This Holden Commodore Seems To Have Excessive Water Dripping From Exhaust
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We just received an email from GM Authority reader, Noel, in Australia who recently purchased a ZB Holden Commodore with the 2.0L turbocharged four-cylinder LTG engine. Despite the fact that the car is basically brand new, our Australian friend noticed something a bit worrying: excess water dripping out of the exhaust pipes.
“Even when driven and reaching running temperature, the car spits water, not water vapor, but water from both exhaust pipes,” Noel says in his email. “The mufflers are starting to rust and the car has done only 2,800 km (1,740 miles).”
Granted, a little bit of water out of the exhaust is totally normal. Along with CO2, H2O is a naturally-occurring byproduct of an engine’s combustion process. However, looking over the pictures provided by our concerned reader, it does appear as though the amount of water dripping out of this particular Holden Commodore’s exhaust does seem to be excessive.
For example, this first picture is after the car was driven 12 km (7.5 miles), and the water drops seen on the ground were continuous throughout that 12 km drive.
This second picture is after the car was driven for 12 km, then left to idle for five minutes. It’s hard to tell from the picture without some frame of reference, but the water puddle does appear to be somewhat sizable.
If there is anything wrong with the car, it might be a head gasket issue, with coolant leaking into the cylinders. However, that would typically include a burning smell and thick smoke, as well as lost coolant from the tank, all of which Noel says isn’t occurring.
Nevertheless, our reader is still concerned about the health of the engine in his new Holden Commodore, particularly how all this excess water may affect internal engine hardware and associated systems, such as the exhaust system.
What’s more, if this is an issue with the turbocharged 2.0L LTG engine in the Holden Commodore, then it could also impact the U.S.-spec Buick Regal (2018 and newer), since both are essentially the same car with the same engine. Hence, it’s entirely possible that the issue – if there is one – will also turn up stateside.
“I have contacted GM Holden here in Australia, and they say the amount of water is ‘normal,’ even though five other 2.0L turbo cars do not produce water from the exhaust,” Noel’s email states.
So we leave it to you, dear readers – is this a reason for concern, or simply normal operation? Let us know by voting in the poll, and make sure to post your diagnosis in the comments section.
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12km isn’t that far to evap standing condensation. need to run 100km. continual short trips will never burn it off
Hello….When I was sold the car i was never told I had to drive 100 kms to do the shopping…..Five other Holden dealers said this shoud not happen ,,,I have raced and rallied turbo car for years and never had this much water run out of rhe exhaust pipes before…The car was taken for a 300 km run and the next day the water ws back…
Some things to consider here.
#1 It is not a head gasket or intake. You would get smoke and you would have an Oder and you would need to be adding coolant.
#2 Most places on the east half of Australia are very humid climates.
#3 because of the humidity car exhaust in some cases can contain a large amount of humid air that condenses and turns into drips of clear water. Some exhaust are more productive of moisture than others.
#4 the exhaust is stainless and should even with moisture hold up for a long time and in most cases as long as the car will last.
My 85 Pontiac is still on the original stainless exhaust.
Clearly not a problem or issue here.
Hi Scott3..
The humidity on the day the pictures was 32% very low in Australian standards…The day the same model car was run in the sales yard was 42% humidity but produced no water from the tailpipes…
The ZB Commodore sold in Australia come standard with a mild steel exhaust system not stainless steel and rust is already starting to form on the muflers..
Thank you NOEL
The burn of gas (mixture of hydrocarbons) produces water. Most of it is not seen most times because it comes out as vapor. It is a no brainer: water vapor condenses mostly when it comes in contact with something lower in temperature. Raising pressure could also cause condensation but it is less likely to happen during the exhaust process. Could it be that maybe the exhaust is running close to an AC line? Etc.
Im sorry to say that the A/C over flow pipe is at the front of the car not at the back under both mufflers…According to a chemist at a major fuel company in Australia to produce this amount of water through combustion of the fuel the car would have to use 220 liters of fuel an hour…..I can assure you this car does not use that much fuel…Thank yo Noel
My 2 cents: When I was a police officer, we often left our squads running while locked as a way to take off more quickly if needed. This would often cause more condensation to form within the exhaust. This was especially bad in the Ford Crown Vics as the design of the exhaust allowed the moisture to pool in certain parts and it would only come out under higher pressure (such as revving the engine or taking off under heavy throttle. There were times you could walk past an idling Crown Vic and hear the water gurgling. Stomp on the go pedal and you would see a lot of water come out the back.
I don’t know nearly enough about the design of the exhaust on the Regal/Holden model here. But maybe like the Crown Vic, it might have a spot which allows the moisture to pool. Thus it would take much longer trips to burn (dry out) the moisture.
@Noel Gibson: My suggestion would be to give the car some heavy throttle and be sure to kick in that turbo a few times on your next trip. The pressure will (should) push the water out more, allowing the normal heat to dry it up better. See if that helps. Also, did anyone check the drain holes in your exhaust to be sure they are not blocked? Simple but could be it. At least I think they still put them in the exhaust. Hope that helps.
Sir i appreciat your comment but how often does your wife go shopping and leave the car running in the carpark till she comes back…In Australia we compare apples with apples not apples with babanas
I’m not sure if this is a GM specific issue. When I was in Georgia, I had the same problem on my mazda speed 3 in summer. It was close to 100 and humid much of the time, and I’d always see a puddle of water under my car. I was told by service that running the AC hard in summer causes this problem. Didn’t have rust issues though.
The water comes from an external source. I had a car that had oil regurgitating in it’s air intake and getting sucked in. I’d check the intake manifold and exhaust system for locked moisture, either by rain water or condensate no
The dealer checked the car and said everything was ok…..I even asked them to check if the air filter was “dry” as its the only place water can be sucked in by the turbocharger….They refused to check it ..So i did and its compleatly dry…So i have no idea where this water is comming from…
As already mentioned, when hydrocarbons burn, they will produce water (the hydrogen combines with oxygen producing heat and water). If conditions are right, the vapour will condense inside the exhaust system. My ’13 Silverado exhaust water drains out of the muffler drain holes. With our long winters, by spring I have a rather large glacier in my driveway, I have to sand it regularly, it is quite the hazard. Also, it is “winter” in Australia.
A change of gasoline brands may help, you might chance upon a hydrocarbon blend with less hydrogen and more carbon content, but probably not enough to notice a difference. I would also check to see if the muffler drain holes are plugged, if there are any. Even in the summer, I have thought my truck had a large leak, only to see the large puddle is water dripping from the muffler.
Hello Davis…
We dont have snow or glaciers in north Queensland in Australia and this water happens every time the car is driven…As I said before a chemist from major fuel company in Australia worked it out to produce the amount of water shown in the pictures the car would have to burn 220 liters of petrol per hour….A jumbo jet engine uses less than that….Its winter here and night temperatures are around the 12 to 15 degrees celcius thats is 53 to 59 degrees fahrenheit at night …..The car was checked by the dealer and they say they couldnt find any faults and ALL cars no matter what make or type of engine produce this much water…..A complete fabrication of lies…
So everyone agrees that moisture/water vapor from the exhaust is normal. And it can vary, depending on temperature, humidity and how the vehicle is driven. So what is excessive? How would you measure it? Who walks behind their car to check that anyway? If you see people behind you turning on their windshield wipers, then I might get concerned. I say drive the car and enjoy the ride. If there is anything wrong with the car, and highly doubt there is, its sounds like you have your concerns well documented with the dealer if your mufflers fall off. But now I am curious enough to check my Tourx . I am going for a 12 km run at full throttle and its humid as hell here in New Jersey. After I get back I am going to have my favorite Service Manager stand behind the car and I’m gonna spray him down.
If I wanted such a stupid comment i would have flushed the toilet……..Who said it was as you say ” full throttle”…
I’d be demanding a replacement vehicle. The dealer will just string you along until you go away unless you make some noise. Give it back to them and buy a real commodore, a VF SS.
Fuel mix could also be in play. If you were running a gasoline/ethanol blend it may be a function of the ethanol absorbing water from the atmosphere. (Ethanol is hygroscopic and draws in water if it is available.) This gets worse if you have less fuel in the tank. Perhaps running a tank of higher octane gasoline will address at least some amount of this.
The recommended fuel is 98 octane and thats what I run the car on and only that…As far as water from the fuel a chemist in a major fuel company saw the pictures i sent and did tests and calculated the the rate of H2O and CO2 emmissions the amount of water (H2O) the car would have to burn 120 liters of water an hour …Thats two tank full of petrol per hour….
I tend to agree that it is a fuel quality problem. Here in Aussie our fuel will have full power for only six months, wether it has got ethonal in it or not. So I assume that the fuel is acting hydroscopically. Thats why it’s no good after 6 months. The tanks at the gas station maybe they have water in them to sometimes. The gas station owner does not care. Maybe you are buying water for the same price as petrol !
Noel: have you just put your finger into the liquid; then smelled your finger to tell if it’s H2o or Fuel?! If your exhaust is steel & the lower level of the exhaust is level enough; then it could drisl out?! If it’s fuel: then your ECU is running too rich!?
Hello Noel.
I’m just a long time shade tree mechanic here. In spite of that, I’ve been told a very good one. Sadly, todays cars are out of my reach in technology and price. That aside, here in the US, in our state of Missouri, they change the blend, or formulation of the fuel being sold, to compensate for summer and winter driving.
If they do that in Australia, could that be a cause of your excessive water problem? I’m just thinking out loud here.
I had a VN commodore and it did the same thing for about 6 years till I sold it. Don’t know what the cause was but didn’t seem to break anything or cause any damage. I just ignored it.
The engine is running idle, and the power turbine on the turbo is robbing enough energy that water vapour from combustion is condensing on the cold exhaust system.
Give it some beans and it’ll evaporate.