sross

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A friends car started running rough out of the blue and started getting misfires (blinking SES light). The misfires were on cylinders 5 and 7 so my first thought was blown head gasket so I did a compression check. All the cylinders came out to about 170 PSI while cranking except 5 which was at about 150 - 155. Although that's certainly a discrepancy, I'm not sure it's a head gasket. The oil and water look good but I realize that it could be blown between the cylinders without leaking water. Is that enought of a difference to be certain that the head gasket's gone? I didn't think it was so I checked a bunch of other things. The header temps at idle were all 500+ degrees except 5 and 7 which were about 130. I swapped plugs, wires and coils but the problem always stays with 5 and 7. The coils will arc across to the coil bracket so I'm sure I've got good spark. Also, I lifted the fuel rail and made sure the injectors were firing. I'm not really sure what constitutes "good" but 5 and 7 looked the same as 1 and 3. I can crank the engine over with the valve cover off and the valve train looks good as well. There is no unusual sounds either. By all indications (as far as I can tell) it's got a blown gasket but I guess I'm hung up on the 10% discrepancy. Isn't that a little low to point to a blown head gasket?

By the way, the car runs terrible.

As long as I'm on the topic of compression, anyone know where I can get a decent leak-down tester?

sross

iTrader: (1)

t.t.t.