Coolant smell issue, no leaks anywhere.

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by unsub, Oct 6, 2013.

  1. unsub

    unsub Member 1 Year

    2001 Burb LT.

    Since it started cooling down up here recently I've been smelling a slight but noticeable and constant coolant smell after engine has been running a few minutes, throughout use and after engine has been turned off. This happens whether I have fan running or not, and it's more noticeable when thermo is turned to 70 degrees or more. I have actually smelt a slight coolant smell since purchase but it is more noticeable in cooler weather now. And it seems the more I run the heater the less it smells but when I turn fans down low or off it smells more. Maybe I'm just going insane. IDK

    No leaks from radiator, levels remain the same since purchase and pressure checked at radiator cap and overfill cap. Overfill tank at normal levels. Lines going in and out of radiator are old but no visible leaks. Hoses running to heater core are both warm/hot when heater is running, no leaks seen or felt on passenger or drivers side floors.
    Heat did go cold once when I was testing heater core by running heater and fans in late July but when I took it to my mechanic later that day I could not get the heater to blow cold again or since. Mechanic could barely smell coolant and thought maybe heater core leak but pressure checked out and no sign of leaking on floors.

    Thinking owner before had heater core or other coolant issues he fixed and maybe leaks caused it to pool somewhere leaving it coated somewhere so that I smell coolant now. Thermo isn't opening and closing properly. I just don't know. I have removed and replaced two heater cores in my life and they were both horrible experiences so I'm hoping to avoid that.

    Is there a second heater core for the rear/cargo area?

    Any help appreciated.
  2. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    Usually when the smell is detected inside the truck, it is a heater core.

    It is probably a very small leak and is drying on the core without dripping onto the carpet.

    A lot of the long wheel based trucks have rear heater cores, you probably do as well.
  3. unsub

    unsub Member 1 Year

    Ya that is the usual suspect but being I don't have 8 hours to do it myself the labor would be astronomical so I'm hoping it's something else. I'm sick and tired of replacing heater cores, this would be my third in 12 years and one a lifetime is enough. Only a few auto manufactures have figured out it is more cost effective for the consumer to have the core unit installed on the engine side of the firewall and not in the dash and Chevy is not one of them. I'm seeing for Burbs one goes through the dash from up top to get to it so maybe it would be easier but when alldata shows 8.2 hours labor for this fix I'm not so sure. Throwing on a full lift kit is 1 hour less labor than a heater core in the books.
    The fact I'm not smelling it in engine bay and only inside lead me to believe it was the heater core to. I was just hoping for a easier fix like water pump gasket leak or cabin filter needs replacing. Not so lucky i guess. If I was still in WI I'd be fine, my old mechanic charged $30 an hour, here in MN I'm just another sucker. Will check symptoms over this next week to verify and I will post back. I may have to take my only one day off a week for this because winter here can come at any time.

    You know all about snow and cold up there I bet RayVoy. Thanks
  4. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    Real lucky if I stay around home, we get some snow, usually ice storms. I'm right on the Bay of Fundy and the water temp keeps the real cold weather away; but, go inland 50 miles and we have cold and sow galore.

    Ya know, sometimes a short cut is the right thing to do. I'm not a big fan of using most of the leak plugs that are available, but sometimes it is the best way to fix a problem, just saying.
  5. unsub

    unsub Member 1 Year

    Well the coolant smell continues to get worse yet I can spot no leaks or lower coolant levels. I have to assume it a tiny leak at core that is evaporating causing the smell but no leakage. It can only get worse and I refuse to add in any stopleak snakeoil so I guess a new heater core has to be done. Being I refuse pay most shops 8 hour labor quotes of 650-850 plus the cost of core I will be doing the job myself with the help of a youtube video. Looks as if taking the dash apart is the biggest job as once off the core is right there up top on passengers side. Much different then the last heater core job I did on a Olds which was in the typical tight spot down low underneath the dash. Will post pics in a few weeks.
  6. unsub

    unsub Member 1 Year

    Kinda just replying to myself here but I decided to have this new mechanic I found here locally take a look with me and give me his opinion and there are absolutely no leaks in the engine bay or inside in, under and around the dash. I even had him drill a hole to test out his new camera that snakes in a few feet and nowhere are there any signs of a present or past leak. While he was down there I grabbed a pair of new cabin filters as mine were toast, probably stock from factory. Left the shop and have driven it 10 or so miles with heat full blast on and coolant smell seems much less noticeable. I assumed it was a pin hole leak that caused coolant to immediately evaporate causing the smell and no sign of leak but maybe it was as simple as new cabin filters. Time will tell.

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