2003 Nissan XTerra

The lower heater hose was leaking. Note: NOT the radiator hose.

Ordered a replacement but kept driving wile waiting for it to come in. Got to the point that I had to fill the radiator before I left and again before I came home, but was generally able to keep it from overheating.

Didn't refill with anti-freeze, saving for getting the heater hose replaced.

One morning, water poured into radiator leaks out the bottom and never fills. My guess is no anti-freeze let it freeze. Water comes from right between the back of the engine and front of the bell-housing of transmission.

I'm afraid it is fatal. Any guesses what actually happened?

  • Can you tell us what the climate is like where you live? As an example if you lived in Tennessee you would have mild freezing but if in North Dakota -40 def F is possible. Also, now that the water leaks out, is it still leaking from the heater hose? Can you dry everything off, then pour water in and see where it's coming from now? And in general, water is a great substitute in an emergency when you have to limp to a garage, but the ethylene glycol raises the boiling temperature of the water which prevents it from turning to steam in your engine. Steam does not cool well.
    – cdunn
    Commented Jan 25, 2016 at 16:19
  • @cdunn Heater hose has been replaced now. Haven't tried to start it without water. I think it got to around 0 that night here in Nebraska.
    – BWhite
    Commented Jan 25, 2016 at 16:52
  • I'm not sure I know what you mean by "start it without water". Does the cat still leak coolant? If not, replace that water with the right glycol / water mix and drive happy. If it is still leaking, where is it leaking from?
    – cdunn
    Commented Jan 25, 2016 at 16:54
  • 3
    @cdunn - It sounds like they popped a freeze plug. Commented Jan 25, 2016 at 17:50
  • @Paulster2 Well that's the most promising thing I've heard all day. Looks like we need to take the engine out.
    – BWhite
    Commented Jan 25, 2016 at 19:00

2 Answers 2


It's been a while since I've seen one of these engines.

IIRC There's a water pipe that runs through the engine V and connects to the heater hose at the rear of the engine.

One of these is true.

  • The pipe is rotted
  • The hose clamp failed
  • The hose failed
  • A freeze plug failed

Circling back to post the resolution.
I was afraid that the block was cracked, but was hoping that it was the freeze plugs. A quick survey of mechanics that have worked on Nissans suggested there was about a 50/50 chance. Had to take it to 3 different shops, but finally got the tranny out and it was the freeze plugs after all. But once they fixed that and pressurized the system, there was enough other damage that showed up that it wasn't worth fixing.

So I won and I lost. I won the bet that it was the freeze plugs. I lost the $450 for removing the tranny and lost the truck.

@Pᴀᴜʟsᴛᴇʀ2 wins the prize for the right answer.

  • Sorry to hear that man. rough story. too bad it wasn't the water pump or something. Commented Apr 21, 2016 at 21:32

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