Engine Head Studs Replacement: All You Need to Know
The engine of a car is one of the important parts that requires constant attention. The cylinder head is perhaps the most vulnerable part of it. In the event of malfunctions, significant repairs may be required, up to overhaul. Even dangling hairpins will bring a lot of unpleasant moments.
Features and benefits of cylinder head studs
Almost every car, for attaching the block head, is equipped with Head Studs, and not serial bolts. The steel used for their manufacture can significantly increase the level of tightening of the gasket under the engine head. This ensures a reliable seal of the gasket and eliminates the possibility of oil and coolant leaks.
Cylinder head gasket seal
With prolonged use due to aging of the metal, this cylinder head part needs to be replaced. Possible breakage when removing the head. The work is quite painstaking and requires a lot of effort.
All work must be carried out in stages and follow some recommendations.
Replacing the stud
It is better to carry out the planned replacement of studs and repair of the head at the same time. With a simple replacement, before unscrewing it, it should be moistened with brake fluid or VDshka. It should be unscrewed with a special twist of pins or a gas wrench. Twisting, especially at the beginning, should be carried out smoothly, without jerking.
If there is not enough force, an extension cord can be used. It is important here to feel the effort and not to miss the moment when the hairpin begins to twist and break. At the first sign, it is best to reapply the brake fluid and let it stand. Take care of the next detail. The hairpin is unscrewed, go to the next. After unscrewing all the pins, we return to the soured part.
Unscrewing the studs
We are trying to unscrew it. It can work, but often such a detail breaks off. If it works, we install the head with the gasket in place and begin to tighten the nuts according to the scheme, observing the tightening torque:
- First, we tighten each nut, walking in a circle with a special wrench with a dynamometer;
- Then we pass several times after a short break to seal the gasket;
- We make the final tightening of the nuts. The cylinder head tightening torque is different for different engine models, it is better to find out this value from the repair manual.
How to unscrew the thread remaining in the block?
There are two options here, but each one starts by drilling out the debris. To do this, cover the engine block with a thick cloth to prevent sparks and dirt from entering the engine, then cut the upper part with a grinder and screw it strictly in the middle.
Drilling out the thread of a broken stud
With a drill of a slightly smaller diameter, we drill out the debris on a drilling machine, and most often with an electric drill. It is very important to keep the tool strictly vertical, without skewing. We reach the edge of the trim and try to unscrew the rest of the thread. To do this, before unscrewing it, you can try to drive it with a tap or try to hammer the metal edge inward with a thin chisel, freeing the threads.
Now you have learned what to do if your mechanic finds a broken stud in your car engine. It will help you make the right decision whenever you deal with this kind of situation. Thanks for coming here and we liked your company.