TameImpala

I’ve got a 4th generation maxima that is leaking coolant BEHIND the engine, really far down. This bad boy is expelling white smoke from the hood during operating temp and dumping coolant.
i went ahead last night and bypassed the heater hoses, just to see if that was my issue, but to no avail. Turns out the leak back there is BELOW the heater hoses (they were dry). I’m just having trouble figuring out what else has coolant down there!
I don’t have any white smoke from the tailpipe or any milky oil (just drained it last night and it was perfect).
I’m at my wits end, hopefully someone can assist a newbie like myself

KP11520

Maybe try a coolant pressure test, obviously with the engine NOT running, so you can hear/see where air and/or coolant is leaking. White smoke ? Probably hitting the exhaust on its way out. You have a water pump behind the timing chain cover. ???? Or the lower radiator hose mounts somewhere around there below the timing chain cover. Lift the car on ramps or jack stands and remove the plastic shields and have a real good look.

TameImpala

I’m going to give the pressure test a try today after work. I’ll also try and snap some photos.

dsonnylal

iTrader: (3)

I’ll put $5 down on the leak being the u-shaped coolant hose that’s on the upper intake manifold.

TameImpala

dsonnylal if youre right you deserve way more than that!
what is that hose connected to exactly?

TameImpala

You were right!!!
we jacked it up, gave it a pressure test, and it was that little u shaped hose behind the intake manifold!
It’s in such an awkward position I’m not sure the best way to go about reaching it honestly

dsonnylal

iTrader: (3)

part number 14056NB

I believe it’s referred to as a bypass hose

aq12

I think the easiest way to reach that hose would be to pull the entire intake plenum. It can easily be done in one afternoon. Might as well replace that plenum gasket while you are there and knock sensor to save yourself a headache later on. Use this youtube video as a reference.

Reality sucks

iTrader: (3)

All you need to do is remove the Iac to reach this hose. I looped mine to bypass the manifold and its been fine for years. Keep it simple its just a hose, if the car has been running fine otherwise my suggestion to you is the leave well enough alone for the time being. The 4th gen is ageing, the more you take off the more you'll have to replace to put back.

pethelman

It's also possible that one of the hard pipes onto which that little "U" shaped hose attaches may have given up. Last time I pulled the intake on my '96, mine was so badly corroded that I wondered if I could even re-attach the hose. The pipe disintegration issue could definitely force your hand on the by-pass option.

TameImpala

You guys are geniuses!!
took me a few hours, but I replaced the little u-shaped hose and it’s been holding up wonderfully for about a month! Thanks all you maxima gurus!