Diesel Exhaust Leak?

[Hunter65]

2012 Chev Duramax, 90k. I am nowhere near being a mechanic as far as this goes.

I'm not sure what diesel exhaust smells like before it gets treated in the exhaust system, so I am unsure what I'm smelling. I have smelled diesel exhaust before, prior to all the emission controls these days, and its obviously diesel. This is not. The odor is very pungent. Mostly noticeable while near the truck when its running. I thought something was burning ie wires, battery, or some other component. Truck runs fine otherwise, no warning lights on the dash etc. A little smell in the cab while driving. No obvious exhaust coming from anywhere other than the tailpipe. Seems to clear up after shutdown.

Is there any way a non mechanic like me can test for a leak before I take it in somewhere?

And does diesel exhaust have a real funky, strong odor to it before it goes through the exhaust system?

Thanks
Mike

[LKILR]

To find a leak in the exhaust you can temporarily plug the tail pipe and start vehicle then inspect the system as quick as possible. A potato or an apple works well to plug. Don’t ask me why I know this as I will plead the fifth. Lol

[bagwan]

Its possibly in the re-gen cycle when you happen to smell it. I backed my trailer into a campsite with a 2013 Dmax and thought I had a major problem. Let it finish and then ok. I haven;y had this happen yet with my 16 but it uses the DEF so might be just a matter of time.

[Hunter65]

Its possibly in the re-gen cycle when you happen to smell it. I backed my trailer into a campsite with a 2013 Dmax and thought I had a major problem. Let it finish and then ok. I haven;y had this happen yet with my 16 but it uses the DEF so might be just a matter of time.

I think the info center will tell me if it is in regen? How long does regen last? Of the 90k on I, I have never smelled anything like this before.

[cdmc]

Batteries? I know it sounds silly but I had one producing on our dmax putting out 27v and it smells terrible

[Hunter65]

Batteries? I know it sounds silly but I had one producing on our dmax putting out 27v and it smells terrible

Thought about that - i had nothing but trouble over the holidays when it was so cold. Truck wouldn't start (i hardy drive it), charged the batts, still no go, had to wait until it warmed up on Jan 2 or whatever day it was. Thats about the time I noticed the smell, or so it seems. Take it in and have the batteries and exhaust checked i guess. Hope i didn't pooch them.

[Ddawg]

It’s possibly you have a exhaust leak on the down pipe after the 9th injector, happens during regeneration, smell enters the cab, it’s a common problem with your year of truck. It’s an easy fix.


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[reddeerguy2015]

It's probably the Regen smell you are smelling. Diesel smells like - well, diesel. Still plenty of trucks on the road that smell like a true diesel should....pre-emissions.

When regening the exhaust will get VERY hot and burn off all the undesirable soot and crap in the exhaust. It stinks.

Maybe a delete and tune is in order ??

[-JR-]

Double check your coolant level.
Coolant can also have a funny burnt plastic smell .

[Taco]

'12 d'max a def fluid truck? My older LMM truck with the dpf filter deleted will make your eyes bleed if you run it in an enclosed space too long.

[Hunter65]

Double check your coolant level.
Coolant can also have a funny burnt plastic smell .

Coolant level checks good.

[Hunter65]

It's probably the Regen smell you are smelling. Diesel smells like - well, diesel. Still plenty of trucks on the road that smell like a true diesel should....pre-emissions.

When regening the exhaust will get VERY hot and burn off all the undesirable soot and crap in the exhaust. It stinks.

Maybe a delete and tune is in order ??

Pardon my ignorance - but not entirely sure what you mean by delete and tune? In fact, can you or someone explain that? I see it all the time but as stated, not sure what is is exactly. I know, google is my friend. Is it a mini max chip sort of thing? Remove and replace exhaust, remove emission equipment etc? More ponies and better mileage?

My bud had a mini max on his dodge. Quite the difference in everything. Not sure i want to do that, if that in fact is what you're referring to.

I don't mind the DEF every now and then, and the truck is plenty powerful for my needs. Just trying to figure out what stinks. If the stink is all normal, I'm ok with that.

Mike

[gmcmax05]

It’s possibly you have a exhaust leak on the down pipe after the 9th injector, happens during regeneration, smell enters the cab, it’s a common problem with your year of truck. It’s an easy fix.


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^^We have a winner, get your def injector checked, (or 9th injector as it's called) these have been known to leak causing strong exhaust smell in cab.

[gmcmax05]

It's probably the Regen smell you are smelling. Diesel smells like - well, diesel. Still plenty of trucks on the road that smell like a true diesel should....pre-emissions.

When regening the exhaust will get VERY hot and burn off all the undesirable soot and crap in the exhaust. It stinks.

Maybe a delete and tune is in order ??

But it doesn't reek in the cab when it regens, if the injector isn't leaking.

[reddeerguy2015]

Pardon my ignorance - but not entirely sure what you mean by delete and tune? In fact, can you or someone explain that? I see it all the time but as stated, not sure what is is exactly. I know, google is my friend. Is it a mini max chip sort of thing? Remove and replace exhaust, remove emission equipment etc? More ponies and better mileage?

My bud had a mini max on his dodge. Quite the difference in everything. Not sure i want to do that, if that in fact is what you're referring to.

I don't mind the DEF every now and then, and the truck is plenty powerful for my needs. Just trying to figure out what stinks. If the stink is all normal, I'm ok with that.

Mike

Your truck is newer than mine (I've got an 09 lmm duramax). Mine didn't have a def tank...I'm assuming yours does ??

I'm not overly familiar with them, but if what the other two gentlemen said to be true about the leaking def injector (9th injector), maybe follow their advice. But in general most stock diesels when regening get hot and stink. It's normal. But an exhaust leak is not - so there is a difference.

A delete and tune is exactly that - to get rid of restrictive emissions equipment. Delete EGR on engine, tune (EFI live, mini Maxx, etc), remove def and catalytic converter on the exhaust. On my duramax this was done with a turbo back exhaust system. On my dodge it was just a chunk of 4" exhaust pipe swapped onto the stock exhaust in place of these components.

Good luck.

[TylerThomson]

'12 d'max a def fluid truck? My older LMM truck with the dpf filter deleted will make your eyes bleed if you run it in an enclosed space too long.

Hahaha. I've had people come into the lunch room and tell me my 7.3 was on fire. I said nope its just cold out and the engine needs to warm up. That thing will smoke out a city block until it gets to operating temp.

[KBF]

Not sure what the def injectors are like on the pickups but on the line of Ag equipment I worked on, injectors and connections would leak often and def would drip and build up externally and it makes a wonderful concrete like substance that makes it a lot of fun to get the screws out that hold the injector in exhaust pipe.

Where is injector located on the pickups? Tractors were right at muffler

[RZR]

To find a leak in the exhaust you can temporarily plug the tail pipe and start vehicle then inspect the system as quick as possible. A potato or an apple works well to plug. Don’t ask me why I know this as I will plead the fifth. Lol

This is very stupid advice. :snapoutofit: it could be DEF injector

[bagwan]

I think the info center will tell me if it is in regen? How long does regen last? Of the 90k on I, I have never smelled anything like this before.

Your pungent odor is what I noticed and it was hard to take. I stood back and let it finish as that's what I thought was happening. Never noticed it again and the truck was about a year old. Do you have a DEF tank in the 12? That regen finished in a few minutes. My 16 didn't like 34 below either. Needs a fully charged system or no go. Mine sat for three days and turned over very slow. Found out the free oil is not synthetic. I'm not sure if the center tells a re-gen is in progress as I've never noticed. It probably does but theres lots of things on this beast I don't know. LTZ with gizmos that an old geezer never uses.

[coolpete1]

did you look under it and make sure no one stole your exhaust? it happens a lot.

[reddeerguy2015]

did you look under it and make sure no one stole your exhaust? it happens a lot.

Ya because I'm sure he wouldn't have noticed the sound of a missing exhaust on a duramax....:sHa_sarcasticlol:

[Hunter65]

did you look under it and make sure no one stole your exhaust? it happens a lot.

Pretty sure its still there.