Hi all,

I've got a stock Civic Si (D16Z6) with a cold running problem.

When I start the engine from cold:

- For the first minute, if I rev the engine I can hear it hesitating slightly, like there's a timing or ignition problem, but after a minute the problem goes away and the engine revs up smoothly.

- For the next 5 mins, whenever I stop the car, i.e. take my foot completely off the gas, the revs plummet past the idle mark, the engine nearly stalls (couple of times it has), then bounces back up to a normal idle.

Other symptoms:

- Losing coolant - I have to completely refill the expansion tank every couple of weeks.
- Running cold - According to the temp gauge, which never gets above 1/3 - used to run at a steady 1/2.
- Slight petrol smell - Not that bad but just about noticeable in the cabin at times.

My first thought was a leaking head gasket so I ran a compression test:

Cylinder 1 - 225 psi
Cylinder 2 - 220 psi
Cylinder 3 - 215 psi
Cylinder 4 - 210 psi

Anything to worry about there? All 4 cylinders are well above the standard 184 psi, which I assume is due to carbonisation as the engine's done over 150k - would that make sense? There's also a 15 psi difference between cyls 1 and 4 - does that tell us anything?

Or perhaps I'm way off base - any thoughts and suggestions would be much appreciated.

Thanks in advance,

Rob

 

exactly what my car was doing last month, it threw a rod. After i changed the head gasket of course. My compression was way off though.