Where is all my coolant going?

[boulky12]

I've had my truck for about 9 months now. The first day I got it, I noticed the radiator was only half way full, so I know this truck has had this issue for a while now.

Upon inspection, I noticed a few drips under the radiator, so I went ahead and replaced the old copper/Brass radiator, with a new aluminum one.

I'm not getting any coolant drips.
The truck dosent smoke.
My carpet isn't soaking with coolant, so I don't think the heater core is leaking.
The oil is clean and not milky at all, and I'm still loosing coolant.

I've been having to refill my reservoir about every 3 days since I got the truck and it's starting to get kind of annoying.

What do you guys think? I'm sure someone has encountered this issue before.

Thank you

[m3talc0re]

How much are you losing every three days?

[SkinnyG]

Mine was leaking out the back of the intake manifold. 

Some was getting sucked into cylinder 8 (found evidence in the intake port), and some was apparently getting into the oil (never changed colour, but Blackstone Labs reports said there was evidence of coolant), and eventually became bad enough to puddle under the engine at the back of the block. 

It had never puddled before, I'm guessing it was evaporating off the header or something. 

It was leaking about a liter a week or so.

[boulky12]

How much are you losing every three days?

About 2 water bottles worth. Maybe more.

Basically from the full mark on the reservoir until it's empty.

[boulky12]

Mine was leaking out the back of the intake manifold. 

Some was getting sucked into cylinder 8 (found evidence in the intake port), and some was apparently getting into the oil (never changed colour, but Blackstone Labs reports said there was evidence of coolant), and eventually became bad enough to puddle under the engine at the back of the block. 

It had never puddled before, I'm guessing it was evaporating off the header or something. 

It was leaking about a liter a week or so.

We're you physically able to see the leak at the back of the manifold?

What did you do to fix that?

[SkinnyG]

It had been losing coolant for about two years.

Feeling around the back of the head, by the bottom of the intake manifold, it seemed a little wet, but it looked more like oil and dirt.  I didn't want to pull the intake manifold off until I was absolutely sure.  Nice thing about leaks, is they don't usually get better. 

When the engine started puddling on the floor, I could definitely feel wet on the back of the head, and it looks, smelled and tasted like coolant.

I pulled the intake manifold off, cleaned it all up, and re-sealed it.  I had been in a rush last time, in the dead of a Canadian winter, in an unheated garage, and didn't let the silicone set up long enough on the China walls - this time I used Permatex Ultra Black, and let it set up half an hour before plunking the intake back on).  It ain't losing ANY more coolant now

[m3talc0re]

That's what I'm thinking. A small leak around the engine somewhere out of sight. The engine heat then burning it off. Try running the motor for a bit, heat it up then use one of those telescoping mirrors? I'm just getting into these engines and don't really know how the coolant is run compared to my Vigor (Acura)...

[boulky12]

Alright thank you guys for that. I'll definitely give the motor a good inspection soon, especially in the back.

One of my buddies also said I should rent a pressure tester from oriellys or Autozone and that might help to tell where it's coming from.

[big_al273]

Using a pressure tester you can pressurize the coolant system while it's cold and look, listen and feel for the leaking coolant. Simple but very effective so your buddy was right on the mark saying that's how you should start your diagnosis

[philo_beddoe]

Mine was at the heater core, never had a drip, and lost a lot daily. But half way to work it looked like a steam bath inside the cab, and try wiping coolant of the inside of the windows. The air inside the cab tasted like sugar. Replaced core, job done.

[boulky12]

So the other day I gave the engine compartment a good inspection right after I drove the truck and the cooling system was still pressurized, and it's leaking from the radiator.

It's puddling right where the plastic meets the aluminum on the drivers side of the radiator. I'm pretty sure I still have a warranty on it from oriellys so hopefully the next one they give me is a good one.

[roger97338]

It's puddling right where the plastic meets the aluminum on the drivers side of the radiator.

I had a Cadillac with a composite radiator in it. From what I've read, they were so prone to leaking that they came from the factory with stop-leak already in the cooling system. In the Chilton's manual, it also says to use stop-leak when changing the coolant.

At some point, someone needs to understand that plastic isn't the answer for everything.

[SkinnyG]

My truck had one of the copper (brass?) tanks split off the core, and leak that way.  I had a local rad shop re-core the rad with a high-density 4-row core.  It was pricey, but it's an awesome rad.

Interestingly, when I said I had an electric fan, they were quick to poo-poo me, said I should go back to the original clutch fan, said it was better.  When the new rad was in, I drove it down and showed them the dual Ford Windstar fans that suck more current than the alternator provides.  They were impressed.  Said they were expecting a wee aftermarket electric fan.

[boulky12]

So I went to oriellys today and got another radiator under the warranty. Found out its a lifetime warranty so I can just keep taking them back until I get a good one lol.

I installed it and drove the truck for 30 min on the highway. No leaks so far but the real test will be after a week or 2. I'll let yall know

Thank you all for your ideas and information.

[Timberwolf]

One of the most overlooked causes of coolant loss is a bad radiator cap. They will open early, (at lower pressure than spec,) and bleed off your coolant while you're driving. Don't forget to check that with your new radiator.