Last week I changed my oil, and switched to mobile 1 synthetic from standard. Now, every time I start the jeep my oil pressure reads low for a few seconds before going up to normal. Even turns on my "check guages light"

Never did it before the synthetic.

Any idea why it would be causing low pressure at start up, then totally normal?

 

Very possible that you are having an issue with the oil pressure sending unit, located directly above the oil filter.

I don't see how changing to synthetic would cause this.

These sending units fail frequently. If you buy one, buy it directly from Jeep. No lack of threads of people having trouble with aftermarket sending units. Well worth the extra $20 for the factory unit.

 

I just changed the sending unit last summer, that would be pretty crappy if it died already

 

Where did you buy it? As I mentioned, failure of aftermarket oil pressure sending units prematurely is NOT unusual. I buy plenty of aftermarket parts, but this is one thing that I buy only from Jeep.

 

Did you smack that "new" oil sender with the filter wrench when removing the filter? Is the connector loose, dirty, or oily?

 

either advance or autozone. I will have to add a new one on my list of stuff for the jeep