Coolant into engine

[Nikolaidis]

I had my scooter all messed up with coolant inside the engine through the sealings after from an over heat caused from leaking the coolant, i don't know how the coolant escape. The damage cost me lot of money and i wonder if this caused though the modifications or was a bad mechanic work since he repaired the oil leak [ from the small hall under the engine] that i had some time ago. i dont have any mods any more but i want to put them all back. i dont know if this could caused by the tc unit or something.

[waspmike]

Niko,

Likely the head gasket is or was blown which allowed the coolant into the engine but the big question is did the coolant leak out somewhere else before the engine overheated?

Can you see anywhere evidence of coolant leaking outside the engine or around the radiator? Is the top on your coolant reservoir tightly. Is the top on the coolant reservoir or the plastic reservoir split or broken?

If it has been hot there and you ride wide open for long periods that may cause overheating as with after market exhaust you may be running with Air Fuel ratio too low at full throttle.

It is not your variator or the TC that caused the problem.

[Nikolaidis]

Niko,

Likely the head gasket is or was blown which allowed the coolant into the engine but the big question is did the coolant leak out somewhere else before the engine overheated?

Can you see anywhere evidence of coolant leaking outside the engine or around the radiator? Is the top on your coolant reservoir tightly. Is the top on the coolant reservoir or the plastic reservoir split or broken?

If it has been hot there and you ride wide open for long periods that may cause overheating as with after market exhaust you may be running with Air Fuel ratio too low at full throttle.

It is not your variator or the TC that caused the problem.

I think the coolant had leak before the engine got very hot cause it went radicaly more and more hot. i also added some coolant. After the temperature went almost the last line. the box of the coolant reservoir is ok no break over there and i dont think after the overheating situation tha there was a leak from the reservoir instead i think, is just a thought, that maybe after the re-installation of the engine [ from my first problem-oil leak] the mechanic did not close the tubes very well.

[robber57]

Only the big bore kit from malossi is know to give sometimes overheating and/or a leaking headgasket.
The sh is well capable of dealing with heat and another exhaust or O2 controller (which actually makes it run cooler) is of to small influence to give problems.

It is fairly safe to say that something else went wrong, if you look at the abuse i have given my sh during vacation in france; full throttle with passenger,trailer,topcase full and 2 sidecases full going 60-70 km/h climbing uphill in killing heat(35-40 C) and no problem.


There is a flaw in the service manual for previous models 2005-2009, the service manual does not mention the bleeding screw on top of the thermostat housing, if you dont use it to bleed air from the system you dont get all the air out.
I would not be surprised if this is your problem, however it will be difficult to prove.

You could test the mechanic with a question on how he did bleed the system ?(before telling him about the bleed screw).
If he does not mention the bleed screw you have a stick to beat him with.

[Nikolaidis]

Only the big bore kit from malossi is know to give sometimes overheating and/or a leaking headgasket.
The sh is well capable of dealing with heat and another exhaust or O2 controller (which actually makes it run cooler) is of to small influence to give problems.

It is fairly safe to say that something else went wrong, if you look at the abuse i have given my sh during vacation in france; full throttle with passenger,trailer,topcase full and 2 sidecases full going 60-70 km/h climbing uphill in killing heat(35-40 C) and no problem.


There is a flaw in the service manual for previous models 2005-2009, the service manual does not mention the bleeding screw on top of the thermostat housing, if you dont use it to bleed air from the system you dont get all the air out.
I would not be surprised if this is your problem, however it will be difficult to prove.

You could test the mechanic with a question on how he did bleed the system ?(before telling him about the bleed screw).
If he does not mention the bleed screw you have a stick to beat him with.

So i need to know if he bleed the air out for a start. now it runs with out problems.
is this something that has to be done regularly in a part of time and can i do it by my self to bleed out the air and is it possible the scooter run ok with air inside without notice if there is any problem?

[robber57]

Yes, ask the mechanic how he did it and you will know if he used the bleed-screw.

You only need to bleed the system once when you have replaced the coolant and/or drained it, once it is filled and the air bled out it will stay ok,there is no need to repeat over time.

Bleeding is simple, fill up the coolant, start the engine and open the screw until it gives no more bubbles, rev the engine a little and tilt the scooter to the right and left and bleed again with the screw, if youre paranoia you may repeat these steps a few times until you are certain there are no more bubble coming out of the bleed screw,done.

If you dont bleed the system properly you will not get any warning besides the engine possible running hot.

[Nikolaidis]

If you dont bleed the system properly you will not get any warning besides the engine possible running hot.

Runing the engine in trafic 1 line above the midle u think is fine? Its now running half line down the midle.
With my mods get a bit hotter.

[breaknwind]

In the morning going to work at 70deg. f. my gauge is on the first line. Going home at 90deg. f. the gauge is just under the second (middle) line. My fan rarely turns on

[robber57]

It is for me hard to interpret how you are using your bike, some explanation on the thermostat;

The thermostat regulates the water temperature, i have never taken the effort to actually measure the temperature a sh is running on but its about 85 degrees celcius.
That means that in mild outside temperatures , probably up to 20-25 C, it will open more or less to achieve 85 C in the cooling circuit, if little heat is produced it will only open a little bit,if you run full throttle and load it will open up more.
This equals to about the first white line on the temperature gauge (about 1/4 scale).

When you drive in outside temperatures above +/- 20-25 C the thermostat will be completely open so the cooling circuit will run on its maximum , if outside temperatures become higher the thermostat cannot open up more and so coolant temperature will rise above 85 C.
In hot ambient temperatures (30C and above) this may lead to a "normal" working temperature going up to 1/2 to 3/4 scale on the gauge, this may be up to 100 C or higher but the radiator has a "pressure cap" that raises pressure over 1 bar/atm so the coolant will not boil at 100 C but probably at +120-130 C.
This means that if you open the radiator cap when the engine is running hot (but not on the red line) you relieve the pressure and suddenly the coolant will go in to steam/boil burning your face of, never open a hot radiator.

When it really gets in to trouble this may go up to almost the red line and i suppose if you drive slow enough (little wind from driving going through the radiator) and are a lot on full throttle constantly accelerating and braking it may end up coming to the boil and overcook although this is rare.

What may happen: i have heard and experienced myself that if the coolant tank is filled to the "MAX" line and the scooter is driven in high heat it may overflow a bit and leak a bit of coolant, this seems to be a design flaw where the free space above the coolant is not sufficient to accommodate all the expending coolant and some will overflow, filling the container to the "MIN" level will solve that problem.
If you refill it up to the "max" line the next time it will overflow again.
I had this in france coming from the highway in to a gas station, the gauge never reached the red line but coolant was dripping from the front , i did not refill it but just kept on driving and i never saw the problem again, next day when i checked coolant level it was up to the "MIN" line.

So only when it reaches the red line the engine gets in to real trouble, anything lower will do fine although these hot running temperatures will have its effect on engine lifespan.
Make sure your radiator is clean, carefully use compressed air to clean it,do not bent the radiator fins and if some are bent carefully open them up with a small screwdriver, keep coolant fresh, replace every 2 years.

Last but not the least: refresh your engine oil as often as your wallet can bare, old oil contributes to higher temperatures and if your always driving in + 10C you may step up to 10W40 which will also benefit cooling temperature.