Check really good where the ends of the radiators crimp to the end housings. Ford had a bunch that came from the factory with bad crimps.

The last one of mine they replaced they said the previous dealer installed the T backwards and it caused the leak...IDK...might be BS, all I know is the original rads in these trucks are crap. Get them to replace it with Certified Stock. Most guys have had at least one replaced on the 08's.

 

Thanks for the replies.

If I were home, I'd check the radiator as you suggested, Leviticus. I never considered it a problem, as my truck had the venturi T installed before I bought it, and I figured the radiator wouldn't likely be a problem.

I have a question for those of you who had a radiator go bad. Was it leaking to the point where it was actually dripping anywhere? Could you see it from the bottom of the truck looking up? I went very slowly over the entire underside of the truck, including the bottom of the radiator, and found no leaks. Could it be too small to even drip down before it evaporated?

 

My rad. went sour at about 10,000 miles. It was dripping on the left side of the rad./truck. I could see it on the frame, etc. Got a new rad. and the venturi came out about 6-8 months later. Did that myself and no further issues....

 

Both of my radiators that were replaced leaked on the bottom corner, driver side. The first one leaked pretty bad and was easy to diagnose. The second was very slow and I knew it was leaking more because of the smell than seeing coolant on the ground. I'm pretty sure the only time coolant got out of the radiator was when the system was pressurized and pumped while I was driving.

It's hard to say that this is what is happening because you state that you can't smell it. The smell is very easy to whiff so I don't think it's a viable option, but, who knows?

 

Thanks for the replies, everyone.

R-T0r21on and ruschejj, your posts have me convinced that it's likely not the radiator. I've stuck my snout in nearly every area it would fit trying to find a leak, and none was there to be found. No residue, no wetness...NOTHING! Can't smell anything either, and the smell of antifreeze is unmistakeable. On every vehicle I've had before you could easily smell even a small leak when you opened the hood...I don't get that here.

Also, my wife reminded me on the phone as she was taking it in of odd behavior while she was driving it. It's done it to her the last three times she's driven it, and the common theme here was that she was starting with a cold engine each time. When she was accelerating up to speed on the highway, which is about 1/2 mile from my apartment, she heard the engine making an awful noise. She told me she could actually feel it running a bit rough, and then it went away after a few seconds.

This happened to her again on her way to drop it off, and I think it lends credibility to my theory about the EGR cooler. It's my best guess that as the truck is cooling down, pressurized coolant is seeping out into the EGR system. Probably wouldn't be enough of a leak to have any noticeable running problems, but as the truck cools pressurized coolant could begin to collect in the EGR system. I think when she gives it part throttle to accelerate to speed with a cold engine, all that water and coolant is being fed into the intake all at once, causing it to run rough as it ingests it.

Now this noise and running rough has never happened to me before, so I can't say one way or another about it. I can say that the coolant level stayed mostly steady during the previous months I've owned it, and over the last month it's noticeably been going down, and during that time I haven't driven it much.

Maybe my wife broke it!!!

Just kidding...

 

your thoughts make sense to me. Lets hope it is the EGR so you can be done with the problem.

 

Either way convince her that she did it and keep it in the closet for the next time your in the dog house. If you're like me, that won't be long, haha. Good Luck

 

Now that, my friend, is some true wisdom. I'll have to use that!

 

Hey Crazy... as you know I am not s diesel guy, but to diagnose a coolant leak, especially a slow one, you need to get your hands on the radiator pumps... It has a cap, with a hose attached, and a hand pump with a guage. Pump it up tp 15 psi, then start looking.

Good Luck...Its rough being out there, thats why I got off the road... But there aint nuthin in the city now either.

 

Yeah, I'm familiar with the device you're talking about. Not expensive, but free at Autozone as long as you bring it back in working order. Have used them several times when trying to troubleshoot a few older cars I have worked on. Without a doubt, the best tool for troubleshooting a cooling system leak.

The problem is finding an adapter to fit the coolant reservoir on these trucks. If I'm not mistaken, the coolant reservoir is pressurized, and the cap acts like the radiator cap. Never have found an adapter to get the pump to fit onto one.

Regardless, it's at the dealer now. I have an appointment tomorrow morning, and I should hopefully know what's going on by noon tomorrow...

 

If they don't locate the leak it might be a good idea to pull a sample of oil and send it to the lab to see if any coolant is in the oil.

 

very good idea, sgrol. I have a Blackstone test kit sitting at home that I should probably put to good use....didn't think of that! Thanks!

 

A bit of an update, if anyone's still interested.

I called this morning to get a status update, as yesterday all I got was excuses as to why they hadn't figured it out yet.

Their answer today was that I should come and pick it up, as they couldn't find the leak. He confirmed to me that it must be going somewhere, but that the leak is small enough that the tech can't find it. When I mentioned the fact that the low coolant level I bought the thing with was attributed to air pockets in the system, he agreed with me that 3,500 miles should be more than enough to purge them and maintain a constant level.

He told me to keep monitoring it and bring it in if the leak gets worse. I also asked them for a jug of coolant to take with me just in case, which he had no problem doing.

I'm going to get home this weekend and my wife and I are going for a drive to see if I can recreate the rough running problem she's experienced a few times before. If it still does it, I'm gonna park it at the dealer Sunday night to let it cool down overnight, then come in Monday morning and ask the tech to take a ride with me...

 

I would hook up to the biggest trailer you have and take it to the biggest hill and put it to the floor then taks a pic of any leaks if you see them

 

also pull a coolant sample and send it in.
you may need coolant lab results in the future.

Butler CAT in SD if Blackstone doesn't do coolant analysis.