Ok guys... this is not a very good turn of events.

You know how I told you my coolant resevoir was full then after about an hour it was empty yesterday? I put some more in it this morning, thinking maybe air had just escaped, and drove to class. It did GREAT, stayed under the first mark... yet on the way home is started really getting hot. When I got it in the garage, popped the hood and the resevoir was at MAX. But just a min ago...

I went into the garage, and VOILA - all the coolant in the resevoir is AGAIN gone. I look under the car, and NOTHING. I crack the cap, and I hear another depressurized sound...

I found under the front left area, alot of sprayed coolant. I can't tell for the life of me where the leak is from, because of all the spraying. It is even sprayed up underneath the wheel well...

My guess what is going on, please tell me what you think:

There is a leak, but only happens when the system becomes pressurized due to driving. I fill the resevoir, everything is ok. I drive away, the system gets pressurized, starts spraying coolant out of the leak (which is why it's sprayed up under the wheel well, from the tire hitting it), but there is still some coolant in the resevoir. When I get home, the system cools down, and the coolant in the resevoir empties into the system, causing the disappearing act out of the resevoir.

So what gives? I've got a leak, I know, but where the heck is it? I know you all obviously can't see it, but what is a common spot? Like I said I can't tell because it's sprayed, not just dripping.

Phew.

-Matt

 

Matt, Check the coolant hoses that run by the alternator. I know one of mine got cut, by the alternator pulley assembley, and I had the same disappearing coolant problem as you do. I only noticed it when I popped the hood and saw it spraying out after the car had gotten hot.
However, there was no evidence of coolant on the ground.

 

The overflow hose for the coolant resevoir empties into the drivers side front fender area. Sounds like your system is spraying it out the overflow once it heats up. Maybe your radiator cap is bad and can't hold the pressure?? A blown head gasket can also cause over-pressurization and force the coolant out.

Tom
'87 951
'86 Supra

 

Try replacing your radiator cap first. It's very cheap and can safe you a lot of frustration. If that doesn't work, try preasurizing the system with a brake bleeder or some shops have coolant sytem preasurizing tools.

 

I had the same problem, and it was the alternator cutting the hose just like early's post above.

Also, didn't someone a while back post similar symptoms, and it was the water pump. as it leaked, the motor burned the water so there was no trace?

 

Prolly a bad cap. That's EXACTLY what it does...

Get one this evening and try it.

 

You say bad radiator cap. Sounds as good as anything I've heard, so I'll do it...

But (excuse my ignorance) is the radiator cap the same as the resevoir cap? Because when I open the resevoir cap there is a noticable de-pressurized sound, which would tell me it is doing its job...? Or are they even the same cap?

Thanks,
Matt

 

I posted several time in your other post that the cap needed to be replace... but did you listened, nooooo! Two other folks have to say it before you take action... Sorry, I just could not resist.

The reservoir cap is the same cap we are referring to here. It might be keeping pressure but not up to spec. That is why it needs to be replaced. If damage, when enough pressure is build it does not hold as it should.

Good news is that it is an inexpensive fix.


BTW - I went to your website... I see you are taking offers on the car!! Why are you selling it??? It is a nice ride.

 

Jamie,

Sorry 'bout that. I was going back and forth from my computer to the garage. I printed out this thread to try and get it all but I figured that was too easy a fix (plus I thought it had pressure).

But, if I replace the cap, isn't there still a leak? Or are you saying that it is leaking out of the cap? I didn't see any coolant up top.

Thanks a ton.

-Matt

PS
How's O-town?
No longer selling my 944 - I forgot to take that off there from a while ago. Thanks for the heads up (although if someone offers me enough $$$, I could probably part with her and live...)

 

When you are driving your vehicle - the radiator is likely able to cool the system sufficiently to prevent excessive pressure. When you stop moving, heak-soak causes the coolant to heat-up to the point that it begins vaporizing, and then it overflows.

I'd recommend pressure-testing your coolant system if the radiator cap replacement doesn't fix the problem. Any garage should be able to do it for you, or you can fashion a rubber stopper with an air hose fitting and pressurize the system to 15 psi using a good-quality regulator. Do not use excessive pressure when testing the system, as too much can CAUSE leaks or a ruptured hoses or gasket.

Greg

 

Good news: just got home from my Calc final, aced it.

Bad news:

Still sprayed everywhere (with the new radiator cap). I noticed it looked like it was coming out of a small tube, which I believe is a overflow tube coming out of the cap area? Is that right?

So tomorrow I'll go down to autozone and get a pressure tester - is that right? They have a "free" tool loan program, maybe that's one of the tools.

Hmm...

Glad this is happening during FINALS WEEK!

Sheesh.

-Matt

 

You're correct about the overflow tube position. When you get the pressure tester, after seeing if it will hold pressure with motor off, start the car and watch the gauge. Carefully monitor it and see what the pressure gauge reads. If it starts rising quickly to say 14psi or more, I'd say the exhaust pressure is leaking past the head-gasket & over-pressurizing your system. If the pressure rises slowly, then I'd try a new thermostat since it's cheap......but not easy. Hate to add bad news during your finals week, but with Supras, they are known to spray out coolant from the overflow tube when the head gasket is blown, common problem with them. I hope it's not that.

Tom
'87 951
'86 Supra

 

Matt,
You know what it could be... I would definately check in the glove box. That has to be it. Let me know if that is it.


Actually, I'm stumped. I am still having a problem, think it is the whole air in the line bit. Oh well. Its time to dig.

 

It ain't 55 anymore ec. 70 posted, 75 some places. Pitiful by German standards, but hey...

Thaddeus

Meesa no lika no 55...

 

Son of a gun - a blown head gasket?

Crap. Is that a pretty hard fix? I've seen them in the catalogs...

I'm going to try to do the pressure test tonight/this afternoon.

Thanks,
Matt