So I changed my oil about 2000 miles ago and just realized that I didn't put in a 502 approved oil. I used castrol syntec 5w30 because it came in a 5 quart jug. The owners manual says to use a 5w40 or 5w30 if 5w40 isn't available. Walamart only had 5w30 for castrol syntec so I went with it.
Do you think its necessary for me to change this oil to 5w40 immediately or am I ok to go another 3,000 miles and change it out at 5,000 miles. My car currently has 23,000 miles and is a 03 1.8T GTI.
On a side note I've recently developed a clicking noise at idle only once the engine is warm. Could this be related to the lower viscosity of the 5w30 oil??. I think the culprit is the timing belt tensioner, but maybe it could be a lifter (?). Any chance this oil could have caused it? (I prefilled the filter before I put it on so the engine wouldn't be dry at first start). I used an OEM Mann Filter.
Modified by DrTacoElf2 at 7:30 PM 5-7-2009