First time at the track in the 911
11-18-2010, 06:19 PM
#16
Drifting
Thread Starter
11-18-2010, 08:38 PM
#19
uninformed gas bag
(contemplating on whether gas bag is one or two words)
Rennlist Member
(contemplating on whether gas bag is one or two words)
Rennlist Member
I would check the pedal cluster. It can get all ****ted up down there, the bushings wear and can bind. Did you money shift?
11-18-2010, 09:07 PM
#20
Burning Brakes
Join Date: Oct 2001
Location: Hong Kong
Posts: 1,044
Likes: 0
Received 0 Likes
on
0 Posts
It's been known to happen that 911 throttles stick open when the lower hose clamp screw securing the 90 degree rubber elbow running between mass air flow and the throttle body jams throttle wide open. Check the correct alignment of the lower hose clamp below.
Cruise control electronic box under dash can also go on/off unexpectedly, which is why mine is long gone.
Cruise control electronic box under dash can also go on/off unexpectedly, which is why mine is long gone.
11-18-2010, 10:42 PM
#21
Rennlist Member
This is a 125K otherwise original engine? Of course it needs valve guides. But that doesn't mean you can't run it hard. As long as it's not overreved and you have sufficient oil you're not going to "blow it up"merely from track use.
Don't follow the comment at all about low/lower oil level and decreased oil pressure. Operating temperature, oil viscosity/type, the pump and engine speed determine oil pressure. Whether you have another quart static in the tank doesn't matter, except in terms of an overfill and consumption through the breather/intake.
Don't follow the comment at all about low/lower oil level and decreased oil pressure. Operating temperature, oil viscosity/type, the pump and engine speed determine oil pressure. Whether you have another quart static in the tank doesn't matter, except in terms of an overfill and consumption through the breather/intake.
11-19-2010, 07:17 AM
#22
Drifting
Thread Starter
Again thanks to everyone for the replies!
Valve adjust was also done at the 125K service, that was the main reason for taking it in. My plan was to do it myself with the help of my father-in-law but did not have the time on the weekends.
Sufficient oil? Where on the dipstick is sufficient oil? After one of my sessions I did check the oil and it was between the marks but closer to the bottom mark so I added half a quart. Wanted to add a quart but was afraid that would overfill it. What is the amount of oil to take it from bottom mark to top mark? Did not want to overfill it.
This is a 125K otherwise original engine? Of course it needs valve guides. But that doesn't mean you can't run it hard. As long as it's not overreved and you have sufficient oil you're not going to "blow it up"merely from track use.
Don't follow the comment at all about low/lower oil level and decreased oil pressure. Operating temperature, oil viscosity/type, the pump and engine speed determine oil pressure. Whether you have another quart static in the tank doesn't matter, except in terms of an overfill and consumption through the breather/intake.
Don't follow the comment at all about low/lower oil level and decreased oil pressure. Operating temperature, oil viscosity/type, the pump and engine speed determine oil pressure. Whether you have another quart static in the tank doesn't matter, except in terms of an overfill and consumption through the breather/intake.
11-20-2010, 01:19 PM
#23
Drifting
I wouldnt worry as much about oil level unless you are near the max level on a warm engine.
Two real ways to check for valve guides. First is to pull the valve covers , cycle the engine and when the camshaft is not pressing against the wiggle the valve stem. Excessive wiggle usually means wear. Especially look at 3 and 6.
Two real ways to check for valve guides. First is to pull the valve covers , cycle the engine and when the camshaft is not pressing against the wiggle the valve stem. Excessive wiggle usually means wear. Especially look at 3 and 6.
11-20-2010, 01:22 PM
#24
Drifting
The second way is to take to 6000 rpms in 2nd gear an then let off letting the engine brake the car. The vacuum will typically suck oil though the guides and produce plenty is smoke
11-20-2010, 01:31 PM
#25
Race Car
Your going to have a hard time wiggling the valve stem - it will still have spring pressure on it. Valve guides are a tough diagnosis. You just have to know what to look for. Closed throttle decel - smoking, puff of smoke when back on throttle. More and more smoke, and possibly an audible ticking when they get advanced wear on them. Others here may have some tricks to help.
11-20-2010, 02:43 PM
#26
Rennlist Member
Why is there even a desire to assess valve guide wear on an engine north of 100K miles? They're worn, get over it. It does NOT mean they're due for replacement. If you're trying to stretch it to 150+K, fine. You're just kicking the ball down the road for the next owner. (Just don't pretend when you sell an car with an engine that's not been apart by that mileage, to a knowledgeable purchaser, that you won't be discounting it.) If you're keeping the car "forever," might as well budget for it since few of these cars will see another 100-150K miles.
As I always say, if valve guides were as easy to change as brakes (even if not as cheap), they'd get done as a matter of course along the way by obsessive owners. At these mileages, the engine either burns oil to the extent it bothers an owner, or it doesn't.
Now if you're trying to determine the quality or mileage of a rebuild during a PPI, then there's some validity in digging that deep.
As I always say, if valve guides were as easy to change as brakes (even if not as cheap), they'd get done as a matter of course along the way by obsessive owners. At these mileages, the engine either burns oil to the extent it bothers an owner, or it doesn't.
Now if you're trying to determine the quality or mileage of a rebuild during a PPI, then there's some validity in digging that deep.
