Coolant boil-over

[mark in sunnyvale]

I just had my coolant boil over or at least I think it is. I was driving up Mt. Hamilton. The temp reached to the left of the 0. I stopped, and a minute after I stopped, the coolant light flash, there was coolant underneath my car. It came from the read passenger side.

I know I'm gonna get stoned for this, but let's remember that I was all the way up the mountain! Due to where I was, decided to wait for the car to cool down and re-fill the tank with distilled water. It took three tries to get all the air trapped inside out. I lost about a gallon when the tank boiled over. I drove the car all the way down the mountain. The temperature and water level was normal, so I decided to take the risk and drive it home. I plugged in my OBD-2 reader to get a digital raedout of the coolant temp while I was driving. It was normal.

I'm wondering, what sort of test should I ask the dealer to run to see if there was any long term damage from this incident.

This happened about 3 hours ago, I'm letting the car cool down and getting ready to check for more leaks.

[mrmickeymouse]

I would pressure check your system, Also check your fans for function, unless you know already.

BTW- The car will give you a numeric readout if you want it as you drive, without your external OBDII test tool.

http://www.cb-racing.com/boxster_AC.htm

Scott

[Tool Pants]

You did a Mt. Hamilton drive and did not invite the other local Boxster owners?

Sure was hot yesterday and going up hill makes it worse. Sounds like a simple boilover.

[mark in sunnyvale]

I'm glad I didn't invite anyone. I didn't even make it to the top of the hill! It was very embarassing.

I'm praying that it was just a simple boil-over.

Hey TP, I'm trying to find if I can buy a pressure tester so I can do the pressure test myself, any suggestions? I'm hoping the stuff you buy from Kragen will work.

[Tool Pants]

Years ago I was going to buy a pressure tester made by Stant with all the adapters but it was too expensive for the few times I would need it. No idea what Kragens has. Our threaded cap is the same as VW.

In fact, my January 1997 original cap has a the VW/Audi logo on it.

Do it the cheap way and drive around until the car is warm and unscrew the cap and see if you hear the hiss.

You might simply just have a bad cap. If you went to the cooling tech session in SUNNYVALE a few months ago you would know this.

The cap on the left is the current one. The one on the right is the former one. My old VW cap is not in the picture. The new cap is said to seal better so you do not dump coolant on the ground.

If you already have the 01 cap then ignore what I said.

[mark in sunnyvale]

I'm assuming a hiss is good because pressure was allowed to build up? Well, I ran my car for a while to check if I see any leaks. I even removed the carpet to see if any drips will come from the reservoir. After 15 mins, everything is nice and dry.

I'm going to drive the car around to see if I lose any coolant. I'll let you know if I find a pressure tester that will work.

I know, I know. I wish I made it to that tech session.

[Loren]

I'm assuming a hiss is good because pressure was allowed to build up? Well, I ran my car for a while to check if I see any leaks. I even removed the carpet to see if any drips will come from the reservoir. After 15 mins, everything is nice and dry.

I'm going to drive the car around to see if I lose any coolant. I'll let you know if I find a pressure tester that will work.

I know, I know. I wish I made it to that tech session.

Read the part number on your cap. If it is not 996 106 447 01 then you need a new cap. $14.71 retail as of Nov 2003.

[Tool Pants]

I know, I know. I wish I made it to that tech session.

Pics from the tech session. Taken by Vince.

When in doubt, replace the cap. Like Loren says.

[mark in sunnyvale]

Hey Jeff, I have the Audi/VW cap. I will go ahead and get the new cap.

I drove around for 30 minutes today. I left the bleeder valve open to burp the system. I had no loss of coolant. The temp was normal.

Who did the tech session? I might give them a ring in case I need some work done to my car.

Thanks for all the help!

[Tool Pants]

http://www.realmeangarage.com/

Bob Grisby, the owner of RMG. Actually, cooling was the 3rd tec session he put on that I went to. I tell other local out of warranty people to see his shop.

I hope you know that there is a tech session in Santa Cruz next month.

Guess I better get rid of my VW cap as well.

This is Bob at a prior tech session, PST2.

[mark in sunnyvale]

TP,

Where did you buy that tool to remove the spring band clamps? That would've saved me a lot of time when I did the water pump on my Explorer.

I'm planning on replacing the water pump on the boxster a few months from now. That looks like a worthwhile tool to have.

Thanks!

[ar38070]

On the off chance had you loosened the radiator cap at some time in the recent past (to check warer level or something)? If so you may not have screwed it back down tight enough. You really have to screw it down hard otherwise you will get the symtoms you reported. i.e. The car is fine until you stop it, then it spills its guts.

[Tool Pants]

Only one clamp for a water pump replacement. I bought it in case I had to replace the plastic tank.

You can borrow it anytime you want.

Guess what, the dealership has the same type tool.

[mark in sunnyvale]

Thanks for the offer Jeff, I might have to take you up on that offer one of these days.