Re-Torque Head Bolts?

[svmariane]

After replacing the head gasket on my aux-diesel, should I re-torque the head bolts after operating the motor (at load) for approx 40 hours?

Unsure if re-torquing is REALLY needed/recommended or just the local mechanic trying to run up some hours.

Diesel is a 198x, 4cyl Peugeot, model 4D50, "marinized" for raw water cooling by Lehmann.

Background: Head was re-leveled by a machinest; gasket replacement (and other minor work) performed by local mechanic. Original prob was overheating, originally caused by disfunctional heat exchanger that is now replaced. Woulda/shoulda replaced heat exchanger before blowing head gasket.

BTW: Still sweltering in southern Baja, California -- but happy hurricane Jimena missed us!

[speciald@ocens.]

Yes, the head should be retourqued after the gasket has had time to settle.

[roverhi]

Check with the engine manufacturers reccomendations, some newer engines do not reccomend retorquing the head. It's either because of composite head gaskets or stretch/one time use head bolts. If it's older technology, yes they should be retorqued.

[Tellie]

Standard practice has always been to retorque head bolts after so many hours depending on make and model.

[svmariane]

Okay -- re-torque it is. Thanks all!

[Chief Engineer]

Actually, are you just going to put the torque wrench to it?

That's OK

Make sure you go in the order of tightening that the mfr suggests

[fareweather]

If a fiber head gasket was used it is a required step, if it is metal it's not required but can't hurt.

[perchance]

Make sure your mechanic did not use torque to yield bolts. If he did re -torquing is not required. If he used standard bolts you can do it yourself by borrowing, renting or stealing a wrench and follow the tightening pattern in the manual.

[roverhi]

Composite gaskets do not need retorquing according to the manufacturers of my gasoline engines. The old copper gaskets are the ones that need to be retorqued. I'd check with the manufacturer to be sure that you are following the proper procedure.

[cantxsailor]

For as long as I can remember standard procedure has been to retorque head bolts after running the engine up to operating temp and allowing to cool all the way back down. These were of course standard old steel bolts not some new age high dollar type of bolts. As for 40hrs, that would take a couple of years with my engine use........m