View Full Version : 1jz blown head gasket?!?
kelson
10-05-2009, 05:23 PM
I think its a bhg at least. I know its rare on a 1jz but I can't think of anything else it could be. hopefully one of you can. so here are my symptoms:
* popping/sputtering/misfiring as the engine revs down
* misfiring occasionally while at idle
* popping/sputtering/misfiring when the car is in gear, with throttle closed and at low rpms
* white smoke coming out exhaust pipe
* engine overheats
* some of my coolant has gone missing:sarcasm:
so ya I can't think of anything else it could be but maybe its something simpler. thats why I'm asking you guys. I'm planning on pulling off the head tomorrow, but I want to be as sure as I can that its a bhg before I go to all that trouble. so what do you guys think. I took a video. its here http://www.youtube.com/watch?v=Ny7nnvDIIQc Its a windy day so you cant tell but a tiny bit of smoke does come out when the car is at idle. also water droplets form on the inside of my exhaust tip and it doesn't really smoke till the engine is warmed up. I think thats it. so ya if you think of anything else it could be please post something. or if you think it is a bhg say that too. thanks guys in advance.
turboguy327
10-05-2009, 06:29 PM
Do a compression check. That would be the easiest thing to do and you would know for sure without guessing. If a cylinder doesnt check out do a leakdown test and you will know where the compression leak is..
Yeah dude, you can rent one(compression tester) from oreilly's. If the compression is low in a cylinder pour a cap full of oil in it and re-test. If nothing changes then its a gasket, if it does it might be rings.
Please correct me if im wrong.
JonoTurbo
10-05-2009, 07:27 PM
All of those symptoms could be attributed to different things. I would check a few easier things before pulling the head.
For one, hows your ECU? Has it been recapped? If it's running lean you could end up running hot, misfires, popping on decel, etc.
The white smoke could be due to lean condition or blown turbo seals.
A leak in the cooling system causing it to fail to properly pressurize could result in overheating and loss of coolant. A bad t-stat could cause the overheating, so could crummy fans, etc.
Also, does the exhaust smell sweet? That's usually a dead giveaway there's coolant in it.
becauseican
10-05-2009, 08:14 PM
You gotta hammer on a 1jz pretty hard to blow the HG, the only way it can happen is if you had some detonation from some bad gas, or if your crank/ cam sensors was out of whack.
Do a leak down test with the rad cap pulled off, if there is any cylinder with the HG "blown" it will bubble out the rad when testing.
kelson
10-13-2009, 10:06 PM
Ok I guess maybe I was a bit hasty in my assumptions. so I haven't taken the head off(yet). however I did compression check it and its all good. but I've been told that a compression check can't always find a bhg. is that true? but also I took of the coil wire on each cylinder one at a time and checked to see if the smoke changed and it did not. So I don't think it is isolated to any 1 cylinder. I also checked and I'm pretty sure its not a leak in one of the turbos. I am going to recap the ecu this week, but I've looked at the capacitors and they are not leaking or bulging so I doubt that's the problem. any thoughts fellas?
honestabe
10-13-2009, 10:39 PM
Do you have a milkshake? Are you losing coolant?
kelson
10-14-2009, 09:39 AM
Do you have a milkshake? Are you losing coolant?
loosing coolant but no milkshake. and not a huge amount of coolant, but noticable
WeDgE
10-14-2009, 12:32 PM
Aren't the stock twins water cooled as well?
kelson
10-14-2009, 03:23 PM
yes they are but I cut off the supply of coolant to each of them, one at a time, to see if this would make a difference and it didn't. so I don't think its the turbos
Gritz
10-14-2009, 05:14 PM
yes they are but I cut off the supply of coolant to each of them, one at a time, to see if this would make a difference and it didn't. so I don't think its the turbos
How long did you let it run this way?
r45marsh
10-14-2009, 07:58 PM
An easy way to find out if its antifreeze coming out the tailpipe is to taste it. Hold your hand in front of the exhaust, not close enough to get burned. Let some of the vapor condense on your hand. Taste it. DON'T DRINK IT just taste it. Antifreeze is very sweet. Oil isn't.
nightrider760
10-14-2009, 08:01 PM
get a 7mgte jajajaja
suprahero
10-14-2009, 08:09 PM
get a 7mgte jajajaja
I'm going to let this one slide, but this isn't a 7mgte vs. 1jzgte thread. This guy is looking for help and not comedic relief. Thanks., Jay
hvyman
10-14-2009, 10:03 PM
pressure test the cooling system and look hard for leaks. also run a block test to see if there is combustion gas in the cooling system.
Suprapowaz!(2)
10-14-2009, 10:10 PM
pressure test the cooling system and look hard for leaks. also run a block test to see if there is combustion gas in the cooling system.
^^^ This.
kelson
10-14-2009, 11:02 PM
I didn't run the turbos without coolant vary long. just like ~10 seconds. I will try to do a block test or something, but honestly I'm quite short on equipment and cash.
mobes
10-15-2009, 12:27 AM
I didn't run the turbos without coolant vary long. just like ~10 seconds. I will try to do a block test or something, but honestly I'm quite short on equipment and cash.
The coolant passage is completely separate in the casting, so there's no way you could be losing coolant out the exhaust, or into the oil for that matter, via the turbos.
kelson
10-15-2009, 04:29 PM
The coolant passage is completely separate in the casting, so there's no way you could be losing coolant out the exhaust, or into the oil for that matter, via the turbos.
oh ok cool thanks. thats good to know
kelson
10-16-2009, 03:12 PM
An easy way to find out if its antifreeze coming out the tailpipe is to taste it. Hold your hand in front of the exhaust, not close enough to get burned. Let some of the vapor condense on your hand. Taste it. DON'T DRINK IT just taste it. Antifreeze is very sweet. Oil isn't.
ya it tastes sweet
madsupra88
10-16-2009, 03:28 PM
How do your spark plugs look?
kelson
10-18-2009, 06:23 PM
How do your spark plugs look?
spark plugs are fine. I've been talking with my friend who know way more about cars then I do. he has a 500hp twin turbo 300zx. and he assures me that it has to be a bhg so I'm going to pull the head. I'll let you guys know what happens.
JPsToyota
10-18-2009, 07:03 PM
That definitely could be oil. You will smell the coolant, my 1J smokes like that because of (I think) valve seals. It's oil.
I also have alot of the same problems you have listed (overheating even though I just flushed with new cap and hoses) and have been wondering if it is a blown headgasket also. There just aren't enough signs pointing to BHG though... I will do a compression test soon, I suggest you follow the advice of alot of these guys and do the same.
Won't hurt to put a new gasket and do some maintenance while you're in there though, if you have the money and time go for it I guess.
edit - the decel missing is weird though.
kelson
10-18-2009, 10:23 PM
That definitely could be oil. You will smell the coolant, my 1J smokes like that because of (I think) valve seals. It's oil.
I also have alot of the same problems you have listed (overheating even though I just flushed with new cap and hoses) and have been wondering if it is a blown headgasket also. There just aren't enough signs pointing to BHG though... I will do a compression test soon, I suggest you follow the advice of alot of these guys and do the same.
Won't hurt to put a new gasket and do some maintenance while you're in there though, if you have the money and time go for it I guess.
edit - the decel missing is weird though.
I have done a compression check and its all good, but that doesn't rule out a bhg. I am just going to buy the complete gasket set from dm so if it is a valve seal it will fix that too. I think I may be running lean because I have the original fuel lines on(my supra had 237,000 miles on it when I bought it and did my swap) and they may be all clogged up. I bought some fuel injector cleaner and i'm hoping that will help.
I have done a compression check and its all good, but that doesn't rule out a bhg. I am just going to buy the complete gasket set from dm so if it is a valve seal it will fix that too. I think I may be running lean because I have the original fuel lines on(my supra had 237,000 miles on it when I bought it and did my swap) and they may be all clogged up. I bought some fuel injector cleaner and i'm hoping that will help.
Try a cold compression test. Once I retested my compression while cold I found that my cylnder #2 was low but when it was hot it tested fine.
kelson
10-20-2009, 11:42 AM
Try a cold compression test. Once I retested my compression while cold I found that my cylnder #2 was low but when it was hot it tested fine.
when I tested the engine was cold
kelson
10-26-2009, 11:15 PM
WINNER!!!!......in a loosing sort of way that is. I do have 1jz bhg! I finally got the head off today and when I was looking at the gasket I found coolant and oil trapped on either side of the middle piece of the gasket. so I'll get that fixed, but I'm thinking: my heads already off, my engine is in pieces and we just got our first real snow today.....what fun things can I do since I wont be driving much?:naughty:
anyways thanks a lot for all the help guys. oh but one more question what do you suggest I should torque the head to when I put in back on with the original head studs and a new stock gasket?
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