Coolant from valve cover bolt hole

  • Was changing the valve cover gasket on a 4.2 and when I removed the front of the two bolts on the intake side, coolant came out of the hole. Anyone seen this before? Head gasket? Cracked head? The guy who owned it before me said it’s always done it and just put some rtv on the threads for that bolt. There’s no coolant in my oil so that’s good

  • those bolts are right above the t-stat. I dont think i have ever seen them weep coolant, but its possible a repair was done to the treads and they entered the coolant jacket. I would put a heavy coat of pipe sealant on the threads when re-installing and pribably not worry about it.

  • Some of the after market aluminum valve covers for a 4.2 require you to drill and bottom tap some of the guide pin holes to accommodate bolts. If you drill too aggressively you can hit a water jacket in the head. If the is the case, what you want to do is ID the breached hole. Use a steel stud, load up threads on one end with RTV, and secure it snug. Dont crank down or you will bust into the water jacket more. Once the rtv sets, re-sucure the valve cover with a light torque supporting the top of the stud so it does not turn. Don't ask me how I know this.

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    Edited once, last by deadfeat ().

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