Author Topic: Overheating: Overflow tank boils before gauge is halfway (Read 2824 times)

Haraise · « **on:** October 12, 2009, 05:19:39 PM »

Hello,

I just purchased a 1991 318i, and it has been overheating.

The overflow boils before the gauge is half way. The tempurature gauge will change from just barely over half way to close to the red in a moment.

I'm rather sure that the problem is the water pump, which made the head go out. Sound right to everyone else?

Where is the cheapest place to get water pump supplies? (found a good writeup on how to change it, so should be set there)

I've tried to bleed the system, but the first step of bleeding the system is letting it warm up, and it boils before then, with cold radiator tubes, so I'm pretty sure it's the water pump.

There's a sound that sounds like a bad water pump, which I think caused the original problem.

Also, when I replaced the thermostat, the coolant passages were full of "jello." Built up coolant residue. How can I flush the system completely?

Thank you all.

tjts1 · « **Reply #1 on:** October 12, 2009, 05:50:47 PM »

It sounds like a blown headgasket.

HATER-PROOF · « **Reply #2 on:** October 13, 2009, 02:17:45 AM »

Pelican Parts is the Walmart for our cars.

Haraise · « **Reply #3 on:** October 13, 2009, 02:53:28 AM »

I've already priced out a water pump, water pump gasket, new radiator cap (already have a new thermostat installed), BMW antifreeze on Pelican parts. Might just get all new belts while I'm at it too. Recommend anything else?

I have a radiator compression tester and leakdown tester on the way as well, so I should sort this out.

HATER-PROOF · « **Reply #4 on:** October 13, 2009, 03:16:44 AM »

Just make sure you get the WP with the metal propeller

Haraise · « **Reply #5 on:** October 13, 2009, 03:39:49 AM »

Got it covered. The less plastic, the better...