cooling system woes

[jaykay]

I would recommend using a vacum bleeder on your cooling system after you have the res in. The cooling system does have many long runs and nooks and crannies. This would ensure that there are no trapped air pockets which would likely give over heating problems if they are present. I can't comment on the effectiveness of the manual bleeding procedure.

In Canada there is company called uview which makes vacum bleed equipment which should include adapters to properly connect to the coolant fill opening.

I am not able to comment on the symptoms of a cracked head but my guess is that a compression check would only get major flaws. You may want to check this a while down the road as well should an expert deem that this is warranted.

I would post again with this concern as there are many service experts on this site that have a great deal of experience.

Best of luck to you and I hope this helps.

[Mike_Yi]

FWIW, I recently replaced my coolant reservoir. It was a PITA, but not as bad as the AOS. I got mine from Sunset Porsche for about $208. It did take a while to get.

Anyway, I used the UView Airlift vacuum tool to vacuum the system down and vacuum fill it. After I did that, I used the bleed procedure afterwards as I didn't want to take any chances. It's a good thing I did that though. Just running with the cap off required additional fluid (I went to a 25psi vacuum). When I did the full bleed procedure, I had to add even more fluid.

I drove it for 2 days with the bleeder open. Then I closed it and drove it another two days. I then checked the system, and I had to add more coolant.

The cooling system in the Boxster is definitely "over-engineered"! It's a PITA.

BTW, a cracked head will generally result in steam coming out of the exhaust after the car is warmed up (it's normal to get it when it is very cold out and before the car is warmed up). You can tell the difference between steam and smoke as smoke will not dissipate and steam will. If you are also losing fluid, but not seeing any drip on the ground, that is a pretty good indication that there is a cracked head/block or blown head gasket. How hot did the engine get?

[JFP in PA]

If you correctly use a vacuum filling system, there is absolutely no need to open the bleeder afterwards; in fact, you are creating an opportunity for air to get back in to an otherwise air-free system at that point.

[Mike_Yi]

Originally Posted by JFP in PA

If you correctly use a vacuum filling system, there is absolutely no need to open the bleeder afterwards; in fact, you are creating an opportunity for air to get back in to an otherwise air-free system at that point.

Not really. When you remove the bleeder, air gets in the system. I already had to add coolant at that point, before even firing it up. I did use the system exactly as the directions indicated.

[insite]

a lot of people over-think this. open the bleeder & reservoir cap. fill it up w/ coolant. start the car & let it warm up. once the thermostat opens, the coolant level will drop. shut the motor & fill it back up with coolant. now go for a 20min drive with the bleeder OPEN. go home, shut the bleeder, park the car, and DO NOT OPEN THE RESERVOIR CAP. let the car cool off on its own. once it's cool, top it off again & you're good.

important note: once the big bubbles are out, the system is self-bleeding!!!

[JFP in PA]

Originally Posted by Mike_Yi

Not really. When you remove the bleeder, air gets in the system. I already had to add coolant at that point, before even firing it up. I did use the system exactly as the directions indicated.

I’m not sure what you are doing to get air in after filling it under vacuum, we do this just about every day and have never had an issue with trapped air or having to top up a system that tested leak tight before filling. Do you let the Uview pull in the coolant mix until it stops (the vacuum goes to zero), at which point the fluid level in the tank is usually at mid level? We have had cars come back to the shop for other service months after the coolant was changed, and the level in the tank was just fine without any top ups……….

[deptotpr]

I pulled up to destination, reversed into parking space, when I stopped, nothing but smoke out of the side vents, and a viscious dump of coolant. I am hoping it is just a hose issue. I did not even notice during the drive, and did not get any overheating dash warning lights? Anyone else had similiar experience?

[Frodo]

Originally Posted by deptotpr

I pulled up to destination, reversed into parking space, when I stopped, nothing but smoke out of the side vents, and a viscious dump of coolant. I am hoping it is just a hose issue. I did not even notice during the drive, and did not get any overheating dash warning lights? Anyone else had similiar experience?

Sounds irritating simplistic, I know, but basically you start by getting the car on a lift or jack stands and looking for the source of the coolant. Water pumps intermittently die on these cars, and when it happens you tend to see some coolant leakage.

I'm a very long way from being a seasoned mechanic, but your coolant leak seems like a lot---perhaps it is just a hose issue. My pump went many months ago and I did get some coolant loss, but it was a trickle. I would think (again, I'm no expert) that if your water pump had deteriorated to the point where you lost that much coolant, you'd be hearing quite a clatter as well. Was there any noise noted in conjunction with the coolant dump? Had you been smelling hot coolant over the past several times you've driven it?

In my limited experience, I'm thinking it's probably not the pump. Again, you just need to elevate the car and see where it's coming from.