Tappett service
Discussion
mike_e said:
Tappet adjustment is not normally included in a service. This is an extra operation usually carried out at every 12000 service interval.
... But isn't always needed, so if you've got a garage that isn't wanting to rob you blind, they'll just let you know after a diagnostic that it's not necessary.
Julian64 said:
What diagnostic tells them that? Do they just listen or do they use a pressure method?
I honestly don't know, but when I had mine serviced recently, they said they'd checked & no adjustment was needed. I'm sure they'd have happily taken a couple of hundred quid extra off me if it had been necessary! I was talking to another garage a couple of weeks ago that concurred that they wouldn't do it unless it was needed, either. No doubt someone will correct me on this (Joolz??)
Julian64 said:
What diagnostic tells them that? Do they just listen or do they use a pressure method?
As Gazzab says, they take off the cam covers from both banks and measure each valve clearance in turn. They don't always require adjustment, but there may well be a charge just for checking as it's not a 5 minute job.
you can sometimes tell if the gaps have closed alot because the car is fluffy on part throttle and has poor idle and very high (for a cerb) HC value.
There's no way of telling for sure though unless you get in there and measure .. the gaps only ever close up, so a quiet engine is worse than one that sounds a bit "tappetty".
Getting in to check them, and then the act of actually checking them is by far the biggest part of the job, so if they're in there already they might as well get them all spot on, there's usually only 4 or five that need doing, and by the time you get over 36k the valve stems have usually stretched as far as they're going to anyway, but it's 4 hours to check, and extra hour to adjust. 4.5s are easier cos the inlets don't have to come off to get the cam covers out.
I'd be suspicious of any garage that didn't advise you to have them checked, although sometimes on cars I know the history of I can tell "budget" service owners that they can be left if the engine drives well enough, the general rule though if you've got the 200 pounds required is to get in there and check, just in case.
There's no way of telling for sure though unless you get in there and measure .. the gaps only ever close up, so a quiet engine is worse than one that sounds a bit "tappetty".
Getting in to check them, and then the act of actually checking them is by far the biggest part of the job, so if they're in there already they might as well get them all spot on, there's usually only 4 or five that need doing, and by the time you get over 36k the valve stems have usually stretched as far as they're going to anyway, but it's 4 hours to check, and extra hour to adjust. 4.5s are easier cos the inlets don't have to come off to get the cam covers out.
I'd be suspicious of any garage that didn't advise you to have them checked, although sometimes on cars I know the history of I can tell "budget" service owners that they can be left if the engine drives well enough, the general rule though if you've got the 200 pounds required is to get in there and check, just in case.
Gassing Station | Cerbera | Top of Page | What's New | My Stuff