hey guys ive been trying to find an all aluminum radiator for my 98 A4 2.8 QM and ive had no luck. it runs a little warmer then i would prefer it to especially living in the california valley heat. Does anyone know where i can get one if they are available and im also curious if a S4 radiator is similiar and will bolt up or not?

 

If your car's overheating then there's something wrong with the cooling system. I can sit in traffic all day blasting the AC in the middle of a heat wave and the needle won't budge past the middle.

 

well it wont get passed that unless im being a lead foot or going thru the moutains, but id prefer that it would never get passed the middle mark, the only thing that hasnt been replaced is my radiator in my cooling system

 

So you've replaced the fans with higher CFM ones?

 

uhh nope haha actually i havent looked into that yet? i was hoping to find a better radiator but i was thinking about that if I had no luck

 

i just took a 3 hour trip going 80 on the highway with the AC on the whole way and didn't move the needle past the middle. try deleting the mechanical fan and adding a bigger 14" elec fan. Sounds like a potential thermostat also even with the stock system working perfectly you shouldn't have a problem with overheating.

 

I have a 2001 A6 2.8L with similar overheating problems, and I also live in the valley. I only have problems going up the mountains when it is over 90 degrees outside, or in traffic when it is over 100 degrees.

 

I've drive across Nebraska all day when the temp was 100 and the AC was on. Needle never moved. You might have a bad radiator, but a stock one will be fine. Have you ever used stop leak in the system? That would explain a lot. I've seen that crap clog radiators, oil coolers and anything else with small passages.

 

Cruising on the flat is fine when it is 110 out. It is the stop and go LA traffic at 100+, or climbing 4400 ft. mountains at 90+ that overheats the car.

No stop leak ever, and with new reservoir, thermostat, coolant, hoses front and back, and factory fan working properly. You're correct though, something is not quite flowing optimally.

 

Thats odd, my car never goes past the middle mark, i just came back from a mini car cruise and i was smashing in the mountains for a good hour and a half, temperature gauge never moved. New coolant, year old radiator, new thermo, new coolant temp sensor.