Another exhaust smell thread

Discussion in 'Troubleshooting & Diagnosis' started by 7.62fmj, Nov 2, 2017.

  1. 7.62fmj

    7.62fmj Member

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    May 16, 2017
    Jacksonville, Fl
    I recently started noticing a sweet smell in my exhaust. I thought it could be coolant, but there's no white smoke once the engine warms up and the choke opens. I usually fill up at BJ's but last tank was Shell. I was also wondering if winter gas could smell different.

    333 with a Holley 4175 list 80555-1, dual exhaust, no cats.
     
  2. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    Ringgold, GA
    See if you can "rent" a coolant pressure test system from one of your local parts houses. Should tell you if you have an internal coolant leak.
     
  3. 7.62fmj

    7.62fmj Member

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    May 16, 2017
    Jacksonville, Fl
    I haven't noticed any overheating or low coolant levels, I'll do the test this weekend if I can.

    If my cooling system holds pressure what else could cause a sweet smell? Burning coolant is often described as maple syrup which is a dark smell, but my pipes smell like a lighter sweetness if that makes sense.
     
  4. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    Auto tranny vacuum modulator leaking? How's your transmission fluid level?
     
  5. 7.62fmj

    7.62fmj Member

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    May 16, 2017
    Jacksonville, Fl
    Trans fluid is good. Good level and color.
     
  6. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    If you have a mity-vac handy it may be worthwhile to check it out anyway. It doesn't take too much of a leak to create a smell. Other than that I would lean towards coolant.
     
  7. Gary S

    Gary S Administrator Lifetime Gold Member

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    Bismarck, North Dakota
    The sweet smell can sometimes come from a heater core leak. When I've had leaking heater cores, I notice the sweet anti-freeze smell even before it shows up as a film on the inside windows. Keep a watch for film buildup on the interior glass.
     
  8. badazz81z28

    badazz81z28 Veteran Member

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    Las Vegas, NV
    There's no reason to question it,if you smell anti-freeze it's coming from somewhere.....heater core is a common leaking area.
     
  9. 7.62fmj

    7.62fmj Member

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    May 16, 2017
    Jacksonville, Fl
    I'll check that, but I only smell it from the exhaust which is why I was thinking maybe head gasket, but no smoke.
     
  10. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    Ringgold, GA
    If you're only smelling it from the exhaust, the pressure leak down should pin point it, and it should manifest itself with a bad heater core. One point of caution, and it's likely not to happen, but if you push enough water into a cylinder, you can hydro lock the engine. You can also remove the spark plugs, use a cheap bore scope, and look for a piston top that's much cleaner than others. That will be the one that's getting steam cleaned.

    Almost forgot this one. Take radiator cap off, crank engine and let it come up to heat. If you have a cracked head or gasket that's in contact with water, you should see bubbles in the radiator.
     

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