1992 7mgte overheating and blowing head gasket

drewmiller5007 · 07-04-2010, 03:57 PM

i have a 1992 7mgte toyota surpa. the entire engine has been rebuilt, pistons rods gaskets, bored over .20 and cleaned. when i got the car back it overheats about 30 mins of driving, i get out and it has burned the antifreeze out of the car completly and because of that blown the head gasket, this has happened two times. no one can tell me whats causing it to overheat, they think its the turbo? but i had it rebuildt as well?? so??? any thoughts?

Supra_Freak_7m · 07-04-2010, 04:18 PM

When you had the engine rebuilt, Which head gasket did you use? Did any material get taken off of the head? Which Fasteners did you use? ( I.e. ARP Bolds, Studs or factory ) Water pump get replaced at rebuild time? Thermostat? What is your ignition timing set at? Did you jump the proper terminals before you set the ignition timing? Cam/Crank timing set perfectly? Are you following the proper engine rebuild/break-in oil change interval?

Check these things and if you have any questions about what i listed here, feel free to ask....

drewmiller5007 · 07-04-2010, 04:26 PM

i used all oem parts for the rebuild, im not trying to push massive amounts of power. i just need the car to run and run like its supposed to for now until i build it really really well. ive had the car for 6 months and got to drive the car twice and both times the same thing has happened, itll run perfect around town, boost fine, its fast, runs like a top, but i try to drive it for more then 15-20 mins and it overheats and blows the head gasket, it has new rad, hoses, and thermsate. first time it did this all of that got replaced. water pump was tested and working, or so they say?? all they have said is the turbo is overheated and burning the coolant out of then system and overheatiing the car?

Supra_Freak_7m · 07-04-2010, 04:53 PM

If you are using an oem head gasket with the head machined, that could be part of the problem, as the cam timing will be off due to the slightly shorter distance from the bottom of the head up to the pulleys, and where the cam timing is off, the igntion timing is probably off too. This also increases compression, which can cause detonation issiues? Alot of v8 mechanics LOVE to blame that turbo for everything from the car overheating to the tail lights not working.... Its just ignorance for the most part. as long as your not boosting too high for your current fuel delivery capacity and tune, it SHOULD not be the turbo.

SO, with that said,

Did your head/block mating surface get machined?
If So, How much was removed?
What were your head bolts torqued to?

Bill UK · 07-04-2010, 09:23 PM

Quote:

Originally Posted by drewmiller5007

water pump was tested and working, or so they say?? all they have said is the turbo is overheated and burning the coolant out of then system and overheatiing the car?

How did they check the water pump ? BHG`s will contribute to excessive wear on metal coolant parts, when the combustion gases mix with the coolant it turns very acidic and starts etching away at thin metal parts. The stock pump has a thin metal impeller. May be worth removing and checking.

wstanek · 07-04-2010, 09:24 PM

well if you did everything properly it would not have blown! i have a couple wuestions did u tourque the head to the stock specs or to the new specs people have forund for each type of gasket because if u use the stock specs then you probably will have issues and also if u take surface off the head and block you will need a thicker head gasket to compensate for that missing material

07-04-2010, 03:57 PM	#1
drewmiller5007 Stock Join Date: Jul 2010 Location: taylorsville nc Posts: 2	1992 7mgte overheating and blowing head gasket i have a 1992 7mgte toyota surpa. the entire engine has been rebuilt, pistons rods gaskets, bored over .20 and cleaned. when i got the car back it overheats about 30 mins of driving, i get out and it has burned the antifreeze out of the car completly and because of that blown the head gasket, this has happened two times. no one can tell me whats causing it to overheat, they think its the turbo? but i had it rebuildt as well?? so??? any thoughts?

07-04-2010, 04:18 PM	#2
Supra_Freak_7m Intake Join Date: Apr 2010 Location: Montana Posts: 40	When you had the engine rebuilt, Which head gasket did you use? Did any material get taken off of the head? Which Fasteners did you use? ( I.e. ARP Bolds, Studs or factory ) Water pump get replaced at rebuild time? Thermostat? What is your ignition timing set at? Did you jump the proper terminals before you set the ignition timing? Cam/Crank timing set perfectly? Are you following the proper engine rebuild/break-in oil change interval? Check these things and if you have any questions about what i listed here, feel free to ask.... __________________ 1987 Toyota Supra 7MGTE AUTO 1987 Toyota Supra 7MGE MANUAL 1990 Toyota Supra 7MGTE AUTO-> MANUAL

07-04-2010, 04:53 PM	#4
Supra_Freak_7m Intake Join Date: Apr 2010 Location: Montana Posts: 40	If you are using an oem head gasket with the head machined, that could be part of the problem, as the cam timing will be off due to the slightly shorter distance from the bottom of the head up to the pulleys, and where the cam timing is off, the igntion timing is probably off too. This also increases compression, which can cause detonation issiues? Alot of v8 mechanics LOVE to blame that turbo for everything from the car overheating to the tail lights not working.... Its just ignorance for the most part. as long as your not boosting too high for your current fuel delivery capacity and tune, it SHOULD not be the turbo. SO, with that said, Did your head/block mating surface get machined? If So, How much was removed? What were your head bolts torqued to? __________________ 1987 Toyota Supra 7MGTE AUTO 1987 Toyota Supra 7MGE MANUAL 1990 Toyota Supra 7MGTE AUTO-> MANUAL

07-04-2010, 09:24 PM	#6
wstanek 3" Exhaust Join Date: Apr 2010 Location: Stoney Creek Posts: 178	well if you did everything properly it would not have blown! i have a couple wuestions did u tourque the head to the stock specs or to the new specs people have forund for each type of gasket because if u use the stock specs then you probably will have issues and also if u take surface off the head and block you will need a thicker head gasket to compensate for that missing material __________________ 1987 N/A 7MGE manual transmission slight rod knock never driven it yet... legally~

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07-04-2010, 04:26 PM	#3
drewmiller5007 Stock Join Date: Jul 2010 Location: taylorsville nc Posts: 2	i used all oem parts for the rebuild, im not trying to push massive amounts of power. i just need the car to run and run like its supposed to for now until i build it really really well. ive had the car for 6 months and got to drive the car twice and both times the same thing has happened, itll run perfect around town, boost fine, its fast, runs like a top, but i try to drive it for more then 15-20 mins and it overheats and blows the head gasket, it has new rad, hoses, and thermsate. first time it did this all of that got replaced. water pump was tested and working, or so they say?? all they have said is the turbo is overheated and burning the coolant out of then system and overheatiing the car?