Edmunds Answers



  • drtomjones 02/22/10 8:14 am PST

    if you can look at the engine from under the vehicle then take a look near the cylinder heads, you may have a leaky head gasket and a -stained short block with antifreeze smell- might be evident in the area. Also check on places that don't normally have anything to do with antifreeze near the back of the engine, such as the tranmission shift linkage having drops of coolant on it.

  • desperado3 02/22/10 10:16 am PST

    hey to the guy that answered we looked the whole motor over no sign of any leakes
    anywhere . we have looked at every gasket nothing i even changed the oil no sign there
    either .

  • mechinc1 02/22/10 2:24 pm PST

    I hate to be the possible bearer of bad news.......

    We had a handful of customers with the same trucks that were going through about a gallon of antifreeze every 3 -5'000 miles. Checked for head gaskets, intake gaskets etc. Did a block check to see if combustion gases were getting into the cooling system and nothing came up.
    We had one of these customers who wanted a 6.0ltr installed into his truck for more power. We did it!
    After the engine was out (to see if we could find the original problem) we took the valve covers off and found that the driver's side head had many cracks in it!
    We told the other customers what we suspected was the problem and asked them if they wanted to investigate.....All of them had the same problem......All of them on the left side of the motor only. I dont know if it was just a coincidence???
    We called the local GM dealer and asked if this was a problem.....OF COURSE THEY SAID NOOOOOO. We asked them for price and availability on parts to fix truck.
    The parts guy said there was 2 in stock in Waco TX. and as he was looking at the computer screen it started to go into negative numbers. What does that tell ya???
    I honestly hope this isnt your problem....but.......be forewarned

  • desperado3 02/22/10 2:32 pm PST

    thats just it the tank is not going down any no leaks that we can tell just smell but there is no presure building in the resivor tank when you run it the tem satys at 210 one macanic told me to try the cap

  • alaskanj 02/22/10 2:39 pm PST

    Instead of a vacuum test try pressurizing the system. Just might be pinching off a small leak when its in a vacuum. Pump it up and see if it holds the PSI, of course do this with the engine completly cooled off to get an accurate reading of pressure like first thing in the morning. This is obviously a really small leak. cooling systems are a sealed system so there should be no reason for smelling coolant anywhere....

  • karjunkie 02/22/10 2:51 pm PST

    Are you running the heater when you smell the coolant? I'd suspect a pinhole leak in the heater core. Not enough of a leak to produce a drop in fluid level but enough for antifreeze to stink up the cabin.

  • mechinc1 02/22/10 3:14 pm PST

    Have you considered the heater core? It might not show inside the truck so look on the firewall for the condensation drain. (engine side of firewall) Sometimes these get plugged up with leaves and debris and if there is a leak it, the antifreeze is blocked. It's on the right side of eng compartment.

    The rad cap is a good spot to check as well. Like the other gentleman mentioned about pressure testing the system, get them to do a pressure test on the cap as well. If it is getting weak it may give you the smell and no leak. Try pressure test on system cold and then try it hot.
    Good luck

  • drtomjones 02/22/10 10:54 pm PST

    the cracked head theory sounds pretty good. any hoses or connections that aren't tight? sometimes the factory will leave those handy hose clamps that have the slot to keep them open, open. A weak seal like this will only show up when the engine has reached operating temp. and there will be evidence of coolant somewhere. it is a PITA to check every connection but sometimes it can pinpoint a small problem. a coolant smell without an obvious leak/heavy loss of coolant is a really small problem. BTW the heads will look rusty-cast iron or whiteish-aluminum...


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