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Q: Why is my truck overheating from start up?

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Ok so the full story, I took my heads off and had them rebuilt, bought knew push rods, lifters and put everything back together, also put a new distributor in as well as spark plugs and wires. I started it up, the motor sount good, smoke was coming from the engine but I assume it's from the new grease and oil on the heads from the rebuild. I noticed the temp. gage was climbing fast from a cold start. It reached 210 in about 5 minutes, it kept climbing but I turned it off to ovoid any other damage to the engine. I have no clue what this could be, one mechanic I talked to said it could be out of time just a notch. I really would appreciate any help. My truck has been down for 3 months

My car has 149000 miles.
My car has a manual transmission.

A: Hi, I will be glad to help you. On refillin...

Hi, I will be glad to help you. On refilling the cooling system you could have trapped air or air pockets. Such will prevent coolant circulation and the engine WILL overheat. There are typically air purge points in the system that you leave open while refilling. Sometimes you still get air pockets.

Last time that happened to me, I took a couple sharp turns to burp the car (dislodge the pocket of air) and once that happened the gauge plummeted (I'm not kidding, trapped air will cause overheating until the pocket is dislodged).

If heads and block were not flat at assembly, within .002 in. or so, you could have head gasket (exhaust) leak into the coolant. And, yes, timing could be off. Check ignition timing first.

If you need further assistance, by all means a mobile YourMechanic technician could be dispatched to diagnose your overheating issue and help you repair it as necessary.

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