 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / BMW Cars / April 2004valve problem on 330i E46 - sound plausible?
Hi, a friend has had intermittent poor running problems on her year old 330i and the dealership now say that it's the cylinder head valves not closing properly. They've sent the head off to get the valve seats recut. I wasn't able to see the car before the dealership took it away. This all sounds very dodgey to me - the car's done about 20k miles. My concern is that if it is the valve seats won't they wear out again soon?? Surely they need to be replaced if that's possible. If it were me I'd have expected a new cylinder head as a straight swap. It might be possible, but it would be a might difficult to replace valve seats. You see these things are press fitted into the head. The seats are usually ground to fit the specifications of the particular engine. Grinding valve seats is a job that an automotive machine shop is equipped to do, and they have done this many times. The real question, I suppose, is why the seats need to be ground after such a short time. Perhaps the valves never fit the seat. Jimn > Hi, a friend has had intermittent poor running problems on her year > old 330i and the dealership now say that it's the cylinder head valves [quoted text clipped - 6 lines] > soon?? Surely they need to be replaced if that's possible. If it > were me I'd have expected a new cylinder head as a straight swap. > Hi, a friend has had intermittent poor running problems on her year > old 330i and the dealership now say that it's the cylinder head valves > not closing properly. They've sent the head off to get the valve > seats recut. I wasn't able to see the car before the dealership took > it away. > This all sounds very dodgey to me - the car's done about 20k miles. My > concern is that if it is the valve seats won't they wear out again > soon?? Surely they need to be replaced if that's possible. If it > were me I'd have expected a new cylinder head as a straight swap. Sticking valves could be a problem on early 24 valve engines used only for very short journeys, but the usual symptom was a poor idle. This also affected other makers early 24 valve designs. But IMHO it's been sorted by recent synthetic oils. However, I can't see intermittent poor running being caused by poor valve sealing - a valve that doesn't seal allows blow by and gets progressively worse.  Signature*If only you'd use your powers for good instead of evil. Dave Plowman dave.sound@argonet.co.uk London SW 12 RIP Acorn > Sticking valves could be a problem on early 24 valve engines used only for > very short journeys, but the usual symptom was a poor idle. This also [quoted text clipped - 4 lines] > sealing - a valve that doesn't seal allows blow by and gets progressively > worse. Hmm yes, I think this car only does like 5 miles a day & probably never sees more than 3000rpm. > Hmm yes, I think this car only does like 5 miles a day & probably > never sees more than 3000rpm. neither of which is good practice on a regular basis. You need to get it fully up to temperature, and wring it out now and then... -Fred W > neither of which is good practice on a regular basis. You need to get it > fully up to temperature, and wring it out now and then... > > -Fred W I know that, *you* know that...... :-) |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2009 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.