Using coolant.

[MR.T]

Just got back from a trip abroad and although the bike was faultless and returned an average of over 53 mpg. i have noticed the coolant level has gone from the highest level mark to the lowest level mark on the reservoir bottle, probably only about 200ml. I only did just over 1000 miles, is that sort of 'usage' normal. I see no leaks, no oil being used, 2004 model and less than 8000 on the clock.

It was a World War 1 battlefields trip, very interesting, good roads, nice people and thoroughly reccomended to anyone with an interest.

Regards T.

[russh]

Were both readings at the same temperature? I find the coolant expands quite a lot between hot and cold. Around half the distance between the full and empty on the expansion tank.

Another thought, had the bike recently been serviced, which including a coolant change? After changing the coolant on mine it took a while to purge all the air from the system so I had to top the expansion tank up after around 100 miles (well a week)


Really the bike should use no coolant at all.

[fatowl]

My TA has now done about 8,000 miles, and has used no water at all.
I check it now and then (when I remember) but never needs topping up.

[Austin]

my 2001 TA has never used a drop in 55,000 miles

[donkster]

the level will only change is its leaking somewhere, or the head gasket is failing, it doesn't get 'used' like oil might. The real reason for the level change is probably the temp at which you checked the level.

[MR.T]

I took the bike back to the dealer yesterday to have it checked out before the warranty expires.He told me that there is a valve that releases water to ease the pressure. I said i did'nt understand why the bike should have a system to release water that may be needed if on a long journey. He took it into the workshop and when he brought it back out 40 or so minutes later he confirmed that there was no leak, no gasket failure and basically nothing wrong with the bike. He made a note that i had expressed my concern over this matter just in case something materialises.

Anybody heard of this 'valve'?

As i said before the bike has'nt even been getting 'fan' hot.

Regards Trev.

[Orinoco]

Anybody heard of this 'valve'?

Yes, it does exist. When the engine gets hot the coolant expands - you see this as the level change in the expansion tank [hence the name ]. If the tank fills up then water squeezes out through the valve rather than blowing a seal or pipe.

There are only a small number of reasons that coolant might 'disappear' and they have all been mentioned;

Air purging from system after coolant system drained or partly drained. I've done about 200,000 miles on a brace of NTV's and to service the front cylinder you have to remove the radiator to get the rocker cover off. Sometimes after the service the coolant level would drop if the dealer didn't get all the air out after refitting the radiator.

Leaking pipe/gasket or seal

Overheating [as I explained above]

bike hasn't even been getting 'fan' hot

Silly question, but are you making that call because you haven't heard the fan running or because you've been checking the temperature guage?

One of my NTVs had the fan switch fail so the fan never cut in and in traffic it 'wee-ed' coolant onto the street. The biker behind me noticed and pointed it out to me thankfully. Turned out to be a corroded connection that once cleaned up solved that one.

Between services though [with the exception of the incident above] I've never lost coolant in any of my bikes. And the running milage total is pushing 300,000 miles.

[MR.T]

Silly question, but are you making that call because you haven't heard the fan running or because you've been checking the temperature guage?

I have'nt heard the fan come on, the gauge has not gone much above half way and i believe it nearly touches the red before the fan comes on. The fan came on at the garage when he was testing it.

Thanks for all your replies, i guess i'll just have to keep an eye on it and take it back if a fault appears.At least its been registered with them. I've also contacted Honda UK.

Regards T.

[Orinoco]

I was pondering this some more last night, and I remembered that I had a car that used coolant at a slow but regular rate. The dealer couldn't figure that one either. There were no puddles under it after it had been idling for ages and the coolant was good and hot, no obvious leaks or stains on the visible engine bay from anti-freeze - nothing.

In the end the cost of buying anti-freeze was less than the cost of detailed analysis at dealer prices and just kept an eye on it. I suspect that the leak was there, but somewhere it couldn't be seen, like the heat exchanger for the hot air blowers where the water evaporated relatively quickly and thus didn't dribble to the floor.

[The Pheasant]

That's what happened to may last car. I changed it when it got to the point where using the hot air blower filled the car with ethylene glycol-scented steam....