irratic temp Gauge

[zeth]

I have a 2001 Montana. Wife tool van temp gauge went into the red with no power. Checked coolant level found it was low. Topped up level and checked for leaks. Found coolant leaking at the intake gaskets. Replaced gaskets as per the bulletin. Bled cooling system and now it is worse. Have no heat teamp sometimes go in the red but usually returns to normal. Put 1000k on vehicle since repairs. If I bled cooling system every day it maybe ok for the day. I crack the bleed screws nothing but steam. I would appreciate help.
Could it be a thermostat or head gaskets. I have a block tester with dye I purchased. Blue point is the brand name.

[GTP Dad]

Welcome to AF!!

Your issue is air in the system. Somewhere there is air trapped in the system that is not coming out especially if you get steam when you open the bleeder screw. Find a hill to park the van on with the front end pointing uphill. Then try to bleed it. This promotes the air to move to the front of the engine. Also if the van has a cap on the radiator you can leave the cap off while running the engine. Once the thermostat opens the level should drop. Top it off and repeat the procedure. This will help get the air out of the system. If the cap is on the reservoir it is much harder to do. Good Luck!

[cdru]

If GTP Dad's solution did not work, I'd be suspect of a faulty head gasket. A faulty head gasket will either allow coolant to escape out, or allow compression/combustion gases to be forced into the coolant system.

[schnikees]

Hey GTP Dad, I tried bleeding the system while on a hill, with and without the cap on. I still get steam and an erratic guage. If we're driving the temp will peak and we'll pull over and shut the engine down. If we wait a few minutes and start the engine and start driving it usually drops down to 150 really quickly. But pretty soon it's back up again. It's driving me nuts and I can't find a good mechanic in the LA, CA area.

[cdru]

You've been driving a month and a half and still are having issues? Have you been adding any coolant?

[schnikees]

that's the crazy part, the fluid levels don't drop. After the gauge hits the red line I shut her down and lift the hood and there isn't any physical evidence that the car is overheating. My mechanic thinks a bad gauge has been the culprit. I finally took it to the dealer and he says the head gasket is blown. That's two head gaskets in one year. If it's been air in the system the whole time, how do I convince my mechanic that he hasn't been bleeding the system properly? He's the only one to work on the thing and I suspect that evertime he changes a component (water pump, thermostat) he doesn't properly bleed the system. Is there a fact sheet I can show him to prove this point? The van is just sitting at the shop until we negotiate a deal, he thinks I'm at fault, I think he's at fault, and neither one of us can prove our point.