Overheating FJR

[dgrenon]

well not really overheating.... okay bear with me this is a long story......I bought my 2005 FJR used about 5 monthes ago. The day i bought it a rock hit my radiator causing a leak. I poured a small amount of stopleak....the powdered kind into my radiator to stop the leak, which it did. when i got home I took the radiator to get and got it repaired. well when it would heat up it would spew coolant out the overflow tube attached to the overflow tank, and when it cooled off no coolant showed in the overflow tank. This problem was diagnosed as a bad radiator cap. Replaced it. No go. Then I replaced the thermostat. Same damn thing. I just installed a brand new radiator. yep you guessed it same thing. Now I love this bike but I don't think I should have to carry around a gallon of coolant with me at all times. Has anyone heard of such a problems. i wanted to diagnose the problem as best i could before bringing it to a dealership. Also it never has got above four bars it gets to 4, the fan kicks on and cools it to 3. Any ideas would be greatly appreciated! Thanks in advance!

 

[Windjammer]

If I understand correctly, the bike has never overheated, despite coolant loss resulting in an empty overflow tank. So when the coolant spews, and the overflow tank empties, does your radiator start to empty out too or is it always full when you pull the cap? I'm wondering if a vent hose is pinched off or misrouted, or if there is some other venting issue that is causing normal radiator overflow to pressurize the overflow tank.

 

[Ramblin Man]

Well, I don't know, but pouring a half cup of powdered aluminum into an aluminum engine with an aluminum radiator doesn't sound like a good thing, but that's just me.

If it were me though, I would be raising the fuel tank and checking lines that go to the throttle bodies and doing the whole flush and refill thing. The water pump is the lowest piont in the cooling system and who knows how much of that suff sank and attached itself to the pump.

 

[Thug]

Ditto above Complete flush.

 

[dgrenon]

Thannks for the replies. I probably did 5 warchild "********".

 

[radman]

You're not gonna like this. You have a bad headgasket or crack in the block or head. Combustion pressures are overpressurizing the cooling system, hence the pushing out of coolant. You, or the previous owner, did overheat the motor, warping the head, or you introduced cold water to a hot motor, same result. This can be verified by:

1) put a pressure tester on the radiator (replaces the cap) , start the engine, and watch for pressure rise. Anything beyond 10-14 lbs when 3-4 bars showing indicates outside pressure influence.

2) Remove the rad cap, and carefully hold the probe of a 5 gas anylizer at the radiator opening. Any combustion product will show on the screen. Use caution-coolant intrusion into the probe will wreck it. There are also products at parts stores that when added to coolant will show the combustion byproducts present.

I fear expensive days ahead, sorry to say it, but your motor is exhibiting classic signs of what I talked about.

 

[BrunDog]

Perhaps that stop leak (not a good idea IMHO) obstructed something??

-BD

 

[dgrenon]

Trust me guys i have beat myself up over putting any stop leak crap in it was just to make it home and was flushed, blown, drained, and reflushed as soon as i got it home. i have heard the blown head gasket theory before and was worried someone would say that.Well I guess it's time to find a pressure tester that will fit the fjr radiator cap........

 

[jestal]

del

 

[ohiofjr]

if the head gasket is leaking burnt coolant will be evident on the plug in the offending cylinder as a whiteish fluffy looking deposit. so the cheapest thing to do is pull the plugs.

 

[Pepperell]

If you're doing a pressure test, you might want to make sure the crankcase is vented, just in case of some ring blowby. I'm not a mechanic, nor do I play one on tv, so I'm not sure how likely this is.

Pepperell

 

[jestal]

del

 

[dgrenon]

Thank you so much for the in depth respones. your replies have confirmed what i feared. at any rate I am going to try to get the bike in to a dealer this week to see if thay can have a look at it. I will let you guys know what happens.

 

[jestal]

del

 

[Pepperell]

The crankcase is already vented. That is what the PCV system does. There is normally combustion blowby past the rings and such in normal operation so the crankcase of any engine is designed to accomodate that. There is no need to "vent" the crankcase doing a pressure check as described. Combustion pressures reach 1400 PSI or better, albeit for a very brief interval, so the 100 PSI is relatively low for any pressure the system is designed to handle even holding it constant. I have seen cylinder pressure checks done using nitrogen at 700 and 1000 PSI and the PCV system will handling the venting of any blowby fine. You are looking for leakage/bubbles in the cooling system so worry about that.

...I'm definitely not on TV...

 

[jestal]

del