1996 850T Leaks coolant if blower switch is left on

[kimothyanne]

Howdy all,

Recently I ran into a situation where I found a good portion of my engine coolant on the ground. Not all of it, just about 1/3 to 1/2.

After a few of these events, I came to find that if I turned the blower off (the lever which controls the amount of air circulating when air conditioning is on) when leaving the car this did not happen. It doesn't seem to matter whether I turn it off before or after I kill the engine. I do leave the AC switch on. I have tried turning the AC switch (the one with the light over it, indicating whether or not the AC is operational) but a shady tree mechanic told me that it was "bad" to leave the AC off. I don't know why he said that, but I have always just adhered to what he said.

I have also noticed that while the AC is on the "engine" noise is much "noisier" than usual.

Another, perhaps unrelated tidbit...when accelerating from a stop I get a "clunk" which seems to be coming from the front of the car. At first I thought it might be a U-joint but the noise is coming from the front and does not happen if I accelerate very, very slowly.

Any ideas? (Hoping it isn't the compressor but, alas...)

[RussB]

A coolant leak is a coolant leak, and will leak regardless of where you set the knobs or sliders on the HVAC control. You need to find specifically where it's coming from

A clunk is a clunk, and there are many things that can clunk on a 20 year old car

[scot850]

I'll try to answer some of your questions.

1) Leaving the A/C on all the time. That is only the oil producers talking as it eats gas using it. In fairness, not using it, especially with an older car can cause problems due to seals hardening and leaking. The only other issue is that using the A/C is that condensation occurs, and can get trapped in the A/C evaporator and rot them out. The best thing to do here is to switch off the A/C for the last mile or so, and let the air dry out the system. This will also reduce the 'musty' smell you can get when the system stays wet. Living in Western Canada, we use the A/C maybe 2-3 months tops in the year. I had to replace one A/C evaporator on a 93 850 GLT which is a huge job requiring the whole dashboard being removed and all the heating/cooling system behind there. In California, I would think rubber parts may dry out with age, so using the system does help to keep these from drying out. So I can see the mechanics point of view. I would say from a personal position, use as required and all should be good.
2) Heater blower motor on/off. Does your car have ECC or manual levers and cables? If it has ECC I can't see why that would happen as there is no interaction between the 2 systems other than in the heater core. If you said leaving the heater blower running made the issue stop happening I could understand this.
3) Where does the coolant leak out from on the system? That may help us figure this out.
4) The noisier than normal A/C may not be the A/C at all. There are several turning parts on the serpentine belt route that could have a bearing going, or it could be un-related, and be something on the timing belt like the water pump bearing failing. This is serious, as if either belt were to fail it could take out your engine. I suggest you have some knowledgeable check this out ASAP. Removing the serpentine belt and running the engine briefly will either help pin-point or eliminate the parts on the belt route from the noise issue. If the noise persists, it is likely on the timing belt. This should be a quick test for a mechanic.

Neil.

[kimothyanne]

Thanks to all. I am off to do a little more troubleshooting.

Oh, I have looked...I have not been able to determine where the coolant leak is coming from. Time to try again.

[FLXC90]

1. coolant on ground, how frequently does it puke the coolant? does your temp needle sit at three o'clock and stay steady when warmed? Is there a whitish residue on top of your coolant reservoir, shock tower, timing belt cover etc.. ?

2. Clunk in front upon acceleration: check your forward (lower) and upper torque mounts. Grab the engine and see how much you can make it rock forward and back, probably ought to do this when the engine is cold.

[cn90]

Prime candidate in a turbo engine is the turbo coolant hose behind the engine block.
There is another hose near the top (close to reservoir).
Chances are coolant leaks from the turbo coolant hose(s).
Replace both of them at this age.

[rspi]