Loose heads

[ferry58]

I had my 73 engine rebuilt and now have approx. 20k miles on the rebuild. I was informed while having the valves adjusted that my heads were loose. I informed the engine builder and he told me that he would make it right. He ended up just tightening the head bolts and did a leak down and said it was perfect. Now I feel they have become loose again. The case was not time certed and was informed that it was rare that 2.4 engines needed it. Does re-tightening head bolts ever work? Thanks in advance for your response.

[Cliff]

Case Savers vs Time-Serts? ……….Cliff

[304065]

Your studs are pulling out of the case.

When you 'Feel' that they are loose are you using a torque wrench? How are you determining this? Are they leaking at the head to cylinder junction? What is the leakdown percentage.

[ferry58]

I was told that you can tell that they are leaking by starting the engine cold and bringing rpms to approx. 2000-3000 you will hear popping. It was doing this before and has started doing it again. The leak down was done after torqueing the heads back down and was told they were all approx. 3%. Thanks

[RSTarga]

You need a better engine builder, I can't imagine anyone rebuilding one of these without case savers and all the other mods required to keep these puppies together.

[ferry58]

What test will determine that the heads are loose again? Does it ever work to just tighten the head bolts? Thanks

[chris_seven]

If the studs are pulling out re-torqueing will just continue the process until they just pull out completely and this wouldn't help.

You don't really need a leak down just a compression test should do the job.

The stud pulling issue should be less pronounced on 2.4 litre engines with Biral Cylinders as the expansion is lower than the 2.7 motors which used Nikasil but old mag alloy could be suffering from some metallurgical damage which will allow stress relaxation to be occurring.