WTFitsCarter

2005 C2S here.. had to add 60oz's of coolant today. The car was low when i first got it in may but just at the bottom of the coolant tank. I didn't think much of it because when the car heated up it would go up to a normal level and felt it would be fine in the mean time since their was no low coolant warning and the temperature was fine. Well when i finally got my hands on the porsche coolant i ended up having to add 60oz's of coolant! I often check for any kind of leaks under the vehicle (rms/ims paranoia) and never saw anything. my car has 59k on it and under CPO (transferred to me). So im hoping its just the normal coolant tank or cover and not a blown head gasket. BTW I had to use ALL of my power blue in the face and shaking to get the cap off(just to get it started)

I have never smelled burnt coolant that i can remember.. any thoughts on this? The car had an oil change at 55k so I was going to bring it into the dealership for them to do and go through the car real quick since the warrantee is up in November.

Thanks,
Carter

ADias

How does your coolant overflow blue cap look like? Any residue at the bottom around the cap? Is your overflow coolant cracked. These are known (for over 10 years) issues with the overflow tank.

WTFitsCarter

I was hoping that someone would chime in on the cap as i did a search and didn't see how you could actually tell if they were bad or not. When i got the car i cleaned the motor (when i t was cool and scrubbed everything) so it could be a broken tank and i unknowingly cleaned up residual antifreeze at that time. After i added it i took it for a ride but haven't seen anything leaking just yet. i'll have to take a better look at it in the AM since it was night time when i drove it home.

Also i should add that when i assumed the tank was just an inch below the min line i noticed that it was some coolant that just splashed on the ledge and it wasn't at that actual level and much lower (60oz to hit the min line). So I am wondering if it is the tank and it hasn't been leaking because it has been below the crack..

uzj100

Those caps are cheap insurance. Pick a new one up ASAP.

Get underneath and check your water pump hose fittings.

Edgy01

Look first at the cap (usually the problem) and then under the car for a telltale sign of seepage. Sometimes the loss rate (seepage) is such that the heat of the engine burns it off so that you never leave a deposit on the garage floor.

Macster

When I took my Turbo in for some work recently I mentioned I suspected the cap leaking because the fluid level low. The tech had to replace a radiator (not due to a leak but due to the fan coming apart and damaging the radiator) and afterwards he checked the cooling system for leaks and at the same time checked the cap's ability to hold pressure and found the cap bad. Replaced it under CPO warranty (which also covered the radiator, the radiator fan assembly and some other things).

If you don't have a place that can check the cap for integrity, top up the cooling system so the fluid level is near the maximum line and clean the cap -- flush/rinse under hot faucet water -- then make sure the tank opening where the cap attaches is clean and install the cap securely.

Take the car for a nice drive. Nothing gruesome but drive it on surface streets to get the engine and drivetrain nice and hot. Drive with A/C off. This means the radiator fans only come on when the coolant temperature climbs above 212F.

You want to continue to drive the car until you hear the fans come on and then go off, at least several times to be sure the system is as hot as it can normally get.

Pull into your driveway and raise the engine rpms to 2K and hold for a few seconds. 10 to 20 seconds. You want the coolant hot. As soon as you hear the radiator fans come on shut off the engine and open the engine cover.

Be careful. The cooling system contains 4 to 6 gallons of very hot fluid and is under pressure, maybe 14psi or more, so treat the hot engine and cooling system with respect.

Watch, wait, and observe. If you want to get fancy "tent" the coolant cap with some aluminum foil and see if any water condenses under the foil.

Any signs of water is almost certainly from a leaking cap.

Of course, if the tank has a crack/split the heat load of the just shut off hot engine will raise the cooling system pressure and if there's a crack/split you'll know it by the coolant dripping on the ground under the car.

If the cap's part number doesn't end in 03 or 04 (or higher) I'd just replace it. Both the cap on my 02 Boxster and my 03 Turbo have failed and had to be replaced. They just wear out due to I guess age more than anything.

Sincerely,

Macster.

uzj100

Coupled with Edgy's photos, thought these might help? Note the cap is clean, no "milky" looking deposits on the edges. Believe most current cap # is 04 (per Macster's post)

HTH

p-cardriver

There is another potential issue worth exploring. On Caymans there have been several comments about low coolant with causes ranging from leaking head gaskets to improper (low) fills at the dealer or when delivered. Failing to get all of the air out of the system when refilling also has been reported. There is a thread on Planet-9 about this.

If your cap seems to be ok, then have the system pressure tested. That will reveal leaks. Our mechanic puts the tester on at the end of the day, pressurized, and then rechecks it in the morning.

I have not seen reports of coolant loss problems on 997S but since the Cayman's seem to have a few, it wouldn't be a surprise if they pop up on our cars, too.

WTFitsCarter

I just typed out a whole long message and it didn't go through ughh!

I didn't have much porsche antifreeze because I got some from a friend at work. So of that 60OZ of coolant i would say about 85-90% of that was water. I have some on order and plan to added some straight coolant to even out the mixture once it comes in. Thats why i just filled it to the MIN level vs the MAX so I could offset the lack of actual coolant added. On a side note I plan to do the 3rd radiator install this winter and will do a full coolant flush at that point.

A quick run-through for today was a 25mile ride to work.. highway, some heavy foot action on the on ramps. some stop and go at the lights and another 40mil ride back to my hair dresser. I don't normally use the car for this but i wanted to give it a full run since it was about 97 degrees today in MA. I didn't see any leakage at all and don't recall seeing any "white crustiness" on the bottom of the cap when i filled it, but i will do a better investigation tomorrow morning. I should however note that my cap does end in .01 so I will get that $14 cap on order and not even worry about the CPO claim.

Thanks!
Carter

budmanv24

When you say water, do you mean distilled? Standard tap water will leave deposits in your coolant system.

Macster

97F is certainly a warm enough day but if you run with the AC on the fans run all the time and help keep the engine coolant temperature moderated. The engine coolant temperature gets its hottest and stays its hottest the longest and builds the most pressure if you run with the AC off. You want to drive the car long enough to hear the radiator fans come on run a while then shut off.

If you then fast idle the engine until the radiator fans just come on then shut off the engine the build up of heat will raise the pressure in the cooling system and if there's a leak above the fluid level you'll know it. The fluid level in the cooling system must be full though.

As long as there is no danger of freezing you can just add distilled water to the cooling system to bring the level up. However, before winter sets in the system should be drained and refilled with fresh Porsche anti-freeze and distilled water in the proper ratio to protect the engine against freezing in your area.

The ability of the cooling system to maintain pressure once hot more than anything protects the engine against boiling over and overheating.

Sincerely,

Macster.

utkinpol

I only went to NH track for DE so far - are DE rules all the same on all tracks or do some tracks require complete flash of coolant off to be replaced with water? I know club racing rules require it - what about DEs?

kosmo

Distilled only.

WTFitsCarter

I did use distilled water.. i only use tap water on my VW POS Anyway I pulled the cap off this morning and took a few pics. I have a new one on order but do you think this could be the culprit?

The area where i didnt clean and the hoses connected to it had a whitish brown color to them which could have been from some coolant overflow at some point? no pics of that though

ADias

That cap must be VERY tightly re-attached...