Coolant Loss

[ShadowLvr400]

Ok, drove it again, and have learned a few more things. 1, it's not a head gasket. The motor itself isn't leaking, the fluid is coming from under the resevoir, so I have a sneaking suspicion that it's the return line from the radiator.

The car holds its water under normal, gentle driving, for the most part. When I stomp the gas, it bleeds out badly. It is definately coming from somewhere below the resevoir. So, I need to figure out what's under there.

[zonie77]

How do you know it's not a head gasket?

[ShadowLvr400]

The head gasket is part of the physical motor, is it not? This fluid is coming from a spot distinctly not connected to the motor.

[zonie77]

That hose is directly connected to the engine.
It is at one end of the cooling system and it is a continuous system.
If you have a leaking head gasket you have a source of pressure into the cooling system. The antifreeze will come out at the point of least resistance which is the overflow tube.
The antifreeze coming out under load is a pretty strong indicator of a bad head gasket.

[elwesso]

It might just be a loose hose clamp or a broken hose.....

Im sure youve done all the tests to see if the headgasket is bad already, right?

[mcowden]

I just fixed a slow but persistent coolant leak on my '96 SLS. Turns out it was the water pump bearing/gasket that was letting a small trickle of coolant by under full pressure, especially noticeable when it was at full temp and shut off. Replacing the water pump fixed it right up.

If you do this, make sure to carefully clean away all the deposits from the water pump cover/themostat housing gasket and surface before putting it all back together, and torque those bolts carefully. While you're taking it all apart, might as well make sure the water pump drive belt tensioner isn't squeaking/squealing/squawking and that the belt is in good shape. A new belt and tensioner for the water pump probably runs about $50 total.

Water pump at AutoZone was about $65-$70. Borrowed the tool to remove the water pump from AutoZone for $15 deposit. Replaced the thermostat at the same time for good measure (why replace the coolant twice?) for another $10-$15. No more leaks and it was a good opportunity to flush and fill the system with new bright orange DexCool at about 60/40 mix with distilled water.

Good luck as always and

[ShadowLvr400]

At this point, I haven't done any other tests to see if it's a bad head gasket. Anyone want to tell me those tests?

(Side note, if it is a bad head gasket, I'm going to ave to just do a cheap patch, and carry water with me at all times. I can't even begin to afford to replace or repair a head gasket. Unless you all know how. If I have to pull the motor, basically the car will just have to live with it. Though I am a bit bothered that this came on all at once. Went from no leaking at all, to royal problems under hard gas.

[elwesso]

The basic stuff I was referring to was like oil in coolant, water in oil, sweet smelling exhaust (not from NOS ), and obviously it seeping donw the heads.......

Theres been quite a few good threads here about the headgaskts, it may not be a bad idea to peruse those......

[ShadowLvr400]

None of those have occurred. No oil in the coolant, no water in oil, and the only event of a sweet smell behind the car was when I sprayed my buddy's car with coolant as I blew by. He got the sweet smell, probably because his car was hosed down with it.

[Aurora By Olds]

Originally Posted by ShadowLvr400

Though I am a bit bothered that this came on all at once. Went from no leaking at all, to royal problems under hard gas.

I haven't read anything else but this (it caught my eye). It could very well be a headgasket. Mine began suddenly one day under hard driving. After a good run, it looked as though coolant had been spewing out the surge tank cap. After a long investigation, I found out that a head gasket is leaking exhaust gas into the cooling system, causing it to be overpressurized only under high RPM's. Mine had the green coolant though, and was never properly maintained before I bought it at 82k. I will be doing the gaskets myself, and with the materials and time-sert kit, it should be around $500 all together if all goes well.

[DaveSmed]

Get your engine leak down tested. As your watching the pressure gauge, keep an eye on the tank. If you suddenly see bubbles, you found it. Also, leakdown tests are a good idea on an engine with stresses such as yours to check stuff like valve sealing and ring sealing.

[elwesso]

Couldnt have said it better myself!!!!!

[ShadowLvr400]

Here's some more info. Sitting in the bottom of the resevior, is a thin layer of some sort of dirt, or silt deposit. Seems a bit slimy, but can't get enough to really tell. I'm going to try a few tests later today, including revving the motor, and seeing if any water shoots from that release valve.

[ShadowLvr400]

And the oddity continues... I refilled the resevoir, went out and got a snack and came home. I did open the car up, went ahead and stomped the gas. She kept the coolant. Let it cool, and then opened the resevoir. As soon as I opened the cap and pulled it off, all the coolant leaked out. This continues to be weird.

[DaveSmed]

I'm beginning to think that for whatever reason your cap was loose to begin with. Because now as you found out, she seems to be holding pressure just fine.