Jaguar XKE, roadster, 1969
What should be the oil pressure reading be on 4.2L engine at idle and various speeds? How accurate are gauges that are 36 years old? Can they be trusted?
Also, I know that a 4.2 L engine is supposed to take 6 quarts of oil with a new filter. When I changed the oil and filter recently, the oil level on the dipstick went beyond the "full marks" on the dipstick when I filled the engine with 6 quarts of oil. What gives?
Thanks,
Peter
Submitted by jrwalker@ev1.net on Sat, 06/25/2005 - 07:57
Oil pressure at normal operating temperature should be 40 pounds at 3,000 RPM. It will drop at idle, My pressure is around 20PSI at 750 RPM on a 69 2+2 and dead on 40 at 3,000.
The gauges were often suspect when new and most owners do not rely on them to be accurate today. Many have substituted a mechanical gauge and some have "teed" in a mechanical gauge to check the accuracy of the Smiths electrical gauge.
What pressures are you running at what RPM. If they are lower than the above it is probably because you only have 2/3 of the oil you should have in the engine. The 4.2 engine in a 69 takes 9 quarts of oil. If your dipstick is reading overfull at 6 quarts I suspect you may have the wrong dipstick. Pull your dipstick and check the following:
It should have the letter "E" stamped on the flat portion at the lower end of the dipstick about 1/2" from the end.
Overall length is 25"
There is a washer shaped stop attached to the stick, it is 9-7/8" from the lower end of the dipstick.
The crosshatching on the flat of the dipstick is 3/4" long and starts 1-1/8" from the lower end of the dipstick.
Regards, John