Low Coolant Level for 2nd time in 8 months

[TedH]

Late summer 2013, I started getting Low Coolant Level message. Checked the reservoir and it was about half gallon low. Filled it to HOT level with DexCool. Now, February, 2014, I'm getting the same message again. Going to check the tank but I suspect it is down again.

 

I've not observed any exterior engine coolant leaks in driveway or parking lot.

 

Is intake seal replacement a big job?

Truck has relatively low miles for a 2003: 106K miles.

[TedH]

Late summer 2013, I started getting Low Coolant Level message. Checked the reservoir and it was about half gallon low. Filled it to HOT level with DexCool. Now, February, 2014, I'm getting the same message again. Going to check the tank but I suspect it is down again.

I've not observed any exterior engine coolant leaks in driveway or parking lot.

Is intake seal replacement a big job?Truck has relatively low miles for a 2003: 106K miles.

I plan to fill it once more and then take it in for service.

[efritz]

These have dry intakes. NO WATER flows through them, so that will be a waste of time... Check around the water pump for coolant coming out of the weep hole or the block mating gaskets sometimes leak. Some of those engines with Castech heads had porosity issues, but that is unlikely. Just do some prodding around and you will find a source.

[02suburbanZ71]

It could be an air bubble. It happened to me.

[Wires]

I had that with my '00. Turned out to be a cracked rad hose clamp. It would puke a little coolant when you stopped and the engine was hot. I tried tightening all the clamps, and the bad one split in 2 and fell off.

[FriendlyMan]

I had that with my '00. Turned out to be a cracked rad hose clamp. It would puke a little coolant when you stopped and the engine was hot. I tried tightening all the clamps, and the bad one split in 2 and fell off.

I would definitely check for leaks. Just wait for a really dry day and get your flashlight when the engine has been running and look around for wet spots. I had this exact same problem and it turned out I had a very fine crack in my radiator. In my 2000, the radiator is plastic and after a couple years that plastic gets brittle. I would also check the hoses and clamps. One thing to consider is that when your engine compartment has been running, the heat in there evaporates water pretty quick, making a small leak hard to find. It probably would not hurt to take those hoses and tighten up the hose clamps up a bit as well.

[george.underwood]

One of my leaks was around the water pump to block gaskets. Happened about 150K but took months to finally find it. Replaced water pump with new, and had to clean block gasket surfaces thoroughly. (2002 Suburban).

 

The other leak was at one of the "quick disconnect" heater hose tee's to the front and rear heater cores. I ripped both of them suckers out and replaced with hose bib style tee's and regular hose clamps. Got the right hose and used sealant to adapt to the metal tubing where required. Not pretty but it doesnt leak.

[MikeInCtown]

I just replaced the water pump in my 04. the pump was probably still good as I found the gaskets were the source of the water leaking. You couldn't tell with the shroud, belts and hoses on. Once things started coming off is when I was able to see where the water was coming from.

 

I still have a coolant smell, but no idea where it is coming from now.

[XYZ]

I had the mysterious loss of coolant also on my '03 4.8L, turns out my truck had the 706 casting cylinder heads with the porosity issues...coolant was mixing in with the oil.