valve guide wear questions
08-20-2002, 11:21 PM
#1
Intermediate
Thread Starter
Join Date: Aug 2002
Location: California
Posts: 37
Likes: 0
Received 0 Likes
on
0 Posts
valve guide wear questions
When valve guide wear occurs is it most likely the exhaust side or the intake side? Can this be fix just by replacing the valve (the trumpet looking thing)?
What exactly is the guide? Is it the head itself where the valve goes into?
any help would be great, as I believe that I am having this problem with my 993.
TIA
What exactly is the guide? Is it the head itself where the valve goes into?
any help would be great, as I believe that I am having this problem with my 993.
TIA
08-21-2002, 01:38 AM
#2
Passed On
Rennlist Member
Rennlist Member
Exhaust usually goes first; sees highest temperatures.
Valve stem moves up and dowen in a tube; this is the valve guide. Valve generally is not the problem; this tube is. It gets bored/reamed out by the valve motion and heat. So, you need an engie disassemb ly and guides ahave to be pressed out and new ones pressed in generally on a drill press.
Valve stem moves up and dowen in a tube; this is the valve guide. Valve generally is not the problem; this tube is. It gets bored/reamed out by the valve motion and heat. So, you need an engie disassemb ly and guides ahave to be pressed out and new ones pressed in generally on a drill press.
08-21-2002, 03:30 AM
#3
Addict
Rennlist Member
Rennlist Member
Join Date: Apr 2002
Location: Newcastle, WA
Posts: 195
Likes: 0
Received 0 Likes
on
0 Posts
Porsche specifies a healthy engine can use litre of oil per 600 miles. (Converts to 568 miles per quart) Some new engines will burn a little more
oil than this maximum specification. If you're not
burning oil at a high rate, are not hearing
any unusual noise, and have not triggered a
"check engine" light from air injection ports being plugged; your valve guides are probably healthy.
oil than this maximum specification. If you're not
burning oil at a high rate, are not hearing
any unusual noise, and have not triggered a
"check engine" light from air injection ports being plugged; your valve guides are probably healthy.
08-21-2002, 03:44 PM
#4
Intermediate
Thread Starter
Join Date: Aug 2002
Location: California
Posts: 37
Likes: 0
Received 0 Likes
on
0 Posts
I do have a check engine light that comes on and off once and a while. The scan tool says it's a random misfire on cylinders 2 and 3 or 3 and 4 (not sure which ones, teh former or the later). I was thinking that this was casued by wearing valve guides.
I have lots of noise as I'm using solid lifters.
I don't know if I should tear the motor down and use recommended bronze sleeves for the valves or if the valves are ok to remove the rubber seal located only on the exhaust valve side.
thoughts?
I have lots of noise as I'm using solid lifters.
I don't know if I should tear the motor down and use recommended bronze sleeves for the valves or if the valves are ok to remove the rubber seal located only on the exhaust valve side.
thoughts?
08-21-2002, 08:45 PM
#5
Passed On
Rennlist Member
Rennlist Member
Do the following in that order
a) Replace spark plugs
b) adjust valves
c) do a compression/leakdown test
If engine is holding compression and leakdown test is OK, I do not see how valve guides are causing an engine miss. Look at spark plug wires or fuel injector next.
a) Replace spark plugs
b) adjust valves
c) do a compression/leakdown test
If engine is holding compression and leakdown test is OK, I do not see how valve guides are causing an engine miss. Look at spark plug wires or fuel injector next.
08-21-2002, 08:57 PM
#6
[quote]Originally posted by Ray Calvo:
<strong>I do not see how valve guides are causing an engine miss.</strong><hr></blockquote>
I don’t think it is causing a miss. I think the computer is getting confused, and reporting a miss.
<strong>I do not see how valve guides are causing an engine miss.</strong><hr></blockquote>
I don’t think it is causing a miss. I think the computer is getting confused, and reporting a miss.
