ZZR 600 coolant overflow. High temp?

[josiahisyoung]

Just got a 93 zzr 600 as a step up from the gpx and first day riding into uni parked it up and there was lots of steam rapidly escaping out the rear of the bike (from under the seat), later i had a bit of a ride and it happened again.
pulled the seat off and there was antifreeze coming out of the overflow hose from the coolant tank and what ever water that was there had now evaporated....

it rode from hamilton to wellington fine the day before so not sure why this is happening now,

opened her up and the coolant tank was empty so filled up and ran the engine for a while giving it some revs, this made it over flow and bubbles came up and pushed water out, also once turned bike off all liquid drained back down the hose out the bottom of coolant tank..... the 2nd time after running it the water started boiling...

Whats wrong with my new bike?!?!?!?!

help please its hard going back to the 250 once used to 600

[NinjaNanna]

Top up both the radiator and the coolant bottle. The radiator cap may take some finding.

Once the system is full again run the bike and keep a close eye on the temperature gauge, it will be a bit of a judgement call but wait and listen for the fan to come on.

Does it? If it does let it go through a couple of cycles where the fan comes on cools the bike down, fans turns off, bike heats up again, fan comes on etc etc.

Take note of the temperature gauge and when the fan comes on. Its a fairly common problem for the temp switch that controls the fan to go out of spec. On my ZX9 once up to temp the switch needed higher and higher temps before it would turn on (read spewing coolant at the lights).

Another common problem is for the radiator caps to fail and not hold the right pressure, if you have a manual it should list what pressure it should open at, get it tested, or search on line for a recommendation as to what weight it should withstand on a set of bathroom scales before it opens.

The other problem could be the thermostat has given up the ghost, to check this one leave the radiator cap off and run the bike up to temperature, once it up to temp you should see the coolant flowing (if the radiator cap is directly on the radiator and not piped off somewhere else)


I'd say the most likely culprit is the fan switch, when you rode it to Wellington it was highway riding so the constant airflow keep the coolant temps down. Riding it to uni is a different kettle of fish, my suspicion is with a poked fan switch your fan didn't come on hence the spewing coolant.

[CookMySock]

opened her up and the coolant tank was empty so filled up and ran the engine for a while giving it some revs, this made it over flow and bubbles came up and pushed water out

The head gasket is fucked. Don't ride it until this is fixed.

For a second opinion, take it to a (very!) close bike shop and get them to pressure test the cooling system.

I would hazard a guess the seller knew this, and threw a can of bars leaks in it just to get you home.

Steve

[NinjaNanna]

The head gasket is fucked.

Scare monger I purposely ommited that diagnosis until the other cheap simple ones were ruled out.

I got the same advice when my ZX9 spewed coolant, "Oh it must be a phucked head gasket pressurising the system!"

No, it was the fan switch, $36 from Repco sorted.

Don't despair josiahisyoung the sky may not be falling just yet! fingers crossed for you.

[NinjaNanna]

Do take heed of DB's advice not to ride it - until you've sorted it one way or the other though, and make sure you fill up the radiator through the cap don't rely on overflow bottle to refill it - that won't work!!!

[CookMySock]

If it blows bubbles and hurfs water out in a gush when you blip the thottle then its the head gasket. Sorry dood.

PLEASE get a second and third opinion. Get the cooling system pressure tested before you do anything. If you catch it early before any harm is done, you might get off lightly with it, but not so if you ride it and get it hot.

Steve

[slimjim]

yup don't run it..or its gona cost alot more if you do.. and the fan nope it aren't this switch...its head gasket has cracked or a crack in the cyclinder.. cause usually its only air that cause's it to bubble and blow out and that much its the gasket hopefully

[NinjaNanna]

guys I see where your coming from - but the guy hasn't said anything about him refilling the radiator properly (all he said is that he topped up the overflow).

if the radiators still full of air couldn't that cause the bubbles just as quickly as a stuffed head gasket?

[stify]

If it blows bubbles and hurfs water out in a gush when you blip the thottle then its the head gasket. .

no not always, blocked radiators a stuck thermostat or even an unbleed cooling system can cause the same to happen

[_STAIN_]

have had this problem before on ZZR600, cap replacement fixed it.

[josiahisyoung]

Thanks guys think ill take ninja's idea first just because i can check all that myself and will see how it goes and report back

[josiahisyoung]

have it another go, the radiator cap seemed fine and i filled it up with water direct to the radiator and to the full mark in the tank at rear of bike,

let it run for a while and gave it some revs like riding would do and eventually it started to heat up quite quickly, got half way up the temp gauge then the level at the overflow tank rose a bit then after some more revving it headed up lots and stared pouring out the top overflow hose,

turn off, no fan goes on and hear a gurgling/hissing sound, not sure if theres a breach in one of the hoses or if its internal....


So maybe its the lack of fan thats letting it all heat up? the thermometer bung?

[CookMySock]

Yep, possibly just a fan.

These sort of things need to be worked through in an methodical fashion, as the potential for stuffups is great.

I'd suggest you get the system pressure tested before you do anything. If that is ok, then simply book it into the shop and ask to diagnose and report to you, then make a decision.

Steve

[NinjaNanna]

Take a paper clip (or similar piece of metal/wire) and short out the terminals of the fan switch to check to see if the fan works.

If the fan runs then that's great - if it doesn't it could mean that the switch is fine but the fan/fuse/wiring is bung.

BTW don't mistake the FAN switch for the temperature sensor. On my ZX9 the fan switch was screwed into the radiator half way down the left hand side. Should have 2 lugs/posts on it with two wires going to it.

do you have a manual for the bike that you could email to us to help guide you?

[NinjaNanna]

So maybe its the lack of fan thats letting it all heat up? the thermometer bung?

probably but remember the fan switch IS a thermometer, as it heats up it turns on as it cools down it turns off.

The temp gauge/light is driven of a different sensor again.

You need to be really, really, really did I say really careful doing these tests that you don't overheat your bike.

Keep an eye on your temp gauge and if you think its getting too hot stop the bloody thing before you do serious damage that will see you selling it for scrap metal.