Valve guides, when to change

[fredws]

Okay, I am pretty sure I know the answer to this question, and the fact that I am asking it is telling me what I should do, but here it goes.

I have a 1985 380SL, it was neglected and the cams were bad, I pulled the engine to change the cams as well as the timing chain etc. Figured I should change out the valve seals, but now I am wondering how much play is allowed before I should change out the valve guides?

Thanks in advance!
Fred

[ILUVMILS]

Back in the day when we did lots of top-end work we used a simple go/no-go gauge, but this was done with the valves removed.

If you weren't burning too much oil before I'd just do the seals......

[fredws]

Thanks, I believe just the seals is the way I will go. I would like to re-do the guides, but don't think it is worth it for all the extra effort, especially since it wasn't really burning oil.

[speednjay]

Not really related to your engine. On my m104 I did the head gasket and had the machine shop do tge guides and seals. Expensive but it was night and day. It runs like a bran new engine. I’d say go for the gusto

[RobertinMN]

Originally Posted by fredws

Okay, I am pretty sure I know the answer to this question, and the fact that I am asking it is telling me what I should do, but here it goes.

I have a 1985 380SL, it was neglected and the cams were bad, I pulled the engine to change the cams as well as the timing chain etc. Figured I should change out the valve seals, but now I am wondering how much play is allowed before I should change out the valve guides?

Thanks in advance!
Fred

You should have tested the compression before pulling the heads. Valve guides go and a compression test will show that. Especially weak are the exhaust. They don't cost that much and it will make a big difference in the performance.