Triumphrat

chrisell · 07-21-2011, 06:41 PM

I've got a weird issue that I'm looking for some advice on. The coolant level in my overflow is going down, but in the oddest fashion.

I can ride all day and the level stays rock-solid. I park the bike up overnight and come out the next morning and the level has gone down.

I thought it might be getting into the oil through a seal or head gasket, so I checked the oil level. If it was getting into there, the oil level would go up and I'd have mayo on the inside of the oil filler cap. Oil cap is clean, and the oil level was actually down a little (my Tig burns oil about 0.2 litres / 1000 miles so that was normal).

I've checked and re-checked for leaks and found none around the pump or any of the hose clamps that I disturbed during my service. The drain plug on the front of the engine is secure and dry as is the bolt on the top right of the radiator. There's never any puddles on the floor.

The attached pic shows my typical problem - yesterday morning, the coolant was at the top of the black tape mark. I rode 350 miles and parked up last night - coolant was at the same level. This morning, as you can see, it's now gone down to the midway point on the tape.

Note the black marker pen line - that was where I topped it up to when I refilled the radiator after doing the water pump which was about 1100 miles ago.

I've not taken the bike for a pressure test yet - that's my last resort - but there's no evidence of a head gasket failure.

The bike runs sweet with 5 bars on the temp gauge, rising to 6 in slow traffic - historically the 'normal' range for my Tig.

This couldn't just be "settling" after the drain and refill could it? If it is, it's taking a bloody long time to get the air pockets out.

History on this: I did the 12k service myself, and as part of that, changed the coolant. That showed up a leak in the water pump with coolant dripping out of the weep hole. Changed the pump, checked all the 'o' rings and all was good. Topped up the coolant using the technique recommended in the service manual. Now I have a gradual loss.

Any advice would be appreciated - I'm at my wits end trying to find *** is going on.

iansoady · 07-25-2011, 11:45 AM

I don't think you have a problem. The level always drops a bit when the engine cools (sucked back into the engine from the expansion tank which is where your marks are). Tigers are notorious for liking a low level, and many people have found that if they overfill the excess is just squirted out of the overflow when the bike heats up. As this is a little pipe exiting near the swinging arm, it's easy to miss.

*Warning: the above applies to Girlies - may or may not apply to others.

chrisell · 07-25-2011, 12:30 PM

Quote:

Originally Posted by iansoady

I don't think you have a problem. The level always drops a bit when the engine cools (sucked back into the engine from the expansion tank which is where your marks are). Tigers are notorious for liking a low level, and many people have found that if they overfill the excess is just squirted out of the overflow when the bike heats up. As this is a little pipe exiting near the swinging arm, it's easy to miss.

*Warning: the above applies to Girlies - may or may not apply to others.

Surely the level would have to get up to the overflow pipe for that to happen though? My level doesn't change much (if at all) with expansion. I would expect the level to go up when riding and down when cooled off.

N5XL · 07-25-2011, 11:08 PM

Chrisell,

A faulty radiator cap comes to mind, but it might be time for a cooling system pressure test.

Look closely in the bottom of your oil pan for water / antifreeze mix the next oil change, which I would do pretty soon. You can have a coolant leak and not have a milky mess.

iansoady · 07-26-2011, 06:58 AM

Quote:

Originally Posted by chrisell

Surely the level would have to get up to the overflow pipe for that to happen though? My level doesn't change much (if at all) with expansion. I would expect the level to go up when riding and down when cooled off.

That's true but the overflow takeoff is on the side of the tank (exactly where depends on model). If you don't top it up does it continue to drop or does it stabilise where it is?

chrisell · 07-26-2011, 09:29 AM

Quote:

Originally Posted by iansoady

That's true but the overflow takeoff is on the side of the tank (exactly where depends on model). If you don't top it up does it continue to drop or does it stabilise where it is?

Hard to say. I topped it up once but that was after the water pump change so the drop could be all the nooks and crannies getting rid of air. I'll keep watching.

cdubya · 07-26-2011, 10:38 AM

I had a very similar issue when my Girlie was new to me last fall. Assumed the worst but ultimately one of the two fittings coming out of the overflow tank was leaking ever so slightly. I believe it was a combo of Slightly higher pressure at running temp but mostly just sloshing around while riding. I replaced the plastic fitting with a copper one and a new rubber bushing between the overflow tank and the fitting.

Belton · 07-30-2011, 10:50 AM

just hope you havn't got a nick in the head gasket like i found out.

head gasket tester, will tell you if you got gases from the exhaust in the cooling system.