My car overheating issues(pics)

[Pblesh85]

Ok I have been having some overheating issues with my car ever sence the swap was done. Here are my specs as listed.



1993 240sx SE with hud


S13 SR20det blacktop 30k miles(Auto..yep Auto, it was cheap)
Tub manifold with Metal gasket
GT2560R-466541-4 (GT28R) Dual Ball Bearing Turbo w/Internal WG
Alum adap's for the turbo
S15 oil return
S14 water neck
Earls oil and coolant lines (with restritor)
upgraded exhaust elbo
3" down pipe
3" test cat
3" exhaust
oil catch can
new water pump
New gaskets
30x12x3 FMIC
HKS SSBOV (New Style)
WAL 255 fuel pump
Battery relocated to trunk
New Radiator with dual Mishimoto Fans
DIF fan contoller
Alum coolant tank
Brake Heat sheild...
All new hoses and Belts (gates)
Mobile 1 synthetic
Nissan Matic D trans fluid...
KYB Silver with AG springs 1.8 drop (less 1500 miles)
Cross drilled rotors
New brake pads..

Mint S13 carpet
JDM turn signals
S14 seats
AEM tru Boost
G/S AIR fuel
Center vent with (G/S Boost/Volt)
HKS Old school Turbo timer
Kenwood CD player
Kenwood 6.5 front and rear..
Front and rear upper Strut bars.

not installed yet:
New Excedy clutch kit
New 15lb Flywheel
Sr20det 5 speed starter
New trans Spacer shim
New Manual Trans Bellhousing bolts
New SR pressure plate bolts
New SR flywheel bolts
New Nissan shift boot
Clutch Pedal
Brake pedal
Clutch Master Cyl
S13 Manual Drive shaft
S13 manual Cross member

pics:
http://s105.photobucket.com/albums/m205/Pblesh85/My%20damn%20car/

So thats what im packing for now(more to come SOON, alot more).

My problems: After about 15 min driving my car starts to overheat.

So my fix: I bleed the cooling system and the air trapped inside.

Results: It seemed to help then it started to do it a bit worse. It melted the fluid level tube in my over flow tank(fixed with some samco hose I had laying around) and would overheat alot faster.

So my fix: I bleed the cooling system and the air trapped inside(AGAIN).

My problems: When I screw the bleeder bolt on the water neck back in it strips the water neck.

So my fix: I buy a new s14 waterneck from west covina.

Side note: I did not know it was ported to run your coolant line for the turbo directly off the waterneck. Thats cool and all but I do not want to reroute my coolant lines until I build my block up(after my deployment in july). So I went to NAPA and bought a oil drain plug and screwed it in with a gasket(fits perfect, looks oem). Just food for thought if you want to buy a s14 waterneck and do not want to reroute the water lines yet.

My problems: So it helped out a bit but its still heating up.

WTF ??? I think its due to a few things. Im running a new oem ka rad. and I know its too small. I also think that because the auto trans requires coolant that it adding to the problem.

I am going to order my koyo this comming week(3-4 days, waiting on a check to come in) an hope to god that when it comes in it will solve the issue. Im doing my 5 speed swap in a day or two and hope it will relieve some excess heat.

Other than that my car runs perfect. Aside from having to drive with the heater on after 15 min.

So if you have any thoughts please help me out. Also please read all post before offering advice as your suggestion may have been covered.

[GSXRJJordan]

The fact that you're running a KA rad shouldn't overheat the car in 15 mins, unless you're on the track/driving WOT for those 15 mins.

My guess, and this is just probability speaking here, is that you're not bleeding it right/long enough. Take a look at the FSM for steps that need to be taken (S14 SR20 FSM has the steps for SR20). Make sure the heater's on, and it may help if you elevate the front of the car a little bit to help the air get out.

[corriganjoshua]

Have you checked your thermostat to see if its getting stuck?

[GSXRJJordan]

Yeah, that's a good point... is the lower radiator hose heating up, or just the upper? You might have a pocket of air around the thermostat that isn't letting it open.

[Pblesh85]

Im running the heater when I bleed it, im not jacking it up, but im parking on a hill facing up. I open the rad. cap and loosen the bleeder bolt. I fill the rad. until it stops bubbling and lowering(fluid level), then I put the cap back on and keep the bleeder bolt open for 10-15 mor min. The heater is on high the whole time.

As for the thermostat, its a brandnew nismo unit. I have tried two brandnew ones. And my waterpump is a brandnew oem unit.

[RedtopTech]

I also agree that the thermostat is likely the culprit. Also i have never seen an s14 waterneck but could the plug that you installed be protruding into the neck to far and limiting flow?
Also with the engine cold and off, fill the radiator with the bleed screw removed until fluid comes out. Next start the engine and allow it to warm up to normal temperature with the heater on and continue to top off the fluid until this time. Then install the bleed screw and take a quick drive. Without shuting down the engine, remove the screw again, top off as necessary.
With these possiblities ruled out, i would recommend that you chemical test the coolant system for the presence of hydrocarbons ($30 at any repair shop) which would indicate a leaking headgasket (at best.) You could also have the rad cap off while at idle to look for any air bubbles which would indicate the same issue. Small leaks that occure at higher temps and higher cylinder pressures wont always show up in a compression test although it is another test to try. If you have access to a leakdown tester you could perform this test with the rad cap off which would also show up as air bubbles.

[Pblesh85]

Thanks for the info, I will give it a try in an hour or two.

[Pblesh85]

Ok I bled it as you said. I did it for 20min or so and went for a 10 min drive. It did help but it started to climb again. Not as bad as norm. but it still went up.

It was boiling when I took off the cap after my drive(car still running) but there were no bubbles. It did overflow into the overflow tank, 6-8oz. I replaced the lost coolant and topped it off. I then turned the heat on and it stopped climbing.

The red area is the ideal temp. The green is what is going on if I do not run my heater when I drive after 15-20 min.

Also there are no visible leaks or signs of leaks on the ground.

[downshift_sideways]

Try replacing your coolant temp sensor.

Are you leaking any coolant whatsoever??

[WangonwWarrior]

KEEP BLEEDING lol could be sensor ^^^

[Pblesh85]

I will replace it when my rad. comes in. And NO coolant is leaking.

[RedtopTech]

headgasket.....

[GSXRJJordan]

If it's getting better, keep bleeding it. I was having problems as well when I put my engine back together, and what ended up being easy/quick (and worked) was once the car's hot, crack the bleeder bolt enough to feel pressure escaping, and then once you get water dripping down constantly, tighten it back up. Leave the rad cap on.

Takes 10secs, can be done/repeated anywhere, and will bleed the air from the system. After 10 times or so, I wasn't getting any air at all (as soon as I'd crack it, water would come out), and my temps are good.

... if it doesn't get better, it's probably your head gasket. Compression test may or may not tell you anything, but you might as well do one.

[Pblesh85]

I will try and check it tomorrow. I will post my results.

[Pblesh85]

Ok, I did my compression and its 164 in every cylinder. Im still not sure what the issue is.

[downshift_sideways]

how did you perform your compression test?

164 is an above average compression.

What size is your restrictor by the way for your coolant line?

[Pblesh85]

oops my bad, I meant 154. I just used a standard compression tester(autozone type)

[mifesto]

even 154 isnt bad. are you overheating on cruise too or at idle/low speed? or both

[Pblesh85]

At speed too, but not as bad. If the heat is on it almost stops it.

[Pblesh85]

oops my bad, I meant 154. I just used a standard compression tester(autozone type)

Scratch that, I wrote down each cyilinder as I did it and I was correct the first time. Its 164 in all cylinders.

[S13_SideWayz]

well i havent seen any one w this idea yet. bt here goes nothing.
try running it without a thermo. c how it runs..
and while ur at it.. get ur thermo. and put it into bowling water c how it open. closes.

[japslapsilvia]

the best way i found to bleed these car's is to take 20oz waterbottle cut the bottom off wrap the neck with electic (sp) tape (the end you drink out of) put that in the radiator where the cap is..ite must make a tight seal if not keep wrapping with tape...use that as the fill point....keep the bottle at least half full....and bleed normally...u will see the bubbles come out of the bottle...

[Pblesh85]

the best way i found to bleed these car's is to take 20oz waterbottle cut the bottom off wrap the neck with electic (sp) tape (the end you drink out of) put that in the radiator where the cap is..ite must make a tight seal if not keep wrapping with tape...use that as the fill point....keep the bottle at least half full....and bleed normally...u will see the bubbles come out of the bottle...


I will give that a try, thanks.

[Pblesh85]

I went to go bleed the coolant system, but the water was at the top of the radiator just below the tiny hole to go to the overflow tank. There were no bubbles coming out even after I turned the car and the heater on, and loosened the bleeder bolt.

I believe my coolant system is bleed as best you can.

How far should my overflow tank be filled with coolant?

Im thinking that when the fluid starts to boil and the radiator cap opens (1.3 bar) and fluid is let out into the overflow tank that air is coming back in through the hose linking the overflow and the radiator.

But if this were happening then how would the air escape after the car is shut off and cools down? If this were happening and air was being sucked into the coolant system then when you open a radiator cap bubbles would come out if the fluid were at the top of the radiator neck.

Any thoughts? My compression is fine. There are no visible leaks. If the engine and gaskets were all in proper working order; what else could it be? (Assume that my thermostat and water pump are working correctly- they are NEW-Nismo thermostat brand new, and OEM water pump also brand new)

Could an automatic transmission be causing any problems with my cooling system seeing how it requires coolant. I don't know crap about automatic and it won't be that way long before I do my 5speed swap.

[S13_SideWayz]

ok ur overflow tank has a little mark that says max! well up to there.. and i had da the same problem .. am telling u .. take out the thermostat.... run it like that.. c how it runs! do u have an aftermarket thermo? or OEM? if so OEM is ALWAYS better! run it without the thermo. and lmk.

[Chrischeezer]

raise the front of the car up (so the rad. cap is the highest point of the car.) about 3 feet off the ground then bleed the system out at 2k rpm's
all the air will rush to the top.

[mifesto]

i've heard of people installing the thermo backwards, that can overheat you for sure :)

[njd07]

sounds like you have a leak in the system. check the heater hoses, hoses under the intake manifold and the radiator hoses. I can alsmot gaurantee you have a leak somewhere. worse case scenario its the headgasket.

[downshift_sideways]

Even the smallest leak will make you overheat with a turbo'd car.

I had a small leak @ my heater core/hoses...it was only dripping...and my car overheated within 10 mins of driving.

Your overflow tank is a pressurized system...but even if air got inside the tank...it wouldn't force oxegen into the collant lines. (60% or so of 240sx owners have a cracked coolant overflow anyways :keke:)


1. Bleed coolant system. CHECK*
2. Check compression in cylinders. CHECK*
3. Check for any possible coolant leaks. CHECK*?
4. Check coolant temp sensor...
5. Check Thermostat? (If working fine..try running without it)


Well I re-read your post and you stated that this problem happened soon after you swapped in the motor.

So something is wrong with the motor.
Your also running a KA radiator on an SR. So You needed to run a larger hoses to fit. Which is no problem...and running a KA radiator shouldn't make you overheat.

I'd suggest you check the heater hoses located on your firewall.

You could have possibly broken the neck that goes inside the firewall during the swap..