2000 B3500 5.2L van. I have a coolant leak that I can not see. I took it to tires plus to have a cooling pressure test and they said that they could not see any leaks but that indeed the system was losing pressure. I have checked the coolant a lot the past month and when I fill the overflow tank it only takes two days for the level to drop drastically however it always will leave some at the bottom of the tank even if I don't fill it up for a long while so it doesn't seem to completely drain. When I pick it up from tires plus i did notice white smoke after starting it out the tail pipe which then diminished but it was also only about 34 degrees out so not sure if weather related or not. I also do not have any heat coming out of the vents. It only blows cold. any input would be appreciated

Thanks
Marc

 

check your heater core. it could be leaking. one way to checkis to feel the carpet on passenger side of the motor and see if it's wet. if it is, then your core is leaking.

 

If it was a head gasket, would it leave any coolant in the tank and radiator or would it burn it all? I did not notice any wetness on the passenger side. a few different times when i was making deliveries I think that there was a faint smell of coolant.

 

forgot to ask wouldn't they have notice the core leak at tires plus when they did the coolant system test?

Thanks
Marc

 

not if it's dribbling out. pull up the carpet on that side and feel under it. if you have a leaky head gasket, it would blow white smoke on the often side. it would also tend to run crappy if it's a big enough leak. how many miles/days does it take to require a re-fill?

 

it is about three days or 360 miles. but then after a while i decided to no fill it up for a while as I was told that as long as there is some coolant in the overflow tank even if minimal then not to worry. so i went about three weeks without filling but checking often and noticed that it never drained all the way. temp gauge remained normal. this van does have 525,000 miles on it. at times after starting and first driving it revs up but takes off slowly after that it drives fine.

Thanks
Marc

 

forgot to say that when i turn the blower on it squeaks at times and during loud squealing there will be no air coming out

 

whoever said that the overflow tank is your "reserve" (so to speak) and your ok was an idiot. your rad cooling system needs attention and with the # of miles on it, i'd be the head gasket is leaking. one test the mechanics can do is test for hydrocarbons in the cooling system, this would indicate exhaust gas is getting into it thru the head gasket. however if this was the case you'd be overheating. you might want to check the block on both sides to see if there is any evidence of leakage out any of the freeze plugs or seepage coming from where the head meets the block.

 

Steve,

I checked around the motor today and did not notice any leaks besides a tiny bit of wetness around the valve cover but nothing alarming as for around the head did not notice anything. there was no wetness on the passenger side either. also I paid more attention to the way it drove and the engine feels smooth and strong, nothing different than when I bought it a year ago before the coolant leak. I have read on this blog about a guy that the same problem with illusive coolant leak and he found out that there was a core hose leak even he could't not see any wetness anywhere.

Thanks
Marc

 

well thats good to here, couple of places to look for a leak would be at the t-stat housing, it is a common leak area and may be dribbling out, the weep hole on the water pump and also heater core (I think you said you checked and found nothing). another reason for loosing coolant is a bad radiator cap, however with you having a mechanic look at it, it sounded like he put a pressure cap on it and put 15~16 lbs of pressure and you watched it bleed down. one other thing you might do is bring it back to him and ask him to put the pressure pump back on, then go look for the leak.