Need help with coolant leak

[OughtNotSoToBe]

I bought a 2013 3.8 sedan last November, and I love this car! But it seems the honeymoon is over, sadly, and I’m dealing with three major issues. The most urgent is a new coolant leak that has developed.

There’s precious little online to help me, but I have found a couple mentions of a leaky thermostat housing. My leak appears to be near the rear of the engine.

I’ve scoured the Internet, but I can’t find any information on the location of the thermostat in my car, let alone instructions on how to access the cursed thing. So, I’m about to attempt to remove the entire intake manifold (or whatever that huge hunk of Tupperware is on top of the engine) so that I can maybe see what the hell is going on back there.

Someone please stop me if there’s an easier way!
(Or if I’m about to make a huge mistake)

:/

 

[mikec]

Look at the fat water hoses going to/from the engine. One will end in a fitting bolted to the engine; this fitting has 3 bolts around the triangular-ish shaped fitting. The thermostat is underneath this fitting.

The V6 engine has other external water plumbing items. Some on the backside of the engine:
1: the hoses to/from the heater core for passenger compartment heating.
2: A funky "water temperature control assembly" which has several hoses and tubes connected to it. It is physically located at the top/rear of the engine, above the bellhousing.
3: Water lines to keep the throttle body above freezing.
4: Water lines to the left and right side of the engine.

Like most cars today, the engine is covered by a large slab of plastic. This "pretties up" the view when the hood is opened and serves to lessen engine noises. The V6 has a lot of wiring, vacuum hoses, coolant lines, etc. underneath this cover; it's rather a mess under there. One magazine writer dubbed the Genesis V6, with this cover removed, as "Darth Vader without his helmet." On the V8 Genesis cars, the cover simply snaps into place. I don't have any direct experience with the V6s.

mike c.

 

[OughtNotSoToBe]

Wow what a metaphor! Well I can work with that - I’ve already removed Vader’s snap-on helmet. The hunk of plastic I was referring to is the largest part visible from the top, and near the passenger side, rear of the engine, the throttle body bolts on to it. That’s why I think it’s probably the intake manifold. And honestly I’m afraid to remove it, first, because I think it’ll open a can of worms, and second, because it might not even help me find my leak.

From what I’ve pieced together, the thermostat is on the passenger side. But when I inspect with a light, the evidence of leakage that I can find is on the drivers side, rear. With the engine running or not, I can find no evidence whatsoever to indicate where, exactly, the leak is coming from.

And by the way, this is a huge leak. I’ve already gone through 1.5 gallons of the green stuff, and I’m not interested in blowing a head gasket!

Am I really the only guy to have a coolant leak in a 3.8 sedan? There’s literally nothing online to help me.

 

[Ozy44]

COOLANT LEAK

I have a 2009 Hyundai Genesis 3.8 V6 with a small coolant leak that’s causing air to come in the system and spikes my temp gauge. Had it seen by my shop and said they located leak by thermostat and water distribution housing at the rear or engine (diagnosis picture attached). He explained the...

genesisowners.com

Check out the above link.

 

[OughtNotSoToBe]

TL;DR:

I’m diving in, and I’ve taken so much apart that I’ll probably never get it back together again! But this seems to be a rare issue, so I’ll document my process and the result in detail so that someone else might be helped by my experience in the future.

Okay here are the boring details of where I’m at with this so far:

I ended up setting an appointment at a shop that I trust, but nothing is available until next week. So while I wait for the appointment day and time to roll around, I did what comes naturally (for better or worse)... I started tearing into it myself.

First I removed the intake tube/pipe between the air filter and the throttle body, then I removed the throttle body itself. I figured I should take this opportunity to give the TB a good cleaning! Next, I removed both metal coolant pipes on the left and right side of the engine. With those out of the way, I decided to try to get a better view and better access by moving the wiring harness out of the way, so I started unplugging electrical connectors all over the engine until I could move out enough... Now I’ve removed so many that I’m getting nervous about putting this all back together!

There is so much in the way of plumbing on this car that it’s almost over the top. And I hate to remove too many items because I know that it’ll be twice as difficult getting it put back together. But I don’t think I’ll be able to tell where the source of the leak is unless I can examine parts, and I can’t do that with them in place. Now with the wiring harness able to be moved around, my access to and view of the plumbing is much improved, even though it’s still pretty awful.

At this point I called a dealership and spoke with a service advisor to ask if there was a particular part that might be prone to leakage, and he said he didn’t know of any coolant leakage issues and suggested I try asking in the Genesis forums!

Since the majority of leaked coolant is on the drivers side, I’m going to attempt to remove that thing that mikec described as a ‘funky "water temperature control assembly"’ first.

The further I go with this, the more nervous I get. But whatever happens, I’ll update this thread with plenty of detail, since this doesn’t seem to be a very common issue - maybe I’ll be able to help out some other poor guy with a leaky Genesis in the future!

 

[OughtNotSoToBe]

I think I may have found the leak! But I need to dig deeper to confirm. This is nuts. I've removed what I believe is called the surge tank on top of the intake manifold, and I believe I will need to remove the fuel lines and the intake manifold next...

If there is any interest, I made a video. I would welcome any comments on it! (I.E.: Am I on the right track? etc.)

 

[Peteoutside]

I have the 2009 V6 sedan, no coolant leaks yet. It's at 155000km. Thank you for sharing.

 

[G-10842]

I just did a rebuild on my 2013 3.8 that pipe that you think is the issue is a very rare failure and you should also be careful and check the oil send switch as it sits in the bottom of the v . The coolant has nowhere to travel once it leaks into the v. By saying (V) I am referring to the space underneath the intake manifold.

 

[OughtNotSoToBe]

I ended up taking it to a reputable indy shop, and I spent over $1100 to get it fixed. Had to replace the throttle body. What?? Yeah, for some weird reason, coolant goes through some tiny tubes in the throttle body.

Now it is leaking slowly once again. I'll wait until the weather is better to figure it out. But dang...

 

[joegr]

I ended up taking it to a reputable indy shop, and I spent over $1100 to get it fixed. Had to replace the throttle body. What?? Yeah, for some weird reason, coolant goes through some tiny tubes in the throttle body.
...

That's not weird, it's very common. It's to keep the throttle from icing over in certain conditions.

______________________________

Help support this site so it can continue supporting you!

 

[G-878915]

That's not weird, it's very common. It's to keep the throttle from icing over in certain conditions.

Hi mate is there an update on the genesis leaking or losing coolent mines overheating and losing coolent but can’t find where, I’ve replaced the thermostat and all rubber o rings replaced water pump replaced radiator and replaced all the heater hoses all with new genuine parts, and still the same issue I’m having ,

 

[toxicavenger70]

Hi mate is there an update on the genesis leaking or losing coolent mines overheating and losing coolent but can’t find where, I’ve replaced the thermostat and all rubber o rings replaced water pump replaced radiator and replaced all the heater hoses all with new genuine parts, and still the same issue I’m having ,

See if you can get the system pressure tested for leaks.

 

[Gunkk]

UV dye test for leaks. If there are none visible, then you know there is only one option left: head gasket.

 

[Charlie1982]

Hi mate is there an update on the genesis leaking or losing coolent mines overheating and losing coolent but can’t find where, I’ve replaced the thermostat and all rubber o rings replaced water pump replaced radiator and replaced all the heater hoses all with new genuine parts, and still the same issue I’m having ,

Do you get any smell of coolant inside the car?

 

[G-815877]

Do you get any smell of coolant inside the car?

I’ve had the same issue,just replaced thermostat and water pump and the car runs hot and you can smell the coolant