Disappearing coolant

[slow6]

Re: Disappearing coolant

yes, I would think so!
f-bodys are notorious for cooling system leaks
1) I recommend totally topping off the radiator
2) bleed excess air
3) repeat 3x

BLLDOG> if you have a hotter thermo (like the stock 195*) wont a hotter thermo invite pressure a little more than a cooler thermo(which the cooling system was designed for pressure).
Therfore hotter thermo = normal (and higher) cooling system pressures (~ 18 psi)
and a cooler thermo(160F) = less pressure? (~ 15 psi)

Does the system have to be close to boiling temps (212F) before it will start building pressure?

I should probably just read howstuffworks.com again

[FirebirdGT]

Re: Disappearing coolant

Oh it's leaking from somewhere. Take it to a shop and have them pressure test it. My disappearing coolant mystery ended up being the lower intake manifold gasket.

X2

Never saw any coolant. Had the gasket replaced - no more low coolant levels.

[black98V6]

Re: Disappearing coolant

I'm gonna be different and vote water pump weep hole. You can loose a boat load of water from this and not realize it. Please let us know how it turns out.

[smithtim]

Re: Disappearing coolant

Thanks for the replys all.

I did some searching on the forums here and the intake manifold seems to be the common denominator so far.

My car runs fine. I took into a shop about 4 weeks ago for a big tune-up, I failed to mentioned the problem, but apparently they didn't notice anything out of the ordinary.

I'm going to take it in tomorrow morning. I'll post what I find out.

What am I expecting to pay if its the intake manifold gasket?

-Beav

I am getting ready to pull a cylinder head on the right side of a 97 3.8 bird and Pepboys quoted me $129 for the whole gasket set including intake (up&low) + valve cover + cylinder head and some accessories.. so what you need should be way less than that... I would guess a third of the cost??


The job your talking about isn't hard to do and is really detailed in the usual Chilton book (only challenge is taking of the fuel rail + fuel lines... get the little $5 fuel line quick connect separator tool)
For having a shop I would expect they would say 3-4 hours of labor, probably at 60ish per hour??

[99RedDragonCamaro]

Re: Disappearing coolant

Just got the call from the shop.......

He spoke a little fast but they found a leak, I believe he said, in the lower intake manifold. He said somthing about it leaking onto the head and they don't do that work because of the location. But he was fairly confident its not leaking internal. He said I need to take it to the dealer and it should run me about $500 (parts & labor). I'll ask more questions when I pick up my car after work and I'll fill you all in.

Stupid question....

Since it is an external leak, can I put off fixing for a bit longer because I just don't have the money right now? Like I said, this has been going on for months already and it hasn't got worse as far as I can tell. No performance loss or anything. I know its not good to just leave problems alone...but level with me.

FYI, I have never noticed any white smoke at all.

-Beav

[youngsc]

Re: Disappearing coolant

If you can isolate it to a specific point I would think you could use some RTV as a temp fix to get by a little longer. I wouldn't use that as a permanent though.

[smithtim]

Re: Disappearing coolant

yes, I would think so!
f-bodys are notorious for cooling system leaks
1) I recommend totally topping off the radiator
2) bleed excess air
3) repeat 3x

BLLDOG> if you have a hotter thermo (like the stock 195*) wont a hotter thermo invite pressure a little more than a cooler thermo(which the cooling system was designed for pressure).
Therfore hotter thermo = normal (and higher) cooling system pressures (~ 18 psi)
and a cooler thermo(160F) = less pressure? (~ 15 psi)

Does the system have to be close to boiling temps (212F) before it will start building pressure?

I should probably just read howstuffworks.com again

good idea to do before pouring money & time into the enginge/intake side possibility

Also, I am going to add this but it is probbbaly trivial.. when ripping/repalcing the radiator if you have spring release hose clamps when fianlly putting it back on reaplace all of the spring hose clamps as they do slowly wear out, and could let some air into the system if they are really bad...

[youngsc]

Re: Disappearing coolant

if you have a hotter thermo (like the stock 195*) wont a hotter thermo invite pressure a little more than a cooler thermo(which the cooling system was designed for pressure).
Therfore hotter thermo = normal (and higher) cooling system pressures (~ 18 psi) and a cooler thermo(160F) = less pressure? (~ 15 psi)
Does the system have to be close to boiling temps (212F) before it will start building pressure?

The thermo is similar to a pressure cooker. Every 1 psi of pressure raises the boiling point 3 degrees. Thus a 18 psi thermo raise the boiling point to 266 degrees a 15 psi raise is to 257. They system is sealed properly will be under pressure from the get go, the idea of the thermo is to raise the boiling point and longevity of the fluids and the system. Somebody please correct my numbers or info if im wrong, been a while since I payed attention to this kinda stuff.

[HokieBird]

Re: Disappearing coolant

The parts for it are pretty cheap, but labor is going to run the price up quick.
I put my repair off because I wasn't seeing a lot of coolant lose or a significant raise in temp, but eventually that gasket is going to fail and it will over heat your car. It isn't something that you can predict so I would say fix it asap and if you absolutely can't afford it now carry a bottle of antifreeze with you and try not to drive more than you have to.

[99RedDragonCamaro]

Re: Disappearing coolant

Just picked up the car.......

IT'S A LEAK!!!

Its leaking from the lower intake manifold gasket. They highly recommend taking it to a dealer because its quite a job.

I willing to bet that I didn't see a leak because its a small leak and its leaking onto the head then evaporating some hence not leaving much evidence to the naked eye. That's my theory.

I'm going to keep an eye on the coolant (like I always do) and probably take care of it in a month or so.

Congrats to those who guessed the intake manifold. I guess this is pretty common on our f-bodys.

Thanks for all the posts fellas.

-Beav

[CDNFB]

Re: Disappearing coolant

Ah-ha! So there was an external leak! Try to get it fixed ASAP. Lots of people have killed their motors by ignoring that leak. Some people have gotten the repair partially paid for by GM cause it's such a common problem.

I having trouble understanding what's so difficult about removing the upper and lower intake manifolds? Lot of guys in this forum have done it (without the luxury of a shop), yet the shop you took it to couldn't? What's with that?? Maybe they want you to take it to the dealership cause you can get GM to foot some of the bill if you argue enough?

[99RedDragonCamaro]

Re: Disappearing coolant

Thanks for heads-up on GM. Worth a try. I consider myself a master debator.

{Couldn't resist.}

[smithtim]

Re: Disappearing coolant

Just got the call from the shop.......

He spoke a little fast but they found a leak, I believe he said, in the lower intake manifold. He said somthing about it leaking onto the head and they don't do that work because of the location. But he was fairly confident its not leaking internal. He said I need to take it to the dealer and it should run me about $500 (parts & labor). I'll ask more questions when I pick up my car after work and I'll fill you all in.

Stupid question....

Since it is an external leak, can I put off fixing for a bit longer because I just don't have the money right now? Like I said, this has been going on for months already and it hasn't got worse as far as I can tell. No performance loss or anything. I know its not good to just leave problems alone...but level with me.

FYI, I have never noticed any white smoke at all.

-Beav

If there is a possibility of stuff leaking into your engine I wouldn't put it off; I had a 3.8 that did a simmilar thing (after long drives on the interstate I could smell a weird smell almost like wing sauce cooking no kidding) anyways I was lazy and let it go and sure it lasted for a few hundred miles, but then I found myself overheated and stuck on the side of I-95 calling a tow truck (thank god for free roadside istance with my insureance) then got the car home and ended up doing a full engine swap because it caused bad internal damge (bearing & valve) when overheated.. so I geuss the story is worry about it early and possibly save an enginge

[UDLOSE98]

Re: Disappearing coolant

If there is a possibility of stuff leaking into your engine I wouldn't put it off; I had a 3.8 that did a simmilar thing (after long drives on the interstate I could smell a weird smell almost like wing sauce cooking no kidding) anyways I was lazy and let it go and sure it lasted for a few hundred miles, but then I found myself overheated and stuck on the side of I-95 calling a tow truck (thank god for free roadside istance with my insureance) then got the car home and ended up doing a full engine swap because it caused bad internal damge (bearing & valve) when overheated.. so I geuss the story is worry about it early and possibly save an enginge

qft, spun a bearing on my first motor

[99RedDragonCamaro]

Re: Disappearing coolant

Boy. You guys know how to make a fella nervous. ;)

My mechanic said that the leak is very small and he said it was cool if I wait about another month until I can pay for it as long as I keep an eye on the coolant level. {crossing my fingers}

Of course, if anyone is willing to float me about $500 (paypal) that would be fantastic. ;)

I wonder if I could rig something up so that it doesn't leak onto my head?