Isuzu Repair: Draining anti-freeze from cynldr head 2000 Trooper, silicone sealant, combustion chamber

Question
I have a 2000 Trooper (85,000 miles) with a cracked cylinder head, and subsequently, chronic mis-fires (it has LOADS of other problems as well). Our mechanic said there is anti-freeze that got into the head and that is a lot of the problem. He drained it but to fix the crack it was $$$$$$$. My husband is going to fix it with Blue Lightening (?) but anti-freeze is back in the head. What is the best way to get it out? Thanks!

Answer
Hello, there. Sorry for the delay in answering your question (I've been gone for the holidays). Anyway, you say that your cylinder head is cracked? Ouch. Well honestly, in that case you are better off getting a new cylinder head. You see, the cylinder head is put under such extreme pressures and temperatures that it is really important that the cylinder head be completely solid. I'm guessing that the "Blue Lightning" you are referring to is a silicone sealant, which will not repair a cracked head because it can't hold up to those kinds of pressure. If the crack isn't that bad, then you could possibly weld it (probably why the mechanic gave you such a high price) but even then there is no guarantee it would hold. I looked on Ebay and found a pair of used cylinder heads in good condition for $180. Here is the address:      http://cgi.ebay.com/ebaymotors/3-2L-3-5L-ISUZU-CYLINDER-HEADS-COMPLETE-NICE_W0QQ...

Now, as far as draining the antifreeze, it depends on where that crack is. Antifreeze is SUPPOSED to run through the head to keep it from overheating, but it is supposed to stay in the coolant paths. Since your head is cracked, the coolant could be leaking into either the oil, the valve covers, or into the combustion chamber itself, all of which could result in further damage. If the antifreeze is in the oil, then the only way to get that out is to drain the oil like you normally would. Then you really should replace the oil filter to make sure the oil isn't contaminated. If the antifreeze is in the combustion chamber... then you've got to take your heads completely off. But since the head is cracked, its got to come off anyway... like i said, its best the replace the heads. A good used one will be cheap and you could have it rebuilt before you install it so that it is just like new.

If you need to know anything else, feel free to ask me.

Best Regards (and good luck!)

Travis