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Discussion Starter #1
My dad was a mechanic. Which means I helped rewire a 1969 Toronado (with a 1967 harness) because I had no brothers and mom wouldn't go out the door, but I wasn't even taught how to change my oil, my job was to marry well someone that would support my parents in their old age. I'm a disappointment.

Shop labor has cost me a bundle on my vehicles, and bad shop labor has taken one from a $5000 car to a $75 piece of junk in 2005. By the same token, following a Haynes book doing valve cover gaskets on my 1975 chevy pickup in 2017, it instructed me to torque vc bolts to 5. One I heard break at 2 footpounds (I think). I learned to use a reverse bit but one of the top, of the 3 that broke, wouldn't come out, so I have an oil leak on it, until such time as I either tap and die that hole out for a larger bolt or change the head. For right now I just try get plugs changed a couple of times a year to remedy the fouling, and the shop that hadn't messed up before left one of my plug wires loose the last time they did the plugs. (I need to learn the appropriate amount of tightening on plugs and quit being afraid of them.... and now would be a good time.)

A 1975 chevy is easy but it has heavy parts. lots of them. Supra is lighter, it does fit in the garage. I not only don't know what pressure the heads were torqued to the last time I had head gaskets done, I don't know exactly what head gaskets I bought (I think they were metal, they cost $300), where to buy parts that are reliable and appropriate, and I kind of want to learn this stuff, it sounds like fun. I've been fixing sewing machines for years and they are not nearly as much fun....

so I need a head gasket. I have no decent metric wrenches, and no metric sockets over 11mm but I do have a breaker bar, a torque wrench, a selection of ratchets, a cheap and possibly dangerous 3/8" impact wrench and a compressor.

I might have a choice between paying someone else at least $1000 to potentially screw my car up, or try to do it myself.... besides metric sockets what am I missing.
 

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there is a service manual somewhere on this site dowload it and i think its tells you everything you need for the supra.. i am going to be using it in the next few weeks myself .
 

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Discussion Starter #3
there is a service manual somewhere on this site dowload it and i think its tells you everything you need for the supra.. i am going to be using it in the next few weeks myself .
I will look for it, thank you. I have a Haynes manual for the appropriate year and I took a look at the oil change section and that's how I ended up joining this site.
 

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The TSRM aka the Toyota Supra repair manual:

Sounds like you've gotten your hands greasy plenty of times, but the 7M Supras are kind of a weird world unto themselves.

You'll need shallow and deep well 3/8 drive sockets in 10, 12, 14, 17, and 19mm sizing. I prefer 6 pt sockets. For the headbolts themselves you'll need a 10mm hex socket (think a big ass allen key) for the stock headbolts or a 12pt 14mm deep well if they're ARP headstuds or headbolts (it's a 12pt head on the ARP stuff). I also like to have box end wrenches in at least 10, 12, 14, 17, 19, 21, and 22mm sizing (gearwrench or similar for the 10,12,14, and 17 especially) and at least one 8mm box end wrench and socket of some kind. You'll also need a quality torque wrench, preferably two - one that does 0-30ft lbs in in-lbs increments (inch pounds and foot pounds are VERY different!) and another that does 30-150ft lbs for the beefier stuff. A good assortment of pliers and screwdrivers, shop rags, gloves/googles etc, drain pans for the various fluids - it all snowballs rapidly!
The JIS brand gasket sets available online are not too bad for the non-headgasket stuff. For the headgasket itself I would strongly recommend the Toyota Genuine but the JIS gaskets work fine for near-stock replacements in my limited experience with them. You'll want a few tubes of the Permatex grey RTV silicone sealant goop and you'll need lots of brake cleaner and rags to clean things up as you take them apart. Expect to need to replace various hoses and lines and such as you take things apart on these older cars.

It sounds like what may have happened in your case is that they used a metal headgasket (singular, as an inline 6 there's only one headgasket since there's only one cylinder head) but did not properly prep the block deck to take a metal headgasket (sometimes called an MHG or MLS headgasket for short). So the best option for a DIY solution is to go back to a Toyota Genuine composite HG and torque whatever hardware you've got to 75-80ft lbs and call it a day.

The HG job is a LOT of work and the cylinder head itself is a big heavy beefcake. When doing a HG job with the engine in the car, I prefer to use an engine hoist to lift the head off the block if possible, and if not, invite a friend over to help. Because it's a lot of weight and it's awkward to wrestle it out of there with perfect control even if you took everything else off of the head, and dropping it or scraping the headgasket surface of the head against something can potentially ruin the head.

I applaud your motivation to dive into this job, but from the sound of things, this is going to be much more technically involved with a lot more wiring and misc other pieces than anything else you've ever done. Based on what you've posted, I'd guess you've done stuff up to about a 3/10 difficulty but the 7M headgasket job is a 6/10 or 7/10, with 10 being most difficult/easiest to screw up.

It's a big undertaking but if you're willing to invest in the tools and time and effort, a headgasket job can be done at home.
 

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Discussion Starter #7
@Wreckless Thank you for the solid information. It is significantly above anything I've done before, and I am not sure I am up to it, but it is good to know what I'd be getting into. If nothing else the more I learn about what is going on with the car, the more informed a consumer I will be when dealing with a shop, I can choose better, more appropriate parts and maybe find a turbo gasket for it? The last time they made a turbo gasket. And the turbo hasn't worked right since

I have a one car garage, that also stores work equipment, so I think before I take this on I may have to have a garage built, or I may have to chicken out. There is no room for an engine hoist to lift the head off with. And I know I don't want to damage it. On the bright side I have a lot next to my house that if annex to the house lot I can throw a garage on, and if I put one on it that will fit my full size chevy pickup, I'd have a place to work on the Supra.
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I can think of cheaper cars to pay your personal mechanic's tuition on.
Where are you in TX? Most shops have an insurance liability if the customer is in the workplace, so I wouldn't plan on hanging out much while the work is being done.
Most Japanese cars can be taken apart with an cheap assortment of metric hand tools. Engine work will require a torque wrench. That said, try to save money with no idea what you are doing to the engine, and blow it up. How much will that cost you to replace?
Don't get hung up on 'garage built' for ego if you can't afford it. A good shop will do you right on the labor, and won't cost you the extra cost of fucking up mulitple times and buying tools you don't need because you have no idea what you are doing.
 

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Discussion Starter #9 (Edited)
You are absolutely correct, no one allowed in the shop. which is why I have no idea what they did, but it's a matter of trust. At least whatever I learn here will get me parts to match their work, Wreckless said something about preparing the head for a metal gasket, I think I bought them a metal gasket the first time, but I don't know if they prepped for it. Going to a composite sounds like a good idea and I think it might be cheaper.

And my foreign car shop has been ok, while I've been thru 4 screwups on a chevy. or attempted (and occasionally successful) ripoffs. The last chevy gouge was $2200 worth of unnecessary knock sensors and I picked up a truck that nearly didn't run AFTER I'd already paid the bill. The 2005 needed catalytic converters, the knock sensors were new, and the sales manager pulled a con. Because I'd used them for front end work that was good in the past I believed him.

Because of the popularity of 4Runners and so on, I have no idea when or if the foreign car shop will have time to work on the supra again. Will see.

The shop that worked on my 2005 chevy, I'd blow my car up myself before I gave them another nickel. It is one thing to be a guy and take a car into the shop. It is a whole different thing to be a woman. Shops I trust, I'll use again, I know enough about a vehicle to know when I am being lied to as long as it is an older vehicle. I got had on the 05 because of the OBD, it wasn't working, shop picked the most expensive part to change and pronounced my truck ready and I didn't start it before paying the bill. I don't like getting had. It's not fun. I may not know much, but 2 of my daughters can change their own oil and the one that used to own this supra rebuilt her 88 supra.
 

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@Wreckless You know, I think the hardest jobs I did on a car before my first head gasket job were changing out the water pump, and replacing a door with no glass on my 1980 Corolla. So... yeah, the difficulty ramp up in this thread is definitely a big one, but I'm proof it can be done! Not sure how long my HG repair lasted, but it made it at least another 15k or 20k before I last saw the car.

Also, 2x4's can make for a cheap and easy "engine hoist" for the head. Just gotta get a second person, a couple ~6 foot 2x4's, and a means of strapping them to the engine hooks on either side of the head. Lift carefully and smoothly, and it shouldn't be too hard. Trying to pull the head out of the engine bay by yourself is a rather onerous job.

@Texas Grandma May we call you Grandma, for short? The tooling concern isn't too big of a deal, as Wreckless pointed out. I'm fairly confident that I could completely tear a Supra apart with the tools I could fit into a small bag. Lord knows I've torn these cars apart a time or two haha.

On the subject of spark plugs, NGK plugs have a nice simple diagram on the packaging to explain how to tighten them. It basically amounts to "hand tighten plus a certain amount of degrees" and what I'd recommend is using a spark plug socket. Usually these are sold in 5/8" or 13/16" so you probably have one already, they often have a rubber insert in them to hold the plug. Put that socket on an extension to reach, as needed (I think a 6" will probably work here, if not can always stick two together, or use a 9" or 12", whatever works for you), and what I like to do is line it up vertically, and spin LEFT, slowly, until you feel and hear the threads "reset".

At this point, start turning it to the right to tighten it up. Don't use the ratchet for this step, just do it by feel and the extension. You'll know when it's hand tight, you won't be able to spin the extension anymore. At this point, attach the ratchet, and I like to line up the ratchet facing away from me, or at a "3 o'clock" position. Then turn however many additional degrees are required to set the plug at the required torque. Doesn't take too much, and you REALLY don't want to cross thread or break off a plug in the head, as I'm sure you more than understand.

So, you mention that your daughter rebuilt her car? I don't need details nor am I one to pry into a person's privacy, but is it possible for her to help you with this? If not, no worries, but often a second set of hands, especially experienced ones, is a good idea.
 
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Discussion Starter #11
@te72 You may call me Grandma for short.

And the daughter can't help, she is too far away, covid is not helping with visits but she simply moved far enough away that the car won't get to her (and she doesn't have a garage anymore), and she can't be away from home to come up here. It's time I grew up and changed my own spark plugs, lol. I did on my Buick back in 2000, had my mechanic check me, he said that I was lucky they hadn't blown out on the highway as I didn't have them tight enough. Now, I paid that man, but he was a friend and probably he was truthful. I can try it again. It is pretty hard to mess up a 1975 chevy pickup. That is what I will experiment on. Iron block. Iron heads. Lotsa iron.

Right now I'm more worried about making money than fixing the car. Like most people I have bills. I gave it 3 weekends messing with the oil filter. And if it needs head gasket it just gets everything at once, whether me or the shop. If I devote a week to the car when I have work I'll lose twice what the shop charges in labor I suspect. If I don't have work, I lose nothing, I'm self-employed, kinda fluctuates around here.

Thank you for the engine hoist idea. 2x4's I have, in plenty. But for now I am going to read the link when I get a bit of time, and meditate on this.


@Wreckless You know, I think the hardest jobs I did on a car before my first head gasket job were changing out the water pump, and replacing a door with no glass on my 1980 Corolla. So... yeah, the difficulty ramp up in this thread is definitely a big one, but I'm proof it can be done! Not sure how long my HG repair lasted, but it made it at least another 15k or 20k before I last saw the car.

Also, 2x4's can make for a cheap and easy "engine hoist" for the head. Just gotta get a second person, a couple ~6 foot 2x4's, and a means of strapping them to the engine hooks on either side of the head. Lift carefully and smoothly, and it shouldn't be too hard. Trying to pull the head out of the engine bay by yourself is a rather onerous job.

@Texas Grandma May we call you Grandma, for short? The tooling concern isn't too big of a deal, as Wreckless pointed out. I'm fairly confident that I could completely tear a Supra apart with the tools I could fit into a small bag. Lord knows I've torn these cars apart a time or two haha.

On the subject of spark plugs, NGK plugs have a nice simple diagram on the packaging to explain how to tighten them. It basically amounts to "hand tighten plus a certain amount of degrees" and what I'd recommend is using a spark plug socket. Usually these are sold in 5/8" or 13/16" so you probably have one already, they often have a rubber insert in them to hold the plug. Put that socket on an extension to reach, as needed (I think a 6" will probably work here, if not can always stick two together, or use a 9" or 12", whatever works for you), and what I like to do is line it up vertically, and spin LEFT, slowly, until you feel and hear the threads "reset".

At this point, start turning it to the right to tighten it up. Don't use the ratchet for this step, just do it by feel and the extension. You'll know when it's hand tight, you won't be able to spin the extension anymore. At this point, attach the ratchet, and I like to line up the ratchet facing away from me, or at a "3 o'clock" position. Then turn however many additional degrees are required to set the plug at the required torque. Doesn't take too much, and you REALLY don't want to cross thread or break off a plug in the head, as I'm sure you more than understand.

So, you mention that your daughter rebuilt her car? I don't need details nor am I one to pry into a person's privacy, but is it possible for her to help you with this? If not, no worries, but often a second set of hands, especially experienced ones, is a good idea.
 

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Ahh, being self employed definitely makes for a unique situation. Take it at your own pace and as you have time, you'll get there eventually. You can always come to us with questions, and you'll often get an educated and / or experienced answer. Some of us (not me) have been playing with these cars since they were still new haha. Once they get the hook in you, you're just kinda a Supra person from that point on.

In all my years, I can think of two guys I've known who sold their Supras and managed to not end up buying another one. They're definitely special cars when everything is well with them.
 

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Discussion Starter #13
I was thinking about selling this one, when I saw a 95 Honda Accord with a standard transmission for sale with less than 50K miles. But she wants a bit more for that than I want to spend, then to turn around and immediately put a clutch in it. I like a standard transmission and my supra has an automatic. I figure the Honda's clutch at a shop, plus whatever problems she isn't talking about, will cost me about as much as a head gasket on the supra at the shop. (unless the Honda clutch turns out to be a slave cylinder, which then is a very cheap repair....).... I have grease in my veins. My dad had about a dozen cars, most of them ran. I've got 2 pickups and a supra. They all run. Nobody's perfect....
 

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Well, I wish you lived near me as it is one of my superpowers to help neighbors and friends with car issues in addition to my hobby wrenching. Last summer I was jogging and a new neighbor with a 5 year old Mercedes stopped at a stop sign as I jogged into our street. Car was squealing. I stopped and asked about it. "$780 estimate for a new serpentine belt at the dealer, I'm bringing it in a few weeks from today." I said "stop by the house when you finish your errand." He did and it was a $21 belt idler. I told him the part number and to let me know when he had it in hand. It arrived, I went over and installed it in 11 minutes (I asked him to time me for fun - he's 78).

Anyhow, wish you were close as I'd have a field day with your Supra!!
 

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Discussion Starter #15
Lol, and thank you. Somebody needs to have a field day with it. I just want to keep it stock, and operational. It had 180,738 when the odometer quit. The AC works (although ac oil is coming out a little on top of the compressor). Heater coil probably is out, been on bypass since I bought it, but we don't need a lot of heat in Texas and I don't drive it very much. I am suspicious that an oil leak is related to the head gasket, but it's not a big leak, and barely drive the vehicle, so ....yeah. I'm not in a rush. I figure in 10 or 20 years the value will have gone up enough to cover the parts.
 

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Discussion Starter #16 (Edited)
And what are the odds of a radiator cap fixing a head gasket? I'm not holding my breath, but since I changed the radiator cap at the suggestion of an old chevy mechanic around here, I haven't had to add coolant. I've only run it a couple of 25 mile trips, and it's winter. Still needs an oil change, and I don't know what the supra equivalent for a choke is but the car runs very ragged until it warms up, then it's fine. I did not do donuts in the parking lot at the store. too many cars.
DSC_2957.JPG
 

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Heh, odds are zero. However, your Chevy guy is/was right on the money. These caps age and won't hold pressure. Water boils at 212 degrees at sea level but it turns out if you place the water under pressure, it won't boil until higher temps. That's the caps function - cause pressure. Without the pressure the water boils, which instantly means it needs to instantly expand and it will blow pressure/coolant out of the system somewhere. Guaranteed. So, smart guy. What else might he/she know that can help you....?
 

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Discussion Starter #18
I'm pretty sure he can change spark plugs but his hands are too big to get to that oil filter. Something tells me I'm going to be having him do a little work, at least on my 75 chevy... And I owe him a 6 pack
 

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And what are the odds of a radiator cap fixing a head gasket? I'm not holding my breath, but since I changed the radiator cap at the suggestion of an old chevy mechanic around here, I haven't had to add coolant. I've only run it a couple of 25 mile trips, and it's winter. Still needs an oil change, and I don't know what the supra equivalent for a choke is but the car runs very ragged until it warms up, then it's fine. I did not do donuts in the parking lot at the store. too many cars.

Well i have seen what looks to be a BHG, actually be a PIN HOLE leak on the radiator that would only leak when the car warmed up.
I have also seen the radiator cap fail and cause what appeared to be a BHG.

On both, the obvious sign is that you will SMELL the sweetness of the coolant but the exhaust is normal without any additional smoke.
 
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