Cracked Block 1FZ-FE

[LuckyOreo]

It leaks because it's under pressure.

It doesn't matter what someone places on the outside of the block, it will leak because it is pushing from the back side with 15 PSI.

That's why I have suggested the Permatex #1 or #2 and use a finger to apply it to the crack from the INSIDE while the freeze plug is out.
(Clean and dry the area inside first, of course...)

Then apply some to the freeze plug hole before freeze plug installation.

Bar's leaks is what it needs to be until someone decides they need to do a flush with an acid-based product to clean out all the rust (and sealants) in the cooling system.

Good Luck!

Yea I did apply some permatex when I had popped the freeze plug out but maybe not enough or not the right area. I'm constantly monitoring the coolant temp because prior to my overhaul, I had a bad radiator and was over heating, and the leaking coolant wasn't helping either. But so far it has been holding temp around 186-194 I haven't seen it gone highe than that yet. But also isn't very hot summer yet or have gone on long drives yet. My long term plan is to source a low mileage used engine and do a complete rebuild on the side, so that when the engine goes, I can swap it out. In the mean time hopefully bars stop leak will do.

 

[BILT4ME]

Yea I did apply some permatex when I had popped the freeze plug out but maybe not enough or not the right area. I'm constantly monitoring the coolant temp because prior to my overhaul, I had a bad radiator and was over heating, and the leaking coolant wasn't helping either. But so far it has been holding temp around 186-194 I haven't seen it gone highe than that yet. But also isn't very hot summer yet or have gone on long drives yet. My long term plan is to source a low mileage used engine and do a complete rebuild on the side, so that when the engine goes, I can swap it out. In the mean time hopefully bars stop leak will do.

What Permatex did you use?

 

[BillyGoatMTB]

So after I put her back together, and ran her for a couple days, the jbweld couldn't hold the leak. View attachment 2704305You can see in the photo that it broke through the jb weld and is leaking. Maybe a bad application of jb weld or just not the right fix for the job. So i resorted to using bars stop leak. It's been two days of driving, and the leak area has been dry so far. Where as before bars stop leak I could actually see the leak area sweat and form a droplet of water every few minutes. View attachment 2704306

Looking forward to seeing what results you get with the bars stop leak.

Maybe I'm old school but if the bar stop leak works I think running it for a while then doing a full drain and fill coolant replacement might be a good idea.

Just going on what I always heard from pops and grand pops not to leave that stuff in long-term, maybe the technology has changed though.....

 

[LuckyOreo]

What Permatex did you use?

Permatex #1. But I was very light on the application

 

[BillyGoatMTB]

Yea I did apply some permatex when I had popped the freeze plug out but maybe not enough or not the right area. I'm constantly monitoring the coolant temp because prior to my overhaul, I had a bad radiator and was over heating, and the leaking coolant wasn't helping either. But so far it has been holding temp around 186-194 I haven't seen it gone highe than that yet. But also isn't very hot summer yet or have gone on long drives yet. My long term plan is to source a low mileage used engine and do a complete rebuild on the side, so that when the engine goes, I can swap it out. In the mean time hopefully bars stop leak will do.

I had a brand new aisin blue fan clutch not working well, did the 30cst silicone and rotated the fan clutch to 97°.

Just throwing this in there in case you have the problem this summer again.

 

[LuckyOreo]

Looking forward to seeing what results you get with the bars stop leak.

Maybe I'm old school but if the bar stop leak works I think running it for a while then doing a full drain and fill coolant replacement might be a good idea.

Just going on what I always heard from pops and grand pops not to leave that stuff in long-term, maybe the technology has changed though.....

Yea I am still running just distilled water right now so I plan on draining it in the next few days and flushing it out for the Toyota red

 

[BillyGoatMTB]

Yea I am still running just distilled water right now so I plan on draining it in the next few days and flushing it out for the Toyota red

Awesome, looking forward to hearing the results.

 

[fj80pb]

Hello again Mud!
After replacing the freeze plug last September-and confirming the leak was the hairline crack, I added a bottle of Bar’s 1111.
3500 miles after, I can confirm the leak is basically gone-perhaps a drop when the block and engine bay is heat soaked. I’ve noticed the working temperature is around 5 to 7F higher than before the Bar’s application. Still well within range. But it bother my OCD brain as before the application rarely reached 190F. Now 193 to 197F is quite normal (in both cases during summer, with the AC and same driving conditions. Winter isn’t an issue).
I haven’t done any mountain pass or similar, just regular driving and easy trails, so I can’t inform on demanding driving conditions and engine load
FWIW, the entire cooling system was rebuild 8.000 miles ago
Do you think a thorough flushing and a new thermostat would do any good?
Cheers!

 

[BILT4ME]

Hello again Mud!
After replacing the freeze plug last September-and confirming the leak was the hairline crack, I added a bottle of Bar’s 1111.
3500 miles after, I can confirm the leak is basically gone-perhaps a drop when the block and engine bay is heat soaked. I’ve noticed the working temperature is around 5 to 7F higher than before the Bar’s application. Still well within range. But it bother my OCD brain as before the application rarely reached 190F. Now 193 to 197F is quite normal (in both cases during summer, with the AC and same driving conditions. Winter isn’t an issue).
I haven’t done any mountain pass or similar, just regular driving and easy trails, so I can’t inform on demanding driving conditions and engine load
FWIW, the entire cooling system was rebuild 8.000 miles ago
Do you think a thorough flushing and a new thermostat would do any good?
Cheers!

A thorough flushing will remove the "plug" that you did with the Bars Leaks. Counterproductive IMO.

 

[LuckyOreo]

So I flushed mine out and it started leaking again.

 

[fj80pb]

Thanks for the feedback guys!. I let it be as it is.
Perhaps in the near future I'll try @BILT4ME idea of putting Permatex at the internal part of the hairline crack...but the entire process is a real PITA
Cheers!

 

[TomH]

@Rifleman suggested using Loctite 290 for repairing cracks in the aluminum head. Might be worth a try for the block.

Help with a LX450 oil leaking buy

I suspect this is what @skhochay is referencing. I'm not sure I would consider it 'typical' but not an isolated incident. I had cracks around number 2 and number 5. https://forum.ih8mud.com/threads/external-cracked-cylinder-head-leaking-oil.1128699/#post-12251167...

forum.ih8mud.com

 

[fj80pb]

Thanks @TomH I'll investigate it further....we'll see. Fact is the leak has basically disappeared and, as @BUILT4ME says, the real culprit is inside the block
Rest assured if I test the Loctite 290, I'll report it back to the forum
Cheers!

 

[Pin_Head]

If it ain’t leakin’ don’t fix it.

 

[fj80pb]

Thanks! I'll live it as it is
Cheers!

 

[fj80pb]

Drove her quite a few hours last few days. Saw an small drop of coolant at the crack this morning. Of course it only happens while the engine is cold. When it's heat-soaked the expansion seals it. It's most annoying for my OCD cranium...already thinking on other avenues to deal with the issue...and preparing my wallet
Cheers!

 

[Kernal]

Does it leak less with the vehicle's nose pointing toward the ground?

 

[leonard_nemoy]

Sorry to hijack the thread, but is there any known way to prevent this crack? My rig has not yet developed this crack and I would like to keep it that way.

Thanks

 

[flintknapper]

^^^^^^

To treat the 'OCD' then just forget about the leak. A few drops of coolant after a drive isn't worth fretting about.

 

[BILT4ME]

Sorry to hijack the thread, but is there any known way to prevent this crack? My rig has not yet developed this crack and I would like to keep it that way.

Thanks

Yep!

Don't drive it!