Overheating at Autocross - dead aircon display

[TFish]

Hey y'all,

I have a 2007 Lib GT-B sedan (postface BL) and I've been autocrossing it. The event can involve sitting in a line up for long periods with either the engine on or off after thrashing the car and wanting aircon in the cabin.

For about 12-18 months the dual zone climate control display has been dead. The system seems to work perfectly as I remember how to use it, set the temp with the dial, auto, fan down, mode to change the fans around, off for none etc. I did take it out and can't see anything obviously wrong with it like burnt out wires.

Recently, I'm sharing the car with 2-3 others for events and it's started overheating at the end of the day. The heat is coming from the turbo being put in a start stop state. A 1-2klm drive usually sorts it but I'd like it to be more reliable or have a procedure to keep it cool and not cook a head gasket. The top res cap spilled a very small amount of white after checking later, just 1 dribble by the looks. Nothing else seems to have spilled.

I've been looking in to a manual thermo fans switch so we can keep the fans running and how to do this. I've added a replacement sti pressure cap at the top res just in case the cap was to blame.

So, I changed the oil today and ran it for a bit while torquing the wheel bolts (to get the oil circulating and do a final top up) and I noticed the a/c pulley and fans clicking on and off a lot. About 28c day, just started the car first time for the day. The a/c would be set to max cold/18c and cabin closed.

I'm wondering if there is a common problem with a/c that can mess with the thermo fans and add to my overheating problem? How to diagnose?

Thanks,
Tim

[TFish]

The low temp thermo fan seemed to be clicking on and off with the a/c, there were maybe 14-15 clicks per minute until I turned the a/c off and no more clicks

[Ric]

When was the A/C last re-gassed?

[Yowie]

As a separate issue to the car working properly (which is what you're chasing), it occurs to me that the car has a very hard time of it (Re thermal management) if you're thrashing it in autocross events then idling the car stationary with AC running.

I suspect that the system isn't really designed for thrashing then stationary idling with AC.

When I come in from a few dirt track day thrash-laps I'll drive/idle for a bit to let the temps come down with fluid still circulating, then switch off & pop the bonnet to let heat out of the engine bay. I'll also push the non-running car in neutral along in the starting queue (still with bonnet up) to keep temps down right up until I'm close to heading out again.

[TFish]

When was the A/C last re-gassed?

Not sure Ric, has not been regassed in the last 4-5 years since I've owned it. Aircon is very cold usually, the aircon going hot is a sign the temp gauge is about to go up, hasn't ever hit the red zone though.

As a separate issue to the car working properly (which is what you're chasing), it occurs to me that the car has a very hard time of it (Re thermal management) if you're thrashing it in autocross events then idling the car stationary with AC running.

I suspect that the system isn't really designed for thrashing then stationary idling with AC.

When I come in from a few dirt track day thrash-laps I'll drive/idle for a bit to let the temps come down with fluid still circulating, then switch off & pop the bonnet to let heat out of the engine bay. I'll also push the non-running car in neutral along in the starting queue (still with bonnet up) to keep temps down right up until I'm close to heading out again.

Absolutely agree, for one driver those strategies work but with 2x and needing to line up in queue order it ends up overheating late in the day. Was considering getting a portable, eg. Ryobi, fan for when it is sitting in service.


Thanks for the replies! I'm keen to find out if anyone knows how to diagnose the frequent clicking on and off of the compressor and fan #1 with a cold engine. When I think back, it has always clicked in the driveway a lot since I've owned it. Also any advice on how to best set up a manual thermo fan switch without upsetting the ECU, eg. where to splice in. Any ideas about how to get the climate control display working again? Try a different control/face unit?

[Ric]

When was the A/C last re-gassed?

Not sure Ric, has not been regassed in the last 4-5 years since I've owned it. Aircon is very cold usually, the aircon going hot is a sign the temp gauge is about to go up, hasn't ever hit the red zone though.

That's the easiest thing to check first then. A full re-gas should be well under $200.
It's easy not to notice the A/C efficiency dropping slowly, and it sounds like you're due for an A/C service.

[TFish]

This is a cold start - https://youtu.be/Xr4DlctBXYc

[TFish]

Just wanted to update this thread. I found out that the dead climate control display (but working system) could be because dry solder points on the stereo that provide power to the display. I'll be taking that out and repairing soon.

[TFish]

Thanks for replying. Yep, I took it out and had a good look at the boards, no dry solder or any signs of damage. Had a mate look at it too and can't find anything, looks in perfect condition, especially for age. Next step to try a replacement module. Connector i88 doesn't seem to have split power that would allow it to function but then have nothing on the screen. Definitely hasn't taken any hits or damage. I guess the screen part can just die.

Will update if a working module solves the problem.

[JezzaH6]

Unfortunately I'm not sure what leads to the aircon display dying, but I thought my 2c may be worth something in regards to temperatures.

Keep in mind though mine is an EZ30, which does face different cooling issues compared to the EJ25t, and it is in a track environment, which does treat the cooling system somewhat differently to autocross.



One of the best tooling investments I made for track days was a portable fan and pressurised garden sprayer. Once I got these, after a cool-down lap and I'm back in the garage the bonnet gets lifted to allow for hot air to escape, the radiator (and AC condenser) gets liberally misted with cold water (being very careful to avoid getting it on the brakes or anything else seriously hot) and then the fan I use to ensure airflow through the engine bay. In the 1 hour between sessions this sees coolant temps drop to low 60's, and oil down to low 50's, and the car requires a short warm-up period before the next session.

Obviously this wouldn't get your temps that low with the engine running and the AC on, but a misting every few minutes and the additional airflow of the extra fan will make a decent difference.

I now have an additional two portable fans which I use to cool down the front brakes at the same time.

Any heat you can prevent getting into the engine is a good thing, especially in high-performance situations. Turbolag has a good write-up on his member profile (http://forum.liberty.asn.au/viewtopic.php?f=10&t=36287&start=15) where he rigged up a misting line to his TMIC, which saw a good reduction in intake temps and ultimately slightly lower coolant and oil temps.

We also found removing all front removeable panels (fog light covers, front grill) made a noticeable difference- I picked up almost an extra half hot lap before getting too hot! Tidying up things under the bonnet to ensure good airflow through the engine bay is also a good idea.

I also had really good results changing my coolant. I'm now running 15% glycol, 15% redline water wetter and 70% distilled water. This combination is an issue if you live somewhere that freezes, but if it doesn't the combination of higher water concentration (which has a higher thermal capacity and is more thermally conductive than glycol), as well as the anti-cavitation and anti-boundary layer properties of water wetter saw me pick up almost a full hot lap over the oem coolant configuration.