[ravisghosh]

Recently, I went for a coolant change. Sharing my experience so others can be aware and seeking some advise as well.

The car manual suggested 6.4 L capacity of coolant. Hence, I got 3 L of concentrate and a 5 L can of distilled water (1.5 l to be used for other purposes).

What the garage did:
They poured 3 L of concentrate coolant and some water. The coolant level wouldn't go down even after starting the engine. They narrowed down the problem to faulty thermostat valve (vehicle was running fine so far).
1. They removed the thermostat valve altogether and glued the pipe! When I asked the rationale, the mechanic said it is not required in hot climate, required only where it snows. (I was stupid to let them do that).
2. They filled the coolant with some more water but I'm sure the mix is not 50:50, it is more concentrated. Also, they filled it beyond the max level.

Later I learned about the importance of thermostat valve. Unfortunately, it is not easily available for my car (Chevrolet Sail UVA 1.2 Petrol). Hence, I couldn't get it installed right away.

"Please be aware of such ultra-knowledgeable mechanics!"

I will be going on a long drive of 2000 km over the next 1 week. As I understand, it will be okay to run without a thermostat valve temporarily.
Will it be okay to drive with higher concentration of coolant and a level which is higher than max coolant level?

[abhishek46]

Originally Posted by ravisghosh

1. They removed the thermostat valve altogether and glued the pipe! When I asked the rationale, the mechanic said it is not required in hot climate, required only where it snows. (I was stupid to let them do that).

Regarding the Thermostat Valve
The thermostat valve regulates the flow of coolant into the cooling circuit.

When the valve is in the open position, coolant is able to flow through to the cooling circuit, which will result in reduction of the engine's temperature.

When the valve is in the closed position, coolant is NOT able to flow through it, which will result in increase in the engine's temperature.
When the engine is cold started, the thermostat valve stays closed, till the engine reaches the optimal temperature.
Once the engine reaches the optimal temperature, the valve opens and the coolant flow starts, so that the optimal temperature is 'maintained'.

In your case, the valve has been by-passed.
This is result in the engine taking much longer time to reach it's optimal temperature.
This will lead to increased wear and tear of engine components, after extended use.

When you get a chance, get this valve fixed & working.

Regarding Coolant level

By design, there is always some buffer above the Max coolant level mark, in the coolant tank.
This is because the coolant expands (1-2 cms increase in level) when the engine is fully hot.
Please make sure that there is enough space/buffer in the coolant tank, for this expansion to happen.
Else, the coolant tank cap may rupture and coolant will spill out.

In summary, a little above max level mark should be okay, as long there is size-able space left in the coolant tank for expansion.

P.S. Coolant level should be checked on a fully cold engine.

[ravisghosh]

Thank you so much Abhishek. Appreciate your detailed response. Yes, I am planning to add the thermostat as soon as I reach my destination.

[Indian2003]

Originally Posted by ravisghosh

What the garage did:
They poured 3 L of concentrate coolant and some water. The coolant level wouldn't go down even after starting the engine. They narrowed down the problem to faulty thermostat valve (vehicle was running fine so far).
1. They removed the thermostat valve altogether and glued the pipe! When I asked the rationale, the mechanic said it is not required in hot climate, required only where it snows. (I was stupid to let them do that).
2. They filled the coolant with some more water but I'm sure the mix is not 50:50, it is more concentrated. Also, they filled it beyond the max level.

Later I learned about the importance of thermostat valve. Unfortunately, it is not easily available for my car (Chevrolet Sail UVA 1.2 Petrol). Hence, I couldn't get it installed right away.
\

No problem if the mixture to too concentrated but the ideal is a 50:50 mix. This should withstand temperatures down to -35 degrees. I checked mine with a refractometer in January and it withstood -45 degrees. mine is more like 60:40 for extremely cold temperatures.


I find it strange that he claimed that the thermostat was faulty and removed it. Modern thermostats always stays in the open position when faulty and the engine does not risk overheating.

I think he was rolling the dice and guessing. If you have too much coolant in the expansion tank, you can siphon a little out with a cold engine.

Most thermostats are standard units that fit a wide range of cars. This if you dont have a special sealed housing with the thermostat built in. It will help if you post a picture of the thermostat.

While true that the thermostat is not needed in hot countries, it was not his business to remove it without asking you. It will only increase the time for the engine to reach operating temperatures. You can safely drive on your long trip.

I drove to Romania and back without the thermostat once while flushing the system with Bars Nural, a distance of about 7000 km. I just removed the thermostat and filled up with water having a much weaker solution.

If you have taken the old thermostat with you, you can check if open or closed. If open, it is faulty. If closed, put it in a pot with cold water and bring to a boil and it should fully open at boiling point.

[ravisghosh]

Originally Posted by Indian2003

If you have taken the old thermostat with you, you can check if open or closed. If open, it is faulty. If closed, put it in a pot with cold water and bring to a boil and it should fully open at boiling point.

Terrific idea. Let me try it tomorrow.

[ravisghosh]

Originally Posted by ravisghosh

Terrific idea. Let me try it tomorrow.

You were right. The valve opened after boiling. So, the valve is good. I'll go to another garage and ask them to put it in.

[akshay4587]

The thread title needs some editing.
I am came here wondering, as if Garage (Parking Space), is messing up with the cooling system, if there is lack of ventilation or something.

[ravisghosh]

Originally Posted by akshay4587

The thread title needs some editing.
I am came here wondering, as if Garage (Parking Space), is messing up with the cooling system, if there is lack of ventilation or something.

Understood. Is there a way to edit the title? I don't see an edit option in the first post.

[akshay4587]

Originally Posted by ravisghosh

Understood. Is there a way to edit the title? I don't see an edit option in the first post.

Report it to the mods, and they will edit it for you.