Worst cooling system find EVER

[erict716]

So I in the process of taking my carbs off to give them a good cleaning. Keep in mind I picked up this bike mid last year and after buying a house it sat while I played the "what does the house have in store for me" game which included a leaky roof and blown hot water heater and a few other fun and expensive shenanigans.
Digressing, I take the tank off and notice that the overflow tank for the cooling system doesnt have any hoses actually connected to the cap of it . My heart started beating faster. I take the overflow tank out and dump whatever is actually in it into a bottle (see picture below). Curious I look at the radiator cover and run my hand down the overflow hose, to find it firmly capped with a bolt jammed into the end of it. I then take the cap off the radiator (see picture below of what I found lurking under there).

Needless to say I am stressing a bit on what this would cause and how much it will cost. Anyone have any idea what the hell would cause that crud? Also What are the steps to flush the entire cooling system and start a new.

Thanks!

[greg737]

Looks like a concentrated oil+antifreeze mixture (with a bit of cooling system corrosion thrown in for good measure).   If my interpretation is correct and the sludge does contain engine oil it suggests that the bike has a problem at one of the two places where the oil and coolant come into close proximity: either at the water pump (bad o-ring seals and/or water pump bearings) or a failure of the gaskets at the engine cylinder water jacket.

[erict716]

Would this leak also carry over into the oil, causing the oil to also have antifreeze in it.
I ask that because when I changed the oil it didn't appear to be contaminated.

Is there a way to check for leaks other than taking the water pump apart. 
I am hoping its not the cold water jacket because I believe that entails spliting the engine in half.

[greg737]

As far as contamination of the oil is concerned the answer is "it depends".  I've seen situations where both the oil and the coolant were cross-contaminated (a situation where you drain the oil and it comes out of the crankcase looking like dirty mayonaise) and I've seen a situation where only the coolant was contaminated.  I think the result you get when a leak like this occurs is very specific to where and how the leaking/contamination is occurring.  A complete failure of a rubber seal or bearings in the water pump or an engine gasket failure (due, for example, to something like cylinder head warp from being overheated badly) will almost certainly probably result in both oil and coolant cross-contamination. 

But the leaking could be an intermittent condition that is dependent on pressure differentials that develop within the engine during operation or that only happens when the engine heats up or cools off.  In this scenario you might only get coolant contamination rather than cross-contamination of both (my brother's Nissan Maxima did this when the water pump seals hardened up due to age).

Your Bandit is 20 years old now.  The rubber seals in the water pump have got to be pretty hard.

[erict716]

I'm assuming that plugging the overflow hose with a bolt and hose clamp doesn't help the issue and introduce rust from the bolt into the loop.


Does anyone have a picture of where BOTH hose on the coolant overflow go. I looked in theanual and parts fiche and it shows one hose from cap to tank but the second hose is cut off on the drawing.