave the shell so that that it doesn't let ALL the coolant flow freely.

[prodigyJJ]

This is a stupid question that I am about to ask, but I've seen this a million times. Are you filling up your radiator/overflow tank with the motor off. It is a super-basic question and I'm sorry if you get offended, but make sure you top off your coolant system with the motor running.

[youngkadafi]

Edited

Delete

[Bigsyke]

What racepar said is spot on.

Get a swirl tank, if your going to put gas in your car, you might as well spend some $$$ on a swirl tank and adaptors.

May be the fact your using water wetter and 25% glycol and distilled. Ive researched this up and down to come to the conclusion, you want 50% coolant due to (osmosis (sp?)) which will also help with hotspots in the head that will cause pockets of steam with 25% glycol. Even with a 1.3bar cap, you still want 50% coolant.

Using water wetter and 25% glycol you can actually burn a hole in your aluminum when it boils. I bet your boiling in the head, thus causing air pockets to register on the temp sender. I ran 20% coolant, 1 bottle of WW and distilled water for about the 1st half of summer. I was losing coolant with the OE cap 0.9bar. Even with the z32 cap I was losing coolant because i removed the EGR system. Again if you read below ive changed my coolant system about 10 times in the past month (ie. newer hoses, thermostat, blow radiator, capped some lines, clipped the jiggle valve etc) I have waiting at home are some new OE hoses, nismo thermostat (required IMO esp if you have AC)Swirl tank adaptors and some fresh honda type II coolant.

If you live in a warm area, snip the jiggle valve off the OE thermostat ($15). GMB water pump only, and use honda Type II coolant.

Again use the water wetter, but with 50% coolant, running 75% water will not help your engine run cooler, in fact it could make it run worse when the hot spots in the head boil over at a microscopic level.

If you dont need a heater, id remove the whole heater core assmbly and loop the lower heater core lines, this will make bleeding a breeze, and REALLY allow the engine to work air bubbles out of the system as you drive because they dont endup at the highest spot (heater core hose @ firewall)

Make sure your PS belt tension is correct and its not slipping.

You probably are loosing coolant, which can be impossible to tell even at the resiviour and if you open the cap.

I had a small leak under the water pump and lower thermostat housing for months and didnt detect it untill I did a pressure test adn held it for 15 minutes at 19lbs.

Plus ive sait it 100 times. Its nearly impossible to fully bleed the system without the snap-on bleeder kit or a swirl tank.
In the past months ive probably drained/refilled my cooling system about 10 times. You need to pour the honda type II coolant slowly in the snap on funnel, and keep the front elevated. I usually fill the funnel almost to the top, elevate the front and run the engine untill the OE fan comes on @ 203F. Once that happens I shut it off and wait about 30 minutes for the air pocket to work its way from the thermostat. If you have clipped the jiggle valve you can continue to keep the engine running. The OE fan should stay on for about 8-10 seconds, if its any longer than that it has tripped coolant fan relay #2 which kicks in @ 212*f, thus you need to shut if off quickly and start squeasing hoses.

[LA_phantom_240]

I think I finally got it. I bled the shit out of it, keeping the funnel in the radiator neck full, squeezing all the hoses, and I drilled an extra hole in the thermo for air to escape. The jiggle valve is in a retarded location cause it's not all the way at the top, so I drilled a hole as far up as I safely could.

Funny, really, everyone complains about the KA being a bitch to bleed, and this is the first one that gave me trouble. Hell, me and a friend did his last week in his S14 like it was nothing.

[Def]

These engines aren't hard to bleed if you follow the FSM. No idea why everybody ignores the coolant bleed bolt and then complains that they can't bleed the system...

Nismo thermostats are also a waste, especially for a street car. Who wants a thermostat that opens before 150 deg F?



The reason why most cars here run so hot in traffic is the average person tosses all their underpaneling on the car, and you end up recirculating hot radiator exit air back to the front of the radiator again and again. Hard to cool things down like that. Plus they ignore the FSM for how to bleed the coolant, so they have air pockets in the system.

[LA_phantom_240]

These engines aren't hard to bleed if you follow the FSM. No idea why everybody ignores the coolant bleed bolt and then complains that they can't bleed the system...

Nismo thermostats are also a waste, especially for a street car. Who wants a thermostat that opens before 150 deg F?



The reason why most cars here run so hot in traffic is the average person tosses all their underpaneling on the car, and you end up recirculating hot radiator exit air back to the front of the radiator again and again. Hard to cool things down like that. Plus they ignore the FSM for how to bleed the coolant, so they have air pockets in the system.

This has been the first KA that gave me trouble bleeding, honestly. My car didn't come with the factory underpaneling.

On the plus side of things, the car's running perfectly. Only one fan comes on (176*) usually, unless it's incredibly hot and idling for a long time. So it's definitely not getting as hot as it used to before it started giving me trouble.

[Pacman]

Who says KA's are a bitch to bleed? You want a bitch bleed? Try a Celica/MR2 Spyder with the jacked up system of the pressure cap is on the reservoir. Takes FOREVER if you don't have a vacuum bleeder. I have never had a problem bleeding a KA.
Try getting one of these Amazon.com: Lisle 24610 Spill-Free Funnel: Automotive (http://www.amazon.com/Lisle-24610-Spill-Free-Funnel/dp/B001A4EAV0/ref=sr_1_21?ie=UTF8&s=automotive&qid=1245297526&sr=1-21) which allow you to fill the radiator and keep it full wheil bleeding. Raise the front of your car as well. Run the heater while bleeding to feel the heat with no kick-ups. Running no t-stat can cause overheating since the coolant isn't regulated. Just food for thought.

[LA_phantom_240]

That funnel is bad ass....

Yes, I'm running a tstat, and everything seems to be working fine now.