Like the title says, my coolant boils over, fills the reservoir (now a turkeybaster), but will not get drawn back into radiators.

The overflow is a line to the turkey baster, hose clamped on both ends, and open to atmosphere at the top of the baster (with another hose).

Does this with water, water with water-wetter, and most recently anti-freeze/coolant 50/50 mix. I an finding that i have to constantly be putting lots of coolant in with this warm weather. Recently i went to check it, and it was bone dry. god knows how long i was running with no coolant....

So this would suggest a leak in the system allowing air to get in when the coolant cools down and shrinks in volume right? my radiators are completely thrashed on both sides from years of my abuse but there are no visible leaks.

any thoughts? thanks fellas.

 nsh29, on 18 July 2012 - 04:45 PM, said:

If there is no obvious leaks and no coolant in the oil, I would start by replacing the radiator cap.
If the bike is old, it wouldn't hurt to replace the hoses as well.

Edited by Thumpin_Black_DRZ, 18 July 2012 - 05:17 PM.

If the reservoir is completely empty, radiator topped off, how long does it take for it to draw coolant into the overflow after the bike has been running?

I just dealt with this issue, if you look at my recent threads, and it ended up being a blown head gasket.

+1 headgasket.   summer.  low coolant.  engine overheat causing gasket failure.  now causing extra overheating from high pressure combustion air blowing into cooling system and pushing coolant out.

Either the Radiator Cap or the hose between the Radiator and the Overflow tank is leaking and drawing air in (instead of coolant from the overflow tank) as the cooling system cools down and contracts after the engine is shut off. See this link for an explanation of how an overflow tank works: http://auto.howstuff...ing-system7.htm

Hi,
I would start by doing a compression test then pressure test on the cooling system. These test will give you a good idea on condition of the cooling system and head gasket. Start from there and let us know.
Sammy

 teedubb, on 18 July 2012 - 05:34 PM, said:

starts overflowing as soon as the bike is warm, also with the radiator cap off, it will bubble as soon as i give it any gas, it will really surge upwards.
yea starting to sound like gasket failure.

 slowriding, on 18 July 2012 - 11:26 PM, said:

Yup, same idea, thanks.

 sammy29926, on 19 July 2012 - 06:40 AM, said:

great ideas, i might have the equipment available at my schools workshop, can't really pay for these services though, broke-as-a-joke college grad waiting for my big boy career to start, HR is sitting on their ass and doesnt seem to care that i need to buy bike parts, and more bikes for that matter!!

which begs the next question.... how long can i run with my leaky head gasket and just filling up the radiator all the time. gasket is not so cheap...

is it gonna blow up any second?

 nsh29, on 19 July 2012 - 07:23 AM, said:

There is no way of guessing how long.. an hour a week, next start up.

The gasket is about $20......
http://www.ronayers..../687/SKU/111799

Add oil, filter and coolant to that..

BUT FIRST.. understand what is wrong, if the head gasket is leaking, why?

I would ask a few questions if I may.
Did you add fluid to the overflow so you could watch the expansion contraction?
Did the engine blow off coolant into the overflow, where you observed it and then not suck it back into the engine?
Did the overflow coolant level stay even or rise?
Did you take the radiator cap off and look for liquid level?

thanks

 Ryel, on 19 July 2012 - 10:18 AM, said:

ok so i just hooked up a compression tester. the cylinder head held the max amount of air i could put in it. 80-90 psi, and i could not hear an audible leak anywhere in the system. furthermore, no bubbles were observed in the radiator at all.

im thinking the head gasket is OK now. replaced the radiator cap with a new one, tightened all the hoses (again) waiting for it to cool down and see if it draws it back in.

Didnt draw back in. Still scratching my head.

+1 head gasket. If it is pushing out coolant and not drawing it back in you have a leaking head gasket.
Combustion pressures are much higher than 90 PSI.
Don't just replace the gasket. Inspect and find why it is leaking. They don't just start leaking for no reason.
One of your surfaces is probably not flat anymore.

 carbon_unit, on 19 July 2012 - 06:32 PM, said:

While anything is possible, and this should always be checked..... it's not likely with a DRZ head and cylinder... actually, Ive never seen one warped, nor read of one either.

as stated before, i found the radiators completely empty, and it is likely it overheated and caused problems. I will check and inspect everything when i swap the gasket.

When you take it apart, use a socket and ratchet so you can feel if any of the bolts were not tight. That might help you figure out what went wrong.

ok so updates on my problems.

Got a new head gasket. removed the old one, cleaned the surfaces. put the new one on. torqued to spec, yada yada. here's some pics of my head. thoughts?





i still had the same issue. bubbles coming up into my overflow, losing coolant, and not getting drawn back into the radiators from the overflow.

thinking i screwed up putting the head gasket on, i took it all apart, cleaned everything again, put on a head gasket sealer on both surfaces. reinstalled. same issue. bubbles and coolant loss.

so i hook up a pressure gauge and an air supply, and lo and behold, i have an air leak in my right radiator, just underneath the outlet hose port to the right side radiator. threw some jb weld on and i'll let it cure for the rest of the day!

What a pain in the ass. Hope that fixes it.

Hi,
I am glad you are actually listening the advice given here. If you have done the coolant pressure test after the compression test you would find out about the leak in the coolant system and fixing that would be your first step. Part I do not understand is why were you so eager to open the motor. Comp test came out good with no leaks and that confirms that your top end is sealed and in hood condition. We are here to help and save you time working on your bike. Comp test and coolant pressure test would have taken no more than an hour to accomplish. Opening the top end not once but twice would take you at least 3 hours and cost of head gasket ect. I hope you have learned a lesson and fixing that leak will fix your problem.
Sammy

Hi Sammy,

Because i like doing things the hard/long way

Actually I was eager to open the motor, I have yet to dig into the DRZ's heart, and i learned a lot along the way. I'm no longer scared of the valve train for one.

Edited by nsh29, 30 July 2012 - 07:32 AM.