Rory McLeod Posted January 14, 2001 Share Posted January 14, 2001 Hi all. Following a severe thrash at Anglesey there is a very loud tinny rattle (sounds a lot like a loose exhaust manifold bolt would sound) that comes on every time the throttle is killed or at the start of a power sequence. It is coming from inside the head. I intend to get the head off to solve the problem but I am no car mechanic so would appreciate all and any pointers as to what YOU think it might be so that I can check for all possible events. My first thoughts are valve guide-ish (if I had tappets I would assume these had opened right up) The car got me back to Surrey (approx 350 miles - scenic route) with no power problems at all however. All advice gratefully received! (except the rude stuff smile.gif) Link to comment Share on other sites More sharing options...
StewartG Posted January 14, 2001 Share Posted January 14, 2001 Sounds like Mobil 1 to me Link to comment Share on other sites More sharing options...
Peter Carmichael Posted January 15, 2001 Share Posted January 15, 2001 How do you know it is inside the head? Do a compression check. If this is OK then it is unlikely you have any internal head problems. Other rattle suspects are the plug leads cover allen bolts, which seem to work loose and always give the uninitiated a scare. Stewart's comment about Mobil 1 isn't too wide of the mark, but the manifestations are different with a k compared to a VX. K's like Mobil 1. K's need a runny oil for their design of hydraulic tappets. If you were running without an Apollo tank, then you may have had aeration in the oil going to the hydraulic followers. This would have allowed them to pump down and they occasionally stick like this, giving a nasty rattly noise from the drivetrain. Normal driving should sort out the followers which is why I don't think this is the problem. The aeration in the valve train would not of itself have caused a problem for the engine. The problem would be the same aeration affecting the main and big end bearings. If the main bearings have been run, you would get a grumbling noise at idle (test with a long screwdriver held against the block with the handle in your ear. If the big end bearings have been run, you will get a thump thump noise, tested by the same means. I don't think you have an engine problem. Convince yourself with the compression check. Link to comment Share on other sites More sharing options...
Mike Bees Posted January 15, 2001 Share Posted January 15, 2001 As Peter says, plug lead cover come loose. I doubt you'd get a tinny sound from *inside* the head. Mike Link to comment Share on other sites More sharing options...
Powderpuff Posted January 15, 2001 Share Posted January 15, 2001 My plug lead cover came loose shortly after my head rebuild, (whilst giving someone a demo ride for charirty), I really thought I had b*ggered the engine big time until I found the culprit smile.gif Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted January 15, 2001 Share Posted January 15, 2001 Rory. I hope for your sake it is a plug/lead cover coming loose. I too had this and chased the problem for a while; bl%dy annoying!!!!! Good Luckthumbsup.gif Link to comment Share on other sites More sharing options...
Rory McLeod Posted January 16, 2001 Author Share Posted January 16, 2001 Grrnarrghharf!! *-*$$%^! Well I just went to check the plug cover, both SHCS's seemed tight enough, but OK I will remove it just in case it is a loose plug. Hmm 1st CS undoes after 1 turn the 2nd after about 5. Oh look! the Ally stud supporting the cover has broken away from the head leaving a nice round hole - how interesting! Why on earth did 'they' cast the heads leaving a hollow approx 10mm long projecting through the centre of these studs leaving about a 2.5mm wall at what would be a point of high stress when tightening/loosening the SHCS's - absolutely insane.thumbsdown.gifthumbsdown.gifthumbsdown.gif idea.gifI am opting for a rh/lh stud solution (if I can locate my very old taps and dies) with a final ally weld around the base for strength. Anyone know who Caterham use for their ally welding? To 'cap' it all I am still not sure if that was the cause of the rattle! BEWARE: Dont do those SHCS's up too tight!!!!! Link to comment Share on other sites More sharing options...
StewartG Posted January 16, 2001 Share Posted January 16, 2001 What's an SHCS, does it stand for Semi Homosexual Corsets a Speciality? Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted January 17, 2001 Share Posted January 17, 2001 Knowing Rory, YES!!!!!!!! Bet the 'rattle' goes away nowthumbsup.gif Link to comment Share on other sites More sharing options...
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