Well, the other day I was driving in extremely hot and humid temps in the city (95+ not including like 80% humidity) and my temps started to rise to about 3/4 of the way up the gauge. Also, my exhaust began to smell sweet. However, I have checked my coolant and do not seem to be missing any. In addition, the smell has completely gone away since that one time of driving. I have searched on various tests and such posted in this forum and will come back with some conclusive answers but was wondering what some of the more experienced members on this board could possibly conclude. Reason being, I was planning on flushing the cooling system within the next few days anyway. Thanks in advance.

 

If it doesn't overheat or drink coolant, you're fine. The bubble test is an easy one too. Just idle the car (cold) with the radiator cap off to look for them. 3/4 is about 220F on an S4, so it's not quite to the rebuild zone. I've seen temps that high after an e-fan failure, and the engine was fine.

 

Alright. Thanks for the response. Will do bubble test this evening as well just to be safe.

 

You can get a head gasket failure test kit from napa for $40. It uses a chemical that changes color if there is exhaust gas present in the coolant. Works the same for rotary coolant seals

 

Did bubble test. All panned out fine. However, in a related concern; a slightly modified NA S4 with all the ducting, a Koyo, as well as a 2900 CFM fan with a shroud should not reach half gauge temps am I correct?

The only problem with my cooling system that I see so far would be that the previous owner wired the fan to turn on with the accessories like an idiot.

I plan on flushing the entire coolant system soon. When I do I may just install a thermoswitch if that will alleviate the problem.

 

The whole problem is probably your fan not turning on.

When my old 88 na had a bad clutch fan and ran up to halfway (200 f) right after warming up.

After replacing it with a good fan their was a very noticable difference.
Now Im not sure what temp is best for the fan to.turn on but id say 180 since thats when the stock.thermostat opens. That way you have the fan.and radiator both initiating cooling it at the same time.

Or install.a switch to.toggle it on and off yourself.

 

If fan is on the whole time and its running you might want to try getting an underbody tray if you don't have one.

My car ran up to 195 according to my manual temp gauge i installed on the tstat neck and it wasn't even up to half on the stock temp gauge

I was using stock clutch fan and had underbody tray.

However, I later blew my coolant seals 25k miles miles later, they were blown when i picked up my car from impound oddly , i did run it up to halfway a few times before i figuring out my clutch fan was bad and replacing when i first got it. It would make gurgling sounds after i shut it off out the overflow.

It wasn't smoking until after they blew at 25k. Trust me you'll know when yours blow.

 

I have all the original ducting and what not. I believe the issue may have been in relation to my license plate blocking all incoming air. (previous owner) Still, car runs fine now after relocation and has no signs of typical blown coolant seals. Maybe I lucked out?