Coolant gone. . . but to where. . .

[zero97tsi]

Hey, obviously new here, and Ive run into my first real problem since getting my Tsi about 2 weeks ago.

After changing the oil me and a friend went to get some food and when we got to Subway (eat fresh) I noticed my temp gauge was maxed out. so I got it home, and heard the sound of boiling water in the overflow tank but it wasnt boiling water, it was outrageously hot air blowing into the water that was in the tank.

So I checked the oil, still clear, still just oil. there was no coolant to check so I filled the coolant system, ran it watched it, cant see any brown or filth of any kind. however the system is getting air in it, a tiny bit. At the mouth where the cap goes air flow out of the tube, from the engine side, not the rad side.

So with clean oil, clean coolant, the only descision ive come to is that my coolant is just leaving.

Im gonna try a compression check, but like I said the oil and the water stay clear as crystal so unless my engine runs cleaner than a surgery room, I cant see it being the HG.

Any ideas?

 

[diablos991]

Go to a local radiator shop and have them pressure test the coolant system. It is possibly a small leak that only develops when the system is pressurized.

 

[fourreGsixty3]

Yes. Pressure check the system, and pressure test the radiator cap. Also you might not see any fluid on the ground from the leak cause it might be leaking on a hot piece of metal, and evaporating off. Generally if the HG is gone you will see coolant in the oil, or oil in the coolant, but it is possible that it is leaking between cylinder's and burning off in the combustion chamber. If this is the case the exhaust will smell "sweet", also the spark plug's will be decently clean.

 

[talon187]

sounds like the problem im having. if you want to do it yourself go to autozone they have a tool you can use to presurize the system when the cars off. good luck with yours it looks like mine is leaking off the slave cyclinder so were thinking it's the freeze plug behind the clutch

 

[zero97tsi]

Yes. Pressure check the system, and pressure test the radiator cap. Also you might not see any fluid on the ground from the leak cause it might be leaking on a hot piece of metal, and evaporating off. Generally if the HG is gone you will see coolant in the oil, or oil in the coolant, but it is possible that it is leaking between cylinder's and burning off in the combustion chamber. If this is the case the exhaust will smell "sweet", also the spark plug's will be decently clean.

The exhaust has a strange smell to it, but I dont know if its "sweet" or just less putrid than that of the 88 Olds Toronado Ive been messing with.

It seems like the coolant empties to fast to be just a small leak that would evaporate so quickly, but hey... its a car, anything could happen. I will check what has been recommended and report back.

 

[jastermerrel]

Definitely do that compression check pronto. I just got finished with the same problem on a mustang. The coolant would just "disappear", the exhaust wasn't even smokey and no coolant in the oil, but a compression check told me what was happening. Head gasket.

I'm glad DSM's only have 1 head, .

 

[yesItsdsm]

I had similar problem now that the weather is heating up. If your temp. gauge was reading high then most likely you overheated your engine or was on the verge of overheating. That boiling sound is likely your coolant boiling (which happens when your car overheats) and if that is the case then boiling coolant will evaporate fast, and also escape through the overflow hose as it boils in the overflow tank.

In that case change your thermostat to start with. It could be faulty, but luckily they are cheap. Then if your problem persists move on to more drastic measures.

 

[fourreGsixty3]

Definitely do that compression check pronto. I just got finished with the same problem on a mustang. The coolant would just "disappear", the exhaust wasn't even smokey and no coolant in the oil, but a compression check told me what was happening. Head gasket.

I'm glad DSM's only have 1 head, .

Just do a leakdown test. That will atleast say if its a leak between cylinder's, or where ever. Either way it sounds like you will end up replacing the HG.

 

[95GSXBLUR]

Before going crazy... it could be something as stupid as your radiator cap is shot. Replace it. They're cheap.

 

[ZmanIV]

Blown head gasket.
Cylinder compression is greater than the radiator cap can hold and the water is going out the overflow discharge.

I need reputation points for that one.
another way to tell is to fill up with water leave the cap off and start the car. If there are bubbles in the water then the head gasket is blown

 

[ZmanIV]

Before going crazy... it could be something as stupid as your radiator cap is shot. Replace it. They're cheap.

Doubt that is it since the exhaust smells funny.

 

[fourreGsixty3]

Blown head gasket.
Cylinder compression is greater than the radiator cap can hold and the water is going out the overflow discharge.

I need reputation points for that one.
another way to tell is to fill up with water leave the cap off and start the car. If there are bubbles in the water then the head gasket is blown

Dont ever ask for rep. point's if your post's are worth while then you might get them.

 

[diablos991]

Doubt that is it since the exhaust smells funny.

He is actually on the right track. When diagnosing these problems, why not try the easiest things first?

His diagnosis of the smell of the exhaust gave us no indication as to what was burning. It could be any number of things from a clogged catalytic converter, to the car running rich, to trace amounts of oil seeping past the turbo seals that would cause peculiar smells.

Until we are sure what he is smelling, we can not make assumptions based on those smells.

I still say that you should get the pressure test done to check for pinhole leaks or any other flaws in the coolant system. Followed by a compression test to see how that head gasket is doing.

 

[95GSXBLUR]

Start small before you go big... How pissed would you be if it was the radiator cap and you had the head pulled off?

I know I would be. Whatever. It's worth a shot.

When I blew a head gasket in my truck, I would poor coolant into the radiator and it went straight into the exhaust manifold/Piping BEFORE it started to mix with oil...

leak down/compression test... your interior isn't soaked is it? noticing maple syrup smell? feel behind your center console for dampness... maybe your heater core is leaking.

just a thought.

 

[fourreGsixty3]

Yes start with the small stuff first, then work your way up. It will save you money.

 

[ZmanIV]

That was why I also posted to see if there were bubbles in the coolant.

 

[Gs Dewd]

As was mentioned before you probably blew a head gasket. Mine did the exact same thing. Overheated blew bubbles in the overflow bottle. My oil was clean as was my coolant. I pulled the head checked for warpage, put in a mls headgasket and arp studs and all was good again.

 

[diablos991]

A simple hydrocarbon test can also be done by a radiator shop along with the pressure test to determine if any exhaust fumes are getting into your coolant.

These tests are simple and extremely cheap. I got them for free because they were so easy to do and the guy at the radiator shop owned a DSM back in his day.

 

[zero97tsi]

So I went and bought myself a compression tester. All 4 cylinders read 180 exactly.

So now Im back to the begining. Coolant leaves and I dont know to where.

Do you think maybe into the turbo? Like I said in the last thread My exhaust pumps some white smoke so SOMETHING was getting in there. . . and the coolant WAS bubbling.

Im gonna go out and check under carpet, but it doesnt smell in the car even with the vents open.

Any other ideas?

 

[95burgundyesi]

I would check the radiator hoses around the clamps or maybe you have some pin holes creating a slow leak.

I would check your termastate, take your cap off and fill it up, are there any bubbles? If you see them then air is getting in from somewhere. I would guess a head gasket. When you change your oil, see if you can see if it has been mixing.

 

[luv2rallye]

White smoke = coolant into combustion chamber or turbo. Using a coolant system pressure tester will help you find it.

 

[Jake30]

If there is white smoke, usually that means coolant is getting into the combustion chamber/exhaust as stated before.

Check the throttle body to make sure that isnt leaking coolant into the intake, I've seen that happen before.

Just a thought, if for some reason no coolant is leaking into the exhaust...

I had an issue with a radiator cap having the spring bad and/or too soft and when the car would get hot, a lot of the coolant would go into the over flow tank and out the over flow tube. It took me awhile to figure it out, but after a few months and a few over heating issues, I changed the cap and no more loss of coolant.

 

[zero97tsi]

Check the throttle body to make sure that isnt leaking coolant into the intake, I've seen that happen before.

The TB has a coolant line in it?

I am seeing some white smoke and a wierd smell from the exhaust. Could it be leaking at the trubo or is there even a coolant line near the exhaust side inside the turbo?

Im feeling a bit lost now.

 

[freshlane]

Yes it does. One is the coolant feed and one is the coolant return. The purpose of coolant in the TB is to melt a wax pellet in the FIAV once the car warms up. Do what luv2rallye said and pressurize the coolant system and see where it comes out or buy a dye kit (it will only show visible leaks, not leaks inside parts)

 

[zero97tsi]

Excuse any noobism, Im very new to all this cool new car stuff, but what is a FIAV, and why do we want to melt a wax pellet in it?