blown head gasket on 61040 head. Just 5k after rebuild (1 Viewer)

[sheepdawg]

I am sick to my stomach. I just had my 83 fj60 rebuilt only 5 k miles ago. It had been running great then all of a sudden I started noticing antifreeze on my garage floor. Not a big deal, my thought was winter is hear and I have been dropping down to 20 degrees at night. Then I noticed my reservoir was overflowing with antifreeze and I could hear my radiator bubbling when I turned off the engine. My normal operating temperature usually runs about 145 to 150 degrees and now I noticed I was running about 160. This was with a mechanical temp gauge. I took it in to a radiator shop and they put about 13 lbs of pressure to the system and no leaks but he did notice that I was half a gallon low on antifreeze. So he refilled it and said to monitor it. after he put a new radiator cap on it.

Well, low and behold, the antifreeze started overflowing again and I started noticing white smoke coming out of the tail pipe. Shut it down and looked at the oil. Not really milky but maybe I was just catching it when it started. So I do a compression check after warming the engine up for 10 minutes. More white smoke and a sweet smell coming out of the tail pipe and now even antifreeze coming out of the tail pipe.

I remove all the spark plugs and noticed the #5 plug was very hard to remove. When I started doing the compression check, antifreeze shot out of the #5 plug hole.

Pressures read as follows:

# 1 130 lbs, #2 115 lbs, #3 115 lbs, #4 115 lbs, and #5 190 lbs, and the #6 125 lbs.

Does that seem right? I thought I would get a lower pressure where the leak was, or do I have it the opposite.

I recently learned that the 61040 heads had a tendency to crack. So I have an extra sitting on my shelf. What is your opinion?

Very pissed off at my situation, because I just don't have the time to mess with this project since I am rebuilding another 2f for my fj40.

Needed to vent.

 

[Output Shaft]

I know your grief..
It is what it is. The head has to come off again.
No big deal. You can do it in two days.

1. The block deck has to be reasonably flat
2. The head has to be flat
3. Head magnafluxed for cracks AND pressure tested
   
4. Use a Toyota HG only (dry)
5. Get all new head bolts (if you want to be crazy about the bolt elasticity thing)
   
6. Run a tap down all block head bolt threaded holes so bolts turn without friction.
7. Do not over oil the head bolts when assembling. A very light coat is all that is needed. Excess oil can contaminate the HG when it spews out when tightening.

My 2F started burning coolant slowly just after a head job (5 years ago). I removed the pressure spring valve on the radiator cap to unpressurize the cooling system and ran it like that with no problems for 5 years.
I was convinced the head was cracked... but after careful examination (MF) and pressure testing, it was found to be ok. So my issue was the HG.. It was an aftermarket HG.

 

[LAMBCRUSHER]

and retorquing the head several times will also go a long way to prevent this- even when using an aftermarket gasket.....

 

[gregnash]

and retorquing the head several times will also go a long way to prevent this- even when using an aftermarket gasket.....

Everything I have read says that you are supposed to retorque at 100, 500, 1000 miles to ensure that everything has seated properly.

 

[Spike Strip]

No way around it, Rick, head has to come off. And you are correct, the 61040 head does have a tendency to crack.

FWIW, this was mine when it blew between 4/5 cyl. Compression was not very low, either. And you don't want it to sit too long, even with good antifreeze, as you can see why.

Was a Toyota HG used?

 

[gregnash]

Wow that is nasty looking!!!!! So what do you do to clean something like that up afterwards? Is it something that you can simply just go after it with 000 steelwool and clean up the cylinder walls and piston top or is something else needed.

 

[Spike Strip]

The motor had 213K mi at that point, so I decided to pull it and do a complete rebuild. Head was still good and it's the one on the truck, now.

Jim C. posted a pic somewhere of where the heads usually crack. Can't find it at the moment.

 

[sheepdawg]

Spike Strip,
Yes a OEM head gasket was used. I sure hope it does not look like that when I pull the head. I did not retorque the head bolts though but I will this time. Mark is coming up to my place to help pull the head and I will take it in to my machinist to be fully checked.

 

[Mace]

No reason to replace the head bolts, they are not torque to yield..