i assuming bad?

[sprayzz]

wow just read your link to hydrolock, yeah you would be unlucky if that was to happen to you,major internal damage. i wouldn't have guest coolent would play such a large role over time in your engine. actually i dont think most people would, but i will be now thats for sure

The gasket's break down and crack pretty much anywhere the silicon is impregnated into them, not just on that spot.

No real problems over time except when there is no coolant/corrosion inhibitor or if it's not changed on the recommended regular intervals, if you use plain water the alloy intake will slowly get eaten away and the coolant passages can open up and let coolant go where it's not meant to...... into the valley and to the sump

Worse case scenario into the intake and through the combustion chambers, slow leaks into the combustion chamber won't cause major problems (unless you leave the engine sitting for extended periods of time and the rings rust to the bore), you'll just have to keep topping it up, a massive leak that dumps heaps suddenly can cause what's called hydrolock but you'd have to be really unlucky or completely ignorant to the prior symptoms for this.... Hydrolock - Wikipedia, the free encyclopedia

once an alloy intake is corroded to far it may be unserviceable and need replacing (sometimes it can be welded up but not always)

 

[someguy360]

When the inlet gaskets went on my V8 the coolant got down the valley into the sump and started mixing with oil......keep an eye on your dipstick....if this happens dump the oil and change the gaskets straight away, when coolant gets into the oil you are no longer getting desired lubrication and if it gets bad enough you can severely damage the engine....if the dipstick is milky or the radiator cap/reservoir has oil in it then change the gaskets.

(As mentioned above hydrolock is also a bad one)

It all depends on where the gaskets crack/split as to where the coolant gets sent.

 

[Jxfwsf]

Good point someguy360.

Another symptom is a greyish/brownish sludge on the filler cap, now this one is not always due to an internal coolant leak, if the engine is only run for short trips repeatedly (say to the shops and back 1 km down the road or only to church 500 meters down the road on sunday) the engine won't be getting up to full temp and the moisture that would normally be evaporated and taken care of will just buildup giving false signs.

 

[sprayzz]

sorry for late reply. yeah i always wondered why you would get this brownish sludge and car would still run fine, and wouldn't think anything of it. but would you really know if it is a false sign? is there a way you would know for sure? losing coolant over time maybe?

 

[Jxfwsf]

yes, loosing a noticeable amount, milky oil on the dipstick as suggested above, to test for a head gasket leak there are a few methods, compression test cylinders, state of spark plugs, combustion gas test from the radiator (requires correct equipment) and last simple one is to make an adapter that screws into the spark plug hole and force compressed air into cylinder with the radiator cap off, if you get air coming out of the radiator filler hole then there's a problem.