Why do a head gasket as preventative maintenance? (1 Viewer)

Joined
May 16, 2008
Messages
339
Location
Longmont, CO
Mine runs great other than the use of oil. For me it comes down to why keep driving till it fails when I can do it now and have it working like new as long as im alive.

I think I uttered nearly the same words. I was 54 when I did it. And I thought, in the next 15 years I could drive this thing with it running better than it has since new or driving around a vehicle, while still reliable, that is 20+ years. That equation has just gotten worse. My 95 is 26+ years old now.
 
Joined
Jan 13, 2011
Messages
1,012
Location
Corrales, NM / Boulder City, NV
In my case, at 225k I decided to pull the engine and do the head gasket along with a bunch of other maintenance. I'm glad I did because I discovered the sealing ring on number 1 cylinder had split and was just starting to leak combustion gasses into the timing chain area. I'll bet it wouldn't have gone another 500 miles. It was running fine but wanted the peace of mind and figured it would be a good quarantine project.
 

TexasJack

SILVER Star
Joined
Apr 5, 2010
Messages
1,309
Location
DFW
My rig has 285,000 on it - all my miles except the first 20,000. I replaced the head gasket at 220,000 but only because I was blowing huge amounts of white smoke and had Toyota red all over the bottom of plug number 6. It was pretty obvious the gasket was gone and pulling the head confirmed it. Doing predictive maintenance should be done when you know neglecting it will absolutely result in problems. This isn't true with head gaskets. Many of our rigs will never need a head gasket replacement until the engine needs a rebuild. Why incur that cost when it isn't absolutely needed. In my mind doing a head gasket replacement when the previous gasket isn't blown is like saying "eventually the transmission will wear out" and replacing it as a preventitive measure. Unless you have imperical evidence that the transmission will definitely wear out at a certain usage point (like 300,000 miles), why would you do it?
 

flintknapper

SILVER Star
Joined
May 22, 2004
Messages
9,948
Location
Deep East Texas
My rig has 285,000 on it - all my miles except the first 20,000. I replaced the head gasket at 220,000 but only because I was blowing huge amounts of white smoke and had Toyota red all over the bottom of plug number 6. It was pretty obvious the gasket was gone and pulling the head confirmed it. Doing predictive maintenance should be done when you know neglecting it will absolutely result in problems. This isn't true with head gaskets. Many of our rigs will never need a head gasket replacement until the engine needs a rebuild. Why incur that cost when it isn't absolutely needed. In my mind doing a head gasket replacement when the previous gasket isn't blown is like saying "eventually the transmission will wear out" and replacing it as a preventitive measure. Unless you have imperical evidence that the transmission will definitely wear out at a certain usage point (like 300,000 miles), why would you do it?

For many its a matter of how and where they use their vehicle and the inconvenience (or worse) it would cause IF it failed with no warning.

Personally....I'd rather replace it under my own terms, at a time and place of my choosing and when I feel like it. To me.... that is preferable to being 500 miles from home 'stranded' until fixed or having to leave it somewhere.

There are enough failures (documented) to rightfully consider the OEM head gasket a 'wear part' IMO. Mine held out for 316K miles....so I did pretty good. Yes, others are still running with higher mileage than that...but many are NOT.

If you are 5 miles from home in the Parking Lot of Lowe's when your temps suddenly climb, no big deal.

If you are several States away with the Wife, Kids, your dogs... and break down on the freeway in August. Well.....try to explain to the Wifey why you just didn't think it was necessary.

There's a high end to "if it ain't broke don't fix it".
 

60wag

SILVER Star
Joined
Jun 25, 2003
Messages
1,974
Location
Boulder, CO
I've written about this before, but I believe what degrades the head gasket is heat cycling of the engine, not the total miles driven. Every time you heat up the engine from ambient, wear takes place. Once the engine is at operating temp, stuff is pretty stable. If you have a 60 mile daily commute, you may get 400k out of your head gasket. If you have a 3 mile commute, the gasket may fail at 120k. If the truck had a cold start counter gauge on the dash, I think the data would be very interesting, but since all we have is an odometer, the confusing data leads to may different opinions.
 

flintknapper

SILVER Star
Joined
May 22, 2004
Messages
9,948
Location
Deep East Texas
I've written about this before, but I believe what degrades the head gasket is heat cycling of the engine, not the total miles driven. Every time you heat up the engine from ambient, wear takes place. Once the engine is at operating temp, stuff is pretty stable. If you have a 60 mile daily commute, you may get 400k out of your head gasket. If you have a 3 mile commute, the gasket may fail at 120k. If the truck had a cold start counter gauge on the dash, I think the data would be very interesting, but since all we have is an odometer, the confusing data leads to may different opinions.

There is no question that 'heat cycling' (under normal operating temps) is responsible for the eventual wear/failure of the gasket. For engines with aluminum heads and cast iron blocks....the two dissimilar metals expand and contract at much different rates. Then too....the length (profile) of an inline six pretty much guarantees significant stresses will occur in the lengthwise direction.

As for mileage...you are correct. It offers little in the way denoting 'usage'. There are so many variables. It only tells us that in the aggregate, the engine was 'run' quite a bit.

It can't tell us:

  • How hard the engine was used. (Leisurely drive to the store or pulling a trailer up a mountain pass).
  • How many times the engine was started and stopped. (twice in a trip or 20 times)
  • How hard the brakes were used. (reasonably or you thought you were at Watkins Glen).
  • How many hours the engine was idling vs. being run at speed.
  • The general health of the engine or maintenance. (well maintained or grossly abused).
But in the end, the head gasket for this era engine is a design and material that was Toyota's best guess at the time.

A markedly better product exists now. So IF you plan to keep your vehicle for a long time, use it regularly and don't want to be stranded somewhere, it might be worth considering the newest offering.

In my case, I wanted to see just how long mine would last. I am retired and don't take extended trips in my Cruiser. It just so happens mine failed right after I did an engine flush. Nothing I hadn't done before several times. I just happened to 'push it over the edge' this time. I feel it was an impending failure.

Like so many others, mine failed at cylinder #6 but cylinder # 1 had notable damage at the fire ring as well.

I've had my Cruiser for 21 of its 24 years and have always maintained it myself. I would say on average it has seen easier use than most and much better maintenance than many with multiple owners.

My opinion (and that's all it is)....is that the OEM head gasket is nearly bound to fail at some point. I wouldn't say it is the Achilles Heel of the vehicle but a very real possibility at some point.
 

Users who are viewing this thread

Top Bottom