Question:
I am having problems with the oil pressure on my 2.0L XE. I have new SBD inner ring and outer ring and relief valve kit. I have 5 Bar pressure at idle, cold oil and 3.1 - 3.5 Bar maximum at 4000 rpm and above.
Answer:
The oil pressures we recommend are for hot oil with an oil temperature between 80 - 120°C. This is using a 10W60 oil, fully synthetic.
Possible causes for reduction in oil pressure:
1. When fitting new gears, you must be sure a genuine GM oil pump housing is used and that it is either new or in perfect condition. If the housing is worn, then a reduction in oil pressure will occur. 2. The bore where the oil pressure relief valve runs must be checked to ensure that it is smooth and has no particles or distortion. Check that the relief valve runs freely within it. if not again the oil pump housing should be replaced as this shows signs of the condition of the rest of the pump body. 3. You must ensure that the journals and bearings on rods and crankshaft are in good condition and within tolerance. Also that the whole engine is in a good working condition. 4. If you are using a thinner oil, the oil pressure will drop lower as the oil temperature rises. 5. All of the above points should be checked before attempting re-shimming as you may be disguising engine wear by carrying out this modification.
The oil pressure can be varied on the engine by adding addition washers to trim the oil pressure.