Do I need to change my Exhaust valves?

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Fox67
Posts: 8
Joined: 23 Jan 2022, 13:21

Do I need to change my Exhaust valves?

Post by Fox67 »

Hi,
I have changed stem seals on my Peugeot 208 (EB2 engine).
When I was doing that I damaged one valve so I had to take the top of resulting in a bit bigger job :)

Now I am cleaning the valves and noticed the exhaust valves I cleaned looked like this.
I have given it a lap with paste but I do not want to do that too much.
The intake valves look fine and in the top it also looks fine.

Should I change the valve if they look like this or another round with paste?
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ozvtr
Posts: 417
Joined: 13 Oct 2020, 01:11
x 125

Re: Do I need to change my Exhaust valves?

Post by ozvtr »

No. Don't attempt to lap them any further.
That's very strange. The valve seat is very good but the valve face is toast!
Find out the cost of new valves, then contact your local machine shop and find out the cost of re-facing the valves. It might be cheaper to re-face the valves...depends on how deep that pitting is. You can only grind the face until the margin is so thick, or you'll burn the valve! So the machine shop might not even attempt it.
PaulC5
Donor 2024
Posts: 322
Joined: 06 Jun 2023, 15:26
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Re: Do I need to change my Exhaust valves?

Post by PaulC5 »

The machine shop will likely also want to replace the valve guides since these will be worn and unless done any oil consumption would not be reduced for long. Also it will help when grinding in the valves so they are not moving about sideways slightly.
Gibbo2286
(Donor 2020)
Posts: 7232
Joined: 08 Jun 2011, 18:04
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Re: Do I need to change my Exhaust valves?

Post by Gibbo2286 »

For fifty years we cleaned up those exhaust valves by putting them in a slow speed electric drill and using a fine file to clean up the faces before lapping them in with the sucker and paste. :)
Man is, by nature, a lazy beast, he does not need twice encouraging to do nothing.
Fox67
Posts: 8
Joined: 23 Jan 2022, 13:21

Re: Do I need to change my Exhaust valves?

Post by Fox67 »

I have measured the valve guides by putting a screwdriver in. One with a diameter of 5,06 mm did not fit. I could just get it in. The valve measured 4,97 mm and with that one in I can move it a little bit sideways. I do not think I need to change the guides so I go for new valves. I have already changed the Intake Valve that I damaged.
Hopefully I do not need to change the Valve Pistons.
I did measure the gap to the Valve Pistons before i took it apart.
Is the diffrence ok?
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