Coolant leaks underneath like shower

[masiuwai]

I just bought a 99 Boxster S (Tips) with 41K KM in Hong Kong. Everything is good except a very minor engine oil leaks (checked my mechanic).

I have changed the coolant yesterday. (It was pure water but not coolant before the change). After the change, I found the temperature is slightly higher than before says 85 -95 but below 100. Drive thur highway and city, parked my car and have dinner. The temperature light was flashing when I start the engine. Pull over and check. No coolant at Coolant tank. top up with 1.25 litre distilled water in immediately. Drive home by 10 minutes (normal temperature) then stop and check it again. No leaking.

In this morning, check coolant level again. Nothing wrong. I wanna drive to office and have a check by mechanic after work. 20 minutes from home to office (everything is normal, temp around 85-95). Parked my car and hear waterfall sound. Bulk of coolant on floor and seriously leaking like waterfall. Open the trunk, found the radiator cap is beeping and leaking (not serious but leaking). About 2 litres on floor. Now, I wait for cool down and top up with distilled water. Any idea? I have searched the radiator cap. I knew that this is common problem. But, does it make the coolant leaks like waterfall when you stop your car?

New to Porsche and to Forum. (have been waited for 25 year, dream comes true) Really need help.

Thank you

[nick49]

Congrats on your dream car!

I don't think this is too serious or expensive either. The coolant reservior holding tanks on early '97-'99 or '00 were prone to cracking. There have been a few subsequent tanks that are improved with updated part numbers. Have it checked and replaced with the latest part available.

Good luck'

Nick

[rushrevisited]

I agree - probably coolant tank. I just had to have mine replaced due to crack (in an '01). The labor on it killed me. Total bill was around $800+.

[Chuck Jones]

$800 to replace a coolant tank??? Holy Smokes....I'm going to go into the business. I bought the tank from Sunset for $168, and even though I'm not what you'd call a master mechanic....using the DIY pictures and instructions from this forum, I printed out the pictures and text and did it myself. Someone who knows what they're doing can probably get thru it in 30 minutes.

I don't see how this can be an $800 fix....hells bells...even if they charged $150 an hour, that would be four hours labor plus a $200 part. I'm a novice and have never done a DIY project on a Porsche.... and I did it in two hours.

[RFM]

I see that you have changed the coolant without the special vacuum tool, so your problem are rather air bubbles.

The best you can do is jack up the rear end of the car, remove the black plastic plate with the M 6 bolt on the coolant tank and open the press. valve by pulling on the metal ring, top up the tank and close the valve, let the engine running and look Wat the coolant level does, when dropping : top up, when rising : close the filler cap. Let the engine running till hot whit, the AIRCO OFF, and wait till the fans on the front are activated while you keep an eye on the temp. gauge.

Let the engine cool off and top up.

I dont believe in a cracked tank, in this case you got 2 liter of coolant in the trunk and only a few drips on the floor (986)

[masiuwai]

Problem solved. It was the problem of the radiator cap. I jacked up the car and have checked the hook, pipe and etc very carefully. Nothing wrong. I pulled up of all the trunk carpet and found nothing.

Started to think about the radiator cap. Checked with parts number and search on this useful forum. Thanks for all of you providing information and your experience. The old cap is "00".

Go to the dealer and buy a "01" cap at HK$141 (around USD18) immediately. Changed it and doing what RFM recommended (release valve for avoiding bubbles). Everything is fine and the car is perfect right now. The temp is around 80 - 90.

One question, how can I know my collant tank is the old one or the improved one? Do I have to pull it over and checked the parts number? The dealer price of the coolant tank is HK$2100 (around USD269), sounds terrible.

Thanks for Renntech and all of you guys.

[rushrevisited]

Had to pull the receipt after seeing your reply - was $709, but that was with a "20% discount"... Please review and tell me if I got royally screwed: