Overheating....then OK??

[Horst]

Hi Gents (and Ladies)
I've been out of commission for a while Clipper-wise - just too busy trying to keep the business afloat, paying bills, dealing with family issues, blah blah etc., etc.
So I took the Clipper out for the first time in a while for a weekend trip. It got too hot (200+) pretty quick, and I was already committed, could not pull over, etc.. Anyways I overheated badly, had to pull over, and all the fluid was just boiling - the overflow resevoir fluid was actually boiling.
I let it cool down, waited 30 minutes, and then took off again, refilled the resevoir with 50/50 coolant/water  and it ran perfectly, and within normal temp ranges....what the heck??
So my questions?
1) I was told once you boil over as bad as I did, that I need to replace my thermostat - true?

2) Any ideas as to what happened? Why it started out running too hot, and then after the big boil-over, it runs normal temp?

(On the way home it ran fine, maybe just a bit hotter than "normal")

Thanks Gents - and I hope to find time to pop in again once in a while - but this has been a tough year, in many respects.
Later
Horst

[bulldog 1995]

your thermostat got stuck and yes you need to replace it before you drive it again as next time it might not unstick it will more then likely stop the intermittent overheating problem that your having

[Horst]

thanks Bulldog - hope to swap in a new one this weekend - going to flush the radiator while I'm at it

[Horst]

Just a quick update - yep - thermostat was very sticky/gucked up.
Radiator was funky too - but my friend and I flushed the heck out of it as best we could from top and bottom - got lots of crap out, and it looks much better, and runs much cooler.
Still, a new radiator is just another item in my future I fear.

[pop427]

The best way to flush the cooling system is to drain the antifreeze. Fill with water and put a cup of dish washing machine soap. Drive around for a week or so. Drain and look inside, If it is not clean, repeat. Dish washing machine soap does not suds or foam or hurt gasket material. I was shown this many years ago by a very smart radiator man and have used it many times restoring very old and hard to replace radiators.

Doug in Big Ditch  aka Arroyo Grande

[John Eversoll]

Who'd of thunk--- dish washer soap....huh....

Thanks for the info!!!    John

[retrorob]

Whoa! Wait a minute.DO NOT USE MACHINE DISHWASHER SOAP IN YOUR COOLING SYSTEM!!!!! Machine dish washer soap contains sodium hydroxide. It will attack and destroy aluminum!! Want proof? Put anything aluminum in your dishwasher and when you pull it out it has a dull gray oxide on it.

[LARRY RAY]

Unless the cooling system has changed, all the old Clippers had copper radiators I do believe. I am wrong?
Possably.

[pop427]

The dish washing soap I use (Cascade) DOES NOT contain sodium hydroxide! I looked on the box label. Sodium hydroxide is LYE soap or drain cleaner. Dish washing machine soap contains sodium carbonate and sodium silicate.
I have use it for years on Corvette and race car aluminum radiators and never had a problem.

I would be interested in what brand soap has sodium hydroxide so I did not use it by mistake.

Doug in big ditch

[retrorob]

Well, Cascade liquid dishwasher detergent does have sodium hydroxide but the powder doesn't. I was unable to get the MSDS for Finish, Elecrosol or any others so I guess the moral of the story is check the ingredients before you dump it in.