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chengny · 07-07-2014, 07:34 AM

Disregarding everything else (sounds like there was a lot going on - and things tend to get misinterpreted in the heat of battle) and just using the info contained in the last couple of sentences - I would lean towards a head gasket issue.

There are not many things that can make a SBC overheat (or appear to over heat) while idling.

The three things you observed; a sudden spike in coolant temperature indication, excess pressure in the coolant system and maybe most importantly, the fact that what was venting off did not appear to be steam - would indicate a combustion space to coolant system leak in the head gasket. To me anyway, someone else may have a less tragic diagnosis.

There is no way your radiator could be plugged up up - right? It's only 6 months old. Try pulling the t-stat and looking down into the outlet tank. Rev the engine and note whether the level in the outlet side drops quickly and about at least 2-3 inches. Also confirm that coolant can be seen gushing from the ends of the tubes into the tank.

07-07-2014, 07:34 AM	#13
chengny Registered User Join Date: May 2007 Location: New Hampshire Posts: 349	Re: Baffled!! The truck won't fire. Disregarding everything else (sounds like there was a lot going on - and things tend to get misinterpreted in the heat of battle) and just using the info contained in the last couple of sentences - I would lean towards a head gasket issue. There are not many things that can make a SBC overheat (or appear to over heat) while idling. The three things you observed; a sudden spike in coolant temperature indication, excess pressure in the coolant system and maybe most importantly, the fact that what was venting off did not appear to be steam - would indicate a combustion space to coolant system leak in the head gasket. To me anyway, someone else may have a less tragic diagnosis. There is no way your radiator could be plugged up up - right? It's only 6 months old. Try pulling the t-stat and looking down into the outlet tank. Rev the engine and note whether the level in the outlet side drops quickly and about at least 2-3 inches. Also confirm that coolant can be seen gushing from the ends of the tubes into the tank.