I have an 01 mustang gt . Two days ago I checked the oil level in the dipstick when my car was warm and it was way above the maximum level . I parked it and checked it again today the oil level was below the minimum with no mejor clicking noise in the engine . What is going one with my car ? Do I have a bad oil pump ? Or is it because of the oil sending unit?
Many dip sticks will have lines on one side for cold and the other for hot, and occasionally both will be on the same side. If the different marks are not available, refer to owners' manual for the temperature being indicated.
Regardless, check your oil with the engine off. When the engine is running, oil fills galleys, pumps, etc. and is moving around in the sump. This can lead to all sorts of anomalous readings.
The differing temperatures will have a bearing on your readings, but more than anything it's that you're checking with the engine in various states of non/operation.
If you have too little oil in the engine, this can obviously lead to oil starvation, etc. If you have too much, you can create an entirely different set of issues: shearing, windage, high oil pressure (which can burst lines and fittings), etc. Refer to your manual for proper lubrication in terms of the type/weight of oil, intervals, procedures, etc.
A few points worth mentioning when checking oil level:
Never rely on the first reading, especially when the engine has just been run
Always take out the dipstick and wipe it clean with a rag before reinserting the dipstick to check the level.
Never take readings with the engine running
The dipstick level markings are supposed to be used with the engine off.
Some engines need to be warmed up, others left cold
The owner's manual will usually clarify under which conditions the reading should be taken.