3.0 overheating? WTF?
 

Here's the backstory...I went to KY for camping about 4 months ago. We took the truck off road (it's 2 wheel drive) so I didn't get on it hard enough to break anything but slung lots of mud. When I get back, I was driving a few weeks later and the truck overheated. I couldn't find where the leak was coming from so I drove it down to the local repair shop and the guy said the thermostat housing had cracked! He ordered a new one and replaced it. I had him drain and fill the radiator and replace the theromstat while he was at it. Everything went fine.

Then cold weather hit. The first cold morning I drove it out the thing redlined for about 10 seconds and then the gauge went back to normal. That seemed strange but as long as the engine was warm it was fine. So it happened again. And the next time it actually made a slight THUMP and then a SPPT! Then it was fine again. I figured this couldn't be right so I went to Napa and got a new thermostat that is made in the USA and replaced the one from the repair shop and drained and filled the radiator again. This time I noticed what looked like light brown mud under the radiator cap and in the radiator fill hole. So after doing all this it still overheated when it went from cold to warm again.

What could be the problem? I would think it is possible the radiator could be stopped up with rust but why would it start flowing well after it gets warm? I filled the radiator up on a slope so I was hoping to get all the air out of the system. I'm thinking of replacing the sending unit and radiator cap tomorrow but the gauge seems to work just fine so I don't anticipate either of these will help. Any other suggestions on what could cause something like this?

Since cold weather is upon us, ANY help would be appreciated. (Sorry the post was so long. I wanted to make sure I covered all the questions. Heh)

Well I just walked outside and opened the hood to check the overflow reservoir and it had popped the top off of it, spewed all over the underside of the hood, and down the side of the wheel well. If it's overheating to the point it's overflowing the reservoir, would this be an air bubble, a bad radiator cap, or something worse?

Light brown mud under the cap ? Check the oil after it gets up to temperature . Does it look milky ?
Get the cooling system pressure tested . It sounds like you may have a bad head gasket.
Also , when the local shop changed the antifreeze , did he replace it with the same type that was in the system to start with ? Different types (Gold ,orange,green) don't mix together and can cause problems.

x2

A mech should have this blue or green liquid...think its blue...He puts it in a little cylinder in place of where the radiator cap should be...Then starts the car...If it changes color, it means there is exhaust gasses getting in the cooling system, so you have a bad head gasket...Happened on a pontiac vibe...He didnt charge my ex anything to test it either...

That's just it. It didn't look or smell like oil. It looked more like rust and it had grains to it...almost like mud. I got it warm and changed the oil and it looked and smelled fine. I haven't been losing any oil, either. I would agree with this usually but nothing seems to point to a head gasket leak.

The fact that you overheated it (when the thermostat housing cracked) does point to a blown head gasket.

The cracked thermostat housing was said (by the repair shop) to be caused by a defect in the housing. I've replaced the cheapo radiator cap and bled the air out of the lines and so far (knock on wood) it has been steady. I'll keep everyone informed if this fixes the issue.

u have a blown head gasket i had the same problem....its building pressure and will soon start popping radiators...if the overflow tube gets gunked up with rust..i ran mine for a while by removing the thermostat and runnin a vented cap with the vent open until i got the time to replace it make sure u get ur heads magnafluxed (checks for cracks) and warpage

If that is what it turns out to be, what did it cost to have it redone?

Well it turned out to be two things (according to the shop): the radiator was full of rust (and the shop owner says this is normal for Rangers?) and the water pump was shot. Here's the final that I'm hoping I can get some help with. They replaced the radiator, water pump, and upper and lower radiator hoses. It fixed the overheating. But it caused another problem!

Now when I get on the gas hard (when it goes into the passing gear) the whole drivetrain rattles! I can feel it in the floor. It was NOT doing this when I took it into the shop. The owner said it felt like normal drivetrain noise and dismissed it. I took it back to him twice and he said he checked the motor mounts and they were perfect. What could make this happen just because they changed the radiator and the water pump? He said, "I don't know as much about these trucks as some guys. You should take it to another shop and have them test drive it. Let me know what they find out." At this point, I'm p@##$d off because he should have told me he didn't know s$%t about my truck before he charged me to fix it and actually made it worse!

Any ideas would be appreciated. When I sit in the driveway and hit the gas really hard with it in park, the entire engine lurches to the drivers side. My dad worked in the Army motor pool during the Vietnam war and he says he doesn't know that much about trucks but he knows that isn't right. He thinks the motor mounts aren't good but the shop owner got underneath it and SAYS he had a good look. I just know I can't continue to spend money on this thing and I can't be happy driving it until it's back to where it was before this idiot got hold of it.

It's normal for every vehicle in which people put tap water in their radiator instead of distilled water or buying pre-mixed antifreeze.

As for your other problem, if the motor does move excessively, then yes, the mounts are shot. They are also your only line of defense in NVH (Noise-Vibration-Harmonics) between the drivetrain and the chassis.

Your truck is 10 years old, I'm pretty sure most of the rubber in the original mounts is pretty rotten by now.

Well this just took an ugly turn. The first water pump had a bent shaft so he put another one on it (at his cost) and the second one busted. He said they tested the head and now they know the gasket is leaking! It supposedly caused the pressure build up that popped the new water pump. So instead of the $1300 he usually charges for a head gasket replacement, he's going to do the whole job for $600. He's pulling it down tonight. (sigh) Just what I needed at Christmas time.

Oh well. Looks like I'll be driving the Camaro for about a week. Thanks for the info, gang. I had hoped it wasn't a head gasket issue. :/