Head Bolt Thread Sealant

[squealingtires]

I will install a new head gasket on a 1974 124 1800 motor. Should I use a thread sealant on the head bolts? I was puzzled when an engine technician familiar with these Fiat motors did not recommend thread sealant but rather recommended a light coat of oil on the threads and above the washer. On my block the threads extend into the water-jacket. What should I do? Thanks!!! Also, in the case of using a thread sealant like Permatex, is it safe to assume that the sealant offers adequate lubrication for the install with the recommended headbolt torque specs or is there an adjustment factor?

[131]

I was puzzled when an engine technician familiar with these Fiat motors did not recommend thread sealant but rather recommended a light coat of oil on the threads and above the washer.

Stick with this bloke, he knows what he's on about.

[carl]

Proper torque of head bolts is critical and you need properly lubricated head bolts to attain this. As noted, your mechanic's advice is spot on. Also critical that the threads in the block are clean, they can get dirty and bind up the head bolts before they are properly tightened. I have attained the factory torque setting on head bolts with the washer under the bolt head still loose because the threads were so dirty the bolt had tightened up to the torque spec.

carl

[squealingtires]

With only oil on the threads wouldn't the coolant leak? So maybe oil on the lower threads and a dab of sealant on the last threads of the bolt that enter the block.... Am I overthinking this?

[vandor]

> With only oil on the threads wouldn't the coolant leak?

No, it does not. The factory did not use sealant and the factory repair manual does not mention it, thus it is not needed.
Not statistically valid, but I never used sealant on any of the engines I've build. Only a few dozen, mind you...