Thread: Coolant Leak From Under Intake Mani.

Hello, my SE-R Sentra is leaking coolant from under the intake manifold. It's dropping on the exhaust and creating smoke. Also the lope at idle does not sound stock at all. And the car has more power upon higher revs.slow off the line. But yeah, where could I look for that leak? The coolant hoses? Or heater or whatever. It's a small leak just dripping pretty much.

There's several things it could be.. heater hoses, throttle body lines, one of the hoses on the water pipe that goes to the back of the water pump housing on the block..

just gotta get under there an check..

I did check on a lift. The leak is on the passenger side by the IACV. RIGHT about the primary iac.

Looks like it might be one of those. if indeed it is, then you're going to have fun replacing it lol.

Good luck!

One of the reasons these pipes can leak coolant, is due to corrosion. They like to corrode heavily between the hose and pipe, causing an uneven surface and potential leaks. Be sure to remove corrosion if you spot any. This is what the coolant pipes on my SR20VE looked like after only ∽15 years


There are also a multitude of coolant sizes. Heater hose matrix, throttlebody coolant lines, and main water thermostat high temp line (huge diameter, not pictured). If you need to replace some, its easiest to just take one with you and head on over to a rubber store. Pick up some good quality hoses that is specified for coolant. You don't want to revisit this job.


Oh, and finally, the hose clamps themselves like to break. The flimsy design of the ring clamps like to corrode and fail over time. I like to replace them with bigger and stronger types.

Where can I find the hoses?

Junk Yard
Nissan Dealer
Auto Parts Store