Combo engine problems

daniel.b · Post by **daniel.b** » Thu Dec 16, 2010 8:40 pm

Zelandeth wrote:What Gadget said!

Just make sure that the metal strap which supplies power to them is kept well away from any earthed metalwork (or better, pull the relay for it) if the ignition's turned on. Otherwise you'll at the very best get a terrifying shower of sparks when it shorts out.

I found that out while doing a compression test on an old Astramax - scared the living daylights out of me.

I normally disconnect the battery before doing anything under the bonnet, a close call with a air bag sensor while at work experience, nearly a very expensive headlight bulb change.

daniel.b · Post by **daniel.b** » Fri Dec 17, 2010 5:00 pm

Didn't even get to pull a glow plug. I just pulled the dipstick out and it shot a pressurised jet of oil and water out

. Then took the lid off the air box, same story full of oil and water.
New engine it is then, just need to find one now.
thanks again
dan

GadgetBoy · Post by **GadgetBoy** » Fri Dec 17, 2010 5:02 pm

And a bottle of anti-freeze.

daniel.b · Post by **daniel.b** » Mon Jan 10, 2011 6:56 pm

Currently stripping the engine down before the new one arrives. Head off, cylinders are full, sump was full of oil/water mix most of coolant hoses contained just coolant.
My Q is...
Should I see any signs of damage, i.e cracks.
Also theres a few "plugs" they look like core plugs but smaller in the head. what are these for?
Thanks again,
Daniel.b

EDIT: Is the damage likely to be inside the head and therefore un-see-able?

Zelandeth · Post by **Zelandeth** » Wed Jan 12, 2011 6:35 pm

Whether you'll see any damage will depend as you suggest on A: Where the damage is, and B: What failed.

Water is lazy, just like electricity. It'll take the path of least resistance when under enough pressure. The question though is where that was!

I'm assuming that the head is aluminium, and the block cast iron - in which case when the temperature dropped, the head would cool faster as it's got less thermal mass than the block - so the water in there would have frozen first I'd have thought.

It's quite possible that the only thing which actually physically failed was the head gasket. It may also have warped the head rather than actually puncturing anything. I'd have thought though that the head/block joint would be at least one of the weakest points though.

I imagine the "mini core plugs" are just a result of the casting process - they may also serve a purpose for sensors/pipe tappings or something on another version of the engine.

I've only ever had one freezeup (well, so far!), and that was only a couple of days after I got the car before I'd had a chance to change the coolant - the only casualty of that was the heater matrix, so I counted myself lucky!

Don't know whether there's any way to check the head short of sticking a new gasket in and bolting things back together. If you've a bit of spare time and the necessary bits, might be an interesting experiment.