Boiling coolant

Nessus · Post by **Nessus** » Mon Feb 19, 2007 11:54 am

Here's the problem...

My brother has bought himself a GSXR1000 ex-superstock race bike. The engine sounds good, and it pulls really well.
However........

When the engine starts to heat up, coolant comes spewing out of the expansion tank. Turn the engine off, let it cool, and the coolant retreats back into the engine. The engine temp never gets any higher than about 70 degrees, though

Due to the fact that the thermostat and radiator aren't getting too hot, but the engine block obviously is, my initial thought is that the water pump may have gone, or there may be a blockage in the coolant system (there was some crap in the coolant system, apparently). The head gasket is another possibility, but the water seems to be coming out far too violently for that to be a realistic cause of the problem - the oil seems to be free of contamination, as well.

Anyone got any other thoughts???

Shrek · Post by **Shrek** » Mon Feb 19, 2007 12:01 pm

Just sounds like an air lock or faulty thermostat, try it with thermostat out

Nessus · Post by **Nessus** » Mon Feb 19, 2007 12:52 pm

The thermostat was on the list of things to check, but I'd not thought about an air lock, cheers

IZINBARD · Post by **IZINBARD** » Mon Feb 19, 2007 1:23 pm

Head gasket

Shrek · Post by **Shrek** » Mon Feb 19, 2007 2:20 pm

If it was the head gasket the Radiator would still be heating up... I would have thought

Post by **Gazza** » Mon Feb 19, 2007 3:03 pm

It wouldn't just be coolant coming out of the expansion tank either.

Nessus · Post by **Nessus** » Mon Feb 19, 2007 3:16 pm

Shrek wrote:If it was the head gasket the Radiator would still be heating up... I would have thought

The radiator is getting slightly warm, but nowhwere near as hot as the engine block itself, which is what led me to think that it could be the water pump or a blockage in the coolant system, although the thermostat is an option

IZINBARD · Post by **IZINBARD** » Mon Feb 19, 2007 3:46 pm

The thermostat is certainly the easiest option and cheapest fix to try first.

coullstar · Post by **coullstar** » Mon Feb 19, 2007 4:23 pm

My friend had the same on his 1000. Turned out to be a dodgy thermostat.

metallninja · Post by **metallninja** » Mon Feb 19, 2007 4:32 pm

I`d also go for thermostat first, blocked radiator second.

Try the old thermostat in a jar of hot water (even better in a kettle with a thermometer).

stu

Post by **Zathos** » Mon Feb 19, 2007 4:50 pm

metallninja wrote:Try the old thermostat in a jar of hot water (even better in a kettle with a thermometer).

Just remember to rinse off the antifreeze first

IZINBARD · Post by **IZINBARD** » Mon Feb 19, 2007 5:12 pm

f*ck all that, just change the bloody thing.

Nessus · Post by **Nessus** » Mon Feb 19, 2007 5:43 pm

IZINBARD wrote:f*ck all that, just change the bloody thing.

I think that's what he's doing (plus a lot of finger crossing and praying!)

metallninja · Post by **metallninja** » Mon Feb 19, 2007 6:21 pm

Nessus wrote:
IZINBARD wrote:f*ck all that, just change the bloody thing.
I think that's what he's doing (plus a lot of finger crossing and praying!)

Ah, the Shirl@ws technique.

Nessus · Post by **Nessus** » Mon Feb 19, 2007 10:47 pm

metallninja wrote:Ah, the Shirl@ws technique.

Well funnily enough it was an ex-shoelace mechanic who helped him fix it this evening :I can't believe it's not butter!

The cause of the problem is a real bobby dazzler......
There are 2 pipes going into the top of the radiator - one from the thermostat, the other is the return from the radiator cap to the expansion tank (used to stop the system from over pressuring).
Whatever eejit had last re-connected the coolant hoses had routed the exit from the thermostat straight to the expansion tank (instead of the radiator), so that as soon as the coolant got hot enough to open the thermostat, it was all directed staight back into the expansion tank. Easily fixed

If I were him, I'd be checking every inch of that bike with a fine tooth comb before it goes anywhere near a racetrack.....

dale123 · Post by **dale123** » Tue Feb 20, 2007 8:45 am

So tell us what Eejit he bought it off. Need material for abuse. :I can't believe it's not butter!

Wheres he racing?

Nessus · Post by **Nessus** » Tue Feb 20, 2007 10:39 am

Sorry Dale, it wasn't a racer he bought it off. It was an ex race bike that someone had used it as a trackday bike for a couple of years before selling it.

He's not racing this year, I reckon it'll be next year before he starts. The Scottish Sport Production Championship looks like what he wants to do.

dale123 · Post by **dale123** » Tue Feb 20, 2007 11:16 am

Cool. Good for him.

Does he know that the license structure has changed so that you cant start off on the thous now? Novices are restricted to 600cc or below.

Nessus · Post by **Nessus** » Tue Feb 20, 2007 11:24 am

I don't think he does, but he'll soon find out

It doesn't really matter, as the Gixxer he's bought is too old to race, anyway. It was just for getting as much track experience as he could this year. He'll just need to change it for a 600 when the time comes, I suppose.