After-run coolant pump...does it do anything???
Thread Starter
AudiWorld Member
Joined: Aug 2009
Posts: 110
Likes: 0
After-run coolant pump...does it do anything???
So I read in an AW thread that someone had wired their Blitz II turbo timer to their after-run system instead of the ignition. I have two questions about this. 1) is it enough to safely cool our turbos with water alone and not water AND oil? 2) I see after-run thermo sensors online at a few VAG performance shops that are supposed to lower the temp threshold at which the after-run system deems it necessary to run. Anyone use one of these products? I guess the onboard cooling system for the turbos (post shut down) RARELY kicks on due to the high temp threshold and is essentially useless. Any thoughts??? Here's a link to one of the switches I've found < http://www.034motorsport.com/engine-...p-p-20394.html
Last edited by 12vWhat; Jan 30, 2012 at 07:32 PM. Reason: Adding link
Audiworld Basic Sponsor
Joined: Feb 2011
Posts: 9,948
Likes: 8
Its scolding hot oils temps in the turbo that cook the seals. Allowing the turbos to "cool down" allows the oil to keep circulating and from standing in the super hot CHRA.
Simply circulating the coolant would help cool the body of the turbo down but while its cooling down the oil would not be circulating baking the seals which is what causes blown turbos.
Jason
Simply circulating the coolant would help cool the body of the turbo down but while its cooling down the oil would not be circulating baking the seals which is what causes blown turbos.
Jason
Thread Starter
AudiWorld Member
Joined: Aug 2009
Posts: 110
Likes: 0
I knew it was the oil that was the issue...
Just dont know about the effiency of the after-run system, or the journaling inside of the turbos for water in relationship to oil (heh, the path of the coolant within the turbo might cool the oil in there rather quickly???). I'm guessing that I'm better off leavin my butt in the seat for a couple of minutes or putting a TT in there. Any other input would be greatly appreciated. Someone out there had the 'low-temp' sensor/switch installed for a while and want to review them???
Audiworld Junior Member
Joined: Jul 2011
Posts: 67
Likes: 0
From: Blacksburg, VA
I put one of lower temperature switches in last summer. I think it is from a Vanagon. I did find that it made the after run system work on hot days. Before I made the change I hadn't heard anything. I think these are the numbers:
021919369 Thermo switch
N90316802 O ring
032121142 Retaining Spring (clip)
I bought mine from here:
http://www.purems.com/Products/02191...Run-Fan-Switch
It was under $25 and easy to change out. There is a how to somewhere, but I don't recall where I found it.
I am always gentle on my turbo cars in the last few miles of driving. I have a friend that lives at the top of a long hill and I always thought that would probably drive me to get a turbo timer.
021919369 Thermo switch
N90316802 O ring
032121142 Retaining Spring (clip)
I bought mine from here:
http://www.purems.com/Products/02191...Run-Fan-Switch
It was under $25 and easy to change out. There is a how to somewhere, but I don't recall where I found it.
I am always gentle on my turbo cars in the last few miles of driving. I have a friend that lives at the top of a long hill and I always thought that would probably drive me to get a turbo timer.
AudiWorld Senior Member
Joined: Mar 2005
Posts: 809
Likes: 3
That sensor sits on the driver's side of the rear coolant pipe and is easy to get to. You have to remove the small engine cover by the valve cover and carefully remove the valve cover breather tube and you'll have easy access at the sensor. If its been in there a while, then you'll need to pull it out with a pair of pliers, as the o-rings get stuck and the sensors seize in the pipe sometimes, so make sure you get the o-ring and clip also.
Trending Topics
AudiWorld Senior Member
Joined: Mar 2005
Posts: 809
Likes: 3
I put one of lower temperature switches in last summer. I think it is from a Vanagon. I did find that it made the after run system work on hot days. Before I made the change I hadn't heard anything. I think these are the numbers:
021919369 Thermo switch
N90316802 O ring
032121142 Retaining Spring (clip)
I bought mine from here:
http://www.purems.com/Products/02191...Run-Fan-Switch
It was under $25 and easy to change out. There is a how to somewhere, but I don't recall where I found it.
I am always gentle on my turbo cars in the last few miles of driving. I have a friend that lives at the top of a long hill and I always thought that would probably drive me to get a turbo timer.
021919369 Thermo switch
N90316802 O ring
032121142 Retaining Spring (clip)
I bought mine from here:
http://www.purems.com/Products/02191...Run-Fan-Switch
It was under $25 and easy to change out. There is a how to somewhere, but I don't recall where I found it.
I am always gentle on my turbo cars in the last few miles of driving. I have a friend that lives at the top of a long hill and I always thought that would probably drive me to get a turbo timer.
AudiWorld Stories
Bringing Audi to Life for Audi Fans
Top 10 Most Expensive Audis Ever Sold on Bring-A-Trailer
Brett Foote
10 Audi Features & Options We Miss the Most!
Joe Kucinski
Audi Recreates Crazy-Looking Speed Record Breaker From 1935
Verdad Gallardo
Coachbuilder Recreates the 1995 Audi TTS Concept
Verdad Gallardo
Every Audi V10 Car Ranked!
Joe Kucinski
9 Audi Designs That Aged Like Fine Wine
Verdad Gallardo
2026 Audi Q5 Buyer's Guide (Every Model Explained)
Brett Foote
Ranking Every Current Audi 'S' Model From Worst to First!
Joe Kucinski
10 Best Audis That are FINALLY LEGAL to Import to the U.S.!
Joe Kucinski
Thread Starter
AudiWorld Member
Joined: Aug 2009
Posts: 110
Likes: 0
i found a write up at allroadfaq.com where there is some testing (via vag-com temps after shut-down, with and without the lower temp switch) and the results ARE NOT convincing. Yes, there are results. Yes, its a 10 minute job. Yes, the part is cheap. NO, its not going to save your turbos or prevent a post-shutdown heat soak. Turbo timer or wait it out.
AudiWorld Member
Joined: May 2010
Posts: 114
Likes: 0
I've done this temp switch upgrade. Anytime the car comes up to temp and I shut it down the afterrun "system" will function. It doesn't matter winter/summer. (I'm in MA and it gets cold here) It's virtually impossible to say good/bad and fruitless to argue whether it's doing something or not. If the system were running over the life of the car who's to say it didn't extend the life of the turbo's 10 or 20k? Unfortunately most AR's have had their stock thermo switch in for years before a 2nd/3rd/4th owner decides to do this mod so I don't think there will ever be definitive answers.
But the whole system is already on the car so you might as well let it do its thing. The stock temp switch will virtually never let the system run. That said the stock AR pump is known to leak/crack etc so some people just like to leave it off. Audi has a retrofit kit with a new pump and it moves it out from under the intake manifold and down next to the alternator. I've done this mod as well the last time I had the front end of my car off. I didn't want to be left stranded somewhere because I leak all my antifreeze out. Too many other places for that to happen.
But the whole system is already on the car so you might as well let it do its thing. The stock temp switch will virtually never let the system run. That said the stock AR pump is known to leak/crack etc so some people just like to leave it off. Audi has a retrofit kit with a new pump and it moves it out from under the intake manifold and down next to the alternator. I've done this mod as well the last time I had the front end of my car off. I didn't want to be left stranded somewhere because I leak all my antifreeze out. Too many other places for that to happen.