PontiacBonnevilleClub.com

My vented coolant reservoir cap has never quite fit right. As a result, coolant keeps evaporating, and every other week I have to top it off.

The only cap I find at parts stores is a Dorman unvented cap. I bought one and it fits great. Now I'm wondering if my first cap is original or not. Maybe a past owner put the wrong cap on there. I don't want to use the unvented cap if the car should have vented.

SSEi owners: what do you have: vented or not? You can tell by looking at the cap. Unvented is a solid flat cap. Vented has two tiers.

Ken_W

The original cap is not vented, the tank has its own vent built in. I've never even seen a vented reservoir cap.

The coolant is not evaporating, you probably just have a leak.

Thanks Haro -- I'll put the good-fitting new cap on and see if I still lose coolant. You may be right about there being a leak, but I want to rule this out first.

Ken_W

If your original cap does not quite fit well, just wrap some electrical tape on the threaded part on top of the reservoir and then screw on the cap, it should fit nice and tight.