91 Subaru Legacy starting noise

I have this grinding noise when my car first starts it lasts only a secant or two and then it sounds fine. Any ideas what this could be

Is this noise coming from the engine compartment, or is it coming from underneath the car?
Is it affected by the ambient temperature or other variables?

If you enlist the help of someone to start the engine while you have the hood raised, you can help us to help you. Try to localize the sound.

This noise is worst when the car has been sitting for more than a hour i have tried starting the car in nurtural and that made no difference. I might add that my oil light flickers during the sound i thought perhaps it was bad oil so I added some thick additives and still no improvement i have not pinpointed its location but it sounds like I coming from under the engine

If your oil light flickers, that is not a good sign, as it indicates low oil pressure. That light, coupled with the undefined noise, makes me wonder about bearing damage–but this is all still just guess-work.

I would suggest that you stop using “oil thickeners”. The new information that you supplied convinces me that the engine needs to be checked by a competent mechanic.

It could be many things. If it has ABS there is a self test when starting that may sound worse after 19 years. It also could be your starter gear not disengaging right away. It

Oil light may simply be a red herring but likey would not be a grinding noise involved from it.

ABS on a '91 Legacy? Not likely.

My 1990 Legacy wagon had ABS and was a mid-level model. For the poster, you can tell by clicking the ignition far enough so all lights oil light, check engine light, brake light illuminate in their test cycle and see if an ABS one is there too.