Cracked Engine Block - reweld??

[Ryan89 Lurker Find all posts View Profile Close Ryan89]

I have a 2003 V6 4L petrol Prado and recently durin a 4wd trip, i was travelling over some rocks and one seems to have pierced my bash plate and put a small (5mm) crack in my engine block. It missed my sump by about 2 inches. I have spoken to some mechanics and they are leaning towards putting a new block in. Obviousley i dont want to spend 10k + on a new block (current block only has 100k on the clock) and was wondering if anybody had heard of a small crack being welded or sealed somehow??

It is leaking oil at about 1 drop every 5 seconds.

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

Its hard to say without with out seeing it but I would be more inclined to drill the crack out, tap a thread and screw a tapered plug in with a suitable sealer. That method will depend on whether there is anything behind the area in question and the thickness and a maybe a few other things.

I have a repair like that in my transfer case, been perfectly sealed for nearly 5 years and 85k or so.

Cheers Andrew

[D4Dforme Senior Member Find all posts View Profile Close D4Dforme]

Excuse my ignorance but are they an alloy or cast iron block?.........Either can be welded depending ofcourse on the location and extent of the crack.

I have welded up a couple of motorbike crank cases that have had similar rock damage and as far as I know they are all still working fine.

Dan

[Ryan89 Lurker Find all posts View Profile Close Ryan89]

Ill try and get some photos of the damage.
It is approx 50mm in front of sump basin and about 5mm long. It is an alloy block.
I do not know what is on the other side of the crack. Hopefully just empty space for the oil.
I am a bit worried about welding it as it may distort the block and create more damage.
The drill and tap idea might work, i will just have to see what is on the other side of the crack.

[Playdoh96 Member Find all posts View Profile Close Playdoh96]

Is it leaking any fluid at all.

[Rusty62 Advanced Member Find all posts View Profile Close Rusty62]

Aluminum welding is relatively easy if you have the right gear, and someone who can use it. Agree to above find the end of the crack, drill and tap a thread and fit a grub screw. This will relieve the stress of the crack and stop it going further.
Can you post a pic of the damage?

[adrian5800 Advanced Member Find all posts View Profile Close adrian5800]

Give us some photos, it's a bit hard to suggest a fix without seeing the damage or the area of the block your talking about.

Welding cast aluminium isn't impossible but you'd need to strip and clean the area thoroughly as any oil in the crack will make it very difficult to seal. As you said you need to be mindful of distortion in the material with a weld repair.

Metal stitching is another option.

[Ryan89 Lurker Find all posts View Profile Close Ryan89]

Engine Oil - Approx 1 drop every few seconds

[Ryan89 Lurker Find all posts View Profile Close Ryan89]

[Ryan89 Lurker Find all posts View Profile Close Ryan89]

[Razorback81 Advanced Member Find all posts View Profile Close Razorback81]

i haven't seen one of those engines out , but don't they have a 2 piece sump steel lower, alloy upper

( that way they can fit the same engine into different cars just changing the lower sump units)

that looks like it is in a sump section as there are too many radiuses to be at the bottom of the block

look a bit higher up to see if the is a horisontal joint above that, if so you can weld it or replace it

[gspy4u Senior Member Find all posts View Profile Close gspy4u]

I'd drain oil, clean it up and try some JB Weld or similar on it to start with. It's not a high pressure point so shouldn't leak.

Have JB Welded my transfer after some experienced Toyota mechanic decided to tighten the filler plug too much and cracked the case. About a 2cm crack that has been JB Welded now for about 2years and doesn't leak a drop. Worth a try to start with nothing to loose and real cheap fix.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Can you drop the sump off without removing anything else? Have a look on the inside and see if you can patch it of drill it out.

[Dabeanian Member Find all posts View Profile Close Dabeanian]

Hi Ryan,
Wife had a leak on camshaft rubber seal where the rocker box goes on the head (vectra) was about to replace the gasget but she needed to use the car ,I gave it a quick wipe , (and it had been leaking for some time) rubber was soft anyway got some kneed it, the two pack putty stuff for radiators and the like , put it over the gasget that I could see and the ali head not really thinking it would hold and she went off, it's been on over 12 months now and not a leak, bit of a story but I would give kneed it a go,good luck. (Good clean with Metho and a bit of a rough up )
Alan.

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

Try to get an aluminium epoxy compound like Devcon. It's made to perform the type of repair you're trying to do. I've used their steel putty before for bedding and thread repair. The stuff works well but is a bit expensive.