Dealership can't solve coolant leak - Need advice
 

Good afternoon once again everyone. I drive a 2013 G37 RWD Journey, and it began to leak a few months ago. I took the G to the dealership and replaced all hoses in the radiator and assured me this would fix the issues. A few days later, the car leaked a good amount of coolant in my parking lot. Took the car to the dealership and informed me that the hose was not tightened properly and now they did a proper install with a compression test. Yesterday, I noticed the G leaked a good puddle of coolant in my garage. I once again took it back to the dealership and the advisor seemed baffled about the issue. I had to leave the G over the weekend until Monday. I am not pissed, but fairly frustrated with the issue. It is a hassle bringing it back, and at times calling in late for my shift. Anyone have an experience with this? I read the the VQ37s are truly reliable engines, and I am really not wanting to get rid of it. Thank you for your time.

Did they check the water pump "weep" hole?

I don't believe they had. I will be waiting for their call tomorrow. I am hoping they will find the cause. Around how much would be the water pump hole repair? Lol.

Water pump repair requires the timing cover to come off and timing chain as well. Your looking at 1500 plus easily at the dealer.

That is pricey! I am hoping that is not the issue because my G is still fairly young with only 80k miles. I will be waiting for their call tomorrow. One of the salesmen was already giving me hints of trading in and I am not going that route lol.

Pretty sure there's no weep hole in a 2013, the water pump is completely buried under the front timing chain cover. I checked the service manual and there's no mention of it, so if anyone knows different, please correct me. A weep hole would indicate there's a passage for leaking coolant to drain to the outside, vs mixing with the engine oil. That would be a major relief because I've always worried about that pump being inside a sealed oil cavity.

I am not very mechanically inclined, but I will take this as a statement for a peace of mind. I simply don't understand how they can keep messing up with tightening the hoses with the right specs. I will have to look for a reputable indie mechanic if the issue persists.

My top hose always leaks because the adjustable worm clamp keeps backing off for some reason. Ive changed it and after tightening it a few weeks later it starts dripping again because the worm keeps lossening

There is a weep hole.
Here is the rear timing chain cover:

https://cimg2.ibsrv.net/gimg/www.myg...f1dc0c4b8e.jpg

And the weep hole in the water pump:
https://cimg3.ibsrv.net/gimg/www.myg...91662099ff.jpg

Finding a leak in a cooling system is not difficult. The shop should use a florescent dye.
They should quickly wash / rinse with water, add a florescent dye to the coolant, then go for a drive to mix in the dye.

Then they will use a special light to find the glowing dye and done!

Darn, SonicVQ beat me to it!
ALL water pumps- be them internal or external- have weep holes. Here is some additional pics for reference...
https://cimg2.ibsrv.net/gimg/www.myg...bead56c4fe.jpg
https://cimg3.ibsrv.net/gimg/www.myg...58020bdaaa.jpg
The o-rings go on each side of the weep hole which prevent the coolant from leaking into the oil chambers.

To be honest, I was surprised to post a reply before you. You are very quick to help :)

Excellent information, Thanks! That definitely takes away a big concern of mine, right behind the oil gallery gaskets. Puzzled why there's no mention of it in the service manual.

I wonder if other G owners have this issue. I had my car for over 8 years and this is the only time I am having issues with the leak. A loose hose is what the service advisor told me the second time I had to go back.

Generally, coolant leaks are not a common issue... BUT as the car ages, the plastic heater hose coupling does start to fall apart and leak or split into two.

The old style "worm gear" clamps are not good. They have uneven pressure and tend to "pinch" just below the screw.
Most factory cooling system use a thick spring loaded clamp. This provides even clamping force around the hose and can even expand and contract a little (due to temperature change) if necessary.

If a worm gear clamp is getting loose, it isn't the clamp... the hose is being squished to the point of permanent compression (aka compression set) and it looks like the clamp is loose.
Then the clamp is tightened more and the process repeats.

I would remove the leaking hose and clean up any coolant residue on the inside of the hose and where the coolant mounts to, get the proper factory spring clamp and that should do it, IF the hose is not too compressed.

Alright fellas. Got a call back from the advisor, and they still cannot figure out the issue. The car was taken on a test run and it is indeed leaking a good amount of coolant. They think it is a leak from the gasket. I did not understand the information thoroughly, but he informed me I would need a new engine if that was the case. The car will stay at the dealership for further inspection. Sad day. It is such a shame because I never abused the car. It was always properly maintained and was primarily run in the highway.