Russ Jackson Posted June 21, 2001 Share Posted June 21, 2001 I am an ex-motorcyclist of one week, with my first Caterham, a 1994 'K' series 1400 supersport. Only 7000 recorded miles ( joke) but has a very noisy top end. Haven't viewed the internals yet, but have changed the oil and so on. Starts off pretty quiet and then gets noisier, especially noticeable at 2000-3000 rpm under light loads i.e when slowing down off the throttle. More annoying than a real problem in itself. Anybody got any ideas on the cure and likely costs? Thanks Russ Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 21, 2001 Share Posted June 21, 2001 Depends on the type of noise. As a top tip, check the spark plug cover bolts for tightness. Link to comment Share on other sites More sharing options...
Russ Jackson Posted June 21, 2001 Author Share Posted June 21, 2001 Tried that. It's definitely internal valve / cam type of noise emanating from the camcover area. An 'AA' mechanic thought that one or two slightly worn cam followers is the likley problem. He suggested changing them all. Link to comment Share on other sites More sharing options...
Delberts Wallet Posted June 21, 2001 Share Posted June 21, 2001 Mine has recently started doing that. I'll be interested to hear what other have to say. Cheers Gareth I can get 4 people in my 7 wink.gif Link to comment Share on other sites More sharing options...
murph7355 Posted June 21, 2001 Share Posted June 21, 2001 Don't want to doubt anything checked so far, but the symptoms sound *exactly* like the plug cover. Even with the bonnet off I couldn't tell whether it was the plug cover or something more expensive on mine (which either demonstrates how hopeless I am or how the plug cover can make hard to pinpoint noises). Rather than check it for tightness, have you tried taking it off altogether and seeing what gives? I had one that felt tight but was in fact not. Ended up with a new cam cover as one of the bolts had sheared off in it. Do you know how many miles it has really done, what the service record was like and what oil has been used etc? Have you checked all other bolts on/around the engine are sound? Link to comment Share on other sites More sharing options...
Russ Jackson Posted June 21, 2001 Author Share Posted June 21, 2001 Thanks Andy ( is your nickname 'Spud' by any chance). I have the camcover off tonight. Cam lobes look clean, oil is newish. I have measured clearances between the back of the cam lobes and the top of the hydraulic tappets. Inlet measures around 0.2 mm and exhaust 0.25 mm. I would have expected no gap whatsoever??? Do I need new tappets??? I will try leaving the plug cover off, but it seemed very tight to me? I have also taken the alternator off because the rotor has a half inch play backwards and forwards when i rev the engine. This makes a little noise but is not the main problem i am sure. Link to comment Share on other sites More sharing options...
Roger King Posted June 21, 2001 Share Posted June 21, 2001 Russ, Are you sure that your engine isn't fitted with non hydraulic cam followers? There should be a zero clearance between cam and follower in a hydraulic engine. If you have some lazy tappets you might find that some of them do have a clearance, but yours seem remarkably consistent in their gaps; not only that, but the exhaust clearances are slightly larger, which is normal for a solid engine. In addition, the clearances that you quote are fairly typical for non hydraulic K-series cams. I don't know how long you left it after turning the engine off before checking, but it is possible that if you have hydraulic followers, they had collapsed against valve spring pressure. Of course, this would not apply to the followers that were not being held open in the position that the engine stopped. Solid cam followers demand a different ramp profile on the cam compared to hydraulic followers, but in the past I have seen hydraulic cam profiles use with solid followers - resulting in noisy valve gear. There are plenty of proper solid cam profiles around for the K-series too - these will be a little noisier than a hydraulic setup, but shouldn't sound like a 'problem'. Possibly, all of this has something to do with your problem, but it is just as likely it is the plug cover vibrating! If you want to be certain, you will have to remove the cam carrier and cams to have a look. Link to comment Share on other sites More sharing options...
Paul Ranson Posted June 21, 2001 Share Posted June 21, 2001 Are you sure the tappets are hydraulic? Solid tappets were (AFAIK) standard fit on the 1.4K race cars. (But tappet noise wouldn't vary with load) Paul Link to comment Share on other sites More sharing options...
Peter Duce Posted June 25, 2001 Share Posted June 25, 2001 Have you got an anti-cavitation tank fitted? My 1.6SS sounded like a bag of hammers on occasions, which was down to air in the oil. Cured immediately by putting more oil in and checking oil levels with engine running. Since anti-cav tank fitted no problems at all. Surprised no one else posted this ... (so did I miss read the topic;-)). Link to comment Share on other sites More sharing options...
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