Would A Loose Tank Cap Cause Coolant Loss?

[George7941]

Just noticed low coolant in surge tank. Truck had been in to a shop for exhaust manifold gasket replacement and they did drain out some coolant. Level was fine when I picked up the truck from the shop. a couple of weeks ago

When I noticed the low coolant level I checked the cap and saw that the shop had not tightened it. I wonder if that might have caused the coolant loss. I don't think the coolant would have boiled over because it has a low temperature thermostat. Coolant temperature

had always maxed out at around 180F. Engine is a 2006 CAT C7.

Perhaps it was trapped air in the system working its way out. I can't see the coolant sloshing around so much in the tank that it would leak past the loose cap and then drain through the overflow hose. There are no signs of any spilled coolant anywhere.

 

[Jetronic]

it could have but that leaves signs. Much more likely some left over air in a pocket made it to the tank.

 

[Kira]

I've never seen a "DO NOT USE STARTING ETHER" label before.
Would it melt the plastic?

 

[George7941]

Engines with intake air heaters (same function as glow plugs) could ignite the ether in the intake manifold and cause extensive damage.

 

[oldcodger]

I have seen intake manifolds blown off tractors because of mixing ether and glow plugs.

 

[eljefino]

That's a pressurized cap, so, yes.

You lose a very small amount anyway as water vapor "breathing" in and out, but you lose more if that water vapor isn't held under pressure.

You also could have burped air from the job.

Too full is better than not full enough. Worst case is it makes a little mess.

 

[Jetronic]

That's a pressurized cap, so, yes.

You lose a very small amount anyway as water vapor "breathing" in and out, but you lose more if that water vapor isn't held under pressure.

You also could have burped air from the job.

Too full is better than not full enough. Worst case is it makes a little mess.

but not full enough would be a near empty tank.

 

[vavavroom]

With a pressurized cooling system I do not expect to see more than half an inch of coolant loss in the overflow thank over a 6-month period. Because coolant contracts and expands with temperature I check with the engine cold when it's around 20°C outside. With the coolant fully at operating temperature I want the coolant level at least at the minimum index on the reservoir.