Quick synopsis:

I changed the timing belt on my car. Car ran rough/misfire. Hypothesis is Piston #1 doesn't detonate. Change plugs, wires, distributor, rotor, crank (or cam) sensor, electronic temp sensor and have the timing marks lined up perfectly.

Had the injectors cleaned, replaced the O-rings on them. Get spark at #1 cylinder, the injector gets voltage too. The order of the injectors was not repeated, so I know it wasn't a bad injector or plug.

If I remove the plug wire from plug, while engine is running, makes no difference in engine running. Same with removing the injector plug/connection.


It's an automatic, 194K on it. doesn't burn or leak oil.

I think that's all that it vital, although I'm sure someone else will ask something.

I performed another leak down test yesterday.

The first time I did it, weeks ago, the results indicated intake valve was the issue (the air came out of the intake/IAC area).

this time I did the test, I was far more diligent with the TDC. Not that I wasn't before, but this time I tested it repeatedly to make sure. Watched it intently as the screw driver (in the plug hole) went up as I rotated.

Anyway, so this time when I ran the test (on the #1 cylinder) t, the air came out of the exhaust. There was *slight* amount of air coming out of the oil cap, but minimal.

(I also did a test where I was just a hair off of TDC, and the results were coming out of the intake, like my earlier test. This is what makes me think I must've not be as TDC as I thought)


What I noticed this time, that I didn't earlier, was that there was air coming out of another plug. So I tested cylinder #2, and air was coming out of another cylinder, but no where else.

So I THINK it was coming out of 1 and 3, and 2 and 4. It might have been 1 and 4 and 2 and 3, but that's besides the point.

I did a search online for leak down test results, and this is one thing I found.

"Air escaping from adjacent cylinders indicates a blown head gasket or cracked block."

Could this be a sign of a head gasket issue, or is that common in Volvos?


I don't think it's a cracked block, as it doesn't show any symptoms of it (radiator fluid is fine, oil is fine, not smokey and it never has even come close to over heating).