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View Full Version : overheating problems... help :(


DaPCWiz
05-31-2009, 11:11 AM
My setup:
'96 s14
sr t25 on stock ka @ 7 psi
mishimoto radiator
altima cooling fans
obx overflow tank (stock tank doesn't fit, lol)

okay so I had to pull my turbo setup apart due to a gasket leak issue. Everything came back together well... ended up taking till like 1 am, but I wanted to take the car for a spin. Went a few miles down the road and it drove great... pull into a parking lot, and pop the hood to do a visual to make sure everything is good.

Things look good... its idling for a few minutes and I start to hear a hissing sound. I check my gauges... water temp is at 220!! I'm like wtf... I kill the car and start to look around. There is a ton of coolant under my car. I look around my engine bay and I notice my efans (altima fans) aren't powering up. I check the fuse and its completely melted! so I rip out the main power wire for the fans and connect it to the +12v in the fuse box... get the fan going. I let it cool down for a while with the car off... and then start it up and limp it home, shutting it off a number of times on the way to let it cool down (didn't let it cross 200 on the way home).

Next morning, I check the car... one of the coolant hoses to the turbo wasn't clamped down well and was pissing coolant. I rewired the fans so the fuse doesn't melt on me again, and I fixed the hose running to the turbo. Cleaned everything up, fired it up... look good. Drive it to my buddy's house like 30 miles away... temps 180-190 the whole time... seems to run really nice, no issues.

Car then sits pretty much for a week. I turn it on to warm it up, it seems to be running a bit warm for idle (normally idles at 180... I dunno what compelled me to check, but it was noticeably above 180). I use a rag and pop open the radiator cap... hiSSSSS! a ton of hot air comes out and the coolant level is noticeably low.

I top it off, fire it up... drip drip drip drip I see coolant coming down. I'm like wtf. I search the car desperately for a leak and can't find anything. I give up and assume the radiator itself is leaking. I swap out the radiator for the stock radiator. exact same problem! at this point I'm really confused... so I take it to a local mechanic that I know.

He looks at it and says everything looks okay... so we pressure test the system w/ the stock radiator. Coolant pissed out the overflow. We block off the overflow tank, pressure test to 18 psi.... no leaks, everything is perfect. We then pressure test the mishimoto (off the car) no leaks... perfect. Turned out the "leak" was from the overflow tank being overfilled and it was just dripping coolant. Basically he just told me to keep the tank half filled and it should be good.

Okay great. I take it home, swap out the stock for the mishimoto, put everything back together all nice, fire it up. everything works. 180 degrees at idle... like 195 cruising in traffic... 180-190 cruising on the highway. I even put it in 3rd and 4th gear for a couple miles cruising (to keep the revs constantly high... 4000-5000k), with the a/c on... 185-190 solid. car drove great.



I leave the car overnight (track day the next day)... fire it up early in the morning to drive out to the track day. Warms up, everything looks good. Not 4 miles out... temp is like 210 degrees... I'm like wtf. I pull over, check the overflow... its full and pissing out coolant. Shut off the car, let it cool down... temp drops to like 150 (car off, fans on) and the radiator starts sucking coolant back from the overflow.

I then tried to limp the car home... literally had to stop every mile, pull over, let it cool off... do another mile, repeat till I got it home. Additionally what was wierd... on the way home, the stock gauge showed that the car was overheating, but the aftermarket gauge I have was showing 180-190. Also had the heat on full blast to help with cooling.. and even when the stock gauge said "H" I was sometimes getting cool air from the vents...

I guess I have air bubbles now... but I don't understand why.

I don't think its the headgasket because I changed the oil... no coolant in the oil... and the coolant looks clean too, no oil in the coolant. No wierd smoke out the tail pipe, and the motor runs smoothly.

wtf is wrong with my car :( I missed a $265 track day today cuz of this. I just took my DD and went and watched in sadness.

fliprayzin240sx
05-31-2009, 10:53 PM
Did you bleed the system properly after you filled the coolant back up? I'd check the thermostat to see if its sticking, how olds the water pump?

I'd double check the water lines for the turbo and make sure theyre not leaking at all...

oni jake
06-01-2009, 01:18 AM
Do a compression test. I have a feeling it's going to be your worst fear.

DaPCWiz
06-02-2009, 03:08 PM
haven't tried anything else yet... but just did a compression test.

180-182-180-184. Gonna try again in a few to make sure. That means HG is good, right?

the 182 and 184 are best guesses between 180 and 185... u kinda have to guess between 180 and 185 there's no marks on the gauge.

redsx13
06-02-2009, 07:19 PM
your thermostat is sticking

I LUV MY S13
06-02-2009, 07:33 PM
i'd check tha thermostat

godsmack
06-03-2009, 01:50 AM
def. thermostat. think about it. engine pumps water out but cant pull any in so water builds up in the overflow then you notice the temps and then the water goes back into motor after you shut off the motor so it pulls some water out of the overflow.