mktsc

Ok I was having a problem with my car heating up too much. The high fan was coming on pretty much every time I drove the car. On long trips the temp gage would sometimes sit between the 2 dots about 3/4 of the way up. I replaced the coolant tank and cap, and had the dealership change the coolant. Since then the car's been running much cooler. However yesterday it was about 70 and sunny out, and after about 1/2 hour of stop and go traffic on the way home from work, the high fan kicked on and the temp gage reached the first hash mark past 12 o'clock.

I'm just wondering what's normal for the temp gauge? I dont know where it's supposed to sit, and whether or not to get worried.

Any help would be great.

Thanks,
-Matt

AudiMick

...or convert to an EFK.

Jretal

your fan could be going out (I got the one off my car if you want, email me if interested), or it could be the radiator not flowing properly, it could be the elec a/c fan isn't kicking on at the right temp (the temp switch in the radiator is bad if that's the case.. had that issue on my car), or your thermostat isn't working 100% (like it's not opening all the way).

those are just a few thoughts of the top of my head. The needle should stay at the 12 o'clock position at all times when the car is warmed up. I've had mine go up to the first tick after stopping the car, shutting it off, then restarting it... that is normal, but it shouldn't rise above the 12 position while running

mktsc

Sorry forgot to specify, it's a 93 90CS quattro. Both fans kick on, so I dont think that's it unless they're wired backwards.

-Matt

Jretal

and if that doesn't do the trick, your thermostat is probably going south...

orr, the temp sensor on the radiator isn't kicking in when it's suppose to... if you pull the radiator, replace this sensor since it's only $13 and easily accessible w/ the radiator out.

mktsc

I'll try to replace the thermostat. I just ordered one from Blauparts. It's fine on the freeway, and if I'm driving constantly, but the stop and go will elevate the gauge. It's alot better than it used to be though.

-Matt

AudiMick

My A4 runs at 12 noon all the time but just occasionally it will inch up half a notch or so but not enough to kick in the secondary fan.You can buy a new radiator for about $150. I wouldn't waste time having 10 plus year old radiator cleaned.

Jretal

i replaced the radiator fan temp switch on the radiator and put and independent thermostat for my EFK and that seemed to solve the issue on the streets, but unfortunately it still did a lil overheating (first tick) at the track causing my oil to go to the 250 mark... I don't like it when that happens!

moribundman

Within a specific coolant temp range, the gauge will remain steady at the 12 o'clock position. Under US-typical street driving conditions, the gauge needle will not go past 12 o'clock. Sitting during hot weather with the A/C running in taffic, going uphill in summer heat with three passengers, or racing the car, the needle may move past 12 o'clock. It is important to know that the coolant gauge, unlike the oil temp gauge, is really not much better than an idiot light -- which comes also standard (in mini-check display).

The coolant gauge shows only two conditions reliably: It shows when the the thermostat opens (needle promptly indicates quickly rising temperature towards 12 o'clock) and when the coolant is getting rather hot (past 12 o'clock). What the actual "normal" coolant temp range is remains unclear, although I GUESS it's between 80 and 90 degree C.

Why the dead center design? Most people would think something is wrong if the coolant temperature gauge were to constantly fluctuate.

AudiMick

Mine is 11 years old. I have a newer one (off of a 2002 Passat) on its way.

I will see if its any better, otherwise I may go the EFK route. I like the idea of a second (lower temp setting)switch. Wiring the two fans in parallel never made much sense to me.