LR4 - Coolant Under Pressure When Cold

[M32H32IS]

It’s at it again. Last time I bypassed the heater core due to a leaking hose. Now the pressure when cold is back.

Doubting blown HG, as I can drive it 150 miles with 0 overheating issues.

 

[BigBriDogGuy]

@M32H32IS That's interesting. I will need to check that too. I feel like my engine compartment has been pretty hot lately (intermittently). Seems to happen more on short trips than longer drives. Why is that pressure when cold a problem?

 

[f1racer328]

I would do a pressure test and a block test.

I had a car fail a block test (due to a bad head gasket) and it ran perfectly, without overheating.

Why is that pressure when cold a problem?

Shouldn't be pressurized that much after sitting overnight.

M32H32IS where is your coolant level when your engines running/after shutdown?

 

[M32H32IS]

Coolant level fluctuates, which I assume is understandable given the intense heat we have right now.

Sometimes I smell coolant and have to add some, and sometimes the level rises MUCH higher than others.

I monitor coolant temps with the GAP tool and they’re always the correct temp according to others on this site who have posted theirs.

No over heating driving 150 miles across Texas on a 102 degree day.

Intermittent smell of coolant

New crossovers, water pump, radiator, overflow tank, cap.

 

[ktm525]

That smells (pun intended) like a head gasket/block problem. High combustion pressure forcing it's way into cooling system but not able to escape back. Like a one way valve..

We don't have a proper rad cap where you can remove it and watch the coolant flow by. Pull a rubber glove over the neck and watch the vehicle blow up the balloon.

 

[powershift]

A compression test might be helpful. If you are losing compression it could be from a leaking head gasket.

 

[f1racer328]

I wouldn’t really take the heat into consideration.

I live in AZ and my coolant temperature/level is the same regardless if it’s 50° or 115° outside.

No loss of coolant or smell. You definitely have something else going on.

 

[BigBriDogGuy]

Removed the cap to the coolant reservoir this morning and no pressure.

 

[powershift]

I think it is normal for some pressure relief. It is a pressurized system, by design.

 

[M32H32IS]

Did the “balloon test” over the coolant bottle and 0 inflation even when I rev it up to 2k rpm.