Offical 1FZ head gasket debate (1 Viewer)

[Gumby]

Why use an aluminum head over a cast iron one? Aluminum sheads heat better and weighs a lot less. You can run significantly more timing advance in a cool head. Aluminum heads have been used with varied success for decades. The 1FZ motor has a pretty good track record compared to other I-6s of cast or aluminum design.

Keep it cool and service the cooling system. Running an I-6 of any design hot is asking for a head problem.

Aluminum blocks with cast heads? GM was the only company stupid enough to do this, IFAIK, and the dumb-asses did it twice. Both times the engines were a disaster.

I'd like to see a poll of HG PROBLEMS, not PM replacements, but actual problems and if the motor was overheated prior.

 

[e9999]

ask and ya shall receive

Poll going on now!

CDan, didn't mean to take over this topic, of course, so if you'd like to do your own poll instead, I'll delete mine...



































(dang these tyrannical guys with firepower and needed parts... )


































j/k, oh Great One!

 

[Klunky Chris]

I've heard a leakdown test can show you if you have an issue.
I've also heard a standard compression test won't tell you anything.

I have to add to the mix by asking those that HAD failure if they ever re-torqued the head prior to failure?

I too have an 87 Supra turbo and DID have a blown head gasket on that one. only a hi pressure leak down test showed the failure. It ran normaly unless you were under boost.
I ended up with a warped head and put a HKS metal head gasket in instead of the Toyota (which I heard still failed although it was a better design)

The Supra community seems to believe that regular re-torquing is necessary to keep the head gasket good.
I wonder if this is an issue on the 80's

anyone ever re-torque their head and find it had worked loose???

data point: my 93 FZJ has 180k on the clock and doesn't have a HG problem AFAIK.....

we REALLY need a confirmed test to know if we're in danger!

 

[MH_Stevens]

AND it seems an aftermarket temperature gauge that works. Any recomendations for an additional temp gauge that actually read degrees of heat. I have a shoot radiant thermometer that I can use to read the temperature of the head. At maximum, what should ot be? And at what temperature does the a/c cut out? Can i do a leakdown at home?

 

[MH_Stevens]

Just done some research and at Troubleshooters.com and it says very often overheating that leads to HGF is caused by gas/steam blocks in the thermostat cavity and recommends drilling a 1/8th inch hole in the flat outer flange of the thermostat. This made me think that for thoses of us who live in hot/temperate climates might it not be a precaution to just remove the thermostat. I lost my tranny in a Chevy 350 because the thermostate stuck closed.

 

[Critter]

Why use an aluminum head over a cast iron one? Aluminum sheads heat better and weighs a lot less. You can run significantly more timing advance in a cool head. Aluminum heads have been used with varied success for decades. The 1FZ motor has a pretty good track record compared to other I-6s of cast or aluminum design.

Aluminum does cool better because of its chemical composition so that makes it a logical choice, but do you think weight is really a legitimate reason for Toyota choosing to go with an aluminum head over a cast version? I mean I seriously doubt it given that a stock 80 weighs what… just shy of 3 tons?

Running advanced timing on a late model stock motor is asking for trouble past a certain extent. I was screwing with my timing the other day trying to get that spark detonation rattle (the one that I have recently discovered is often misdiagnosed as “valve rattle”) to stay down but get some performance back I lost with the timing turned back. I did it by ear, then went back and got out my timing gun. Go figure this; I managed to get it to exactly 3 degrees which is what the FSM calls for on a factory motor. I am guessing my rattle is being caused by some crud in the cylinders which I am in the process of fixing. If I crank the ignition up much above 3 degrees then I get the rattle under load. I had the shop working on it a couple of weeks ago to turn it back a little to help with rattle, but some serious fuel cleaner and it had stopped the rattle and the performance was almost unbearable so I cranked it up a notch and nailed the factory spec. If I go much above 3 degrees then the detonation rattle comes back. The “bad” I have heard about cranking the timing up on a stock motor is hardly worth the power gained.

 

[Critter]

AND it seems an aftermarket temperature gauge that works. Any recomendations for an additional temp gauge that actually read degrees of heat. I have a shoot radiant thermometer that I can use to read the temperature of the head. At maximum, what should ot be? And at what temperature does the a/c cut out? Can i do a leakdown at home?

Autometer might have something along the lines of what you are looking for.

www.autometer.com

 

[powderpig]

Well I hope some one can find my old posts on this matter. I really have not done a head gasket in several months now. It seemed like almost one a month for the previous years working at Slee.
I believe that toyota's engeenners did the best they could in the beginning with the 1FZ. But once they went into production thing happen. With the 93-94 and OBDI stuff the engine runs richer than the 95-97. This may contribute to the HG problem we see in later years (with the alu rad also contributing). I do believe also that Maintance of the cooling system was not maintained as well as it should be by most previous owners (since most of us have not owned our cruisers since new). I do beleive their is a problem that has been mostly fixed by the replacement gasket that toyota sells. More metal, different size and shape of some coolant passages. Smaller holes at the back to slow down the flow to caputure and pull the heat away from this cylinder.
MH stevens, I know you are new to this list, you travel to way out of the way places, you would be some one that would be stranded big time with out help being close(one big tow bill). You (in my mind) would be a good canditate to have a HG done just so it would be no worry. I have had lots of these 1FZ apart. The head gasket on these engines have a problem, if it is a daily driver, no worries, short tow. The 93-94 is less of a problem, not usually blowing out like the 95-97 ones I have seen. When it does go, not much in the way of coolant gets in the oil(which is good).
I can do a compression test and see if a problem is brewing, I have done standard cylinder leak tests,, that have no yeild any thing. Not every one has the experence I have with the 1FZ.
You can retorque the head bolts and it will prolong the problem or make it worse it not done right.
The worse one I have done and made it run again(by owner choice) is this one 95 that the guy drove to the shop from about 20 miles away. He would run till the needle was almost to the red(so he said) then stop to cool down, try to add water then run on until it got red again. well he over heated it real bad and warped the head so bad it could not be used(we sold him a used head). The little heater hose blew, and the head had no coolant. but it ran when it was cool. He had no coolant in the oil and the cylinder walls were blue and brown (not too pretty). He still runs it around and uses some oil (burns some). But he could not afford a engine rebuild at the time.

So my bottom line on head gaskets, do it as a Maintaince item and get it over with if you go on long trips with good loads. I have seen the problems in the HG materials and seen the changes for the better toyota has made. Some simple signs, green grey material in the overflow bottom, this same material in the top of the radiator. If your cooling system is totally up to par and you have a over heating problem (even slight) you more than likely have compression leaks into the coolant. The over heating typically show up going up big long hills at a good clip. On OBDII stuff, you can hook a computer up to the diagiostic connector and watch the temps on the comuter witht he right software. Outward signs of HG problem, Old water tracks down the side of the block, crusties if dark and wet looking (at head to block gap) are bad, fresh coolant down the side of the block.
Any how I need to get to do some work and can post more later. If you think there is not a problem live in the land of denial.
Later powderpig, formally Robbie.

 

[e9999]

Well I hope some one can find my old posts on this matter. I really have not done a head gasket in several months now. It seemed like almost one a month for the previous years working at Slee.
I believe that toyota's engeenners did the best they could in the beginning with the 1FZ. But once they went into production thing happen. With the 93-94 and OBDI stuff the engine runs richer than the 95-97. This may contribute to the HG problem we see in later years (with the alu rad also contributing). I do believe also that Maintance of the cooling system was not maintained as well as it should be by most previous owners (since most of us have not owned our cruisers since new). I do beleive their is a problem that has been mostly fixed by the replacement gasket that toyota sells. More metal, different size and shape of some coolant passages. Smaller holes at the back to slow down the flow to caputure and pull the heat away from this cylinder.
MH stevens, I know you are new to this list, you travel to way out of the way places, you would be some one that would be stranded big time with out help being close(one big tow bill). You (in my mind) would be a good canditate to have a HG done just so it would be no worry. I have had lots of these 1FZ apart. The head gasket on these engines have a problem, if it is a daily driver, no worries, short tow. The 93-94 is less of a problem, not usually blowing out like the 95-97 ones I have seen. When it does go, not much in the way of coolant gets in the oil(which is good).
I can do a compression test and see if a problem is brewing, I have done standard cylinder leak tests,, that have no yeild any thing. Not every one has the experence I have with the 1FZ.
You can retorque the head bolts and it will prolong the problem or make it worse it not done right.
The worse one I have done and made it run again(by owner choice) is this one 95 that the guy drove to the shop from about 20 miles away. He would run till the needle was almost to the red(so he said) then stop to cool down, try to add water then run on until it got red again. well he over heated it real bad and warped the head so bad it could not be used(we sold him a used head). The little heater hose blew, and the head had no coolant. but it ran when it was cool. He had no coolant in the oil and the cylinder walls were blue and brown (not too pretty). He still runs it around and uses some oil (burns some). But he could not afford a engine rebuild at the time.

So my bottom line on head gaskets, do it as a Maintaince item and get it over with if you go on long trips with good loads. I have seen the problems in the HG materials and seen the changes for the better toyota has made. Some simple signs, green grey material in the overflow bottom, this same material in the top of the radiator. If your cooling system is totally up to par and you have a over heating problem (even slight) you more than likely have compression leaks into the coolant. The over heating typically show up going up big long hills at a good clip. On OBDII stuff, you can hook a computer up to the diagiostic connector and watch the temps on the comuter witht he right software. Outward signs of HG problem, Old water tracks down the side of the block, crusties if dark and wet looking (at head to block gap) are bad, fresh coolant down the side of the block.
Any how I need to get to do some work and can post more later. If you think there is not a problem live in the land of denial.
Later powderpig, formally Robbie.

So, PP/Robbie, when you say you can tell something is off with a comp test, you mean see if any cylinder shows much lower comp than the other (presumably because of a localized failure of the gasket) when there are overheating issues at the same time, right? But hard to know if itsn't valve, rings etc too, OTOH, no?

 

[Gumby]

Just done some research and at Troubleshooters.com and it says very often overheating that leads to HGF is caused by gas/steam blocks in the thermostat cavity and recommends drilling a 1/8th inch hole in the flat outer flange of the thermostat. This made me think that for thoses of us who live in hot/temperate climates might it not be a precaution to just remove the thermostat. I lost my tranny in a Chevy 350 because the thermostate stuck closed.

DO NOT remove the t-stat of a FI motor. Really, you shouldn't remove the t-stat on any motor. The engine needs to run at a consistant, hot temp to run properly. Failure to do so will result in carbon build up and fuel in the oil, as well as very increased emissions. The FZE-FE has a "burp" hole in the OEM t-stat. No need to drill one. Most quality t-stats are fail-safe these days. They will never fail in the closed position, only open. I don't know for sure if the OEM is fail-safe. Dan?

 

[Gumby]

Aluminum does cool better because of its chemical composition so that makes it a logical choice, but do you think weight is really a legitimate reason for Toyota choosing to go with an aluminum head over a cast version? I mean I seriously doubt it given that a stock 80 weighs what… just shy of 3 tons?

Running advanced timing on a late model stock motor is asking for trouble past a certain extent.

I have run advanced timing for 90,000 miles with no rattles ever. I wasn't speaking of us running the timing past factory anyway. i was referring to the computer being able to add more timing before spark knock for better performance from the factory. Aluminum will allow this.

I think you might want to look for a vacuum leak. You have a problem if it knocks at 3

I do think weight is an issue. A minor one, but an issue none the less. The 2F head is a heavy mofo.

 

[MH_Stevens]

Robbie/PowerPig said................"On OBDII stuff, you can hook a computer up to the diagiostic connector and watch the temps on the comuter witht he right software."

Please direct me to this software. I have OBDII computer and would be much interetsed to do this. My OBDII is a Actron CP9135

 

[RavenTai]

I have the same Actron scanner it will not do these functions. you will need a lap top or PDA, a special cable to connect to the port and software.

There are some older threads about this but I personally would not mind hearing more about it,

https://forum.ih8mud.com/showthread.php?t=42643&highlight=obdII+software

 

[Gumby]

Or you can get a professional scan tool. Snap-On Modus or a Genisys will do it. Be prepared to drop several thousand dollars.

 

[Rookie2]

I have the same Actron scanner it will not do these functions. you will need a lap top or PDA, a special cable to connect to the port and software.

There are some older threads about this but I personally would not mind hearing more about it,

https://forum.ih8mud.com/showthread.php?t=42643&highlight=obdII+software

What about using one of those $50 dataloggers?

 

[e9999]

What about using one of those $50 dataloggers?

which one is that?
lowest price I've seen is $100 and it needs an old fashioned serial port...

 

[Rookie2]

which one is that?
lowest price I've seen is $100 and it needs an old fashioned serial port...

One of these little do-hickies.

http://www.davisnet.com/drive/products/drive_product.asp?pnum=8211

I think you can pick them up off ebay a fair amount below retail.

 

[e9999]

One of these little do-hickies.

http://www.davisnet.com/drive/products/drive_product.asp?pnum=8211

I think you can pick them up off ebay a fair amount below retail.

these things are great for parents with teens!

but no, I want a real-time data reader for display on a laptop or PDA so I can monitor the temp etc as I'm driving... thanks though.

 

[Critter]

I have run advanced timing for 90,000 miles with no rattles ever. I wasn't speaking of us running the timing past factory anyway. i was referring to the computer being able to add more timing before spark knock for better performance from the factory. Aluminum will allow this.

I think you might want to look for a vacuum leak. You have a problem if it knocks at 3

I do think weight is an issue. A minor one, but an issue none the less. The 2F head is a heavy mofo.

Got ya.

I don't have a knock at 3 degrees except under very very heavy load, like dragging up a long hill under slow accleration. Some of that is excess carbon deposits from what I understand. Hopefully the fuel system cleaner I am running will eliminate some of that.

 

[TomH]

AND it seems an aftermarket temperature gauge that works. Any recomendations for an additional temp gauge that actually read degrees of heat. I have a shoot radiant thermometer that I can use to read the temperature of the head. At maximum, what should ot be? And at what temperature does the a/c cut out? Can i do a leakdown at home?

I've considered getting one of these . I like the fact that you can hook up a buzzer to it. Since the Land Cruiser is the wifes daily driver, I worry she won't notice a temperature problem.

Tom