3b head gasket not sealed

[bj70bc]

I have a post on this in the diesel section but wanted to ask a more general audience about head gaskets not sealing and what might be the cause.
I put a turbo on so I did all the head related preventative maintenance
The coolant overflow bottle is bubbling and water temps are trying to overheat upon driving.
The new head was decked, precups set at 0 protrusion, clean surfaces, MLS head gasket was used, multi stage torquing procedure from the center out,
maybe i used too much oil on the head bolts?
maybe should have used the copper gasket spray?
maybe somehow damaged the head gasket on install?
Any thoughts?

 

[Behemoth60]

I trust the head was checked for cracks. The 3B head has two weaknesses.... if they overheat, the casting between the intake and exhaust valves can crack. The water passages are poorly designed for extracting heat, making them prone to overheating in Turbo'd applications. The aftermarket so-called 'High Nickel' Heads, in addition to having a bit better metallurgy, also improved the coolant passages for better heat extraction. The stock heads also have pretty rough intake and exhaust port castings, and I believe they benefit greatly from a good port polishing to improve air flow and resulting heat extraction out the exhaust rather than heat soaking the head through the rough exhaust ports. The factory sized ports in the pre-cups are also itty bitty compared to the mass of air that needs to flow in and out of those teeny holes, which we are effectively doubling when running a turbo at 14 psi, and all that air needs gets heated as it compresses to get through that tiny pre-cub hole. I also advise opening up those pre-cup holes a bit.
The one thing you didn't mention was whether the block was decked? Maybe it was not flat?
I would re-check the torque on all the head bolts, and then maybe over-torque them some... maybe 15-20% more torque than the manual calls for.
If that doesn't work, I would remove the head for another look-see, and another head gasket. I've never heard of it... but it's theoretically possible you got a defective MLS gasket, I suppose.
It's also possible you've got a stretched head bolt. Most people (me included) just re-use our head bolts. Maybe find some new head bolts. Has anyone ever figured out if there is an ARP stud kit that will work on the 3B? I am not sure of that.

^^^^
All the reasons I never recommend turbo'd 3B's to anyone anymore.

 

[bj70bc]

Thanks,
yes, it got a new head, and the head was decked but the block was left alone, the precups were slightly ported and polished.
im starting to consider doing an exhaust gas test to see if the bubbles in the overflow are from boiling or combustion pressure, maybe a bad rad cap.....

 

[lacalvette]

Is the engine had this trouble before removing the head?
To me, sound like a seating issue. Bubbling in coolant, exhaust gaz reach the coolant system…
If you remove the head, look for corrosion on the bloc, they have that spot with number(piston size??) in it which is not cover by the gasket (like it allow you to see the number)
On some engine these hole are very close to coolant passage and comb. Chamber, not that much on 3B but still.
I think the previous gasket type could allow some imperfections but the MLS can’t.
Like said above, these head develops cracks between valve (overheat, cycle), cracks can go as far as coolant..

 

[bj70bc]

The head gasket was only done to access the precups and to upgrade it to a mls one for the turbo.
Ill have a look for that on the block when i tear into it again.
the head was new and decked so it was pretty nice but the block was well cleaned and left as was, ill give it another level of cleaning this time i guess.
I think ill spray it with the copper gasket spay this time as well to perhaps help with some block surface imperfections.

I really hope that does the trick though.

If anyone has any tips for mls head gasket install and dealing with the block surface I'm all ears.

 

[bj70bc]

Just an update....
think i have the issue figured...
i originally bought a teiken HG, turns out the pos is 1.39mm instead of 1.5mm as the toyota one is supposed to be so when torqued down the head is most likely contacting the cylinder sleeve protrusion (fire ring) and not allowing full HG crush in the neighborhood of 0.2 mm....
Live and learn, its my own fault for not buying the toyota one...
on the upside i can tear the head down in record time and know the engine much better........
hopefully the new oem gasket seals up this time

 

[Galem888]

Hello, first of all, sorry for the language. I'm a new member of the forum and I've been having a problem with my Toyota BJ 70 3B engine for a while. The problem is related to the same thing described here. First, I lifted the cylinder head twice and the gasket burned right through the center between the cylinders. Now, my question is, could it be the gasket that isn't the original? Could it be the cylinder head? Does it have some small cracks between the valves? However, they assure me that the cylinder head is fine, but now I'm wondering if the block could also be cracked. I have the same problem with bubbles in the coolant, but the car doesn't heat up. Thanks and sorry for the inconvenience.

 

[bj70bc]

You need to get the MLS (multi layer steel) gasket, not the fiber one (toyota brand only)
Send the head to the machine shop to check for cracks and flatten the surface
block decks needs a good cleaning, gentle scraping and some light hand work with a 3m pad or 1000 grit sandpaper, (very carefully)

Your block wont be cracked (chances are very low)
Your head is probably cracked
use a new head and mls gasket

 

[Galem888]

You need to get the MLS (multi layer steel) gasket, not the fiber one (toyota brand only)
Send the head to the machine shop to check for cracks and flatten the surface
block decks needs a good cleaning, gentle scraping and some light hand work with a 3m pad or 1000 grit sandpaper, (very carefully)

Your block wont be cracked (chances are very low)
Your head is probably cracked
use a new head and mls gasket

Hello, thank you very much for responding so quickly. At the auto repair shop, they assured me the cylinder head was flat and crack-free, but upon visual inspection, I could see some small cracks in the bridge separating the valves on three of the four cylinders. However, they dismissed this after checking with a machine. Another reason I had thought was that the cylinder liner protrusion would stick to the cylinder head when tightened, causing it to burn. I'll try taking the cylinder head to another auto shop, and if it's cracked, put in a new one (I currently have a 11111-58012). I think they only have the 11101-58014 with smaller valves and put original Toyota gasket. Thank you very much for everything; you have a community where I learn a lot. Best regards, I'll keep you posted on my progress.

 

[bj70bc]

you can get the machine shop to cut the valve holes bigger for your valve size and put new valve seats in...
thats what i did to mine as it was the smaller valve version
if has cracks you can see by the eye, its done in my opinion, as when you tighten it down they could open up more, and will crack more soon enough
you can get a cracked head fusion welded, but finding that guy isnt easy

the old composite gaskets and aftermarket gaskets arent worth the time using, mls is the ticket

 

[Galem888]

Ok, first, I'll try a new auto repair shop to have them look at the cylinder head. Second (since I think the cracks I mentioned are causing it to break), buy a new cylinder head and install an original Toyota gasket. By the way, about the cylinder liner protrusion, could it be modified? Could I modify the compression ratio? It still seems to me like it sticks out too much (1.2 mm) for the thickness of the head gasket (1.6 mm). I don't know if I'm explaining myself correctly. Thanks anyway.

 

[bj70bc]

Metal gasket crushes approx 0.2mm, liner protrusion should be fine if you have original liners and use the mls gasket, no aftermarket
no need to mess with the liner protrusion

Post up some pictures

 

[Galem888]

Metal gasket crushes approx 0.2mm, liner protrusion should be fine if you have original liners and use the mls gasket, no aftermarket
no need to mess with the liner protrusion

Post up some pictures

I've got the cylinder head mounted on the engine right now. I'll get to it soon and try to send photos of the process. Thanks so much for the clarification.

 

[Galem888]

For now I'll leave a photo here.