I've been dealing with the notorious sunroof leak problem on the passenger side of my car for a couple years now, but since it is garaged 95% of the time, I only did small things to fix it. This past weekend I cleaned out the piece that drains into the firewall because it was not draining at all. However, the problem remains whenever it rains. I cannot replicate it with putting water into the sunroof. I am going to order a new part for where it connects to the firewall, but I don't think it will actually work since it is completely clean (was completely blocked before).

What else could this be? I am pretty upset that this did not fix the issue.

Also, is this the correct part?

https://www.infinitipartsdeal.com/pa...816-ju40b.html

 

It might not be the sunroof drain, it might be the cowl drains are plugged and water is spilling into the battery compartment and coming in through the penetration for the main wiring harness.

 

Is there a known procedure to fix this?

I have water on my rubber mats too, does this rule this out?

Also, could it leak through the top if the headliner does not get wet at all?

 

It's important to be able to SEE THE WATER flowing into the cabin, I would take off the lower trim pieces so you can expose the ECM/TCM. Personally I would take off the glove box as well so you can see up through to the access panel for the cabin air filter.

Check your cabin air filter to see if it's wet, it might be flowing over the cowl and seeping in through the filter. Then dripping through the duct work, it SHOULD go out the duct drain but that might be clogged also and it would just leak out onto the floorboards at that point.

With everything removed you can put a flashlight on the sunroof drains and make sure you SEE WATER flowing through them when you put water up on the sunroof tray.

Plan on putting a fan in the footwell every day when you're home to dry it out so you can better spot EXACTLY where it's getting wet first as well as prevent the carpet from mildewing.

Don't put the rubber floor mats back down until everything is dry, you're trapping moisture under them.

Definitely pull the cowl and check the drains, they're notorious for clogging and a lot of people end up with IPDM problems because the water pours out of the cowl right onto the IPDM usually.

 

I don't have the mats down when it is wet. I'll look for culprit this weekend. I will likely start at the top this time, and then check the cowls. If it is coming through the sunroof, it takes a long time for water to start appearing. I have not been able to see water come through that way ever.

 

Also, the sunroof drains dump out into the cowl valley near the wipers, that just adds more water to the cowl. It might be that the cowl is filling with water and leaking past the sunroof drain plugs right back into the cabin since there isn't a gasket on the sunroof drain, it just snaps into place.

 

Honestly I would start with the cowl, it's easy enough to remove, it's an extremely common to clog the drains, and it definitely causes water to leak where it shouldn't when the cowl is full.

 

This seems like it could be the likely issue. I have watched where it connects to the firewall with water going in, but I have not seen anything come out yet. Ill spray water near the cowls, and I'll see if I can see water coming in.

How do you clean the cowls?

 

Okay, so I have spent the past two hours trying to diagnose the issue. The water only comes in when it hits the sunroof, so it must be the top drain. Is there a forum post on how to access this area?

 

It's a pretty big pain in the ***, steps are in the FSM. I think you first remove the mirror and the trim that goes up to the sunroof, then the pillar plastics, then the headliner.

So it's leaking out of the ROOF right?

Here's a link to the FSM,

https://www.nicoclub.com/infiniti-service-manuals

 

Well, I think I found the issue, hopefully. I think the seal was poor when I reconnected the piece to the firewall. I decided to reroute the hose to where the AC line is using this guide.

https://g35driver.com/forums/g35-sed...-solution.html

I hope this solves the issue. I could not get water to come out of the top.

 

Still need to remove the cowl and inspect the drains, if they're plugged it will be leaking water either into the cabin or on top of the IPDM which causes pretty massive issues.

I suspect that your sunroof drains were never clogged and that it's the cowl drain that's the actual culprit. It's an INCREDIBLY common issue with our vehicles whereas clogged sunroof drains is much less common.

The attachment on the firewall is just a hard plastic grommet that has a barbed nipple on one end for the hose and a little diversion piece on the other side to let the water pee out into the cowl, there is a little gasket but the water should freely flow into the cowl. When the cowl fills up with water because it's drains are plugged it's just going to let water drain back through that fitting because it was never meant to be 100% waterproof

 

Hmmm, I'll try to inspect those tomorrow. I could not get any water in the car by hosing the front for several minutes. It appeared to drain effectively. It only came in through the sun roof to my knowledge (water started dripping immediately when I hosed the top, nothing happened on the front with several minutes of water), and I saw where the water entered where the hose drains into the firewall area.

Is there anywhere where I can get pictures of these areas? I have searched around a little bit with not much luck. I am very inexperienced with working on cars. I can figure it out with some sort of guide, but I do not know where to begin. Where is the grommet? Behind the battery area?

I would like to check these areas to make sure the problem stops.

 

i am having the same issue and i thought it was the cowl from reading this thread, but i dont see any drains on it or see where it would collect. I have a q40 though so not sure if its a little different.

 

I'm guessing it's a very similar setup to the G35, start by removing the battery, then put a garden hose on the windshield and run water so you can see if it's pooling up in the battery box instead of draining out the bottom. You want the water turned up fairly high for this.

There is no cowl on the G35, it's a cowl-less design, the water drains out from a drain in the bottom of the battery box. What people refer to as the "cowl drains" is the screen/mesh material on that plastic cover over the wiper motor assembly. If those drains plug up the water pools up and pours right onto the top of the IPDM. If the battery box drain plugs up the whole thing fills up with water and submerges the IPDM as well as possibly draining into the cabin.

You can check your sunroof drains by setting the garden hose on the top of the car, the water should trickle out from a small hole on the A pillar right about level with where the wiper cover is