Engine 850: B5234TR/2.3/20v/T5R: Mystery of missing coolant...

[glennethwest]

My coolant filler cap isn't the problem. The cap is a green one by the way.

When I took the cap off this morning I could hear the pressure release coming from the front of the rad.

I'm not having any problems with the temperature in the car. It heats and cools perfectly well. And the temperature gauge is always at 3 o'clock.

[glennethwest]

So the mystery continues.

I drove home this evening (well to Halfords) after topping up with the remainder of my 2 litres of coolant.

On the way home I saw white smoke intermittently coming out of the front of the car so I thought I would inspect things further when I got back.

Anyhow... the reservoir was empty but, when I slowly unscrewed the cap, it filled up with coolant. Then, when I later drove home, it was empty again!

Does anybody have any clues as to what this problem is?

In summary, there is smoke coming out of the grille, there was clearly pressure build up around the radiator, there is no coolant in the reservoir but there is when the pressure is released.

[rippedoffagain]

You have air locks in the coolant. The pressure build up above it prevents it getting back to the expansion tank, then as soon as you take the lid off and release the pressure, it all comes flooding back in.

And you still have a leak, probably the radiator its self from what you describe.

[glennethwest]

Originally Posted by rippedoffagain

You have air locks in the coolant. The pressure build up above it prevents it getting back to the expansion tank, then as soon as you take the lid off and release the pressure, it all comes flooding back in.

And you still have a leak, probably the radiator its self from what you describe.

Ok, thanks again. I'll have a look at it again at the weekend. As a teacher I don't really get any time during a week day.

[rippedoffagain]

Originally Posted by glennethwest

Ok, thanks again. I'll have a look at it again at the weekend. As a teacher I don't really get any time during a week day.

Take your car into school and get the kids to make it a science project. They can learn about heat, and cooling, and pressure and things.

If I remember right, the specific heat capacity of water is 4200

Q1. How many litres of water does the system hold? (kids fill it up to find out)
Q2. How long does it take the engine to heat the water to 80'C from cold? (start the engine and wait)
Q3. Given that the specific heat capacity of water is 4200, using your answer from questions 1 and 2, how many joules of energy has been transformed into heat?
Q4. How long does it take the coolant to drop to 25'C once the engine is off?
Q5. Can you spot anything that may be causing heat energy to be lost during the process (kids look for leaks).

Job done.

[glennethwest]

Originally Posted by rippedoffagain

take your car into school and get the kids to make it a science project. They can learn about heat, and cooling, and pressure and things.

If i remember right, the specific heat capacity of water is 4200

q1. How many litres of water does the system hold? (kids fill it up to find out)
q2. How long does it take the engine to heat the water to 80'c from cold? (start the engine and wait)
q3. Given that the specific heat capacity of water is 4200, using your answer from questions 1 and 2, how many joules of energy has been transformed into heat?
Q4. How long does it take the coolant to drop to 25'c once the engine is off?
Q5. Can you spot anything that may be causing heat energy to be lost during the process (kids look for leaks).

Job done.

lol!

[Merc85]

Hi there, is the car manual, or auto??

[glennethwest]

Originally Posted by Merc85

Hi there, is the car manual, or auto??

It's an Auto

[Merc85]

Hi, have you checked the auto transmission fluid? colour and level? the rad may have cracked inside due to age and your coolent may be entering the autobox because they run through the same radiator.

Just a thought.

[Oly.850]

I'm chasing a coolant leak as well, but I think I've found it. The plastic coolant draincock on the driver's side of the radiator is dripping coolant. I tried some sealant, but it doesn't seem to have worked. Still drip, drip, drip. About 1/2 a litre every week.

I also found the lower radiator hose to have been swollen and goofed up from being saturated with ATF leaking (slowly) from the lower coolant line. I trimmed the end of the hose, but it needs to be replaced as there is a small cut inside the hose ( I have no idea ) that is allowing coolant into the fabric of the hose. Time to go. I'd like to find some heavy duty neoprene hoses like police cars here in the States, anybody seen these for our rides?