Waterpump leak, engine overheating

I am on my 3 rd day of this year's trip around Europe. Were doing some spirited ride in Denmark when I suddenly noticed the temp gauge had only 1 bit missing from maximum!

Looked at the coolant reservoir, it was empty. Dang! Got to the first car shop on the road, added coolant to the reservoir ( not much really, only some 300 ml I guess), started the engine, it picked the temp fast up again to near maximum on the meter. Fans come in ok. The water was leaking from the small hole on the waterpump body close to the engine.

Luckily we were close to Odense, so I managed to get to the local Yammy dealer with no bigger drama. They opened it up, removed the pump to pieces, visually evrything is good. The big question really is : WHY OVERHEATING? It was not much coolant missing and the temps outside were only 20 C. Ok, so we decided to change all the seals.

The bike sits at dealer for the moment and waits for parts, meanwhile we check the local beer with my friends.

I would very much appreciate some comments why the heat went so much up? The mechanic also said its very strange and worrying. He could not locate a reason for it.

Forgot to mentiion the bike is 2008 AE, 70 k km, no other engine problems so far

Enn said:

Got to the first car shop on the road, added coolant to the reservoir
The water was leaking from the small hole on the waterpump body close to the engine.

I would very much appreciate some comments why the heat went so much up?

Click to expand...

THose points combined lead to the points that adding to the reservoir doesn't put in the system...at least immediately. Why didn't you add coolant to the radiator through the cap?

The leaking is likely from the weephole that indicates a failing water pump. Did you change that?

Little coolant, it heats ups a lot.

In fact I did also fill up the radiator, but it was also a very tiny amount.

The pump itself looks ok, shaft and bearings are nice and greased, no bits anywhere

I would suspect the engine thermostat.

If it is not opening fully then you will not get enough coolant to flow through the radiator.

The electrical bit appears to be working OK, display is responding to actual temperature and the fans are switching on.

When you start the engine, try 'feeling' the radiator to determine if the thermostat is operating at all.

The leak is most likely a symptom of the higher temperatures................

Troublesome dribbling. I had higher operating temps and more temp fluctuation underway, and plain old overheating at prolonged stops, resulting from air in the system as a result of inept dealership work. Sounds like (with the dribbling) you have something else going on. Following your situation with interest. I'm at 50,000 miles on my 2014. I've figured out that, between daily riding, and plenty of time spent in stop and go traffic in the southern heat, I have to add a minimal amount of coolant a couple of times a year (okay, once a year I have it changed completely).

The mechanic at Yammy did check the radiator, it was hot all over, so the thermostat should be ok.

Right after filling the radiator and the reservoir I rode some 20 mins to the dealership and during that the temps behaved ok. I of course had a gentle and low rev ride.

When we stripped down the plastics, the mechanic pointed at some white stuff on the exhaust close to the dipping pump and said it must have been doing so for some time. I also recall smelling the burning coolant back to last season but didn't see any leaks then and the level was ok

In about an hour I'll be back at dealer, hope they got the spareparts in time. Will report back if it got fixed

Enn said:

In fact I did also fill up the radiator, but it was also a very tiny amount.

Click to expand...

Thanks for the information that wasn't in your initial post.

I tend now towards the air in the line. Covered on the forum many times.

Ok, it looks like the problem got solved. They replaced the seal sets and pump stopped leaking. I rode some 400 km after that on highway with some 150 km/h and the temp kept well in the middle of the meter.

Will post some pics of the original seal when I am back home, it looked somewhat rusty where it should not be.

Thanks to everybody for your input.

Was the radiator cap fully tight? If loose, then pressure would not have built up properly and the boiling point would be much lower.

Brodie

The radiator cap was tight, I had to turn it in 2 sections to get it off

I am curious as to how many miles or Kilometers on the bike.

Never mind caught it in the second post.

Dave

Hmmmmmmmmmmmmmm?

43,495.9 miles seems awful early to be losing a water pump or seals for that matter.

Dave

By the way, the tech said that when he started the engine the coolant started to move immediately in the radiator hole, so he suspected the thermostat was stuck half open. So that is the next thing to check when back home. I wonder if that is a simple job to replace it by myself?

Useful guide here - just scroll down past the CCT guide.............

Some coolant is always flowing through the radiator even when the thermostat is closed.

Coolant flows continuously through the oil cooler (oil/coolant heat exchanger) and the wax motor controlling the high idle speed when the coolant is cold.

Don't know if that flow would be detected with the radiator cap off.

There's not much coolant in the system. Only 2.75 quarts total. If you lose a portion of this small volume you're likely going to see elevated temps.

<blockquote class='ipsBlockquote'data-author="Donal" data-cid="1366490" data-time="1495701754"><p>

Useful guide <a href='https://www.fjrforum.com/forum/index.php?showtopic=137232'>here</a> - just scroll down past the CCT guide.............</p></blockquote>

Thanks very much, very good link. I was riding the German twisties the whole day today and the engin temps were all good. So perhaps I will survive with this thermostat even if it is stuck half open...

At least you are riding again!

Remember that in any coolant recovery system (those with external reservoirs) the ability to retrieve coolant from the reservoir depends on two things:

1. The engine must be heated, then allowed to cool, so as to create a partial vacuum from the cooling/contracting mass of air and coolant within, and
2. There cannot be any leaks of any kind in the cooling system that would allow air to enter with greater ease than the vacuum can draw coolant out of the reservoir

When you have any sort of coolant leak, the recovery system is functionally defeated, and adding coolant to the resrvoir is generally a waste of time and coolant.