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1991 Toyota Cressida
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Discussion Starter · #1 ·
This issue is driving my son and I crazy.
The background. I replaced the head gasket on a bone stock 1991 Cressida.
The car started right up. The car ran beautifully. Without much driving on the new build I noticed quite a bit of coolant coming out of the tailpipe.
Sadness.
The head gasket repair was done with a high quality Ishino Stone gasket kit.
The head was decked, all valves polished and lapped back into place.
Fresh gaskets all around, ARP headbolts properly installed and torqued to 78 ft pounds.
New valve seals etc.
I did a compression test. 200psi on all cylinders.
I did a radiator leak-down pressure test. The system is airtight.
No bubbles in coolant reservoir, no oil getting into the coolant.
I do have coolant under the valve covers mixing with the oil.
We dove back into it, searching for any clues. Here are the only clues we have.
Since all gaskets are new, they will come off relatively easily along with the part being removed. This was the case except for one gasket. The gasket in-between the Intake and the head was completely stuck right where a coolant port is. (see images)
The other odd thing, is we removed the backing plate from the gas exchanger on the back of the head. Part of the EGR system I believe? From my understanding This area is supposed to only have hat gasses inside. But when we removed the plate it was wet inside, also full of rust and strange white globs.
Any ideas would be greatly appreciated.
Photograph Automotive tire Light Black Tire
 

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One with the farce
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Did you have the head pressure tested to check for cracks?
 

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1991 Toyota Cressida
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Discussion Starter · #3 ·
I did pressurize the cooling system (past toyota spec) And there were no leaks, and no loss of pressure.
Do you think there can be a crack in the head, that does not show up from the coolant pressure test?
Also, looking forward, how does one test for cracks with the head off?
Thank you.
 

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1991 Toyota Cressida
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Discussion Starter · #5 ·
Tomorrow morning I am dropping off the head at a highly rated machine shop for crack testing.
I will update when I get the results.
 

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One with the farce
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One other thing; is there a slight step between the block deck and the oil pump housing? The reason I ask is because my 7m had the block decked, but they didn’t deck it with the oil pump bolted to the block so there was a .010” step. This caused the head to not sit flat on the block, with obvious results after about 55000km.
 

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1991 Toyota Cressida
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Discussion Starter · #7 ·
One other thing; is there a slight step between the block deck and the oil pump housing? The reason I ask is because my 7m had the block decked, but they didn’t deck it with the oil pump bolted to the block so there was a .010” step. This caused the head to not sit flat on the block, with obvious results after about 55000km.
Were you using a metal, or regular head gasket? I just checked where my block meets the pump, it has a very slight step, barely catches my fingernail, not sure how much it is.
 

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One with the farce
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I used a composite head gasket, specifically because the block wasn’t smooth enough to use the MLS type, which needs a specific finish to seal properly.
 

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1991 Toyota Cressida
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Discussion Starter · #9 ·
Machine shop called. Said the head had no cracks. Also said the valves were sealing perfectly.
Guy asked me if it ran great, and I said yeah. But..he said, "it is slightly warped". !
Hopefully this is the reason for my leak. They will refinish the surface, I'll pick it up tomorrow. Gonna keep my fingers crossed.
 

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1991 Toyota Cressida
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Discussion Starter · #10 · (Edited)
I finished the re-build with the machined crack tested head.
The symptoms remain the same, heavy white smoke from exhaust, and it seems to idle a little rougher this time around.
Runs good though.🙃 I feel defeated.
At this point I will be selling the car as is. Thank you for your input.
 

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One with the farce
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Any chance you crossed a coolant supply line with a vacuum line?
 

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That sucks, may possibly have a cracked block :(

BUT WAIT...

One more thing: if your original head gasket (I assume it failed, hence the repair) had a breach between a coolant passage and combustion chamber, and your original symptom was coolant loss and white smoke, you probably have coolant still puddled up in your exhaust (catalytic converter, muffler), and will take time for it to burn off. You said it runs well... then maybe just MAYBE that's your issue!
Now with a new head gasket, once you start the car does it start smoking RIGHT AWAY or 30-60 seconds after you start it?
 

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Discussion Starter · #14 · (Edited)
That sucks, may possibly have a cracked block :(

BUT WAIT...

One more thing: if your original head gasket (I assume it failed, hence the repair) had a breach between a coolant passage and combustion chamber, and your original symptom was coolant loss and white smoke, you probably have coolant still puddled up in your exhaust (catalytic converter, muffler), and will take time for it to burn off. You said it runs well... then maybe just MAYBE that's your issue!
Now with a new head gasket, once you start the car does it start smoking RIGHT AWAY or 30-60 seconds after you start it?
It smokes almost right away, within 3-5 minutes. (why did you put RIGHT AWAY in caps?) But, I also took it for a drive, came back, it was still smoking, coolant will actually drip from the exhaust pipe.
I feel it ran slightly better the first time I did the head gasket, but it still runs well. It has a little bit of a hiccup now and again, maybe because the compression is higher? (shaved head)
This car has me super stressed out. My wife is away overseas, and I have this giant list of other things to do before she gets back, but Instead I've been working on this car to no avail. I'm in big trouble! 😣

Also, would I still have good compression in each cylinder with a cracked block? Is it possible the coolant is entering the exhaust NOT through combustion?
 
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