The Ford Barn

alexiskai · 04-06-2019, 08:26 AM

OK, here's the results so far. I haven't changed out the condenser yet, but I did check the exhaust and the compression.

To test the exhaust, I connected a vacuum cleaner to the end of the exhaust pipe and then cranked the engine by hand with all spark plugs removed. I could feel the suction on each cylinder in turn; no cylinder was open when it wasn't supposed to be. So this seems to indicate that the exhaust pipe is clear and the exhaust valves are more or less working.

To test the compression, I connected a testing gauge and, with spark plugs removed and throttle fully open, cranked the engine using the starter. All cylinders showed 60-65 psi except for cylinder 2, which showed 40 psi on two separate tests.

I performed a wet compression test on cylinder 2 by squirting some oil into the cylinder with an oil can (I made sure to get the oil in the cylinder itself). Rechecked compression and it wasn't substantially improved, maybe 45 psi.

So I guess I have two questions:

Everyone think this is most likely a head gasket?
Is this likely to be the problem that's causing the rough running or is it more likely to be a long-standing problem that I just hadn't detected before?

04-06-2019, 08:26 AM	#11
alexiskai Senior Member Join Date: Apr 2018 Location: Mebane NC Posts: 3,176	Re: Sudden rough running, out of ideas OK, here's the results so far. I haven't changed out the condenser yet, but I did check the exhaust and the compression. To test the exhaust, I connected a vacuum cleaner to the end of the exhaust pipe and then cranked the engine by hand with all spark plugs removed. I could feel the suction on each cylinder in turn; no cylinder was open when it wasn't supposed to be. So this seems to indicate that the exhaust pipe is clear and the exhaust valves are more or less working. To test the compression, I connected a testing gauge and, with spark plugs removed and throttle fully open, cranked the engine using the starter. All cylinders showed 60-65 psi except for cylinder 2, which showed 40 psi on two separate tests. I performed a wet compression test on cylinder 2 by squirting some oil into the cylinder with an oil can (I made sure to get the oil in the cylinder itself). Rechecked compression and it wasn't substantially improved, maybe 45 psi. So I guess I have two questions: Everyone think this is most likely a head gasket? Is this likely to be the problem that's causing the rough running or is it more likely to be a long-standing problem that I just hadn't detected before? Last edited by alexiskai; 04-06-2019 at 08:50 AM.