twotruckeetwinturbos

Spent sometime STFA but couldn't really find a situation like this.

So I'll run through this little scenario and maybe I'm being a little paranoid. Last week driving over Mt Rose Hwy (those of you that have driven know) and it was hot, 95+ at base and cooler at summit 9000ish feet. This road is twisty long and steep. I was driving in a 4000-5000 rpm manner which is typical for this pass with no traffic. I'm stage 2+ and rs4 oil cooler. I had ac running and approaching top 1/3rd of pass and notice oil temp is 250, I have never that seen on this car. I then look at coolant gauge which is one full tick past center and I'm like whoa. Shut down AC drop to 3000 rpms and cruise to top waiting for red coolant light to come on, which never did happen. As soon as I shut down ac and down shift things start to cool off. So I've been watching for the past week and it seems on the days I run the AC, oil temp is a little higher than with it off. Coolant gauge hasn't budged since that day. And yes the fans are running.

Couple pieces of additional info. TB was replaced 8000 miles ago including thermostat. Afterrun coolant pump was replaced 2000 miles ago with coolant, but bled in the manner according to Bentley so hoping no air in system.

Anything to worry on or should I go back to piecing together the best Stage 3 kit.


TIA

E

StoneMan

Also, that's pretty odd that turning off the AC would make it run cooler. If anything keeping it on allows the second fan to run, providing it is working properly.

quickaudi:STFA

maybe the secondary fan wasn't working?

also, oil coolers do block a little flow, don't they?

twotruckeetwinturbos

Went on same drive, under same condition today, with Vag hooked up. Sorry no logs, laptop batt died before I could save. Doh!

With AC on, coolant temp rose to 103 while gauge on dash began to climb, at that point decided to turn AC off. Immediately watched temp coolant temp drop back to 96 in less than 2 minutes with no change in driving style.

Brings up two questions:

Perhaps it is sender to fans not kicking them to increase speeds as temp rises when AC is. Not sure part number, but I know it is a 20.00 part sol by purems.

What temp does everyone see on coolant at idle once warmed up, because I see 96 and I beginning to wonder if my indy put correct thermostat in at TB service?

Thoughts?

TIA

Eric

quickaudi:STFA

runs all the time, no matter what. Does yours? Could be the sender, could be the fan relay, could be the fan, could be the wiring. your coolant temp should be TDC and never waver once it reaches it.

twotruckeetwinturbos

Both fans run when I turn ac on. I question if they are running at appropiate speed as temp rises. I am not hearing them speed up as car runs hotter. Is that fan relay or aux fan switch that controls? Will check Bentley as well, but I'm sure someone here knows this off the top of their head.

Thanks again for the help.

E

quickaudi:STFA

"Integrated in the pressure switch for air
conditioner F129 is the high-pressure switch
for activating a higher fan setting.
The pressure switch is mounted below the
right-hand headlight behind the bumper."

"Components:
F18/F54 Radiator fan thermoswitch
F95 Thermoswitch for continued coolant
function
F129 Pressure switch for air conditioner
(only for vehicles with air conditioner)
V293 Control unit for radiator fan
V7 Radiator fan (induced-air fan)
V51 Continued coolant circulation pump
V177 Fan 2 for radiator (forced-air fan)
(only for vehicles with air conditioner)
1 Terminal 30, positive supply via fuse
on 8-socket relay plate
2 Terminal 61, D+ (alternator) via fuse on
8-way relay
3 Fan activation (only for vehicles with
air conditioner)"

twotruckeetwinturbos

i'll start there for 20 bucks and see. Found a similar issue on forum and that fixed problem so feeling confident. Thanks for help

E

quickaudi:STFA

whatever credit card you used, make sure to keep an eye on it. several of us had issues with ECS and credit card scam stuff in the last couple of years.