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Headgasket(s) as preventive maintenance?

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Just over the past year I think there have been at least 3-4 posters coming on here with blown or leaking head gaskets.  A couple of those were trying to limp their damaged vehicle back to home base.  I know over the years it has been a common theme for these RV's.  And these handful don't account for all the other onlookers who stop in for information, but don't post or register.  (A word to you guys, register here, it is well worth it!!!)


Today, I see another "Check your head gaskets" mentioned in a thread and it gets me to thinking.  I have joked that I would be perfectly fine with changing my 22re head gasket out in an Autozone or Walmart parking lot, and I defiantly am.  But it is even easier sitting in my driveway and doing it BEFORE it has become an actual problem.  


But at what point is this a prudent or recommended thing to do?  In my case the beast only has 32k on it.  Mine looks like the engine had been super well maintained and even has the bright red Toyota coolant in it.  No engine oil leaks.  Mobile 1 synthetic, yada yada.  But it is now 37yrs old.  For me it is easy to do a seasonal block test, so I could probably catch it as it starts to leak.  But again, it is 37yrs old and I don't know if that makes it more likely to have a sudden catastrophic failure, or if it really makes no difference.  


Three is one factor that really tempts me into doing this as a preventive thing.  If I do this before there is a leak and overheat failure, it makes clean up of the surfaces a simpler carbide scraper and roloc disc cleanup.  I just need clean surfaces and no worries about having the head machined and shims ordered.  But is this even realistically necessary?  


There are other preventive maintenance steps that can be done to prevent overheating to begin with.  Changing the thermostat, fresh coolant, pressure testing the coolant system, and adding a bottle of Redline Waterwetter to the mix.  (In my situation, I can even datalog temps and have an audio/visual alarm that goes off if my temps even START to creep out of the normal zone.  Including transmission temp.)  


Obviously, this pre-preventive maintenance is something most of us can and should do.  But is there a point where we should seriously consider adding the headgaket(s) to this list too as a simpler preventative job before it becomes a necessary one?  


It is perhaps an odd question for a mechanic to ask, but I deal with more modern cars most of the time.  I really see a car more than 20yrs old.  This truck is the oldest unmolested car I have ever owned.  While I have had even older cars, they all had performance rebuilt engines and fresh components.  Google essentially says:



It is time to replace head gaskets when there is a loss of compression or when there is internal or external fluid loss.


And for the most part I agree.  I also have a 1985 Porsche with 60k on it.  And zero thought or concern about changing its likely original head gasket.  But it will probably never be driven further than a free tow away from home.



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If it ain't broke, don't "fix" it. Having said that, I'll add don't break it.

 90% of headgasket failures are due to misuse, overheat, bad detonation, lean fuel mix, incorrect valve adjustment.  All are preventable. Replace hoses and belts before they break. Use quality fuel with a good additive package. Maybe a dose of Techron every so often. Doing the valve clearance is easy every couple of years or so.

Retorquing headbolts (with OEM gasket) after this long Is questionable, because you could break a stuck bolt and then you would need to do a new headgasket and helicoil the block after you drill out the broken bolt.

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Good mention of the valve adjustment!  I hadn't even thought of that one.  And ironically, I had purchased two packs of the feeler gauge handles just for doing that at some point in the future.  My valve cover looks, drab.  And the nut gaskets on top are a bit dry rotted.  Somehow it isn't leaking, but yanking it to clean it off, polish it, and replace the 22re sticker that is supposed to be on the front of it is in the sometime future plans to do. I probably got those with the thought to adjust the valves then too.  


Timing is SUPER CRITICAL!  WME covers this with the "bad detonation" above...  But it needs to be specifically touched on.  These engines can run a CRAZY amount out of timing spec and seem like there is nothing wrong.  Power might feel a little down, but since they always feel low on power, it is hard to quantify that.  My timing was something like 40 degrees out, and it still ran and sounded fine until you went down the road.  Even unloaded, our beasts are heavy enough for this to cause some serious detonation issues.  Add old and likely low octane fuel to the mix and POP goes the head gasket!


I may buy an "insurance policy" and pick up a full gasket set, timing chain, water pump...  I can quickly make a little wood crate/box to store the gasket set in.  This is something I have done in the past for my other travels.  And while I have never had to do a head gasket on the side of the road, I have had to use other gaskets from the set before.  The box is easy.  A simple frame large and just deep enough to fit the gasket set in, with 1/8th luan ply screwed to both sides.  I leave it in the shrink wrap, and usually add another layer of saran wrap or press and seal to it.  I do not put the heavy items like the timing chain kit into this.  While a slight overkill, it keeps the set safe.  In a car there is a lot less room to hide this somewhere.  Anyplace you put it is likely to get bumped around at some point.  


Overkill and completely pointless to do if one doesn't have the ability to utilize it.  No shop would want to use this set lol.  But I had one gasket set stored like this in my trunk for 5-6yrs before I tore into it and put a head onto my old VW Rabbit.  That was a few years back and it is still running strong for the new owner.     



Edited by thewanderlustking
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I wouldn't!


HG failure often does not happen immediately. If you have time to spare and are concerning; you can try the compression test, leak down test, and testing for combustible gas in the coolant system to filter out any sign of HG failure.


I tend to stick with the original HG from factory unless it fails.


My 2 cents!

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With my 1988 Toyhome I did a complete new E-Bay head as the temp gauge would start doing wild swings and erratic temps did not make any sense.


Whenever the temps would start swinging upwards or it started getting erratic I would go over everything, timing, valve adjustment, and replace thermostat.

It would come out of it for a few thousand miles then start acting up again.


That was when I did an E-Bay Head that came with everything needed.  It was China made but was of high quality (from a prototype machinsts perspective) , came with new valves, and functioned

as it should until the temp swings started again after maybe 7 thousand miles.


It was back to throwing everything I could at the problem but I was pretty sure the the head and gasket were not the problem.


I finally blew the head gasket and ended up pulling the head and threw it on the surface plate at the shop and it was perfectly flat.

So it was good to go to put a new head gasket with out any machining.


It was then I looked at the bucket of thermostats I had replace over the time of ownership.

Like six of them.  Some were after market others were from toyota.


I took them and put them in a pot of water on my buddys stove. Some worked some did not.  All did not work as they should all the time.


Turns out our rigs really overtax the thermostat and wears them out in short order.


I then drilled three 1/16 holes in the new thermostat and never had another overheating problem in the next 10k miles before selling that rig when I completed my 1991 restore.


Your experience may vary.

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