tapping noise in 2001 GMC Jimmy?

[TIMMAYYY!!!]

so ive had this car for almost a year, and this summer i was having some problems with it overheating, i was going through coolant like nothing. that got fixed then about a month ago i started noticing erratic oil pressure, and a tapping coming from the engine, but only when i first start it up. it goes away and runs fine after about five minutes. any ideas what this could be.
sometimes it lasts longer than 5 minutes and can go on for quite awhile, but not too often.

oil level is fine also

 

[Kody]

my mom had a jimmy and it had problems left an right u might want to get rid of it and get a blazer or something becouse ur gunna end up putting more money into that truck then what its worth

 

[Molson02536]

The oil journals may be dirty and adding a bottle of Marvel Mystery oil will help clean the oil passage way out. Add a bottle about 1000 miles before your next oil change and add a can of Restor to the oil to the next oil change and do this for a while and this may help you get more miles out of your engine. Keep an eye on your engine oil level when adding the Marvel Mystery oil, the oil is thinner and will burn away easily. As for the oil pressure gauge, the Marvel Oil may free up any dirt in it causing the erratic readings. If not you may have to replace it and it's located on the passenger side behind the distributor. Good luck and keep me posted.

 

[QuadFreak400ex]

well Kody this isn't an advice forum on what to buy and what not to buy so why don't not say anything anymore unless it's going toward helping the person out with the problem they have