How reliable is the 7mgte?

uncmk3nut

New Member
Apr 12, 2012
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wilmington, nc
I Have had 3 7m's (two turbo and one N/A) none with a bhg.. The fact that the only ppl standing up for the 7m are the ones that are smarter than your average bear and are the ppl that mostly look before leaping makes sense. It's been said plenty of times but; it's a 27 year old car/engine that is still kicking ass on the street, including all those v-tec engines that take $8,000 to make 300hp! BTW I own a civic with a D16 and just had to fix the BLOWN HEAD GASKET it had from just DD it without any power mods and excess use. The 1jz and 2jz guys make the biggest deal about the 7m b/c it's an engine that can stay with them any day of the week at 1/3 the price, so they hate on it. Also BTW, anything with this much hate must be doing something right, ya knoow... Seriously, if all it takes is re-torqued head bolts to make the engine run with over 350hp reliably then it should be praised and not hated on. Late 1980's tech still being talked about in 2014 should be enough said when it comes to cars which are upgraded and improved every freaking 6 months. The 1jz and 2jz guys should give respect where it's due and support us 7m owners so when they come out with better engines for Toyota's future sports cars they can look back and see that it's possible to keep an old engine that isn't perfect running with the best of the new school tech.
 

uncmk3nut

New Member
Apr 12, 2012
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wilmington, nc
Also, It's funny that ppl just buy a car and don't look under the hood until something is wrong and then they blame the engine. Ummmm, come on dude use that pea size brain you have and don't expect a 1987 engine to run like a 2012 Lexus engine just b/c they are the same car company. BTW, I'd rather spend my money on a Toyota 7mgte, 4A-GE, or 3sgte engine any day of the week than a B16, D16 or whatever 100 hp engine Honda makes that will last an extra 50,000 miles just b/c it's too weak to do anything so you don't have to look under the hood. My mk3 has 20,000 more miles on it than the Honda and the Honda head went first, imagine that (and btw i meticulously fiddle with my engines no matter the car, Cressida, Taurus, or Datsun). Maybe, b/c the Toyota engine is actually worth putting time and money into and the Honda engine isn't. Not saying Honda isn't worth modding or dropping money into, it's just that how much fun can you have with a 150hp fwd car? I mean come on.
 

Grandavi

Active Member
Sep 25, 2008
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Calgary, Alberta, Canada
I have a built 7m and no regrets. However, the 2j is a better platform unarguably. If I could backtrack to day 1, I would run 2jz.

However... My 7m should last the life of the car easily while pushing a fun 400 rwhp.

I capped it at that due to stock head setup and 91 octane fuel. All I need to do is up boost to top 500 rwhp... But honestly, at that point the reliability will start to decrease and my goal was power AND bulletproof. Its properly built so no worries.

But the 7m in original dressings does have a couple issues. Once they are addressed it's just as reliable as the jz. Comparing Hondas is unfair... They aren't built to the level of the Supra, nor were they intended for that. That's like comparing a Porsche to a Ford Escort.
 

super51fan

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Jul 28, 2010
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Indianapolis
I guess this old thread is alive now. The 7M is a great engine.

Looking through the MKIV sections of forums it looks like the 2jz engine that have been worked on are having head gasket issues. This brings me to my point. Most 7M failures are caused by Lack on maintanance IE fluid levels, poor workmanship and assembly errors. IE people not having the common sense to realize 25 ft lbs is way to much for a 8 x 1.25 fastener. Can't even read a TSRM correctly. Or read though it several times before starting on a project.

IMO.

Have a good day.
 

S.A. supra

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Feb 15, 2009
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super51fan;2020112 said:
I guess this old thread is alive now. The 7M is a great engine.

Looking through the MKIV sections of forums it looks like the 2jz engine that have been worked on are having head gasket issues. This brings me to my point. Most 7M failures are caused by Lack on maintanance IE fluid levels, poor workmanship and assembly errors. IE people not having the common sense to realize 25 ft lbs is way to much for a 8 x 1.25 fastener. Can't even read a TSRM correctly. Or read though it several times before starting on a project.

IMO.

Have a good day.

2j having head gasket issues aren't even close! You probably don't know but when they went to a better engine they also went to a better head gasket. The stock multilayer metal one holds up just fine. Stock 2jz can hold 6-700 hp with out going pop. That's why the mkiv doesn't have one of these to it's name::bhg::
 

super51fan

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Jul 28, 2010
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Indianapolis
Maybe you should go do some reading. I never said an OEM unopened 2J engine had a failure. Engine that that have work done IE: rebuilds are having head gasket failure.

Btw your cute picture shows an improperly maintained supra, It should have Toyota red coolant not green. Even more to my point.
 
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S.A. supra

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Feb 15, 2009
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I bought 3 supra and they all had bhg. Even the one I bought from a 60 plus year old man. I have been waiting for a mkiv to show up on Craigslist with a bhg but have yet to find one. Guess I'll just keep looking.
 

IchibanEye

Supramania Contributor
Oct 23, 2013
121
1
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The Honeycomb Hideout
S.A. supra;2020121 said:
I bought 3 supra and they all had bhg. Even the one I bought from a 60 plus year old man. I have been waiting for a mkiv to show up on Craigslist with a bhg but have yet to find one. Guess I'll just keep looking.


Craigslist sure is the place to find quality people and things for sale for sure, not. Unless it is the rare person who has documented information on said "things" for sale. We all know you secretly love the 7M.

BTW O.P. I'm glad to hear that you decided to stick with the car and be you.

S.A. - The number of 7MGTE Supras produced are no where close to as common as Hondas produced throughout those same years.
 

7M4EVR

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Oct 8, 2012
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fah, fah away
Supracentral;1931109 said:
Here's a little more info:

The 7M is essentially a very good design with a few caveats.

The good stuff: First and foremost, it's an inline 6. That gives you 7 maincaps for 6 cylinders. That's a well supported crank. The inline 6 is an inherently well balanced design, meaning less stress on the rotating assembly as compared to other designs. One comparison would be against an inline 6 which is not as inherently balanced and only gives you 4 maincaps for 6 cylinders. The oil system is a high volume, low resistance system which works well. The tolerances, machining and balance are all very high end due to this being a product of mid 1980's Toyota technology.

The caveats: The bore is smaller than the stroke, so this (long stroke) motor doesn't take well to high revs as well as a square (2jz) or short stroke (1jz) design. This is a mixed material motor with an iron block and an aluminum head. This means you've got different thermal expansion rates between these two surfaces that are mated together. The bores are so close on a 7M that the cylinders are nearly siamese and there's very little gasket material between them. The inline 6 design unfortunately forces an extremely long cylinder head. You couple these last few factors together and you've got a design that puts a LOT of stress on the head gasket. Add in a little extra boost, an unmetered air leak, the wrong fuel, poorly done modifications or a failure to address small issues before they cause detonation and you're going to put more stress on that gasket than it can handle.

As mentioned, the factory torque spec for the head bolts was long ago determined to be a little bit too soft. Torquing them to the appropriate new values fixes this issue. Upgrading to a metal head gasket with the proper prep of the mating surfaces adds more insurance. High quality fasteners add a little more.

So with all that said, yes this can be a reliable motor, it's an inherently good design with a few weak spots. The primary being that the head gasket doesn't tolerate detonation well. In the end, as I've said hundreds of times at this point; the weak link in the MKIII is usually the owner. If you don't use your head, perform poorly thought out mods, cheap out or skip maintenance and generally act like a complete bonehead, the 7M will hand you a well deserved world of hurt. Only you can decide if you're going to be the weak link, or one of the stronger ones.

If you can use your head, do the correct modifications in the correct order, perform maintenance as needed and pay attention to details, you'll be fine. However you had better be ready to spend money, this isn't a cheap endeavour and trying to do it "on the cheap" just about always ends in failure.

Nothing else really needed to be said. I'm in for finding out the outcome of the OP though.
 

Grandavi

Active Member
Sep 25, 2008
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Calgary, Alberta, Canada
^^+100!

Supra central' description is bang on.

The only thing missing is high output considerations (detonation melting pistons, tolerance adjustments, valve float, restrictive exhaust port, etc...). However, if your walking into a 500-1000 rwhp build you should be aware of that anyway.
 

uncmk3nut

New Member
Apr 12, 2012
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wilmington, nc
Well at least Toyota's 7m is still relevant, I just get sick of every Tom, Dick and Harry seeing my mk3; and saying "my friend had one of those, what's under the hood? A 2jz right?" stop it! I only picked on Honda engines b/c every Honda owner wants to race me and I hate pulling up to a stop light and there is a Honda head trying to prove himself. I own a Honda but I don't race every fast car I see.
 

KKZ SupraMan

New Member
Jun 2, 2013
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ohio
I had a spare N/A motor with 350'000 put a hg on it and arp studs and turbo electronics and 75 shot of nitrous I ended up driving it for 5 years no problems till the pump went out at the track went 2j after that but I think the 7m is a very reliable motor with proper maintenance and good hg and studs.
 

super51fan

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Jul 28, 2010
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Indianapolis
I got tired of getting explaining that my car is 7m still. So now when people look at my car and say "2j right" i say yes and open the hood and they are like "cool" . It kills me that so many people are "{fast and furious 2 j " and don't even know what they are looking at. Just sayin.
 

gtsfirefighter

SM Expert on White trash
Sep 26, 2006
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Weatherford, Texas, United States
It shows that Mr. Carlson, the op, has not logged in in over a year. I'm curious to know how his situation ended up.

Guess I'll add my two cents as well. I wonder what the average mileage of a 7M is before bhg. My 91 had 133k miles on it when it blew. Most original engines I've encountered have lasted well over 100k miles before their hg let go. In my book that's pretty damn reliable. My current 88 turbo has 176k miles on it. It's stock but the hg has been replaced. Still original block not overhauled. That car has been all over a good portion of the United States. I drove it from Minnesota to OKC where a brake failure stopped me (oxymoron??). Trailered it home to the DFW area. Since then it's been to Houston several times and I'm comfortable daily driving it if I had to. IF this engine fails I'll have it rebuilt, otherwise I'll just wait till it wears out, then rebuild it.

I think this thread, and subject matter, was done a long time ago though.
 

Grandavi

Active Member
Sep 25, 2008
2,663
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Calgary, Alberta, Canada
The problem as I see it is the "value".

A typical supra owner didn't normally drive the car as their main transport. So the first five years were probably well taken care of. Most of the mk3's I have seen average less than 10,00 km per year, but I would bet the first five years were doubl and the mileage decreased afterwards. The cars value decreases to a point where "major" work doesn't seem worth it on an older car so it gets sold. The second buyer gets hit with the bigger priced maintenance and decides against it. So... In the end it gets put in the hands of someone who loves the car. At this point the fiscal reality is very harsh and few can do it. Some are good enough mechanically and the others have enough cash to revive it... But you still have a period of neglect to deal with.

That is why the 7m is notorious for bad headgaskets. The initial "soft" torque spec was dealt with early on... Nobody retorqued their head to the low 50'ish torque... They just don't retorque it period. So, it fails.

Then the true enthusiast who are willing to go the extra mile do it properly and the 7m gains it's actual bulletproof quality. If it's not pushed too far it will last just as long as any newer engine.

People just have a negative picture if the engine because the car is only worth 3000-10,000. You don't normally drop a few thousand in a car with that type of value... You normally walk away.

Welcome to reality.
 

din904

New Member
Oct 25, 2010
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Jacksonvile,FL.
Reality is speed cost money doesn't matter what car you start with if your broke you should avoid modifying cars period!! A stock 7mgte used as a daily driver with a good gasket and torque is a very reliable engine. How many cars do you know of that is 25 plus years old and you start beating on it and it doesn't have issues none that I know of.
 

S.A. supra

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Feb 15, 2009
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uncmk3nut;2020545 said:
That is a good one, I will just tell everybody that "yeah it's a 2j and pop the hood and see if they even know what they are looking at" lol

Yeah, but when you pop the hood and they will see that ugly engine and know you're lying. I'm joking but no really.