Is this normal? What causes this?

I've noticed the coolant level keeps dropping and I don't think there's a leak anywhere since I just replaced the throttle body heater plate - the hose that connects from that point to the bottle was fused pretty badly and got a little jacked up in the process, but I don't think it's much of an issue. This drip at the coolant expansion tank would explain it, though.

Does it happen every time the vehicle is started up?

At the recommendation of someone, I had loosened the cap a full turn (360 degrees from tight).

Should I get the ultragauge and try the thermostat modification next?

I think the coolant in here might be a bit of a mixture of different greens. I had planned to flush it and start over so I know what's in there.

Any advice is appreciated - Thank you

 

Nope you have over pressure possible causes:

• bad rad cap
• Blown head gasket
• Possibly a clogged rad or other clog
• outlier not likely but possible cracked block

 

Should I try to flush the system first to clear any clogs? I’m not sure what else I can check. When I’ve changed the oil (just changed about a month ago), it doesn’t have a whitish appearance to it as I’ve read about when coolant mixes with the oil. I haven’t had overheating issues either. It also doesn’t seem to lack power, but I might just not be able to tell. I planned to flush the coolant anyway since I think it’s a mix of different green fluid and I’m not sure it’s the same stuff. It’s also been a little while. I regularly check all the fluids in the car as was advised.

 

If the cap is one full turn loose, that's why it's coming out of the overflow line. You can gently loosen the cap, maybe a 1/4 turn to minimize excessive pressure...but a whole turn is to much.

 

Thanks, I’ll try that. It did seem to stop when I tightened the cap (fully) again. I’ll have to top the tank up tomorrow and then try running it with just a quarter turn less than fully tightened.

It’s a new cap and it seals pretty tightly. I was told to try a new cap a while ago. When you’ve tightened the cap all the way, then begin loosening it, it stays tight for a turn, then becomes loose, then you can feel the seal tighten again as you continue loosening it. Is there some other more foolproof way of relieving pressure since it’s not easy for me to know exactly where the cap should be with it being tightened or loosened on the cap I’ve got (genuine) which seems that behave a bit oddly?

 

Never mind, I hadn't watched the video, which clearly shows coolant dripping from the overflow pipe.

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Before we all panic ...

Coolant can drip from at least three different places on the coolant reservoir.

1. Coolant can exit via the overflow pipe, as The Deputy noted.
2. Coolant can leak from the nipple on the bottom of the reservoir where the line from the throttle body heater attaches. This is a well-known failure point. The nipple can crack where it joins the body of the tank.
3. Coolant can leak from the seam joining the top and bottom of the reservoir.

The coolant reservoir in my truck has failed and been replaced twice -- once due to #2 and once due to #3.

Please try to identify the source of the leak and let us know what you find. Good luck.

 

If you overfilled that tank it will leak coolant and eventually find it’s level. If you notice the tank level changes with different thermostats
the oem stat you will get half way the 180 stat it’s 1-2 inches lower. Let it settle out

 

I run all mine one turn loose, it will not leak unless there is an overpressure issue. As stated above it will drip a bit if it is overfilled but eventually finds it level. If it does not stop you have a overpressure issue. Normal level is about 1/3 to 1/2.

 

What’s the reason behind loosening the cap?

 

By one turn, you mean one hand turn or a 360-degree turn? I'm worried about this. Will it help to flush coolant and try the thermostat modification you've developed?

I've heard that the line from the expansion tank to the throttle body heater plate can be deleted or that the heater plate itself can be deleted - this line got torn up a bit at the TB end when I had to pry it off the old TB heater plate. I don't understand exactly what it does and if it can just be plugged on both ends? It seems like the heater plate is a regular source of leakage - I recently replaced it and did my best to use gasket sealant so it wouldn't have any problems for a while.

I'll have to take a careful look at the expansion tank to see if it's leaking at any of the points mentioned. I suppose I could just replace the expansion tank since they're known to have problems and they're not too expensive. It wouldn't cause much trouble pumping the fluid out and changing it out, so I might just do that to be on top of things before it has a problem, if it's not already problematic.

I've heard that you can test some of these things by putting pressure through the cooling system, but haven't looking into how that's done or if that would be helpful here.

Thanks for the input, everyone.