WHY do i keep losing my coolant? '90 4Runner

[4R_in_Uzb]

I don't understand why I keep losing the coolant. I had a bad head gasket about four months ago and I had it replaced, but now about every month I have to add more coolant since it get's low. The engine seems to work fine and I don't see any leaks.

The temp gauge dosn't go into red at all. I do think there's a little more steam/smoke coming out BUT I'm not sure it is wrong, it is cold and I look around and some cars have the same amount of that, but some don't.

Can anyone think what might be my problem?

Thanks!
1990 4Runner, 3VZE, V6

 

[josh220]

When you say that you haven't noticed any leaks, you haven't seen any small puddles underneath your truck, especially when it was really cold the night before? It might just be a very small leak, and you just might not be noticing it.

 

[snhrph]

It is obvious, but I'll ask anyway - does your engine oil look normal?

 

[Jaebster]

I don't understand why I keep losing the coolant. I had a bad head gasket about four months ago and I had it replaced, but now about every month I have to add more coolant since it get's low. The engine seems to work fine and I don't see any leaks.

The temp gauge dosn't go into red at all. I do think there's a little more steam/smoke coming out BUT I'm not sure it is wrong, it is cold and I look around and some cars have the same amount of that, but some don't.

Can anyone think what might be my problem?

Thanks!
1990 4Runner, 3VZE, V6

I think the head gaskets may not have a good seal. Sounds to me that coolant is leaking in to your engine and being burned off. That is the reason for the white smoke. There shouldn't be any white smoke coming out of your 4R (unless the weather is really cold and you had just started up your engine). After driving if around for 10 minutes, all the condensation should be burned off and there shouldn't be any smoke coming out of the exhaust.
I could be wrong though so I hope someone else can chime in. I wonder if there is a compression test to check if there actually is a leak or not.

 

[4R_in_Uzb]

Thanks guys,

I'll check the compression.

About the leaks, I am almost definitelly sure there is no leaks.. And the oil level seems fine. The oil itself also looks ok, no foam or anything.

If the gaskets have bad seal how would you recommend to fix it? Can I just tighten the head? Or do I go for the new gasket (again..)

Thanks, I'll let you know what I find out.

 

[toto]

Another possibility is a leaky water pump. I had a water pump leak on a 2000 Tacoma, and didn't know it for months until the truck sat for a few weeks and finally there was a small puddle of coolant under it. Under normal usage, the coolant was quickly evaporating off the hot engine, hiding the source of the problem. I was also noticing that coolant was disappearing, although I didn't know where.

 

[4R_in_Uzb]

Here is what I find out guys,
when the engine is hot i see water leaking from the lower radiator hose connection and I also hear bubbling in the heater. As soon as I release the presure by losening the radiator cap the leaking stops. But then I looked at the level and it was low, I had to add about .3 l of water.
Other than that I don't see any leaks. And it is cold here so I don't know if the white smoke is an anomaly, I do see many cars have the same thing..

I haven't checked compression yet.