: Venting Cooling System?? Drill Hole??

04-25-05, 10:37 AM
Would drilling a hole in the coolant cap help with pressure buildup from a leaking head gasket? I know that the pressure keeps the water temp down, but if there is too much pressure forcing the fluid out and superheating the coolant mabye it would help. I guess coolant would blow out with the air and exhaust. I'll try anything now. I might even try Blue Devil. I'm definitely not one of those that thinks pouring a lot of $$ and labor into the engine of a 5 or 6k car with over 100k (and then having something else go) is worth it. Think there's a call for '99 Deville DeElegance parts??

El Dobro
04-25-05, 11:39 AM
I'm sure if you put a hole in the pressure cap, the antifreeze is going to shoot out of it once everything's up to temperature.

04-25-05, 12:20 PM
Drilling a hole isn't going to solve anything. It will only exacerbate the problem by making it easier to lose coolant and introduce air to the system.

Pressure doesn't keep the coolant temperature down as far as I know. It just raises the boiling point. The higher the pressure, the higher the boiling point will go.

I assume the problem you're having is that exhaust gases are being introduced to the coolant system through a blown head gasket. Nothing is going to alleviate the problem short of fixing the head gaskets. Try the cure-all solutions if you want, it's your money, but I highly doubt it's going to help anything. If that stuff fixed anything, why wouldn't they just use that instead of head gaskets? Why would there be any mechanics who can fix head gaskets? It's a crappy situation. There's no doubt about it. I'm very sorry that you're in this position, but I do believe your best bet is going to be getting the gaskets replaced and block timeserted or a new engine. Maybe try your luck at selling the car off to somebody who wants the project.

04-25-05, 01:37 PM
Just put the cap on loose and you will have the same effect.

04-25-05, 04:57 PM
Don't feel bad!!! I had my car only a few months before feeling the devistating wrath of the bad gasket. I paid $5500 for the car and it has 124k on it. I opted for a replacment motor with 29K miles. Can't tell you how it worked out cause the motors going in this week. Im on my knees though cause nothing will hurt so bad if its a bad motor...

04-25-05, 08:35 PM
Drilling a hole in the cap to vent the cooling system would be like cutting your wrist to lower your blood pressure.

04-25-05, 10:06 PM
Drilling a hole in the cap to vent the cooling system would be like cutting your wrist to lower your blood pressure.

Hmm... does that _work_? :drinker:D

04-25-05, 10:47 PM
Hmm... does that _work_? :drinker:D
Actually, yes. In theory both would work but the side affects would be a bitch.

04-25-05, 11:17 PM
*lmao* :histeric: Y'all are too funny! When I brought my beautiful Caddy home from the dealer fellas, it blew a head gasket THE NEXT DAY!! *lol* Actually it blew before it was traded in, but the dealer done something to it to sell it and get me home - wish I knew what they did. It wasn't Bar's leak because I tried some of that and it had no effect whatsoever.

I would think a '99 DeElegance with 100K miles would be worth more than $6K, Quadrasteer. But if you decide to part it out, I'd like the engine. :yup:

04-26-05, 11:26 PM
In theroy it would work? A basic understanding in automotive cooling systems--something taught in General Technology class in midddle school--proves otherwise. The pressure cap is a purge valve, the reason why it's called a pressure cap. (If additional pressure couldn't escape, the coolong sytem would explode.)

I don't know what the rating is, and I don't feel like going downstairs to the garage and see if the cap lists its rating. Let's say that the cap is 15 to 17 psi, an average cap rating in the old days. Once raidator pressure exceeds 15 to 17 psi, the pressure bleeds off. If the head gasket leak is introducing pressure into the cooling system, the pressure will bleed off once it exceeds the cap's maximium rating.

Disabeling the pressure system is a short term fix for a coolant leak. Let's say that you have a pinhole in the system, and when the system is pressurerized, there is a signifigant coolant leak. If you disable the pressure system, it can slow down, or completly stop the coolant leak.