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Discussion Starter · #1 ·
Hey everyone,
This concerns alot of people doing the 1JZ swap who are sticking with stock turbos. I didn't know this until now, but there are 2 iterations of the 1JZ in the JZA70 (and the soarer or some other 1jz engine'd car). The first gen has a faulty 1-way valve on the intake cam cover and slightly different intake piping for the blow-by gases. The first gen has the blow-by tubing coming out of the cam covers into the Y-pipe of the intake.

The second gen 1JZ has an upgraded 1-way valve which visually looks MUCH more robust than the 1st gen 1JZ. The blow-by piping comes out of the same place on the exhaust cam cover, but the pipe goes into the intake pipe going directly into the front turbo.

What's the problem? Apparently, on the first gen, the turbos are very prone to blowing. Telltale sign is white smoke coming out of your tailpipe.

I was talking with YSR and A.S. Mori about building up the 1jz to see what they would recommend. The first thing they asked me was which generation of the 1JZ I had. I told them I didn't know there were more than 1 iteration of the 1JZ in the JZA70. They explained the pipe and valve differences to me. Little did they know that I was in the US so they told me to take the jza70 in to get it fixed at toyota for free because it was a recall issue. So from what I gathered, here is what happens.

The stock 1-way bleeder valve on the intake cam cover fails. This
causes blowby oil to get into the surge tank (intake mani) and go
into the cylinders to be combusted with the gasoline. The resulting gas produced after the explosion is either corrosive, or the oil/gas mixture is still burning as it goes into the turbos and ruins the turbo seals ruining the turbo.

I looked up "white smoke" and "JZA70" and there is a shitload of
sites documenting this thing. YSR and A.S. Mori both told me that
once the 1jz starts blowing white smoke, there's nothing that can be done about it except a rebuild. They said they didn't know why toyota modified the intake piping, though.

So...the recall entails replacing the 1st gen 1-way bleeder valve and hosing with the 2nd gen 1-way bleeder valve and hosing as well as replacing part of the intake piping.

The parts and part numbers required to fix this are as follows:
1-way valve parts:
Ventilation Hose p/n 12261-88401
One Way Valve p/n 12204-88402�@

Intake Piping and Parts:
Air Intake Connector p/n 17861-88401
Manifold Air Hose p/n 17361-88401
Ventilation Hose p/n 12263-88401
Gasket Air Tube p/n 17376-88400

The other option on the intake side is putting in an oil catch can.

This image is of the 1st gen JZA70 intake side:


This image is of the 2nd gen JZA70 intake side:


This image is of the 1st and 2nd gen JZA70 one way valve; top is 1st gen, bottom is 2nd gen:


Like i stated above, this is a concern for those running stock twins.

I hope no one's blown their turbos yet.

MelloBoy
 

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Boost Dealer
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980 Posts
I have a 1st gen with blown turbos, damn.

I was just about to get my turbos rebuillt, but I'll fiox this little
problem before I put them back on. Thanks for the tip.


Jeff
[email protected]
 

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...make that none again
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1,932 Posts
Finally I can post again! I tried replying to this 3x lastnight. Anyway, great info, and thanks for the pics. I'm ordering my clip next week and will be using stock turbos for awhile atleast. One question about the recall; will Toyota work on an engine that was never imported with a US car?
 

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SF in my veins... sigh
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1,586 Posts
I too tried to reply to this last night to say thanks for the info. I forgot to thank ya on the JZA70 list :)

Unfortunately I highly doubt Toyota will touch this recall in the US... which is no biggie. Several guys can get you the new valve, and the intake piping issue... if you're concerned about it... can probably be had from a buncha guys who have the new pipes off their clip and aren't using them due to aftermarket turbos.
 
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Discussion Starter · #8 ·
i doubt toyota USA will work on it. I will compare and see if the 2JZ uses the same upgraded 1-way valve or not...if the same ones are used, that's 1 problem taken care of :)

an oil catch can should work just as well for the intake side. Anyone care to speculate why the intake was changed subtley? i have no clue...air turbulence in the Y?

MelloBoy
 

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b00st junkie
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433 Posts
where/how exactly should I get these parts? The part numbers arent on the Toyota USA catalog, which means no dealer in the US will be able to get them most likely. Any idea how we can get ahold of some of these.

On a side note, has there ever been a remedy discovered to get the car out of limp mode? I think mine went into it today on my way to the dealership to get my tires changed. NOT HAPPY!!! Any ideas or will I end up hacking my my other harness up and lengthening it after all?
 
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Discussion Starter · #10 ·
i've been told that you SHOULD be able to get the parts as long as you have the part number. Some toyota dealerships are just asses and won't help you out.

worst case scenario, i might be able to get a bunch from japan..it'd take about a month or so tho.

MelloBoy
 

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SF in my veins... sigh
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1,586 Posts
MelloBoy said:
Anyone care to speculate why the intake was changed subtley? i have no clue...air turbulence in the Y?

MelloBoy
Dr.J and I discussed this for a few.. having the vent enter the pipe further from the Y provides for a better "suction" effect caused by the flow of the intake air passing it. Possibly at the Y the air flow was too disrupted and the air in the vent tube stagnated.
 

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Registered
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isn't that 1-way bleeder valve a PCV valve?

if so, can someone explain the difference between the PCV valve and the exhaust cam cover side blow-by vents that go into the turbo inlet piping?

don't they both relieve crank case pressure? wouldn't removing the PCV valve all together and installing a catch can on the exhaust side solve this problem?
 

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SF in my veins... sigh
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1,586 Posts
outofstep said:
BWHAHAHAHAHA

So much for 1JZ reliability ay?
Heh... I was waiting for someone to post this... how many generations did the M series engines go through and still have the issues it had? ;) For a 1st gen engine to have an External valve issue is pretty tiny ;)
 
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Discussion Starter · #16 ·
notice how toyota never really fixed the head gasket issue until what...like 5 years after the 7m came out and even then was a piss poor fix? :) did they even up the torque rating in 91-92?

melloboy
 

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This should be a sticky in the tech section, or added to the 1JZ-GTE swap thread.
 

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MelloBoy said:
notice how toyota never really fixed the head gasket issue until what...like 5 years after the 7m came out and even then was a piss poor fix? :) did they even up the torque rating in 91-92?

melloboy
I dont think they upped the torque.... when i bought my 91T the gasket was slightly leaking at only 109 000 km... thats like 65,000 miles
 
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Discussion Starter · #19 ·
MelloBoy

I think there is a bit of a mix up, if I am wrong, I'm sorry... just trying to help.

The 1st 2 photo's are not where the PCV lives.

You will note the hoses associated with the PCV in your 3rd shot do not resemble the hoses in your 1st 2 shots.

Considering the stir that all recall notices cause amongst all and sundry owners world wide, has anyone actually seen this recall notice you are referring to. If so, could we hav it's number or it's actual text?

Anyway, presuming there was a recall, you will not find the PCV there, it's on the other side of the rocker cover down a bit. Look for the little hoses MelloBoy posted.
 
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Discussion Starter · #20 ·
Michael,
Toyota changed 2 things :)
First was on the exhaust cam side which is in the first 2 images posted.

Second was on the intake side where a 1-way valve is sticking out of the intake cam cover. On the first gen 1JZ, the 1-way valve and rubber tube on the top of the 3rd picture is used. On the second gen 1JZ, the 1-way valve (looks beefier) and rubber tube on the bottom of the 3rd picture is used.

MelloBoy
 
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