Where could an antifreeze leak be that would not be found by a pressurized test?

Answer 1

Your welcome.Off the top of my head, I would guess at a water pump from experience. Although, I would strongly recommend finding the real leak. Anyways here's a list of possibilities:water pump, head gasket, intake manifold, heater hose, radiator hose, bypass hose, radiator, heater core (usually leaks in passenger compartment floor), thermostat housing.As you sit in the driver's seat, where would you say that you see it? Center, right or left front of engine compartment? front middle or rear of engine compartment? How much and how often is leaking? Does it run rough? does it overheat?

Sorry I didn't re-read the initial question.Also add cap, reservior bottle and overflow to that list.One thought: A well known company can still hire a poor quality technician unintentionally and may have not pressure tested correctly or was not aggressive enough to find. There is a shortage of good technicians. if the system was low and pressure tested it may not have turned up. He should have pressure tested the cap to make sure it was good.Another thought: Assume the tech was good, Heat can affect a leak sometimes. I have seen it with waterpumps and head gasket leaks in particular. When it is cold the surfaces contract and seal a leak, when hot they expand and allow a leak-or vica versa.Another thought: Add dye to the system-make sure it is for coolant not oil. Any decent parts store should have this.

Dan,I would add the dye. Based on the location and other normal conditions present, it further leads toward the water pump.However, if it is in the corner right there is a possible seam leak on the radiator. I have seen both of these leak intermittantly.The Dye will help isolate it. Post what you find, thanks,Paul

Dan, I hate to beat a dead horse, but did you put dye in it yet?I had a 2000 Chevy Malibu that wouldn't leak until it was driven about 40 miles. If it wasn't for the dye, I don't know if I would have ever found it.If you can't find the dye, I'll find where you can.

Don't necessarily knock the other companies. It took me a painful 200 miles worth of test driving,6 cans of cleaner, at least 3 hours of labor of dissassembling and reassembling, 3 gallons of dexcool and countless shop rags to find this particular leak. Not to mention that it became a heated issue between the tech working on it and myself. He kept telling me it was a hose and I wasn't buying it. Oh yeah, we did this at no charge as well. She just put $600.00 into fixing the leak because we diagnosed it as a intake manifold leak. Granted she did have the manifold gasket leak and it did need repair, but I think the trouble one was the water pump. I also had deep sympathy for her as well since her daughter was brutally murdered less than a year ago.

If we had used the dye in the first place, we could have saved a lot of leg work, material and headaches.

Dealers have techs like any other shop. Just because they are the " Dealer", still only makes them as good as their techs, their policies, ethics and their perserverence.

Anyways, I am glad you got it resolved.

If you have a bad head gasket, cracked head, intake manifold leak, or even an exahust manifold leak you can have similar signs for all these problems. First question is does your car run hot or has it leaked or overheated recently? Even though you have a new head gasket I wouldn't rule that out. You are running your car around and since the coolant is hot it has expanded to fill the reservoir tank. When you park it at night the radiator will draw the coolant back from the coolant reservoir and empty it. On the weekend fill your reservoir and start your car and wait and watch as it is warming up. You are looking to see if the coolant is being forced out of the coolant recovery tank. This may not happen right away. If so that is a possible leak of one of the items listed above. It could also be the radiator cap so you could try that as it is probably less than $10 anyway. Get a new one with the same pressure as the old on or your car will run hotter (If less lbs). Do you have hard starting in the morning? (Possible that a cylinder has coolant in it). Pull spark plugs and see if any fluid is squirted out of cylinder. Also look at spark plugs. Are the plugs covered in a white ash or extremely wet looking? (Indicates same thing).Do you see white smoke from the exhaust with a coolant (sweet) smell? This could be intermittant. If so then you have one of the leaks listed above. You may or may not get coolant mixing with your oil depends on size and position of leak (Usually this happens when leak happens between cylinders). Look for coffee and cream color of oil. You would see this on dipstick or filler cap.Have a service guy do a block test to the coolant to see if exhaust gasses are present. (Should indicate a leak at any one of those points mentioned). They use a tube that is put in filler neck of radiator (It is filled with dye) if the dye changes color then you have exhaust gasses present.

I may not be a mechanic but I have been looking into this very problem, because I keep blowing the seams out of my new radiators.