Deansdream

So I came back from my 2nd run Fri at VIR, and when I parked in the Paddock, all the coolant ran out. Thankfully the guys from Synergy were there and very helpful. They couldn't find a leak, and concluded air had gotten in and forced the coolant out. Indeed, after a couple of warm-ups and cool downs, a lot of air was released. i was able to do all runs the rest of the weekend and drive home to NJ.

Appears problem solved, but I'm paranoid about this happening next DE or there being some underlying problem.

Any thoughts? Can i relax?

asu_lee

Had the same problem....Filled up coolant in Phoenix. Drove to Tucson for the weekend. Stop and go in Tucson. Came out after breakfast and huge puddle under car. Refilled and all is well. Bad cap?

Mike in CA

The system should not be letting air in or coolant out. If there's no actual leak somewhere (I'd have that rechecked) maybe a bad seal or improper fitting of the coolant cap is the culprit.

Edgy01

You can't just refill it and call it good. Get a proper mechanic to put a pressurized cap on it and determine where the source of the leak is.

The coolant caps are a terrible design. I have gone through at least 3 already (50,000K).

Minok

Air would not force 'all the coolant' out of the car. The air would end up in the overflow tank and lower the level there and cause a coolant level warning. Coolant being on the ground is caused by a leak, not by air in the system. Coolant doesn't compress, air does, so no way is air going to displace coolant in the car and force it out.

asu_lee

Back from dealer. Pressure checked system. Held fine. Cap on the other hand did not. New cap.

I am suppose to watch it now.
-Lee

Edgy01

The caps are crap. Let us know the version cap you just got sometime. It's molded onto the top of the cap. Mine is 996.106.447.04 (Version 4).

asu_lee

It is the 447.04
-Lee

Edgy01

Although that is the latest (to my knowledge) I'm a bit amazed that that cap has had so many versions since 1999 (introduced no doubt with the earliest 996 engines). There is something fundamentally wrong, e.g., it's expected to do too much for the materials used. (Is the working pressure too high?) (Are engine compartment temps taking a toll on the material chosen (plastic) and thus it's breaking down?)

asu_lee

I think the material is crap...needs to be a metal cap. Seems like a way to get you to the dealer.