Hilux 4x4 Forum

Looks like I have a lil crack:
Passenger side, cylinder 3.

This is the second time the leak has occurred and took 40 km's to look like this.
I have recently flushed and replaced the coolant with Toyota Pink which is evidently coming out and when flushing I made damn sure not to cold shock the motor.
No fluid in the oil.
Motor running very well.
Coolant not dropping drastically by any means(only the small amount leaking out I suppose).
Have yet to check the sparkies but they were all 100% about 250 km's ago.
The only thing I can think of is that the flush cleaned out the crack as it looks reasonably established (the old coolant from PO days was sludgy, and may have contained a sealant??)

What do you guys recommend? Additive, weld, or a Lexus?

Thanks chaps.

I have seen cracks like that where an engine had no antifreeze and it became cold enough for the water to freeze inside the block. Would be interesting to know how it started. As to a solution I am somewhat at a loss. Cast iron is very difficult to weld properly. I'm not sure that there is a permanent solution. It would be interesting to hear what the other guys say.

Tend to agree with Marnus that welding is not an easy option, but it can be done by heating up the block before and while welding and it has to be evenly heated. And then slowly and evenly cooled. It's a mission for a smaller work-piece, so a block will be even more of a challenge. It would also have to be skimmed afterwards.

To top it all there will be no guarantee, so you could go through all that hassle and expense (it won't be cheap) and you could end up with new cracks.

A radiator sealant might well be the answer for the short term, or maybe even longer if you keep adding sealant every time you drain / replace the coolant. I'm not a big fan of using those products, they can block smaller passageways and the radiator itself.

For the longer term you can have the crack "stitched". Don't know if anyone still does that, but in my younger day it was a successful means of repair. What it entails is drilling a hole at the start if the crack, tapping it and fitting a grub screw with thread-lock or a sealer, then drilling an overlapping hole and repeating the process all along the crack past the end. It's a tedious process, especially with a longer crack, but it works. Unfortunately it would would mean that you still have to pull and strip the motor and send the block in to be done. It's not something that you can do easily at home yourself - the shop that does it will probably use a mill to 'drill' and tap the holes.

Another option is to get a 2nd had block that's still in good shape and rebuild the motor, or get a complete 2nd hand motor and rebuild that and then just swop the motors at a convenient time. The latter is probably the way I would go if I was intent on keeping it standard, but if you go for a conversion be aware of all the pitfalls (drive-train not strong enough for the torque of the 'new' motor / incorrect gearing for the 'new' motor / adequate cooling and a whole host of other bits and bobs.
Either way you would have to get a police clearance on the block / motor and have the details updated on the E-Natis system at your local registering authority.

Some food for thought.

I beg to differ here..... I really cannot see the crack, just a coolant mark in that area

That pipe in the picture is a water bypass hose to the circulation that feeds from the thermostat housing if I am correct.

Before saying it is a crack in the block what is the chances that the pipe might have a small pin hole /crack that only expands under pressure causing the mark???

Why do i say this.... First hand experience on the matter of heating and cooling that contracts and expands enough with pressure causing that to happen.

I would say drain all the coolant and remove that pipe and inspect it. Then clean the block nicely in the area and test again if the pipe is not showing anything.



PS I rebuilt my 4Y engine at very large expenses for running hot, and only at the last did we realize the engine and block was never at fault. The Radiator had a hairline crack in a aluminium tube which caused the engine to develop a air lock in the cooling system which caused to run hot.

Check the water pipe's properly and if you are not sure replace the pipes as they are much cheaper than a engine block weld / conversion.

Start with the basics. Also that screw in the block there, clean everything properly and then let the engine warm up and check for leaks. No leaks, then go drive it cause with vibrations it might then show where it comes from.

I've come across those external reticulation pipes leaking before, but then they looked a lot worse than that one. The possibility does however exist that although it looks good from the outside, it has rusted from within to create a pin hole, especially if there has been a prolonged period without antifreeze.

That said, I'm going on Tim's observation from his 'up front and close' perspective ... a pic doesn't always do justice. Then anecdotally this has leaked before - by now a rust hole could be expected to have become enlarged.

What you say is of course logical, Johan, but in this case I'm still leaning towards a cracked block.

Mars, judging by the comprehensive service history I don't really feel that this is a freeze crack. The vehicle spent time in Pretoria, Botswana, Saldanha, Klawer and finally Cape Town in that order. Does it get cold enough in these areas for a freeze to occur? As the vehicle has been serviced at Toyota I would hope that proper antifreeze has been used over the years. When I got it it most definitely had evidence of antifreeze within although not of great concentration. But you never know...

I believe that the crack may have been caused by cold shock. When I stripped the interior I found a lot of clean 'river sand' deep under the carpets. This was also evident in the chassis rails, and the rear diff had water ingress damage. I feel that the PO (who was a bit of a cowboy, but fortunately only owned it for 4 years) possibly plunged the poor thing into a river, and possibly left it there for a bit.

At first I hoped it was the reticulation pipe, but I ran my finger behind it and it came off clean, pipe felt smooth, and it looks like stainless steel?? so I doubt it will be a rust hole. I also thought it may be from that little phillips head screw (what is THAT for) but I cleaned the leak area after the first occurrence and it seems to definitely originate above the screw. If you look carefully at the pics you can see a little black line that I believe is the crack.

I still have to check the sparkies today and then will give it all a good clean and run it standing still whilst keeping an eye on it. Am leaning towards pulling the motor and metal stitching it myself - I don't believe I would need to dismantle it to do the job.

I was joking about the Lexus;)

Has anyone heard of a cracked 22R before??

That screw looks like it's holding a small plate in place - and it looks like there is a 2nd screw lower down on the same little plate. If that is correct then I suspect that someone may have tried to "patch" the crack before, maybe when it just started and was only a cm or so long. Of course I could be wrong, but I don't see that screw on my 22R - and that one looks like the head of a 6mm gutter bolt.

Out of interest, when typing '22R cracked block' into Google a number of pics appear with cracks in this precise area. Those big round plugs are apparently freeze plugs and get pushed out to relieve pressure if the coolant ever freezes, mine are still flush with the block, another reason to believe this isn't freeze related.

Other blocks have a similar screw and inscription in the area:
The Yotatech tjommas seem to believe in JB Weld for a temporary (and often long lasting) surface fix. I may try this temporarily whilst I dry my eyes and decide what to do.

Thanks for looking Andy.

Those look like normal welsh plugs to me and they are usually there as machine tooling ports. However since they are in a water jacket area, it's quite plausible that they are there as "freeze plugs" .

I would imagine they are there primarily to enable removal of the interior voids sand moulding after casting.

Manifold removed and the area around the crack cleaned thoroughly with a wire wheel and acetone:
Very fine crack on the rib:
Application of JB Weld:

From chatting to various auto engineering chaps including Allen, this stuff appears to come very highly recommended and I must say it seems to work!
Sets like diamond when compared to other products (Pratleys Steel etc) and after a round trip of 1000 km's at full tilt it hasn't sprung a leak.
I also made a heat shield to help protect the epoxy from the manifold radiance.
A wire brush, some acetone and a pack of JB Weld all stashed behind the back seat will aid immensely in various repairs when out in the sticks.
In Cape Town JB Weld is available from 307 Lubricants.

Out of interest I am going to leave it as is and see how long it holds for - hopefully it lasts until I decide to pull and rebuild the motor (if ever).

..... Let's hope it holds!