[Rich J]

Well I just got out of my car while doing a delivery and I was overwhelmed by a sweet/burning smell. First thing that came to mind was head gasket so I babied the car back to the store and pulled the dipstick, the color looks normal (level was a little low) then I checked coolant color and it looked a little dark but not too dark. What could be that smell and what else should I look at?

[whyxitx]

SMELLS LIKE: MAPLE SYRUP
WHEN: After the engine has warmed or possibly even after it's shut off for a few minutes.
THE CULPRIT: Coolant containing sweet-smelling (but toxic) ethylene glycol is leaking from somewhere. It could be coming from a radiator or heater hose, a failed intake manifold gasket or cylinder head. It might be coming from a leaky radiator cap or the radiator itself, especially if you smell it outside the car. A strong odor inside the passenger compartment probably means a bad heater core.

[Rich J]

Originally Posted by whyxitx SMELLS LIKE: MAPLE SYRUP WHEN: After the engine has warmed or possibly even after it's shut off for a few minutes. THE CULPRIT: Coolant containing sweet-smelling (but toxic) ethylene glycol is leaking from somewhere. It could be coming from a radiator or heater hose, a failed intake manifold gasket or cylinder head. It might be coming from a leaky radiator cap or the radiator itself, especially if you smell it outside the car. A strong odor inside the passenger compartment probably means a bad heater core.

It's only outside, I'm just hoping it's not something major/engine life threatening lol.

[whyxitx]

maybe coolants just leaking somewhere and it's getting burnt? since it's sweet you'd think it'd be the coolant.

[Loki]

Sweet equals coolant....Pretty much always. Lol. Check all your coolant pipes. Check all pipes & hoses for cracks or damage. Check all of the clamps to make sure they still have clamping power. Have you touched any part of your cooling system lately?

[mustangmike!]

someone put sugar in your gas tank :p

[mcqueen]

Look around for coolant leaking. My dad used to have a big ol conversion van that was leaking coolant (never did find out where before he sold it) but it definitely smelled like sweet maple syrup when it burned.

And just fyi, there are 2 coolant hoses on the back side of the engine. Found that out when I pulled them off and had a nice mess to clean off the garage floor.

[bigjohnstud4200]

My guess is you have a crack in the intake manifold.. has it ever been changed out? There's one thing that inevitable with our cars, the cross over pipe on OEM manifold is junk.

[Rich J]

Originally Posted by bigjohnstud4200 My guess is you have a crack in the intake manifold.. has it ever been changed out? There's one thing that inevitable with our cars, the cross over pipe on OEM manifold is junk.

Intake manifold? As in like upper intake? Only things that have been replaced in my engine was both exhaust manifolds and the air intake.

And no I haven't touched anything related to my coolant or anything else for that matter. I parked my car for a few hours with a big piece of cardboard under my car, just checked it an hour ago and nothing leaked.

I mean as long as its not going to break anything it doesn't really bother me. I was just asking.

[Rich J]

Quick question, what does burning transmission fluid smell like?

[Tang Stang]

Originally Posted by mcqueen And just fyi, there are 2 coolant hoses on the back side of the engine. Found that out when I pulled them off and had a nice mess to clean off the garage floor.

Those would be the lines to/from the heater core.

Originally Posted by bigjohnstud4200 My guess is you have a crack in the intake manifold.. has it ever been changed out? There's one thing that inevitable with our cars, the cross over pipe on OEM manifold is junk.

That's true for the SOHC 4.6L's...not so much on the 3.8L's (you're in the V6 section).


OP, just keep an eye on your coolant, oil, and trans fluid (if it's an auto). More than likely it's an external leak, if you're smelling it strongly outside of the vehicle after driving it. You can check all of your hoses, the water pump, the radiator end tank seals, the heater core drain, etc. to track down the source of the leak.

[bigjohnstud4200]

Originally Posted by Tang Stang That's true for the SOHC 4.6L's...not so much on the 3.8L's (you're in the V6 section).

Sorry, didn't realize I was in the V6 section. I guess that's what happens when you use the "new post" button while surfing from work and not paying good enough attention.

[WickedSnake00]

Originally Posted by Rich J Intake manifold? As in like upper intake? Only things that have been replaced in my engine was both exhaust manifolds and the air intake. And no I haven't touched anything related to my coolant or anything else for that matter. I parked my car for a few hours with a big piece of cardboard under my car, just checked it an hour ago and nothing leaked. I mean as long as its not going to break anything it doesn't really bother me. I was just asking.

Just because it doesn't make it to the ground doesn't mean it isn't leaking. Because you're smelling it, that means it's cooking off before it gets to the ground.

Look for a spot that has a white/blue residue on it, like treated roadsalt almost. Spots to check would be water outlet, water inlet, radiator in, radiator out, heater in, heater out, and water pump. They use cheap hoseclamps on these cars, and it could be something as simple as that. Since you're getting the smell it's most likely to be on or around the block.

Also grab the water pump snout and see if you can wiggle it. If that bearing goes out, it will leak pretty good. Plus that's one of those failures where it can only leak while running.

[bigjohnstud4200]

You can also clean the engine bay, run to the parts store and pick up radiator dye and use an UV light to spot where the leak is.

[rfcsoulja]

Originally Posted by bigjohnstud4200 My guess is you have a crack in the intake manifold.. has it ever been changed out? There's one thing that inevitable with our cars, the cross over pipe on OEM manifold is junk.

I have never heard of one of our intake manifolds cracking. I know some of the gts have had issues with their plastic manifold cracking but that isn't a problem with our aluminum intakes. OP, are you sure its your car and it wasn't something outside?

[Rich J]

Yea I am sure, I've smelt it a few times since. I smell it more when I am standing on the passenger side of my car. Also I can't smell it inside.

I didn't smell it often today though, I did notice (I am going to get yelled at for this) the smell pops up whenever I manually up shift my auto. (sorry it's fun to do every once and a while) Thats why I asked what burning transmission fluid smells like.

[WickedSnake00]

Originally Posted by Rich J Yea I am sure, I've smelt it a few times since. I smell it more when I am standing on the passenger side of my car. Also I can't smell it inside. I didn't smell it often today though, I did notice (I am going to get yelled at for this) the smell pops up whenever I manually up shift my auto. (sorry it's fun to do every once and a while) Thats why I asked what burning transmission fluid smells like.

Burnt transmission fluid is pretty distinct, not sweet at all.

Keep an eye on your coolant level and color.

Does anyone know what kind of trans cooler our automatics use?

I know a large number of automatics use a liquid to liquid cooler, which actually exchanges heat in the bottom of the radiator. One of the most common failure modes is the exchanger rupturing and dumping trans fluid into the radiator. You'd notice this in the fluid color though.

The only other thing I could think of related to the transmission would be the increased heat rejection from the trans cooler could be causing fluid to be pushed out somewhere. Maybe causing an overflow and it's dumping out somewhere there? I'm grasping at straws here though.

These leaks are difficult to track down to say the least. My dad's Ram developed a leak in the radiator hose that would only leak during high speed operation, and due to the airflow under the hood you couldn't pinpoint it. Took quite awhile to figure out.

[Rich J]

Coolant color is kind of dark, but its been in there for a while. I am not sure if coolant darkens over time.


EDIT: If I smelt my coolant and transmission fluid was in there would I obviously smell it?