89 240sx timing chain tensioner help

[crzycrkr]

I've got an 89 with about 220,000 miles on it that runs great. About a week ago I noticed anti freeze mixing with the oil. The car is still running great so I am unsure if it is the head gasket. My timing chain has been rattling since before I bought the car from a friend. I am assuming the tensioner has been gone for anywhere between 60 and 100 thousand miles. I have read it could eat through a water jacket. Is there any way I can check this without going through everything listed in the service manual for replacing the timing chain. I don't want to go pulling everything apart if this isn't the problem. Any help would be greatly appreciated. Thanks

[180fan]

pull the valve cover and take a gander down the front where the chain goes. If you see alot of slack on the chain, and if you can move the guide around with a screw driver, chances are you're in for it as the chain probably ate through the front cover and went to the cooling passages.

[crzycrkr]

Okay, thanks. What is the timing cover made of? Does it need to be replaced, if this is my problem, or can it be welded up? Thanks again for the help

[180fan]

front cover = aluminum

If it turns out the chain ate through the block, the block is iron.