Exhaust Has Anti-freeze Smell - Montana Owners Club

MacDR50 · 01-10-2009, 06:34 AM

My new Duramax has a sweet, faint smell of anti-freeze in the exhaust. Should I be concerned or is this normal.

SlickWillie · 01-10-2009, 07:52 AM

Quote:

quote:Originally posted by gpats

That usually indicates a leak in your heater core--

Huh? Heater core? I would think you would smell that inside the vehicle. Been there, done that. My old 6.2 Chevy went through two or three heater cores. Anti-freeze smell in exhaust means leaking head gasket to me. Seems the EGR valve is water cooled also. I would definitely have it checked out. Also might post a question over on Diesel Place forum. There are some serious gear heads over there.

swanny · 01-10-2009, 08:51 AM

not good!!! could very well be the head gasket or crack in the head. also look at you oil for some foaming this would indicate antifreeze in your oil. good luck

hazmic · 01-10-2009, 08:53 AM

SlickWillie is right. Have it checked ASAP. Could be head gasket to a cracked block or head. Keep us informed.

clutch · 01-10-2009, 03:40 PM

The best adviced here is take it to a dealer. That could be very serious.

Trailer Trash 2 · 01-10-2009, 06:30 PM

I would think if he was burning anti freeze in the combustion chamber wouldnt white smoke ( steam type ) be produced out the tail pipe, I know it does on gas engins.
I'd still get it checked ASAP.

Delaine and Lindy · 01-11-2009, 02:21 AM

Are you having to add anti-freeze? If you are its probably isn't good. I would check for head gasket or cracked head. If there is anti-freeze in the exhaust that is just a possible cause. I haven't seen this problem with a Duramax but had read that other people had talked of this situation. But you do hear of problems with the head, I again haven't seen this problem, its always a brother or cousin, you know what I'm saying. Good Luck. GBY...

Montana Sky · 01-11-2009, 05:59 AM

The new LMM is starting to show signs of head gasket problems. There was two in the shop last week while I was having my fuel filter changed for that very reason. My local dealership said, "once they replace the gasket, the problem seems to go away with no further service required."

MacDR50 · 01-11-2009, 08:55 AM

Thanks for the advice. I am going to get it into the dealer. While there is no white smoke coming from it I think I'll play it safe.

skypilot · 01-15-2009, 10:37 AM

MacDR50: Wondering if you had any update as yet?

TAKPAK · 01-16-2009, 12:55 PM

By all means, get it checked. However, one thing I noticed about my new '08 Duramax was the exhaust smell, right from day one. I have been around diesels all my life and this is the strangest smell I have ever "smelled" from a diesel anyway. It has a kind of "sweet, ammonia" type smell, completely different from anything before. What I found out is it is a combination of the new ultra low sulphur diesel fuel, hence no strong sulphur smell, and the new DPF (exhaust filter) system. Standing by a diesel exhaust used to be bad, and would burn my eyes/make me cough. Not so the "new" smell. Although it is not pleasant, it doesn't "take your head off" like the old did. I have smelled an exhaust that did have antifreeze in it, and the smells, at least to me, were close.......although the antifreeze was a bit "sweeter" if that can be said.

That said, "when in doubt, check it out" for peace of mind's sake. Especially while it's still under warranty!

bsmeaton · 01-16-2009, 01:02 PM

MAC, anxiously waiting myself!

It is wierd - I rented an Explorer last week for the week and it had 250 miles on it. I smelled antifreeze the whole week. Funny thing is I smelled ethylene glycol which I don't think they even use anymore.

skypilot · 01-17-2009, 07:31 PM

I just had the oil changed in my Dodge and the dealer filled the windshield washer fluid. Ever since, it has the most awful smell (smells like the old style straight anti-freeze as memory and my nose serve me).... regardless, I went back to the dealer just to make sure they didn't fill with the wrong bottle -- nope -- the current stuff they have smells to high heaven. Didn't think about it until I saw Brad's post above. May it be something so trivial and easy to find!!!

On edit, I did ask if they knew why the company made it smell so bad, dealer had no real answer. Do know that my wife doesn't want to ride with me in the truck right now though - says it stinks so bad it makes her sick. That is not good!!

ole dude · 01-19-2009, 07:17 AM

I have noticed on mine an interesting smell from time to time. In watching the fuel usage on the computor, I think that the smell occurs when the fuel mileage is falling, which leads me to believe the thing is in the regeneration cycle when the odor happens. I get no notification the the truck is in regeneration. Therefore some times when I smell what I smell is when I pull in and stop and turn the engine off. Just my observation.

ole dude · 01-19-2009, 07:19 AM

Oooppps, I am refering to my 2008 Duramax.

MacDR50 · 01-20-2009, 09:38 AM

Thanks again all. Well I took it to the dealer. They did their bulletin check and came up with PIP4135B. This refers to a cooling system leak in the EGR valve. I secured a copy if anyone needs it. They carried out all the tests required including a system pressure test and came-up with negative results. We, the shop foreman and I both then smelled the exhaust before I took back the truck and the smell was gone. (Never would have done that with a pre-ULSD engine!) He asked me to carefully monitor the coolant level when the engine was at normal operating temperature. If I noticed a loss then bring it back in. I asked him about the regeneration cycle and he said he hadn't noticed any smell but he would ask next time they had a service meeting with the regional GM rep. He did say that they have had two faulty EGR coolers in the 200 or so 200708 diesel trucks that they have sold. All involved observable loss of coolant. He then put a note in my file for the service tech to call him next time my truck came in for routine service. Gotta love a dealer like that eh!

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