I have a 2001 A4 and have an issue with a chemical like smell, maybe Dexcool coming into the cabin when the A/C is on? It only happens
when im on the freeway for a while. It doesnt smell when I first startup or for short trips. I don't have any dampness on the floor boards or signs of leakage around the electronic modules. I also don't get any fogging on the windshield. Any Ideas? How do I check the heater core for leaks?

Thanks

 

when you park it do you have puddles under the car? how much coolant are you losing?

 

It doesnt look like im loosing any antifreeze. I have owned the car for three years and never added any. Im thinking this weekend ill check the udders and take a look under the battery tray. I do notice that when I park the car after some freeway driving the coollant tank is bubbling. Not sure if its related.

 

If its the heater core that is a big job. Heres how you replace one.

Disable the air bag system Remove the SIR fuse and the left side sound insulator. Disconnect the Connector Positive Assurance, steering wheel module coil connector, instrument panel module connector and negative battery cable.

Step2 Discharge and recover the air conditioner refrigerant. Drain the engine coolant from the cooling system to a clean container.

Step3 Prepare to remove components within the dashboard. Apply the parking brake, place the transmission in second gear (automatic) or fourth (manual), tilt the steering wheel as low as it will go and turn the ignition switch to the "On" position.

Step4 Disconnect all attachments to the heater/air conditioner module within the engine compartment. Disconnect the battery heat shield, intake manifold, air injection check valve hose, heater pipe assembly, Accumulator hose, evaporator tube and HVAC module drain tube.

Step5Disassemble the dashboard, then remove it with an assistant's help. This includes removing the center console, gear shift boot, ashtray, glove compartment, Connector Positive Assurance, Sensing and Diagnostic Module, blower motor, all panels, connectors, ducts, nuts, bolts and switches.

Step6Remove HVAC module, then remove the heater core outlet and inner covers. Remove the heater core from the case. Discard all seals and remove the core pipe clamp.

Installing the New Core

Step1 Attach the new heater core to the pipe clamp and new core seals. Install the core into the case, attach all clamps and screws and install new outer seals and cavity seals. Reinstall the core cover and outlet cover.

Step2 Install the HVAC module with new seals. Align the dashmat so the module drain seal is fully aligned against the cowl and all fittings and studs correspond with the openings in the cowl.

Step3 Install the dashboard, all components and all engine connections to the HVAC module.

Step4 Refill the engine cooling system. Evacuate, charge and leak test the air conditioner. Reconnect the battery cable and enable the air bag system.

Step5 Start the Corvette's engine and run it normal operating temperature. Check the climate control's operation and check for any leaks in the system.

Good luck.

 

Thanks for the feedback. Seems like a lot of work. Hopefully Ill find the problem this weekend and it will be minor. If not may be easier to trade up.

 

good luck hope you have an easy fix