Catastrophic coolant loss causes spin at Mosport
05-27-2010 | 01:17 PM
#32
Instructor
Joined: Jan 2005
Posts: 136
Likes: 3
From: San Francisco, CA
Happened to my brother's 6GT3 (ex-Mooty, CarerraGT car) about a year ago at Thunderhill. And I believe this was the 2nd time a coolant press fitting failed for this particular car. I was right behind him, saw some white smoke and drove over what looked to be a faint "water-looking" spot. It had rained the day before and parts of the track hadn't dried yet so I thought it was pretty innocuous. Experienced a short-violent slip but didn't spin or go off-track luckily. Def very sudden and scary-feeling.
Any downsides switching from trad. coolant to running water-wetter in our street/track cars?
Btw, I'm in the Bay Area (CA) and don't have to worry about freezing temps.
Any downsides switching from trad. coolant to running water-wetter in our street/track cars?
Btw, I'm in the Bay Area (CA) and don't have to worry about freezing temps.
05-27-2010 | 01:48 PM
#34
Rennlist Member
Joined: Sep 2006
Posts: 1,968
Likes: 0
From: Vancouver, BC, Canada
Yeah. My fav track is in Oregon in the desert. Last Sept when I was there it was just above freezing overnight, like 2-3 degrees above freezing.
Is there a version of water wetter that provides a little freezing protection but isn't slippery like coolant?
Never tried to replace coolant on this car myself. How much of a pain is it? I'm leaving on Monday morning for a 4-day trackfest and there is no way I can get a shop to do this before I go.
Cheers,
Is there a version of water wetter that provides a little freezing protection but isn't slippery like coolant?
Never tried to replace coolant on this car myself. How much of a pain is it? I'm leaving on Monday morning for a 4-day trackfest and there is no way I can get a shop to do this before I go.
Cheers,
05-27-2010 | 03:05 PM
#36
Thread Starter
Drifting
Joined: Nov 2001
Posts: 2,438
Likes: 1
From: Beijing, China
Good call Larry. I'll change it now. I'm surprised at how many people have had this issue. I thought I'd be posting about a rare occurance and debated whether to post it; I assume others thought the same. Now that it's in the open, we see that it's far more common.
05-27-2010 | 03:24 PM
#37
Addict
Rennlist Member
Rennlist Member
Joined: Jan 2003
Posts: 6,583
Likes: 10
From: Los Everglades
My 996 GT3 at Lime Rock had a similar problem, a slow leak of coolant over the top of my left rear tire (Lime Rock is mostly right turns), I noticed the car sliding a little, and I thought I had a RR tire going flat or way overheated. Pulled to the pits, and as soon as I parked I noticed a massive coolant leak that if I had taken another lap around LRP I would have seriously hurt myself.
It should be mandatory by all clubs to not allow cars with coolant on the track. It is dangerous for everybody on the track. Coolant leaks are more common than oil leaks, and coolant leaks are typically massive compared to oil leaks.
Farz, I'm glad you're safe. You got really lucky, it could have been a lot worse, and it has nothing to do with driving skills (as CGT pointed out), it could happen to anyone.
The 2010 GT3/GT3 RS still use the same glued fittings.
It should be mandatory by all clubs to not allow cars with coolant on the track. It is dangerous for everybody on the track. Coolant leaks are more common than oil leaks, and coolant leaks are typically massive compared to oil leaks.
Farz, I'm glad you're safe. You got really lucky, it could have been a lot worse, and it has nothing to do with driving skills (as CGT pointed out), it could happen to anyone.
The 2010 GT3/GT3 RS still use the same glued fittings.
05-27-2010 | 03:34 PM
#38
Three Wheelin'
Joined: Jul 2005
Posts: 1,257
Likes: 1
Hey guys, good guesses. I appreciate the difficulty in diagnosing driving through online videos, but wanted to drag this out a bit to raise awareness of a fairly serious, albeit rare, issue on our GT3 engines.
There is an aluminum press fitting that goes into the engine that is held in by nothing more than some loctite/glue. When the engine gets really hot under track use and high temps, the loctite/glue can let go and your rear tires are now covered in super hot coolant. In my case, it was the left fitting that came out which doused the left rear tire.
I was very, very lucky that there was slower traffic because I normally come down the straight at ~230km/h and enter that corner pulling >1g at 160km/h. On the lap when the fitting popped out, I was only at 213km/h down the straight and I had backed out of the throttle really early to give the guy ahead some space and was down to a very reasonable 130km/h when the pipe let go.
At the 2:45 mark on this video, this is what a more normal pace is like:
From inside the car, my initial reaction was that the Miata I just passed blew its brakes and hit me, the spin felt so violent and random. Next thought was that I missed the downshift and went into 1st, but that didn't seem plausible. It was only when I smelled the sweet burning coolant that I realized what had happened.
Unfortunately, a car behind me lost control over my coolant and did some minor damage to his car in the tirewall on the entrance to 8. I'm trying to work with one of the shops he's using to bring down the cost of the repair, given the circumstance.
There were a few lessons learned:
1. Change the coolant to water and water wetter when on the track
2. When you spin on the track, get the heck off as fast as you can (I was in problem solving mode instead of survival mode after the spin)
3. Check part no. 997.106.039.90 and 996.106.238.71 for any cracks, wear or movement
Hope this saves someone the scare I went through...
There is an aluminum press fitting that goes into the engine that is held in by nothing more than some loctite/glue. When the engine gets really hot under track use and high temps, the loctite/glue can let go and your rear tires are now covered in super hot coolant. In my case, it was the left fitting that came out which doused the left rear tire.
I was very, very lucky that there was slower traffic because I normally come down the straight at ~230km/h and enter that corner pulling >1g at 160km/h. On the lap when the fitting popped out, I was only at 213km/h down the straight and I had backed out of the throttle really early to give the guy ahead some space and was down to a very reasonable 130km/h when the pipe let go.
At the 2:45 mark on this video, this is what a more normal pace is like:
From inside the car, my initial reaction was that the Miata I just passed blew its brakes and hit me, the spin felt so violent and random. Next thought was that I missed the downshift and went into 1st, but that didn't seem plausible. It was only when I smelled the sweet burning coolant that I realized what had happened.
Unfortunately, a car behind me lost control over my coolant and did some minor damage to his car in the tirewall on the entrance to 8. I'm trying to work with one of the shops he's using to bring down the cost of the repair, given the circumstance.
There were a few lessons learned:
1. Change the coolant to water and water wetter when on the track
2. When you spin on the track, get the heck off as fast as you can (I was in problem solving mode instead of survival mode after the spin)
3. Check part no. 997.106.039.90 and 996.106.238.71 for any cracks, wear or movement
Hope this saves someone the scare I went through...
05-27-2010 | 04:18 PM
#40
Three Wheelin'
Joined: Mar 2007
Posts: 1,309
Likes: 43
From: Santa Monica
This happened to me a month ago, lucky for me I did not spin. J fitting came out and later found water pump also had a leak. I replaced WP and pushed the J fitting in and safety wired with some tension on it so hopefully it will not come out again. Turn pic ccw so it is vertical, this is on the right side of the engine as you look at it from the back.
05-27-2010 | 04:55 PM
#42
Rennlist Member
Joined: Aug 2001
Posts: 14,773
Likes: 262
From: san francisco
So if water and water wetter what's the proportion? One bottle 2 bottles? Spun on oil at t10 at thill and 8 other cars. Surprisingly no one hit nething. Never had a coolant hose pop off but what I read now makes me want to prevent this sorta thing from happening. Hey Mikymu- here's another diy project u can work on : ). Mike
05-27-2010 | 05:26 PM
#43
Three Wheelin'
Joined: Mar 2007
Posts: 1,309
Likes: 43
From: Santa Monica
What have others done? Or what do pro Porsche tech. recommend?
Hopefully we can all give info and pics of problem areas to look out for before we go out on track. Just ad the look around to our pre flight checks.
Joe
05-27-2010 | 05:31 PM
#45
Burning Brakes
Joined: Jun 2001
Posts: 890
Likes: 0
From: juno beach, florida
Exactly what happened to me, can't reach it either because it is under the intake manifold. I was doing about 70-80 turn 2 at Homestead. Afterwards they told me that my car was spewing coolant down the front straighaway, but I never knew until after the spin when the "check coolant level" light came on. Would've been nice if I got blackflagged or got the meatball before my spin, but on the other hand, at Homestead there are a lot of turns that total cars, so it could've been much worse.