Small coolant leak turns nasty

[Schiffer]

Ok, so I've been having this small coolant leak lately. It came from under the exhaust side of the engine. I had originally thought it was because of the lower radiator hose, but after inspecting that, it turns out it was fine. So my next guess was the turbo coolant lines. Driving home today, something happened. As I watched the temperature guage, I saw it go up, then back down. It did this a few times. It had done this in the past, and after replacing the thermostat, it was fine. But right as I pulled into my driveway, the temperature rose to right underneath the red zone, and stayed there, and I could hear hissing. I stopped the car, opened the hood, and coolant was spraying somewhere near the turbo. So did I blow the turbo coolant hose? I'm assuming I need to take off the turbo to fix it? Any help is much appreciated. Thanks.

 

[mkIIIman089]

Hissing? You are EXTREMELY low on coolant, and obviously have not been adding enough back in with whatever leak you've got. The hissing you are hearing is steam, because there is no water left to come out at that height in the motor.

This is also why your temp gauge is acting like it is, all thats passing over the sensor is steam, and it reads very hot until enough water settles back down and there is enough to push all the way up through the thermostat housing again.

I am a little stunned that even with an easily audible tracking device you still couldn't locate it. All coolant hoses on that side of the engine are pretty easily visible.

 

[Schiffer]

ok, so yes, im sorry, i can see the coolant hoses, and they look fine, not cracked or blown. and it wasnt just hissing, it was spraying coolant. so where else could it come from. seemed to be between the turbo and the engine. and since i knew there was a leak, i have been keeping a close eye on the coolant, whenever it was cold, and i always added some.

 

[mkIIIman089]

Make sure you're checking the radiator itself too, not just the overflow.

Both turbo coolant lines are right on top, and normally in my experience will have red crust (or whatever color I suppose you're using) around the leak because of the high heat evaporating the water very quickly.

The only other hoses on that side are two 90 degree ones, one on the front, and one on the rear of the head.

 

[Schiffer]

yes, i was adding to the actual radiator. the overflow never lost any.

i did not notice any crust, but on the hose to the turbo from the t-stat housing, its a little bulged on the end closer to the turbo.

 

[Mrbaboon]

Check the block off nipple, at the back of the block on the coolant pipe.

Otherwise I'm going to assume your 90 degree bends (under tstat housing and behind head) are the culprits in this case. I somehow doubt it is the turbo.

 

[IJ.]

Hope it was either cold or running when you added coolant to the Rad.....

 

[Schiffer]

yes, it was cold

 

[IJ.]

Good

 

[mkIIIman089]

I know jj likes to use dyes in his fluids to track down leaks, so thats the next thing I recommend you try if you can't find what the leak.

If you see a hose thats deformed like that it needs to be replaced anyway though.

 

[johnathan1]

Probably one of the turbo coolant lines...there could be a tiny hole in one of them...inspect them VERY closely, with a very bright light, if it were me, I would just replace them if they have unknown mileage on them.

 

[Typhoon]

It may be a welch plug gone bad. I just had a steam experience because this on my freshly re headgasketed engine.:icon_evil
I didn't catch it on the gauge in time, first warning I had was temp gauge at red almost instantly, then mondo smoke from burning coolant. The steam was hot and fast/concentrated enough that it MELTED the PVC insulation tape off the ground wires bolted to teh intake manifold, and engine heat MELTED the spark plug boots to the plugs. I had to destroy some boots/leads to get them off!


Regards, Andrew.

 

[mkIIIman089]

...and this engine still ran OK after all that?

 

[Schiffer]

yesterday, after it cooled down again, i added more water, then started her back up. no, hissing or spraying or anything, but i did notice the straight turbo coolant hose leak a little bit. and coolant was dripping underneath the car both at the rear end of the engine and the front.

ive semi inspected the hoses. the 90 degree hose behind the head seems fine, as does the 90 degree turbo coolant hose. the straight turbo coolant hose had a bulge in it, and was leaking a tiny bit, so ill replace that. havent gotten a close look at the other 90 degree hose. should i just replace them all? kinda tough to get to some of em. should i replace the water pump gasket too?

 

[johnathan1]

Replace every piece of rubber/gasket that has unknown mileage on it...chances are it should be replaced to avoid future problems...

Or you could pressure test your system, and find out exactly where your coolant is leaking from...

 

[Schiffer]

man i wish i had the money to just take the whole engine out and replace everything....

 

[Typhoon]

...and this engine still ran OK after all that?

Yes it did. I have another thread ging which has more detail, and will post my findings as I go along. Looks good so far!
I knew Toyotas were tough but man!

Regards, Andrew.

 

[fiyota]

hmm somebody may have mentioned this but i'll say it just in case... check the thermostat housing gasket (the part in red)... I had this one start leaking on me before.