I've been seeing alot of these problems pop up lately. I too have a v6 and now am kind of worried.

I was wondering:

• Does it happen mostly to 03-05 models, 06-09 models, or all 4th gens?
• Around how many miles on average does this problem usually start occurring at?
• Any proactive maintenance tips to prevent this from happening?
• What are symptoms I should look out for that would suggest a blown head gasket?

I read on here that someone said to help prevent it is to change your coolant regularly with oem toyota coolant as there could be composition change in the old coolant causing a premature head gasket failure.

I changed my coolant a few months ago with oem Toyota coolant and I'm at 50k miles. Just playing it safe.

I also read that if you go to the Toyota Parts department and buy a head gasket from them it will be different than your original. There was a redesign in the head gasket.

What I want to find out is when did this head gasket redesign take place? What year 4runners have this updated redesigned head gasket? Or did this update take place after the 4th generation production?? That would mean we all have the "old style" head gasket in our 4runners through 2003-2009 years. Would be very interesting to find this out!

The City & Chmura I think our resident mech BWINC should chime in on this ? Would be nice to know if this sort of preventative maint. would help ie: replace new head gasket before failure ?

I don't know when the superseded headgasket came out... I think I asked the parts guy to see if he could tell me when it was added but he couldn't find it. I think it applies to all the older (Non-dual VVTi) 1GR-FE engines, but I could be wrong as we haven't had to replace one at our dealership yet.

Sure, preventative maintenance is this: Buy the V8!

But seriously, I don't think there is preventative maintenance for a poor design? I mean you could try a shorter coolant flush interval with Super Long Life Coolant; but I don't think it will guarantee anything?

If you had the money/time/insanity/OCD I guess you could proactively replace the head gasket with the update part... but that's a lot of labor and work to be honest with you? I'm really surprised Toyota hasn't done anything to address this and am waiting for a factory rep to stop by one of these days to pester him about it; all I can say for now is to report them to Toyota as they happen, ***** and complain to them, and hope for the best...

I guess what i'm getting at is , if you had the where withall & $$ would this help to replace the gasket before failure or is it inherently gonna fail because of old gasket ?

Assuming you had the time, resources, and/or fiances to replace the headgasket; based on the nature and common failure point of almost all of the headgasket failures we've had posted on this forum and the T120 forum... replacing it with the superseded part should prevent any premature failure.

With Aluminum block you really want to be careful about making sure your cooling system is working correctly. This means keeping up with coolant changes and using the correct fluid. There are several fluids that make OEM compatible fluids. Toyota fluid is made for them by one of those companies.

Now as Zappa said we're getting to the crux of the biscuit !! Thanks BWINC

am i missing something here?
if you're going to change it anyway...why not just wait until the original one fails, if it ever does?

what is there to gain by changing it before it fails?

The difference I see is that one is planned down time while the other is unplanned down time. If Murphy has his way problems aways happen when it is not convient.

Doesn't the 4runner come with supposedly "lifetime" WS coolant?

This x 1000

The first thing I'd say to those of you worrying about your V6 head gasket is this:

KEEP CALM AND CARRY ON!

Remember that message boards like this tend to magnify flaws and failures.

It's easy to understand why - there aren't too many message boards where people sign up just so they can post "Hey, I just wanted to say my vehicle has 150k on it and everything works fine!" Instead, people who have a problem sign up to post here, and they run into other people who also signed on to post about problems/issues they had.

Since there are, proportionally, so many people posting about problems, a casual reader could get the idea that the problem is more widespread than it actually is.

Many years ago, I owned a 1999 Subaru Outback Wagon with the 2.5l flat 4 motor. Those of you who have any experience with Subarus know that this motor was notorious for blowing head gaskets! I bought mine with 42k on it (before I had done the research and before I knew about the HG problem) and I was always paranoid that my gasket would blow. Any sign of less-than-perfect running would have me panicking and checking the radiator overflow tank and/or the oil.

4 years after I bought it, I traded it in with 120k on the clock and not a lick of trouble. And then I started looking around and saw that there were so many 1997-2002 Subarus on the road (including my brother's, he drives a 2002 Impreza TS wagon with the same HG-trouble-prone 2.5) that there couldn't be that much of a problem - otherwise why would all these cars still be on the road instead of in a junkyard somewhere? Surely nobody's going to throw down ~$3k to fix the HG on a 13 year old POS with 167k on it!

I've also noticed just in my city (Denver) that you can't swing a dead cat without hitting a dozen 2nd gen 4runners or 89-94 pickups (the last version of the Hilux sold in the US, I call them "Pre-Tacomas.") Most of these have the 3.0, A/K/A "Three Point Slow" that is also notorious for eating HG's.

And yet, these old, beat up, dented Toyotas are still on the road. Hell, I went to Lowe's yesterday and somebody had a 2nd gen (1994) 4runner sitting in the parking lot for sale - asking $4500!

Bottom line is that it's important to keep some perspective when you look at threads like this. A 4runner is a mechanical device, and there's no mechanical device in the world that can't break - especially as it gets older (note that in at least one recent HG failure thread the T4R in question had over 200k on it.)

I don't care if it's an T4R, a Mercedes, a LC 100, a Lexus, or a tank, if it's mechanical, it CAN break.

If a given single point failure (say the HG) happens 3 times out of every 100 vehicles instead of 1.5 times out of every 100 vehicles, that's a 100% increase in failure, but it still means you have a 97% chance of it never happening to you.

When all is said and done it's probably more likely that your T4R will get totaled by a texting driver or a soccer mom yelling at her kids, (or by you) than it will suffer a HG failure.

So do regular maintenance and don't worry yourself too much. There are way too many 4th gens on the road now for this to be a significant issue.

Overheating a motor can do damage to the block and heads. sometimes it's bad enough the damage requires engine replacement as opposed to just replacing a gasket.

overheating isnt a gaurantee with a bad HG. its possible for sure. but its possible to overheat with a good HG.
and, often times that is what causes the bad HG to begin with.

pay attention to the gauges, and damage from overheating is avoidable, regardless of the reason.




i just see that people are saying, "lets change the HG before it fails....so we dont have to change the HG when it fails"

it doesnt make any sense.

Totally agree , only reason I ask about preventative maint. But again this was /is design flaw from Toy. Knock on wood nothing on mine , my only questions are for my need for knowledge on this veh. for my own edification I wouldn't spend the cash on this (unless I was stupid rich in which case probably wouldn't have a 4r) just nice to know this stuff , really appreciate the time people take in constructive replies .

NO....WS is the World Standard TRANSMISSION FLUID. There is no such thing as WS coolant.

And if you want to keep your automatic transmission trouble free for the next 300k miles I suggest you change it every 50k miles.