Missing coolant

T

thaxman

Mazda5 the Anti-Van
OK all,
I have not had to come to the forum in some time asking for help, so here it is:

I have been forced to add to the coolant reservoir rather frequently the last several months. We got our Odyssey up and running and have been using it more b/c the Mazda's pitiful A/C + black interior + Phantom Blue paint + Arizona + summer makes for one hot ride, so I cannot be reliable in the intervals more than to say its only been a few thousand miles and I have had to add at least a quart multiple times.
It doesn't appear to be overflowing, so I believe its either leaking somewhere or being ingested, but don't know which. I replaced the T-stat with an aftermarket many years ago, but that is all the work I have done to the cooling system. (88K presently). I am mostly worried its going into the block somewhere. Anyone been through this?
 
A couple of places to check for coolant loss on the 5 is at the water pump weep hole and the hose block at the back of the cylinder head. It's also possible the t-stat gasket may be leaking. An inspection mirror would be required to check all of these. Check the water pump by sticking the mirror under the pulley. The hose block is a little harder to see with all the hoses and wiring in the way but if it's leaking you may see dried coolant on the top of the transmission. In your climate I'd also be checking at the plastic radiator tank seals.
 
Coolant has such a distinct smell to me, I find it pretty easy to sniff around the engine bay to find a leak if there is one.

My last protege5 was doing this, and I could not find any leak. Finally, after looking everywhere for a leak, I pulled the spark plugs and examined them, and I had a #2 plug that had coolant deposits on it. I put a bore-scope down into each piston, and each of the cylinders and piston tops were black and old looking, except for #2 again, which looked shiny and new because it had been steam cleaned by the coolant burning off in the #2 cylinder.

Trying to add to the knowledge base, but also hoping that this is not the issue for you....
 
Go to box store and buy a bottle of coolant dye and a fluorescence black light. Wait for dusk/night, pour dye into radiator, warm car up and observer engine with black light. At temp, go for a ‘quick’ spin around the block (you don’t want to drive too long or fast b/c air flow can catch and splatter it all over) and observe with black light. You can also try a compression test on each cycler. If there’s a leak, the air pressure would want to escape and bubble out of the radiator, assuming there's no leak.


Why do I get a sense of deja vu in this post.
 
loosenut said:
A couple of places to check for coolant loss on the 5 is at the water pump weep hole and the hose block at the back of the cylinder head. It's also possible the t-stat gasket may be leaking. An inspection mirror would be required to check all of these. Check the water pump by sticking the mirror under the pulley. The hose block is a little harder to see with all the hoses and wiring in the way but if it's leaking you may see dried coolant on the top of the transmission. In your climate I'd also be checking at the plastic radiator tank seals.
Click to expand...

I am hoping its not the radiator. Smell is on the T-stat side of the block after a drive, so I will be checking the water pump, the upper hose, heater hoses and all the clamps. Then its on to the radiator. Prob is, radiators are really hard to detect until the crack blows big enough to start streaming coolant. Then its too late and you can only hope you aren't on a road trip when it happens.

I read recently that someone replaced all their OE hose clamps with regular screw clamps b/c the OE clamps don't maintain pressure. I can only hope that is is, although since I only read this 1X, IDK if its really an issue. Of course, seems very few people have feedback, so I think that there is not a regularly problematic issue with the cooling system on these, which is good to hear.
 
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If you are worried on an older car, can just replace the radiator and all cooling houses and clamps as preventative.
OEM clamps are generally better as they don't create pressure points under the screw and apply equal pressure all the way around.
Perhaps just the age is getting to them.
aftermarket radiators and hoses are no terribly expensive.

You can also get a https://www.amazon.com/dp/ (commissions earned)from Amazon for cheap just to test and make coolant is not leaking into the cylinders or something.
 
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OK, so we have been not really driving it since I was trying to empty the gas tank on the Odyssey, but today I took it, and after a 9 mi round trip w/1 hour stop, I got out the flashlight and did some looking. Coolant odor is only coming from the front right between the radiator and the t-stat. No visible leakage. Tried to look around the belt area but I couldn't see anything there either. But no odor toward the rear of the block, so I think its coming from the hoses, housing or right side of the radiator. Don't think I am losing coolant into the block, b/c I haven't really seen a reservoir level change, so IDK, I think I will buy some hoses as the first level fix. The car was registered in 2005, so its been on the road 11 years and <90K mi, so I guess rubber failure is probably likely. Hope its this easy.
 
If you have smell but no leak it is probably radiator.
As it gets hot it would evaporate the water so would be no leakage unlike when a hose develops a hole.
And also a small crack in the radiator plastic would only leak when car is driving as that is when most pressure is present.
 
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