I own a 2000 Grand Vitara JLX with a H25 in it to.
First thing you should do is check your Oil, if it smells like burnt oil, see how much it uses. Does your dipstick come out after running? Excessive blowby creates presure in the crankcase. Try doing a Cylinder leakdown test, your results typically should be around 15%, with no more then 10% variation between readings. If so, worn rings, or valve seats. Mine, with 101,250 reads 15, 15, 14, 15, 13, 15. The reason the smoke is gone is the PCV is picking it up from the crankcase and re-circulating it back into the engine, and the worn rings are allowing oil past the piston.
Or, the most likely cause, the knocking is made by a Pre-Ignition. The compression is igniting the Air/Fuel before the spark, check your timing, try a higher octane fuel, or over tensioned Alternator belt, pulling the crankshaft making the noise, its a common problem, there is a TSB about it.
Thursday, August 2nd, 2007 AT 1:55 AM