CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Blown head gaskets

Are these costly mishaps prevantable? If so, what can I do to prevent(or at least delay) this from happening?

Many people drive for years and years and NEVER have a blown head gasket. There is no guarantee that you will experience this in your life time. On the other hand, if the head gasket is going to fail there’s not much you can do to stop it.

What kind of vehicle are you driving?

You might benefit from pulling the valve cover every 35k miles, and re-tourqueing the head bolts. Heating and cooling can cause a change in head bolt tourque over time, on some engines, and some manufacturers recommend this as part of normal service. I don’t know of anything else you can do to prevent head gasket failure, but if you do have a blown gasket, be sure to follow the manufacturers instructions when you replace it. This includes checking the head and top of the block for warpage.

About the only thing you can do is always make sure that your cooling system is well maintained. But that’s no guarantee…

Never allow your engine to overheat. Aluminum engines simply will not tolerate this. If you do have an overheat, have the head-bolts re-torqued as part of the overheating repair…

With some tender and known problematic engines, (Subarus) I would have the heads re-torqued every 60,000 miles whether they needed it or not…I would CERTAINLY have that done when the equally problematic rubber timing belt was changed…

'97 4Runner SR%
'00 Volvo S80 (mom’s car)
Both have 120k miles.
I have chagned the coolant every 30k miles and replaced the water pump when the timing belt was replaced.

On some engines you cannot retorque the head bolts. Some head bolts are torque-to-yield type head bolts. If these are retorqued it goes past the yield point of the bolt causing the bolt to stretch where it loses it’s clamping force. This then causes the head gasket to leak.

Tester

Also change the thermostat every 4-5 years.