Another coolant puddle

[pilut2]

My 99 Base has about 41K miles it is not my daily driver. A couple of months ago I added some coolant because it was getting close to the min line on the reservoir- at the same time I updated the cap with the latest 04 version. Since then I have had occasional puddles inboard of the right rear wheel. I have opened the purge valve for 3 or so heat/cool cycles but the condition persists. I have pulled the rear carpet and styrofoam insulation and there is no evidence that the coolant tank is leaking, at least into the trunk. The water pump is not leaking. It appears that my coolant is overflowing when the car reaches full operating temp as the coolant rises from mid point in the tank to way over the max line. My temps seem fine only reaching the 0 on the gauge after spirited driving- usually the needle sits between the 8 and 0. Is it possible I just still need to burp air out of the cooling system?

[NewArt]

I bought a new 04 cap from the dealer recently and had this problem. I put the old cap back on and the problem went away! These caps can be pressure tested apparently. Also check for cross threading: a common problem from what I've heard.

[pilut2]

I will try that. How much does the coolant usually rise in the tank from cold to hot?

My daily driver a 2015 Murano has only a few ounces of coolant in the tank when cold- well below the min line. When at operating temp- the level is only slightly above min line. Dealer says that this is normal. My last Murano a 2012 was the same for the 3.5 years that I owned it.

[Mr. Mike]

It appears our problems are similar. I seem to have no leakage while the car is on the road, but shortly after it is parked in the garage, it starts to leak coolant on the right side of the engine in front of the rear tire. I also replaced the cap and it seems to have caused more leakage. The cap itself is not leaking.

I expect that as this is a 2000 S, and that the hoses are all original equipment, that as the engine temperature increases once the engine is shut off, the fluid is being forced out of the bad hose.

Anyone else had this happen? What would you do or what have you done about it.

Regards,

Mr. Mike

[pilut2]

My leak is directly beside the right rear tire

[Roger1965]

Mine had that. It ended up being a cracked coolant tank. Does your trunk smell like antifreeze?

[pilut2]

I suspected that was the problem, but I can't find any evidence. Trunk is dry. I will have a look on the engine side this weekend.

[NewArt]

Really only two possibilities then: bad cap to tank seal, or problems with the bleeder valve. You might remove the bleeder valve and see if it is cracked. This happened to me on the track with unfortunate results: 2 lost track days and an expensive flatbed ride.

[pilut2]

The issue has resolved itself after the coolant tank found its own level. The manual states that the tank should be filled between the low and high marks when cold. For my car at least- the cold level needs to be much closer to the low level- or else it pukes it out. Lots of full temperature driving yesterday with no drips and the level is steady.