The question you have to answer is:
What happens with these in-house parts? Are these parts assembled to the final part?
I am not familiar with your part, but it indicates some type of engine (belts, crank, bolts). the answer is yes.
Do you mean supplier to your company with OEM? (OEM is usually the car manufacturer in the automotive supply chain).
Assuming suppliers, you have to work with your suppliers to get them to enter the information in IMDS. If they are unfamiliar with IMDS, you might have to guide and train them. For most automotive companies IMDS has become a part of their standard operating procedure and has become part of PPAP or ISR.
IMDS must be a requirement for your supplier and documented in your supplier quality documentation.
I am assisting an engine manufacturer and its suppliers in North America to create an MDS for a large automotive engine. We are working with some suppliers to train their engineers and technicians in IMDS.
If a supplier refuses to enter information, you have two choices: 1) work with purchasing and resource the part to another supplier 2) create MDS yourself with the material information from your supplier or public sources.
One tip: when you create an MDS, please start at the bottom on the tree (materials and substances) and build it up from there (component and semi-component). For a complex part you should be spending a lot of time offline from IMDS gathering and analyzing the material information.