Bogging, White smoke.

[TooRandom]

So I finaly installed my MBC yesterday and was running at a good 12 psi. did a few runs to test and see where i was at. Today after i got off work and picked up a friend. When i got to his house my car was shaking and bogging. When I left it felt like my car lost power.

I checked my coolant in the reserve and it was near empty and it just seemed to steam off. when i was on my way home my car started to put out white smoke from the exhaust so i had a feeling it was my coolant. My air-fuel ratio gauge is normaly at rich at the very right with a green light, today it was freaking out blinking (red yellow and green.) I just lowered the psi back to stock but haven't took it out for a ride yet since. The oil was also low but i put a quart of 10w-30 synthetic blend to just make it home.

Any ideas on what to do? Any of those symtoms lead to something specific? I plan to change my oil and flush the coolant tomorrow.

 

[Fletch124]

Search blown head gasket.

 

[TooRandom]

anyone else? ^^i really didnt find much on a 7mgte build on a bhg. but i have directions on how to do it but cant find the torque specs when i bolt everything back up

 

[jdub]

So, let me get this right...you raised boost to 12 psi on a stock motor with no prep. Is that correct?

The torque spec is different depending on the hardware used...stock head bolts, ARP head bolts, or ARP studs...each is different.

 

[Syris]

You really didnt look too hard, if you couldnt find much on 7mgte and BHG haha

 

[87M-GTE]

Dont spend your money on new oil and coolant just yet. Its time for a new Head Gasket!!! and arp head studs...

 

[TooRandom]

yep everything was stock besides my k&n intake. the only reason why i raised it so high was because i asked before installing how much the stock turbo and motor could handle and some guys on i-supra told me it could hold up to 14psi. do i have to buy a whole gasket kit or just the gasket? i got a quote at auto zone and it was 250 + for the whole kit not including new studs and arp studs are 100. im on a budget due to bills.

thanks for everyones imput.

 

[emiliorescigno]

yep everything was stock besides my k&n intake. the only reason why i raised it so high was because i asked before installing how much the stock turbo and motor could handle and some guys on i-supra told me it could hold up to 14psi. do i have to buy a whole gasket kit or just the gasket? i got a quote at auto zone and it was 250 + for the whole kit not including new studs and arp studs are 100. im on a budget due to bills.

thanks for everyones imput.

You've got a lot more ahead of you than that. The best way to genuinely cure the blow head gasket is to pull the engine, remove the head, have a machine shop make both surfaces perfectly smooth, then install a metal head gasket (like from HKS for example), and bolt it down beyond stock spec with ARP hardware.

The slightly less expensive option is to install a new factory headgasket, bolt it down down more than stock spec with ARP hardware, turn down the boost, and pray you don't blow it again.

I'm no expert, specifics will have to be searched for, but expect to spend a lot if you want it done right.

 

[Keros]

yep everything was stock besides my k&n intake. the only reason why i raised it so high was because i asked before installing how much the stock turbo and motor could handle and some guys on i-supra told me it could hold up to 14psi. do i have to buy a whole gasket kit or just the gasket? i got a quote at auto zone and it was 250 + for the whole kit not including new studs and arp studs are 100. im on a budget due to bills.

thanks for everyones imput.

Some 7M-GTE ECU's can do 14... most, from what I understand, hit fuel cut off between 11-14psi though, obviously with the majority hitting fuelcut at 12.5, which is where mine is.

However, your headgasket wasn't up to the task... 'can' and 'should' are two very different reasonings to do 12psi.

Good luck with the rebuild.

 

[gaboonviper85]

aaaaaaaaaaaaaaaaaaaand FAIL!!!!

 

[Whasian]

you deffinantely blew the head. Sorry to say. I recommend saving about a 800 to a 1000 dollars (if you can) and go through the engine with basic mods. rod bolts, hks gasket, head studs or bolts, and have the head clean and prepped. You can get that done for a little less than a grand (if you do the work)

Whasian

 

[TooRandom]

aaaaaaaaaaaaaaaaaaaand FAIL!!!!

wow thats really helpful.

 

[7MGTEsup]

A healthy (new) stock head gasket (with a straight head and block), with fresh bolts torqued down to 72lbs/ft will hold 12psi boost all day long (on a CT26). I did mine 3 years ago and have covered 20,000 miles without so much as a hicup, I did a compression test a month or so back to see how things were 160 psi +/- 5 psi accross the board. The key to not blowing a head gasket is both surfaces need to be straight, the head needs to be torqued to 72lbs/ft minimum and you need to make sure your car is tuned correctly and not running lean under hard load. Bishop92 used to run OEM head gaskets and his engine and boost were far from stock.

 

[TooRandom]

A healthy (new) stock head gasket (with a straight head and block), with fresh bolts torqued down to 72lbs/ft will hold 12psi boost all day long (on a CT26). I did mine 3 years ago and have covered 20,000 miles without so much as a hicup, I did a compression test a month or so back to see how things were 160 psi +/- 5 psi accross the board. The key to not blowing a head gasket is both surfaces need to be straight, the head needs to be torqued to 72lbs/ft minimum and you need to make sure your car is tuned correctly and not running lean under hard load. Bishop92 used to run OEM head gaskets and his engine and boost were far from stock.

thanks a lot. very useful information.


Whasian, are you saying that my whole head is blown? or the head gasket. if im going to have to spend about 800-1000 on just repairing that head than i might as well buy a new motor. but if its the head i was wondering why you think my head is completely blown rather having a bhg. I think if it was blown i wouldn't be able to start yeah? but I've started it yesterday and moved it into my drive way.

 

[MkIII_Jeff]

thanks a lot. very useful information.


Whasian, are you saying that my whole head is blown? or the head gasket. if im going to have to spend about 800-1000 on just repairing that head than i might as well buy a new motor. but if its the head i was wondering why you think my head is completely blown rather having a bhg. I think if it was blown i wouldn't be able to start yeah? but I've started it yesterday and moved it into my drive way.

i would search some more on here and continue thinking a lil while longer on the new motor idea. A replacement 7m will be in the same boat, unless you buy one that was recently rebuilt correctly, and then you will be spending some $$$ anyways.

 

[turbodriz]

u definitly have a ::bhg:: Now as far as everything people say the surface of the block needs to be done for it to be right. I blew my hg and sent the head to the machine shop, did arp headware , and a hks gasket and I never had a problem out of it again.