Identifying a coolant leak

[cherrypicker7]

I have a 05 WR450, that upon startup gives off an odor which suggests anifreeze is burning. I don't seem to be loosing coolant or very much, like I haven't had to add any to the recovery tank, and the suspected leak isn't external. So I was assuming a possible head gasket leak. The local autoparts place had a special on a coolant system tester, a mityvac unit specifically designed for bikes and likely snowmobiles, so picked one up and went through the test last evening. The system was pressurized to 15 psi, as the cap is a 1.1 which equates to 15.6 psi, and I observed a very slow pressure drop, over a 2 minute period. The bike runs great, starts easily, so I am somewhat reluctant to tear into it to check for warpage or gasket leaks. I was wondering if it was possible that the internal water pump seal could be the culprit, or is there some other avenue that the coolant could be entering the combution chamber????

[MANIAC998]

I just had the same scenario, and in my case, one of the hose clamps was slightly seeping. Are you sure your pressure drop wasn't coming thru the adapter used to pressurize the system? I would definately wait on tearing into the engine on such a slow pressure drop. How does the bike run? Any moisture entering into your engine oil? Check all of these things first. Maniac

[cherrypicker7]

I just had the same scenario, and in my case, one of the hose clamps was slightly seeping. Are you sure your pressure drop wasn't coming thru the adapter used to pressurize the system? I would definately wait on tearing into the engine on such a slow pressure drop. How does the bike run? Any moisture entering into your engine oil? Check all of these things first. Maniac

Upon reviewing the check procedure in the manual, I see where the pressure check of the cooling system requires a pressure of 25.6 psi and I had only been pressurizing to 15 psi, and then only for 10 sec? Whatever, when I ran it up to that setting it seemed to hold it. The MityVac had an adapter for the rad cap so I checked that at 15 psi per manual, and pressure dropped immediately, this didn't account for the odor unless some coolant was leaking somewhere it would land on something hot. Anyway, I also have an 07 WR250 and checked the cap on it and same thing, so I am beginning to believe the cap checker on the Mityvac is faulty. Might take both caps into local, well not so local dealer and have them confirm. I'm not likely to tear into it regardless until snow flies and then only because I'm not sure when and if this bike has ever had any engine work done. It's time for an oil change, but in the past I haven't seen any indication that there was coolant in the oil. Will look more diligently this time around. Thanks, Ron