Hi I’m new on here and I could use some help.

I have a 2006 Nissan Maxima and I can’t figure out what is up with my coolant system.

To start I replaced my motor with a good used JDM but before installing into my car I put a new timing set in it as well as a new water pump, thermostat and, after the engine install, new radiator and hoses.

After adding the coolant and burping it I’m still having some issues. The are the upper and lower radiator hoses are very hard and the lower radiator hose and bottom of the radiator is cold to the touch even after driving. And the one that really baffles me is the overflow bottle will lose coolant after a few days. So I have looked and see no leaks and no coolant in the oil so no clue why the overflow is losing coolant.

With all this said my temp gauge doesn’t go past the middle so I assume it’s not overheating.

Has this happened to anybody else? If so, how did you fix it? If not, any ideal what I can do?

  • Welcome to Motor Vehicle Maintenance & Repair! Mar 8, 2018 at 12:03
  • How did you 'burp' it? Is there a hose with a bleed vent?
    – HandyHowie
    Mar 8, 2018 at 12:10
  • I jacked the front end up and used the funnel made for burping it and filled the funnel with coolant and let the engine run
    – user36020
    Mar 9, 2018 at 0:32
  • do a leak down test. You can usually borrow a test kit from your local auto store.
    – agentp
    Mar 9, 2018 at 19:36
  • >>And the one that really baffles me is the overflow bottle will lose coolant after a few days. << It is expected that coolant in the reservoir will get drawn back into the radiator.
    – mike65535
    Jun 21, 2018 at 13:53

3 Answers 3


Since you asked for people with the same problem:

You can often lose quite some coolant before things get hotter than normal. I consistently lose some coolant in my car and only since a few days the needle gets a little past normal temperature. The expansion bottle is most of the time almost empty. And this is a british classic car, mind you, they're notorious for their alleged horrible cooling capacity.(which I very much disagree with) I didn't have the time to really fix it the past half year. Anyway, it's bad practice, and I don't recommend following my example.

The real danger is air in the cooling system around the waterpump, which causes the waterpump to effectively displace virtually no coolant.

My problem is a leaking radiator, small cracks and holes make coolant drip out. Other causes for losing coolant can be:

-A leaking headgasket(very dangerous internal leakage, white sweet smelling smoke from exhaust)
-A broken coolant cap (it will vent off steam when the engine is hot, sometimes hard to see)
-Unproperly sealing hoses (coolant drips can be observed at the connection with radiator or engine)
-Cracked hoses (hoses are hardened/brittle over time and get tiny cracks leaking the coolant. Sometimes very hard to see.)
-Leaking inside the engine, coolant can leak into the oil pan. Also dangerous as it severly decreases the oil's effective quality.

Check for these and try to isolate the problem.


Coolant can overflow if the radiator cap isn't holding the required pressure.

I would have the radiator cap tested and/or replaced.

  • I have a new radiator cap and it still acts the same
    – user36020
    Mar 9, 2018 at 0:33

Did you replace the original radiator hose clamps?

Worm-Style clamps will not work on plastic cooling system components due to expansion and contraction. At a minimum you will have weeping, which allows for introduction of air, as well.

Constant-Tension style clamps are necessary.

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