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

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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.
 
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.
 
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.
 
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?
 
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".
 
I’m just going to repeat @flintknapper ’s reply.

My DD (ish) - popped just under 130K.


The new HG has a different design & like ALL ‘Yotas - a fresh HG makes them way more solid.

Or you can gamble - it‘s yours to do it with.

Anymore, I don’t try to sell common sense - do what you want.
Not my 80.
 
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.
 
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.
 
I just found this thread after seeing a Post on how the HGs are usually in a really deteriorated state around 200-250k miles, especially near where the EGR port goes through the block. Mine is at 226k and the 0401 code has been on since May according to the PO, who more and more in realising just ran this rig into the ground while she had it. Could this 0401 code be contributing to wear on the HG near the back of the block?
 
^^^ Big thing is the OBD2’s got a slight change in coolant passage sizing in the update H/G.

I haven’t done this convo for a long time, but for some reason I think those specific motors tend to manifest the issue if you say buy a warm region 80 & take it to a colder state/freezes in Winter.

Case in point - my old 40th AE went over 320K on the original owner & HG.
He sold it to a guy who was moving to CO, and within 10K-ish, it was at Slee’s shop getting a new HG.
Owner was a priest who changed churches to one near me, new HG had 30K+ when I bought it.

It had shy 375K when I sold, aside from the HG it was on the original bores, and according to the receipt from Slee the only head part replaced were the valve stem seals - it didn’t smoke nor did it use more than 1/8” of oil between changes.

HTH
 
^^^ Big thing is the OBD2’s got a slight change in coolant passage sizing in the update H/G.

I haven’t done this convo for a long time, but for some reason I think those specific motors tend to manifest the issue if you say buy a warm region 80 & take it to a colder state/freezes in Winter.

Case in point - my old 40th AE went over 320K on the original owner & HG.
He sold it to a guy who was moving to CO, and within 10K-ish, it was at Slee’s shop getting a new HG.
Owner was a priest who changed churches to one near me, new HG had 30K+ when I bought it.

It had shy 375K when I sold, aside from the HG it was on the original bores, and according to the receipt from Slee the only head part replaced were the valve stem seals - it didn’t smoke nor did it use more than 1/8” of oil between changes.

HTH
Interesting.. I'm no metallurgist but maybe the metal somehow "accustoms" itself to a certain average ambient temp and once the cold/hot differential is increased, that causes it to warp more?
 
Interesting.. I'm no metallurgist but maybe the metal somehow "accustoms" itself to a certain average ambient temp and once the cold/hot differential is increased, that causes it to warp more?
IDK…..I bought my black 80 out of SoCal in ‘00 w/ ~115 on it, within 7500mi I’d started the HG swap - 1st job I ever did to the 80.

I had a LX450 that came from NV to WA - had some 200K on the org HG & my buddy who brought it here was paying to get a HG inside a yr or so, I bought it from him.

So all 3 80’s I’ve owned either were amazingly beating odds to pop HG when they got here, or it has some merit.

All 3 got the update design where the coolant port size changed out at the firewall end where they all lose the cooling jacket to #6 cyl.

That’s simply my experience with the 3 late 1FZ’s I’ve owned - I’ll let others draw their own conclusions / decide if they want to PM a HG.

Since prices are rising from the Obama-era (generally when I think 80’s bottomed out in prices) - it’s taking more $$ to get into one and generally those same people will have more discretionary income.

In the Obama yrs some guys got 80’s so cheap they couldn’t comprehend HG as PM, but that may again change since a good 80 is starting @ $10K++ minimum.

:meh:
 
I'm at 277K and so it shall stay at 277K until there's a fully rebuilt long block with new OEM parts. Why am I doing it now?
  • I'm slowly losing coolant and don't feel good about driving it
  • After 3.5 years and 47K miles of smiles (the longest I've owned any vehicle), I'm due to experience the best that the 1FZ-FE has to offer within my span of control
  • The longer I wait, the more likely OEM parts will be NLA and I am a veritable OEM parts fiend
Valve springs lose their tension. Valve stem seals get brittle. Plastic chain guides wear. Combustion chambers get dirty. Over time, stuff degrades and performance suffers. I'm biting the bullet now and am really looking forward to a fresh ICE power unit just like Lewis Hamilton this past weekend in Istanbul. Not only this, I'm also replacing all the body mounts, engine mounts, power steering box, rear heater lines and whatever else I can get my hands on within reason to get at that new old truck life.

It all comes down to automotive enthusiast mental maintenance for me. I love cars.
 
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I'm at 277K and so it shall stay at 277K until there's a fully rebuilt long block with new OEM parts. Why am I doing it now?
  • I'm slowly losing coolant and don't feel good about driving it
Have you done an oil analysis? I was losing coolant and it turned out to be a bunch of leaky heater hoses.

But then I've also heard people say even with a good oil analysis, and good compression, the HG could still be about to bite you in the butt. Maybe testing the coolant for CO would be a better way to tell for sure?
 
Since we're all just sharing opinions, I'll throw mine in. My truck is at 255K, I bought it with 215K about 8 years ago. It runs great, very clean and quiet. The guy at the smog shop has told me that I should never sell it and that it runs better than many new cars he sees. He's told me that numerous times. Despite that, I like to explore remote places, often alone, and a failure in that situation would suck a lot.

My older son is going to turn 14 soon, and once we have a 3rd vehicle in the driveway, I plan to pull my engine and do the HG and also reseal the bottom end which is leaking oil. I don't know if it's the rear main or the upper arch pan, but I'm going to reseal both of those when I pull the engine. The idea is to do the HG and a valve job, replace hoses, seal up the oil leak, freshen up the timing chain guides, etc. As long as gas is not costing $8/gal, that is. If it's cost prohibitive to own an 80 at that point, I reserve the right to jump ship and sell my 80. I am a bicycle commuter to work, so I don't have to DD my 80, I'd just like to keep it forever because it can do everything I want and I'm in love with it.
 
Gas was $1.90 for 93 octane 20 yrs ago back in Atlanta, now 20 yrs later, i am in California and paid close to $5 for 91. It didn't stop me now for owning an 80, it won't be the deciding factor for selling yours when it hits $8
 
Gas was $1.90 for 93 octane 20 yrs ago back in Atlanta, now 20 yrs later, i am in California and paid close to $5 for 91. It didn't stop me now for owning an 80, it won't be the deciding factor for selling yours when it hits $8
Why are you putting 91’octane in an engine that is 8:1 compression? 3fe’s will run on piss so it’s been said.
 
Could this 0401 code be contributing to wear on the HG near the back of the block?

potentially the egr can cpontribute, you would have hot exhaust gasses running through a specific portion of that head. the egr should only be working when the vehicle is up to operating temp, unless the valve is stuck open or partially open, so there shouldnt be huge heat differential when the egr is operating but its possible.

p0401 is insufficient flow meaning that you most likely have a clog in the egr system and your not flowing as much as you should
 

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