Hi guys. Out of no where the temp gauge in my s5 gxl just started creeping up. Shut the car off. Waited for it to cool down and drove it home (I was only a mile away). So far I replaced the upper and lower rad hoses l, swapped out with another radiator I had lying around, upgraded to an electric fan, replaced thermostat again and defected out water pump(water pump and thermostat just replaced in febuary) I tried bypassing the heater core to see if that was the problem but its not. I bleed the air out everytime. It never rubs hot while idling. Only while driving, which is y i assumed water pump. Just doesn't make since. I checked the coolant hoses from the intake to the rear housing and the onea through the bac sensor. No clogs. It gets proper oil pressure, thas not the problem. Its not just a gauge malfunction though. As it warms up, water expands and rushes out of the overflow. Please help guys, I've dropped too much money into this the past 2 weeks. Btw, it NEVER smokes. Also, topped off coolant and cranked the engine over. Coolant stays calm. Not a water jacket problem. Thanks in advance guys

 

do you have the plastic under tray in place?

 

No I don't. But I've had this car for over a year now and this is the first tine its ran hot like this. Also, I have an s4 that I've had since 05ish that doesn't have the undertray either and it never runs hot either

 

sounds like you are getting compression into the cooling system.

 

No visual signs of a leak? Any water in the oil? How much coolant are you loosing? I'm kinda new around here,,, Is putting on an electric fan a cooling system upgrade? could need a new Radiator cap The spring sound like it could be worn out??

 

switch back to the stock clutch fan...............an electric fan only runs at one speed as the clutch fan is controlled to run at different speeds with the rpm's of the engine................

 

Well was thinking the clutch fan was bad. Also, been running an electric fan on my s4 car since 06 and its never had a problem. Actualy, before the electric fan my temp gauge sat about halfway and with the electric fan it only sits between the 1/4-1/3 mark. Forgot to mention that the s5 has new radiator caps. What do u mean conpression in the coolant? Like I said, no water slosh while cranking tge engine with the cap off. I let the car idle for over an hour and the temp gauge stayed perfect. Then I drove to the kangaroo just outside of my subdivision but by the time I got there it was running hot. It never does it while idleing. I don't see any leeks. As long as its sitting idling the coolant doesn't dissapear. But as soon as it starts running hot the overflow fills up and begans flowing over. I'm so lost

 

Oh yea. NO coolant in the oil or oil in coolant. And again, no smoke.

 

make sure the cap is releasing pressure. i would get a new cap(s) if i were you. the right ones for your car i mean. mine did the same thing and it was the tension on the spring not allowing the valve to open up to the overflow tank.

pretty much your coolant system cannot "relieve" itself.....

 

did you burp the system?

also, yes. you DO in fact need an under tray. i have recorded a devience of 20 degree in 90 degree heat with and without the under tray. 215 was normal with out under tray, and the hottest it got with undertray was 195. this was all going down the highway for an hour.

 

Pressure test your system,rent one from your local auto store you get your money back.

 

Yes I burped the air out of the system. I have brand new radiator caps. When u say pressure tester, u mean coolant pressure tester? If there was extra pressure in the coolant system, wouldn't it slosh out when turning the engine over with the cap off (Like a bad water jacket)?

 

you know i have a similar problem, but only under hard acceleration and high rpm's. the only thing i can really say is the under tray as well. i dont have mine and am looking for one.

mines an s4 and i also have an e-fan. but it doesnt over heat alot, it goes from 1/4 mark to the half mark, and never passes the half mark.

 

Can't stress that enough. also post a pic of your efan setup. whats the CFM rating? it's likely that is your problem.

There's been alot of dumbshits posting. i never read anything about you LOOSING coolant. but yeah, sounds like you have a leak free system that just can't keep up. what antifreeze ratio are you running?

 

On an s4 would half way mark on the gauge be considered over heating tho? I have an s5 cluster im going to put in.

 

The over heating started before swapping the efan on. Its the same fan that's on my s4 car. My s4 car has the same fan and is also missing the undertray, it doesn't have this problem. Even so though, the undertray has been off the s5 car for many months now and the over heating just started happening. Also it doesn't even run a little hot while idling. Back before I installed the fan relay kit on my s4 car I had the egan ran to a toggle switch. I could keep the fan off while driving and only turn it on while sitting still and would never run hot while driving. I really don't think its the fan or undertray since I have the same set up on my s4 car and have never had this problem. I tried burping it again, the car idled for almost an hour again with the cap off, didn't notice any air bubbles tho. I'm so confused on this...a bad water jacket would cause white smoke like crazy correct? This car doesn't smoke at all. This car has been a daily driver for a while now and never ran hot like this until recently. I was running a 50/50 antifreeze/water combo until it started overheating. As it begins to run hot the coolant escapes out of the overflow (hot water expands, then escapes to the overflow and then overfills it and escapes onto the ground) by now its mostly water because because antifreeze is expensive and until I get this fixed I can't afford to waste anymore. However, my s4 car only gets water. Not allowed to have antfreeze on the track so I never put antifreeze in it. The s4 has never ran hot.

 

sounds like you have air in the system still, sometimes it can be hard to get it all out. Are you sure your burping it correctly? I find that sometimes it helps to take off one of the heater core lines and go for a short drive, sometimes it helps some times it doesnt. Also when it warms up is the lower rad hose cold or hot?

 

After it warms up the lower hose is warm, not as hot as the upper though, by far. Bout the same as my s4 car. In febuary the motor was replaced. At that time, installed a new water pump and thermostat. I had burped the air out and for the past 3 months the car never ran hot. Never had any trouble until recently. So I defectes out the thermostat, then the water pump. Figured defective parts happen,ya know. Then switched to an efan thinking the clutch fan may have failed. Since it started happening a few months after replaceing stuff in the cooling system, I don't think its air. If it was air then it should run hot while idling right? This doesn't though. It only runs hot while driving

 

Do you have an upgraded alternator? If you do not, any efan that will run on the OEm S4 alt is pretty weak. Therefore, I think a bad fan clutch may be source of the original problem. My S4 did the same thing. I put a known good fan clutch in and problem solved.

If you put in an S5 cluster (major repinning on the cluster plugs) the temp gauge will not show that you are overheating till it is too late.

Try getting a known good fan clutch and trying it out.

Good luck!

 

no. the stock clutch fan even if malfunctioning or even completely dead, still churns out soo much air that it will not over heat. the thing has to be in pieces to not function.
also, i have datalogs to prove that at a stop, the temps lower, and at cruise temps RAISE WITHOUT AN UNDER TRAY!

switch back to the clutch fan, put an undertray on, and burp the system properly.

drain the system. flush the system out, and with the system completly empty, start the car. and gradually add coolant till its to the top.

 

is it cool to have efan and a clutch fan operating at the same time?

i have a koyo rad with the godspeed efan, and i have a good 3 in clearance between the engine, so the clutch fan is possible to operate.

wouldnt that be the ultimate cooling?

 

are you seriously asking this question? seriously? stop trolling.

 

I didnt do the efan on mine (its a crappy job and will be replacing it when time/finances allow) but i'd have to find the shroud and the efan and blades (one on an 87 in the junk yard here). where can i order a new tray?

 

I just tried a different thermostat again and used the radiator caps off my s4 car. Now its the same exact set up as my s4 ca. same efan, no under tray. Same set up I've been using on my s4 car for 5 years. It still ran hot but still only while driving.idled for literaly 2 hours without even slightly moving over normal operating temp. To rent a coolant pressure tester here is $170 so its going to b some time till I can front that since I'm broke and unemployed. If any other ideas hit me up. Btw, I don't have the underteay and not a 7 in a salvage yard within a hundred miles....

 

try looking for one online. they are cheap and people often throw them away for some stupid reasons.

teh s5 and s4 units are the same unit and fit universally.