PeachParts Mercedes-Benz Forum - View Single Post - DIY OM603 head pressure test

Maxbumpo · #58 06-14-2018, 07:15 PM

Ah-kay - go for it! I think your test is missing just one element, which is heating the head in a bath of water up to about 80 deg C. Have you looked at the FSM method? They use a block-off plate to do the same thing you did with the coins, and then immerse the head in a tank of water and heat it up to 80 deg C, keeping it pressurized the entire time.

I did a similar test, but I pressurized the exhaust passages via the exhaust manifold. I had two heads to test, neither had visible cracks. The bad head did leak at room temperature, allowing air to pass from the exhaust passage to the coolant passages. The good head did not leak even when heated up.

I made my hot bath by cutting a barrel in half length-wise, setting it up on some concrete blocks and putting a big propane burner underneath. I made a block-off plate for the end of the exhaust manifold and attached a pressure hose connector. I cut rubber seals to make a good seal of all the exhaust valves against their seats.