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Coolant In Exhaust Smell

Discussion in 'Prius c Main Forum' started by Lukey51, Jan 24, 2020.

  1. Lukey51

    Lukey51 Active Member

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    I could be wrong about this but my exhaust seems to smell like it has coolant in it. I had head gasket issues in my '03 Nissan Sentra and treated it twice with Thermagasket which worked well. The 1st application lasted over a year and if I'm not mistaken the 2nd application last 2-3 years or more until I traded the car in.

    I was looking at used cars online again, wondering if I should trade the Prius in and every time I enter the model years and see all the engine problems they've had, it makes me shy away from that idea.

    I know what coolant smells like although once I think Blackstone Labs found it in my used oil analysis which prompted me to do something about it.

    I might do a UOA right now to see if they see coolant in the oil. I don't have any sign of it on the dipstick and am not aware of the coolant level going down.
     
  2. davecook89t

    davecook89t Senior Member

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    The Gen 3 Prius has head gasket issues, no question about that, but it seems they can largely be avoided by cleaning the EGR system components. The Gen 2 Prius, on the other hand, is not known to have head gasket issues under normal operating conditions, and that is the same engine that you have in your Prius c. If you start to notice your coolant level dropping or a dipstick that shows what looks like chocolate milk, well then it is time to start worrying. Otherwise, if you maintain the cooling system properly so your engine never overheats, I think you have nothing to worry about.
     
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  3. Lukey51

    Lukey51 Active Member

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    I had the coolant flushed earlier this week.
     
  4. Lukey51

    Lukey51 Active Member

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    Every time I feel like I want to trade her in I start looking at cars listed and then see how they rate at carcomplaints.com, then seeing many models that have tire wear issues, engine ticking issues, transmission issues, using oil issues, and many other serious problems and it scares me away. Then when I drive the Prius again I say to myself "this car isn't going anywhere" because I like the way it drives and feels. It goes down the road straight and has a good solid feel to it.

    I'll analyze the used oil from it in the Spring and see what I find. Thanks again.
     
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  5. bisco

    bisco cookie crumbler

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    i think you might be a bit paranoid
     
  6. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    These cars have an exhaust heat recovery system. It's essentially a fancy double pipe that has exhaust flowing through the center and coolant flowing through the outer layer. Most cars don't have this. It's a second place where exhaust and coolant are normally quite near each other, and if something leaks they can mix. You'd get exactly the same smell as a blown head gasket, but fortunately it's far cheaper and easier to deal with. I haven't actually heard of one failing yet, but why not? It's an exhaust pipe. Exactly the sort of thing I'd expect to see rust and fail eventually.

    Probably the most positive step you can take is simply to monitor the coolant levels over time. Draw a line on the bottle with a grease marker while stone cold.

    If the level isn't dropping then you don't have a leak and you are probably just smelling some leftover that was spattered on the undercarriage when you had the flush done.

    Also don't put headgasket-in-a-bottle in your Prius unless you are planning to junk the car soon after.
     
    #6 Leadfoot J. McCoalroller, Jan 24, 2020
    Last edited: Jan 24, 2020
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  7. Lukey51

    Lukey51 Active Member

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    I picked up 15 quarts of Castrol Edge 0w20 on sale and I'm going to change the oil & filter in April. :)

    Will do. Thanks.
     
  8. Lukey51

    Lukey51 Active Member

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    Maybe I'm wrong but I never thought Thermagasket was harmful to the engine. With Thermagasket, I drained my coolant, poured in 1/2 of a bottle of each Thermagasket chemical, filled it with water, and drove the car for 200 miles. Then I drained the fluid, flushed the cooling system with water (Thermagasket kits include a back flush kit) and added new 50/50 coolant / water, then changed the oil and filter. I applied it twice on my 2003 Nissan Sentra and it did a good job and the engine didn't burn any oil before or after. It had 90k miles on it when I traded it in, and to be honest with you I wish I still had that car. The 2000 to 2004 Sentras are known for head gasket issues. Other than that it was a great car.
     
  9. Lukey51

    Lukey51 Active Member

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    I could smell the coolant in my 2003 Sentra exhaust, then did a UOA (used oil analysis) done at Blackstone Labs which detected coolant in my oil, so I treated it with Thermagasket based on the UOA. Follow up UOAs found no coolant until 1 to 2 years later so I treated it again with Thermagasket. I wouldn't treat the Prius unless a UOA found coolant in the oil, and perhaps I'd think twice about it if online people don't recommend it.
    If people don't have a good sense of smell or they don't do UOAs then they may have coolant in their oil which may or may not lead to head gasket failure and a loss of drivability.
     
  10. Lukey51

    Lukey51 Active Member

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    Interesting but things like this tend to scare me. Again, we're talking about mechanics who don't dare to touch these things and specialists who want $91 just to take a look at it. Maybe I worry too much but at times I really feel like selling my Prius and getting a regular car.
     
  11. dubit

    dubit Senior Member

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    But all you did was have the coolant changed. It's most likely just some splatter your smelling when it heats up..... I guess I just don't understand the logic. You seem to be one to takes care of a vehicle. If you buy something else, you'll do the same. Some maintenance here / there. Maybe hear a clicking noise then start worrying about a halfshaft going out or unknowingly splatter some fuel and find yourself worrying about why your smelling gasoline.

    Don't mean to be brutal here - but just drive the car. Your in what is considered to be one of THE most reliable vehicles on the road with the LOWEST maintenance costs. Give it a shot to prove that to you.
     
  12. Lukey51

    Lukey51 Active Member

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    Actually those UOAs are kind of a waste of money too. Many people do them but the price of one test would pay for 1 or 2 oil & filter changes.
    I may have a trustworthy garage down the street look it over but I have doubts they'll find anything wrong.

    It would be pitiful if I parted with it and then heard about the new owner putting about 300,000 trouble free miles on it.
    Running it is the best thing I could do right now. The car may never let me down at all.

    The car has at best a unique smell to the exhaust, but it's unlike other cars and that may be the reason why.
    If the coolant level stays put and I think it probably will, the car will probably perform well.
     
    #12 Lukey51, Jan 26, 2020
    Last edited: Jan 26, 2020
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  13. Lukey51

    Lukey51 Active Member

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    Is this part of the EGR circuit you're referring to that leads to head gasket problems in other models of Prius?
     
  14. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Nope. I don't think the big Priuseses have them; certainly none prior to 2010.

    Here's a picture. It lives more or less under your shifter. It's an exhaust pipe with a water jacket.
     
  15. Lukey51

    Lukey51 Active Member

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    I see. So they want to heat up the coolant because the internal combustion engine doesn't run full time as in regular cars?
    Seems like it might be more of an issue in colder climates.
     
  16. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Can't know the specific reason they chose to put it in, but a device like this would help most cars get better gas mileage, especially for short trips. The reasons for not including it include cost and complexity, but apparently Toyota thought it was worth it in this case.

    If you only go 2 miles every morning and the car needs 4 miles to warm up, you'll consistently have terrible MPG. A gadget like this can make that warm-up period much shorter.
     
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  17. Lukey51

    Lukey51 Active Member

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    They actually over filled my coolant when I went back the day after they flushed it, after the reservoir level seemed low. Then he seemed to fill it to about 1 inch over the "Max" line in the reservoir. Today, which is about 4 days and 40 miles after they over filled it, it seemed to be right about at the "Max" line when I checked it about 4 hours after driving it. Would over filling it tend to make me smell coolant in the exhaust?
    I could be wrong but the level seems to have have came down.
    I'll check it again when it's stone cold before I drive it
     
  18. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Overfill can't give the exhaust an antifreeze smell directly, but if it overflowed the bottle then you'll be smelling antifreeze in a few different places. And of course the engine air intake is right there, where it can breathe in some spilled antifreeze fumes or steam from splatters burning off, and then that will quite naturally go out the tailpipe as sweetened exhaust.

    It really sounds like a combination of their sloppiness and your paranoia. Make a mark on the bottle when it's cold, monitor it weekly for a month or two, and have some fun driving it between now and then.
     
  19. Lukey51

    Lukey51 Active Member

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    My 2003 Nissan Sentra had head gasket issues as the 2000 to 2004 Sentras with the 1.8L were known to have. That was not paranoia I had that detected it, that was a head gasket issue. I smelled the coolant in my exhaust with my own nose and ascertained coolant in my oil via UOA, then successfully treated it.
     
  20. Lukey51

    Lukey51 Active Member

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    I wouldn't call it paranoia. I'd call it a keen sense of smell that knows what coolant in my exhaust smells like from past experience.