Valve stem seals and valve guides
 

Since I bought new valve spring kits for my car, I need to know is it necessary to buy these valve stem seals and these valve stem guides? Or just buy OEM seals and guides?

I'd be careful with the guides - 1.8T parts may not necessarily work in the V8 as it has roller cam followers and longer valves iirc.

Given that the original stem seals are still working in most engines after 20 years I would just use OEM or equivalent for those - Victor Reinz and / or Elring make them I think. They are used in lots of other models so easy enough to get.

I didn't know that about the guides. Good thing I asked about that before ordering them. Do you have the part numbers for the OEM seals and guides?

The guides aren't listed as a separate part but the stem seals are 036109675A.

That's a bummer about the guides.

Thanks for the part number on the seals. Holy crap around $10 for one OEM seal? Is this part number for the intake valves or exhaust valves? Or are these the same for both valves? Also in my search with this part number there are different colors for the seals? Why is that?

I did a little more searching and found these valve guides

Thats why I said 'or equivalent' ;) Elring can be found for half that. They are the same on inlet and exhaust. They seem to be mostly green, but there do appear to be a few black / brown versions.

You are not going to change guides and lap the valves yourself, are you?

Just take it to reputable cylinder head shop and they will sort everything out for you. Not sure about 40V engines but on 32V valve guides do wear a bit same like most Audi/VW 4V per cylinder of the same era. Head shop can change them with improved bronze alloy that practically does not wear, I think original on 32V are brass.

I'm thinking about doing this work myself as it's already getting pretty expensive with just buying the parts alone.

Fair enough if you have the tools yourself to pull out and press in new guides and to recut valve seats. When I was looking at it and was talking to head shop their position was that there will be some wear on valve stems as well so they said if using off the shelf valve guides than best to use new valves too. But if they supply valve guides they could do tailored bore size to suit old valves. Not sure how much truth is in it, I never proceeded as I found pair of heads with 2000 miles on them for less than it would have cost to reburbish 1 head.