Coolant Leak / Overflow ??? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

rick3000 · 03-24-2008, 04:40 PM

Hi,
I just got back from a half hour drive on the freeway, and something odd happened. Everything was fine the entire time I was driving and the second I parked the car, and shut off the engine, a bunch of coolant came flooding out of the right rear of the car, a little but inside the wheel. There was no coolant in the trunk, a very small amount of condensation on the trunk lid right above the coolant cap, and a little bit of coolant around the coolant cap.

The only thing I can think of is that I topped off the coolant a few days ago about 1/2" under the max. mark. It was 40° then, and today it was 65°.

Was this a coolant leak, or some sort of overflow drain?

Thanks!

Boxtaboy · 03-24-2008, 05:11 PM

Hate to say it, but I had these symptoms when my coolant tank had a small leak/crack in it. It got progressively worse until I was losing like a quart of coolant each time I shut off my engine. Had to replace the coolant tank, as it had a leak at the bottom of the tank where you couldn't see it, and it released coolant through the bottom of the pass. rear wheel.

It could also be that you have an older version coolant cap. Get a new one at the dealer if the part# on top of the blue coolant cap ends in 00. The updated ones end in 01 or 02. If this is the problem, it's a cheap fix. Good luck.

jwilson95 · 03-24-2008, 05:11 PM

Same exact thing happened to me in my 02S. Coolant coming out of the same area when I shut the car off after getting particularly hot in stop/go traffic in the summer. I thought I was in for a big ticket maintenance bill at the dealer.

It turned out the cap on the coolant reservoir in the rear of the car was either loose or crooked. Porsche does have a new cap (don't know the part number) for like 17 bucks at the dealer which supposedly had a better/new seal to it.

Hope it is the same thing...

Lil bastard · 03-24-2008, 05:33 PM

All good answers. There is another possibility, that a clamp is leaking. Porsche uses a spring clamp, but has issued a TSB to replace these with conventional screw-type worm clamps whenever any of the originals are removed for service work. You're gonna need to get under it to see what more you can find.

If you continue to drive the car w/o addressing it, whatever the problem is could leave you stranded.

While it certainly could be the reservoir, especially w/ a '99. Porsche has since changed the type of plastic being used and it's much rarer on the later cars. If that's what it turns out to be, be certain you get the revised replacement tank. I believe the most current one is PN#996.147.106.07. Good Luck!

rick3000 · 03-24-2008, 05:57 PM

So something is obviously wrong.
How could it be the coolant cap alone causing this?
Also, should I get the car towed? (the dealer is about 30 minutes away)

Thanks Again!

Boxtaboy · 03-24-2008, 06:08 PM

Quote:

Originally Posted by rick3000

So something is obviously wrong.
How could it be the coolant cap alone causing this?
Also, should I get the car towed? (the dealer is about 30 minutes away)

Thanks Again!

I think the earlier caps released pressure faster than the newer ones, or something like that. Regardless, this was a known problem, and hence the update to the 01 cap, and more recently, the 02 cap.

I think you'll be ok driving to the dealer. Just bring like a gallon of distilled water with you in the car, just in case.

juan986 · 03-24-2008, 06:58 PM

My car had a coolant leak in the middle of the car in the passenger side, the leak wasnt that big but it ended up being the water pump.

rick3000 · 03-24-2008, 07:23 PM

So it is probably one of these:

Coolant Cap
Cracked Coolant Tank
Water Pump
Clamp

I have an extended warranty ($80 deductible) which should cover any problem. Is there any way to be certain whether of not it is the coolant cap? I would prefer not to pay the $80 deductible and find out the problem was the $17 coolant cap.
I have an older coolant cap (.01). I also cannot see any coolant reading, it is either too full or too low, to be read.

Also, is there a drain on the coolant tank? How did all this coolant come out if the tank isn't cracked?

Thanks Again!

blinkwatt · 03-24-2008, 07:40 PM

Check underneath the car. If it looks like there is a small hose that fresh wet it's probably the coolant overflow hose. Did you mess with the bleeder valve recently? When you topped the car off was it on or off?

rick3000 · 03-24-2008, 08:05 PM

I have not messed with the bleeder valve, but it was recently at the dealer, because it was heating up more the normal, and they may have messed with the coolant tank (I know that they pressure tested it).

I am going to check everything again tomorrow, and maybe take it into the dealer.
Could it be as simple as overfilling the coolant tank when I topped it off, and it just drained the excess coolant?
If the coolant level is normal, would that signal nothing was wrong?

Thanks!

blinkwatt · 03-24-2008, 08:17 PM

Quote:

Originally Posted by rick3000

Could it be as simple as overfilling the coolant tank when I topped it off, and it just drained the excess coolant?
If the coolant level is normal, would that signal nothing was wrong?

Thanks!

Yes it could have been from you topping it off.

Same thing happened when I bleed my coolant tank,I put a little bit too much and it shoot out the coolant overflow hose which is aiming near the inside of the passenger rear wheel.

Boxtaboy · 03-25-2008, 03:50 AM

Quote:

Originally Posted by rick3000

I have not messed with the bleeder valve, but it was recently at the dealer, because it was heating up more the normal, and they may have messed with the coolant tank (I know that they pressure tested it).

I am going to check everything again tomorrow, and maybe take it into the dealer.
Could it be as simple as overfilling the coolant tank when I topped it off, and it just drained the excess coolant?
If the coolant level is normal, would that signal nothing was wrong?

Thanks!

I doubt it is from topping off the coolant. If you lost a significant amount of coolant after the shutdown, you probably are low in coolant, and you won't be able to read level in the indicator. Your cap, if ending in 01, should be fine. The ones ending in 00 really were the problem ones.

Open the trunklid, and look at the coolant tank area. Take off both the coolant cap and the oil cap, and then lift off the black plastic cover so that you can see underneath it. Do you now see coolant in that area all over the place? Do you see coolant at the bleeder valve area there? If not, and the coolant still comes out from under your passenger rear tire, then it is mostly likely a loose hose down there or a hairline cracked coolant tank.

rick3000 · 03-25-2008, 07:27 AM

I went out this morning and took the coolant cap off. The coolant tank was completely empty, and there was definately some coolant around the cap, but only a little bit. I am going to take the car in today.
My only question is if the coolant is completely empty, is it save to have the car running on only distilled water for about 30 minutes.
Thanks!

Boxtaboy · 03-25-2008, 08:35 AM

Quote:

Originally Posted by rick3000

I went out this morning and took the coolant cap off. The coolant tank was completely empty, and there was definately some coolant around the cap, but only a little bit. I am going to take the car in today.
My only question is if the coolant is completely empty, is it save to have the car running on only distilled water for about 30 minutes.
Thanks!

Just because your tank looks empty doesn't meant there's no coolant in there. There's a lot of coolant in your car, and the tank only shows a portion of it, so don't worry. If you're really low, a light will come up on your dashboard. Yes, you can drive the car safely with just distilled water in it.

rick3000 · 03-25-2008, 08:53 AM

Thanks for all the help everyone!
I just got it towed by AAA for free (Just to play it safe) to the dealer, and when I get the car back I will let you guys know what happened.

Lil bastard · 03-25-2008, 09:40 AM

Quote:

Originally Posted by Boxtaboy

... Yes, you can drive the car safely with just distilled water in it...

Well, Yes and No.

If you're stranded or driving a short distance to a repair service, then Yes, you'll be OK.

But, if you're planning anything other than that I'd say No.

In addition from keeping the coolant from freezing, anti-freeze also provides needed lubrication for the Waterpump bearing as well as corrosion pretection. It wouldn't take much driving at all for damage to the pump or corrosion to occur.

Boxtaboy · 03-25-2008, 10:15 AM

Quote:

Originally Posted by Lil bastard

Well, Yes and No.

If you're stranded or driving a short distance to a repair service, then Yes, you'll be OK.

But, if you're planning anything other than that I'd say No.

In addition from keeping the coolant from freezing, anti-freeze also provides needed lubrication for the Waterpump bearing as well as corrosion pretection. It wouldn't take much driving at all for damage to the pump or corrosion to occur.

Agreed, but he hadn't lost all the coolant in his system, so topping up with distilled water and driving the 30 minutes to the dealer (which was what he was asking if it was safe to do), would be fine. There was a friend of ours who during a 9 hr. drive down to a Boxster event in North Carolina from New Jersey, his old coolant cap let out a huge amount of coolant after stopping. Refilled with (non-distilled) bottled water and went on to go thru the whole 4-day event, and then drove all the way back home, with no issues. Car and water pump are still fine today....

rick3000 · 03-25-2008, 10:40 AM

Well, I am actually glad I called the tow truck, because in the minute or two I had the engine on, to back the car out and onto the truck the light was flashing the entire time, and I started to smell the beginning of a faint burning.

The upside of all this, is that I paid $115 for a diagnostic that didn't show anything a month ago when the car began to heat up higher than normal, and know they are going to reimburse me and I only have to pay the $80 deductible, so my car breaking is getting me back $30-35.

Lil bastard · 03-25-2008, 10:19 PM

Quote:

Originally Posted by Boxtaboy

Agreed, but he hadn't lost all the coolant in his system, so topping up with distilled water and driving the 30 minutes to the dealer (which was what he was asking if it was safe to do), would be fine. There was a friend of ours who during a 9 hr. drive down to a Boxster event in North Carolina from New Jersey, his old coolant cap let out a huge amount of coolant after stopping. Refilled with (non-distilled) bottled water and went on to go thru the whole 4-day event, and then drove all the way back home, with no issues. Car and water pump are still fine today....

Not to put too fine a point on it, but you stated that with " 'just' (sic. only)distilled water you can drive the car safely". That was the basis of my disagreement.

Your friend has added bottled water to the system, but it wasn't completely dry from your description, nor would I expect it to be from just a failed cap. So, while diluted, I suspect there was still sufficient coolant in the car to lube the pump, etc.

D.L. · 03-26-2008, 09:04 AM

Not to hijack this thread, but my coolant levels are sometimes low causing the light to blink on the dash. I think I may have a small leak or a bad cap because I find A LOT of condensation above of the coolant area on the trunk. I always thought this was normal due to changes in temperature, but I guess not. Anyways, I always used regular water to refill... Did I mess up the car doing this, or should I use coolant to refill? I also heard that Boxsters use a different type of coolant. Is there special coolant for our cars?