06 Pathfinder coolant level

[Npath]

I opened the hood the other day to charge the battery as it has been sitting for a few weeks.

I took off the radiator cap and couldn't see any coolant whatsoever, just the cooling tubes. The coolant reservoir is 3/4 full... dumb question here, should it be like this? This is the second time I've noticed this and the first time was about a month after taking delivery new from the dealer back in 2006.

I thought I'd take out some from the reservoir and after about taking out 1L or a quart, the coolant in the reservoir was still the same level and the radiator wasn't topped up.

Any thoughts? No coolant on the ground.

[smj999smj]

The top tank shouldn't be low. When the engine is hot and the coolant expands and developes pressure. The coolant is pushed into the reservoir and as the coolant cools and contracts, it creates a vacuum and sucks the coolant back from the reservoir. You should check the pressure cap on the reservoir to make sure it's good as well as the hoses between it and the engine and radiator to make sure they are not collapsing. Also, make sure there isn't sludge on the bottom of the reservoir that is clogging the hoses.

[Npath]

Thanks smj,

I started up the Pathfinder with the rad cap off. Soon after start up, coolant started flowing out. That's a surprise to me as I usually see coolant overflow when the thermostat opens up and gets hot.

[smj999smj]

Keep in mind the cooling system in the R51 is not like the older Pathys. The radiator cap is not the pressurized cap in the system; it is only used for topping off the radiator. If you look at the underside of the radiator cap, there's no spring or vent mechanism. That you'll find on the cap of the coolant reservoir. It's similar to the system many European cars have been using the past several years.

[Npath]

Keep in mind the cooling system in the R51 is not like the older Pathys. The radiator cap is not the pressurized cap in the system; it is only used for topping off the radiator. If you look at the underside of the radiator cap, there's no spring or vent mechanism. That you'll find on the cap of the coolant reservoir. It's similar to the system many European cars have been using the past several years.

Yeah, thanks, I noticed that. This morning I accidentally put the pressurized cap on the radiator. Don't think I did any damage as the coolant was still cold @ the time.

I checked the level a couple hours ago and the level in the radiator is @ the correct level. Guess I don't have a leak after all since I had the engine running for 15 minutes earlier in the day.