New Project: 7M Teardown and Rebuild

[btc2112]

Whats up gentlemen? I have a 87 turbo 5 speed with 94000 miles that I purchased from a friend about 2 years ago. He was the 2nd owner and says he had Toyota do 2 head gasket jobs while he owned the car, no problems other than the overheating from the bhg's...Car is pretty much stock only thing done was an HKS mushroom stamp intake. I immediately replaced radiator, radiator cap, and thermostat. Did the bosch bov upgrade, kept up general maintenance(plugs, wires, lube, etc.) and had driven the car gently off and on for about a year and a half now with no real problems until about 2 months ago when it overheated on me badly, very badly, basically cooked on the side of the freeway. :nono:

Long story short, cars now sitting in my parking spot collecting dust. I'm 90% certain that the hg is done again, seals are leaking, I have power steering fluid all over the lower left side of engine. I have also spotted a coolant leak in the same area just above the water pump, theres a little 90 degree heater hose that seems to have sprung a leak where it goes into the block.
I seriously considered going for a 1jz but after some input and my current budget constraints it looks like its finally time for me to get on with it already and build my damn 7M. :biglaugh:

I am looking for a 350 to 400 hp, reliable daily driver. I also drive from San Diego up to the Bay Area now and then so a nice comfortable freeway car is a must. I already love the supra on the freeway so I cant wait to see how she runs up I 5 with some goodies on her. Probably eats up the road...

So first things first, as she's not going anywhere I figured I'd start by taking out everything that's gonna have to go anyway. A couple hours and a couple busted knuckles later I am left with the intake mani, fuel rail, turbo, a couple pulleys on the front and a few remaining vacuum lines. Not much left and hopefully tomorrow I can get the rest off and remove the head. My first step is to pull the head and confirm that I do have a bhg. I will be ordering the following in the near future, hopefully next week for most of it...

PARTS:
MHG
Gasket Kit
Piston Rings
Oil Pump
Main Seals
Rod Bearings
Main Bearings
Arp head studs

SERVICES:
Have block resurfaced
Head Resurfaced/Replaced depending on warpage
3 angle valve job

As far as engine stuff goes is there anything else you guys would recommend, anything I missed? I'm aware that I'll need exhaust, suspension, etc but for now I'm trying to stick mainly to engine goodies.

I've attached some pics here and will try to with every update. I also appreciate any advice, comments, personal experiences that you guys may be willing to share. My thanks in advance, Im definitely learning as I go but feel confident that with the excellent support available here at supramania and some blood, sweat, and tears i can restore my supra to her former glory.

Cheers-
Brandon

 

[btc2112]

ok, so after a few interruptions and some minor delays :3d_frown: i was able to finally get under the hood this morning and pull the dang head. it came off relatively easy, 2 of the stock head bolts in the rear on the exhaust side had worked themselves so loose i didn't even have to break them off, no wonder the gasket failed. definitely going with arp studs on the rebuild. as you can see from the pics almost all the coolant passages on the exhaust side are deformed. i also have oil on top of pistons 4, 5,and 6. the plugs i pulled from these cylinders were swimming with oil as well.
any ideas as to how that got there? is it bad valve cover gaskets, bad rings, or could it be from the bhg?

i also have a bunch of oil(maybe mixed with p/s fluid) on the same side of the block up by the water outlet housing. it looks like it could have possibly come down from between the head and block? not sure though... if you look at the last pic there is a cap with a nut below it that had a sensor i disconnected when removing the harness, is there any way oil could be leaking out of there or is it just running down on top of it? im sorry i cant be more specific, i dont know what the little shiny part is called but its right in the middle of the last picture, just in front of and above the oil filter.

anyway, im having the head picked up next week to be checked out and resurfaced if its ok and should be pulling the block shortly after to be cleaned up and milled also. i will update with more info and pics then. hopefully i should have my digi cam back by then too, sorry for the shitty pics. thanks guys!

brandon

 

[btc2112]

:1zhelp: hey guys....any ideas here? i could really use some help. am i not asking my questions properly or is this just something that has been done thousands of times before and nobody is interested anymore? :1zhelp:

my main question is what could cause oil to be sitting on top of my rear 3 pistons? i had a bhg and i dont know if the oil could have leaked onto there through the head gasket or could my leaking valve cover gaskets be the cause? any ideas would be greatly appreciated as this is my first time doing this and i am pretty stumped.

 

[skipbarber]

well the oil on the pistons could've been from when you lifted the head off and maybe some oil spilled from the head or from the headgasket as there are oil passages as well. Also, did the car burn any oil before it was parked or smoke at all?

Leaky valve cover gaskets will lead to oil build up around the spark plugs and causes a misfire. The sensor on the side of the block is the oil pressure sensor and it looks as though the leak is coming from above.

Looks to be like a solid build. If you are going to have the block milled i would just go ahead and check all the bearings in the block and put new piston rings in. Also, new valve seals are a good idea. If the car has been sitting for a long time the seals will dry out and not properly seal again. Hope this helps.

 

[btc2112]

well the oil on the pistons could've been from when you lifted the head off and maybe some oil spilled from the head or from the headgasket as there are oil passages as well. Also, did the car burn any oil before it was parked or smoke at all?

Leaky valve cover gaskets will lead to oil build up around the spark plugs and causes a misfire. The sensor on the side of the block is the oil pressure sensor and it looks as though the leak is coming from above.

Looks to be like a solid build. If you are going to have the block milled i would just go ahead and check all the bearings in the block and put new piston rings in. Also, new valve seals are a good idea. If the car has been sitting for a long time the seals will dry out and not properly seal again. Hope this helps.

thanks for the input skip, just wanted to let you know that i've been following your grassroots challenge build and have been very impressed with what you guys have done with that car on the small allowable budget. i'm very excited to see how it turns out and will be rooting for you guys. good luck to you and your team.

as for the car burning oil, i never saw or smelled any oil burning while i was driving, no smoke or anything like that. it was leaking a tiny amount from the rear main seal, down onto the transmission and i had to keep a quart or two in the car to top off every couple of weeks. also i was pretty careful when i removed the head and didn't see more than a couple drops of oil fall as i lifted it off. i did have oil all over the plugs from those same cylinders(4,5,6) so that's what got me thinking that it was the valve cover gaskets. could that oil have possibly worked its way down past the plugs and onto the pistons or would the plugs stop it and keep it up above indicating a leak from the gasket?

as far as the oil pressure sensor, im hoping that the leak was in fact coming from above it. have those been known to leak oil from where its screwed into the block? my oil pressure was always good when the car was being driven so i'm hoping that's not the case but am just curious if anybody may have dealt with an oil leak from there.

thanks again for the info skip, i appreciate it and good luck again!


brandon

 

[skipbarber]

thanks man! be sure to watch for updates when we get back.

But yeah, i think the oil on the pistons is most likely from oil that could have seeped through the oil passages from the headgasket. Have you inspected the gasket yet? Most likely is will be disintegrated towards the rear of the motor where you found the oil on the pistons. Oil would seep through the spark plug wholes. They are sealed off pretty well as that is where you get your compression of your motor from. I haven't heard of anyone having problems with leaky oil pressure senders but you never know. When everything is out inspect it thoroughly and take lots of pics of stuff you have questions about.

 

[btc2112]

thanks man! be sure to watch for updates when we get back.

But yeah, i think the oil on the pistons is most likely from oil that could have seeped through the oil passages from the headgasket. Have you inspected the gasket yet? Most likely is will be disintegrated towards the rear of the motor where you found the oil on the pistons. Oil would seep through the spark plug wholes. They are sealed off pretty well as that is where you get your compression of your motor from. I haven't heard of anyone having problems with leaky oil pressure senders but you never know. When everything is out inspect it thoroughly and take lots of pics of stuff you have questions about.

yeah, the gasket was in pretty bad shape especially towards the rear, looks like it just cooked back there. plus when i was removing the head bolts there were two in the back that were barely more than hand tight... go figure. im gonna be getting in there today and cleaning a bunch of that crap off, i'll be sure to ge some good pics too.

thanks again skip.

 

[Bluechulappa]

Just read through your thread on keeping 7m or going 1jz then found this thread. Looks like you've got a good start on things. I am about to do pretty much the exact same thing you are doing so I'm gonna keep an eye on this thread.