alaric Posted March 30, 2018 Report Share Posted March 30, 2018 (edited) My TR4 goes very well but for several years has suffered from a dreadful rattle/metallic knock/tinkle. At idle speed it sounds like a bag of bolts! The symptoms are ; Starting from cold, no noise. After 30-40 seconds the noise starts, long before the engine is hot. Increase the engine speed to 1300rpm and the noise stops. Restarting with a hot engine results in immediate idle noise. Engaging and disengaging the clutch does not alter the noise. I can't pin down the source of the noise by listening with a screwdriver and hose. A friend's acoustic device indicates that the noise is coming from below the carburettors, outboard of the exhaust manifold. No unusual smells. Oil changed annually, not analysed but no visual signs of metal particles. Over the years I have done the following work to try and pin point the problem; Replaced the timing chain and tensioner. Replaced the rockershaft. Replaced the camshaft and cam followers. Change from worn fast road to standard spec TR4A Reset tappet clearances at various gaps, no effect. Replaced the original distributor with a 123 programmable electronic unit. (Recommended) Replaced the oil pump and drive shaft, extra 5psi but no effect on noise. Removed exhaust manifold (fabricated TT1100 extractor type) and checked for leaks and cracks. 20 years old but seems in perfect condition. Manifold to cylinder head gasket sound, Experienced mechanics are of the opinion that the noise is not being caused by bearings, mains, bottom end, top end or camshaft. Any ideas? Dick Goodey Edited March 30, 2018 by alaric Quote Link to post Share on other sites
hpremote Posted March 30, 2018 Report Share Posted March 30, 2018 Hi, Dick: l'm a bit foxed by the location from where you report the rattle, ie. below carbs and outboard of exhaust. But experience indicates that some sounds can be 'thrown about' a bit. In my case, l could never locate the source of the rattle until it went off in my face, so to speak. It was present for several years, so like a good, coarse TR- ist, l developed cloth ears and just ignored it. At high engine revs. it merely melded in with the normal thrashing noises you get with a 4-pot TR. Last May, on the way to Jabbeke, there was a bumping sort of feeling/sound and my ign. warning came on (l was in the outside lane of the M2, in p*ssing weather, at dead of night). My water pump pulley had disintegrated, destroying the fan belt and the pump. Miraculously the rad was untouched by the debris. However the trip to Jabbeke was defo off... Closer inspection later revealed that the pulley metal had fatigued, and a crack had grown gradually - over literally years. Mystery solved and things put right, though l continue to harbour a grudge over having missed the rendezvous with MVC 575. Good luck with your quest - might it just be that dreaded pulley metal fatigue..? Tim. Quote Link to post Share on other sites
RogerH Posted March 30, 2018 Report Share Posted March 30, 2018 Hi Dick, have you considered piston slap? Roger Quote Link to post Share on other sites
AndyR100 Posted March 30, 2018 Report Share Posted March 30, 2018 Have you disconnected the fan belt from the dynamo/alternator? Could be something belt-driven. Possible loose valve guide? Quote Link to post Share on other sites
alaric Posted March 30, 2018 Author Report Share Posted March 30, 2018 Forgot to mention them, but changed the pistons/liners at the same time as the camshaft, about 10 years ago. Thanks for responses. Will run without fan belt in the morning. Dick Quote Link to post Share on other sites
stillp Posted March 30, 2018 Report Share Posted March 30, 2018 As above, try with the fanbelt off for a minute. My tinkling was the dynamo rotor hitting the stator. You could probably rock the dynamo shaft with the engine off and the belt slackened. Pete Quote Link to post Share on other sites
RogerH Posted March 30, 2018 Report Share Posted March 30, 2018 Hi Dick, I had a bad rattle/knock on my 4A back in 70's. It turned out to be the front woodruff key that holds the fan extension on. The slot had worn badly and the key was half gone. But I'm sure you would have noticed this in various strip downs. Roger Quote Link to post Share on other sites
TR4TUNE Posted March 30, 2018 Report Share Posted March 30, 2018 Hello Dick, my TR4 makes a similar rattle/tinkle but not really a knocking sound.Like your it starts shortly after start up and I have put it down to something (!) to do with the stainless steel extractor exhaust, Phoenix in my case. It sounds like a couple of small pieces of metal or wee ball bearings spinning inside the exhaust.It seems to have improved with use and now rarely happens....without intervention, other than taking off and re adjusting the front exhaust joints. Please make sure yours is nothing more serious, mechanically speaking, before ignoring it like I did! I hope to start mine up again this weekend so will report back on the noise front. John Quote Link to post Share on other sites
Motorsport Mickey Posted March 30, 2018 Report Share Posted March 30, 2018 How about a recording of it ? phone etc and then post it here. TRouble is Dick is that all the mechanics who have listened to it have said it's not bearings, bottom end, top end and you've replaced almost everything else...somebodies wrong and has missed something. Initially I'd have gone for the timing chain and that might be an easy strip just to see if it's still ok since you replaced it and the tensioner. Also you can run the engine with the rocker cover off at low revs (cover everything within 2 foot around the engine to avoid oil splatter) and see if that gives other clues as to where the noise is from. Another tooth sucker is it's not unknown for tubular headers to have a resonance or occasional noise from within so without a recording guessing like this is all we can do. Mick Richards Quote Link to post Share on other sites
Lebro Posted March 31, 2018 Report Share Posted March 31, 2018 loose fan on the alternator / dynamo ? Quote Link to post Share on other sites
ianc Posted March 31, 2018 Report Share Posted March 31, 2018 Loose lower rear bolt on generator mounting? Loose pulley on generator? Something completely apart from the engine loose &/or resonating when the engine is in that particular rev range? Ian Cornish Quote Link to post Share on other sites
RobH Posted March 31, 2018 Report Share Posted March 31, 2018 Starter pinion hitting ring-gear ? Quote Link to post Share on other sites
Don H. Posted March 31, 2018 Report Share Posted March 31, 2018 In rhe interests of no-stone-unturned, the bonnet prop rod on a sidescreen car can make one helluva rattle where it mounts to the hook and latch assembly. Isolating it with plastic or rubber washers on the pivot bolt can stop it from clattering. Is there something similar on a TR4? For sure the dynamo pulley/fan can make a racket, too. Quote Link to post Share on other sites
RogerH Posted March 31, 2018 Report Share Posted March 31, 2018 Hi Dan, the TR4/4A/5 bonnet stay can get very noisy. There should be a piece of sponge in place but it is often missing. Roger Quote Link to post Share on other sites
alaric Posted March 31, 2018 Author Report Share Posted March 31, 2018 Have run the engine this morning, with and without fan belt. Absolutely no difference in the noise. Will post a fuller reply later. Thanks for the interesting replies. Quote Link to post Share on other sites
AndyR100 Posted March 31, 2018 Report Share Posted March 31, 2018 I can also vouch that even with the rubber and foam on the inner wheel arch there is often a continuing bonnet-stay rattle! One day I’ll th8nk of a way of eradicating it completely! Be surprised if the stay is the cause of the noise described though ....... Andy Quote Link to post Share on other sites
ChrisR-4A Posted March 31, 2018 Report Share Posted March 31, 2018 Are you running SUs, it could be the choke mechanism rattling when it's off and the cables loose. Chris Quote Link to post Share on other sites
rcreweread Posted March 31, 2018 Report Share Posted March 31, 2018 I'm sure I've read on here before that the 1/4 moon plate which fills in the bottom of the bellhousing on the back of the engine can cause a noise rattle but I can't remember why!! Something like if it's fitted wrong way round, it's loose or flywheel bolts can catch it. No time right now to use search facility as off on the next job for you know who! Cheers Rich Quote Link to post Share on other sites
RogerH Posted March 31, 2018 Report Share Posted March 31, 2018 I'm sure I've read on here before that the 1/4 moon plate which fills in the bottom of the bellhousing on the back of the engine can cause a noise rattle but I can't remember why!! Something like if it's fitted wrong way round, it's loose or flywheel bolts can catch it. No time right now to use search facility as off on the next job for you know who! Cheers Rich It can be fitted badly and will make a racket Roger Quote Link to post Share on other sites
graeme Posted March 31, 2018 Report Share Posted March 31, 2018 I'm sure I've read on here before that the 1/4 moon plate which fills in the bottom of the bellhousing on the back of the engine can cause a noise rattle but I can't remember why!! Something like if it's fitted wrong way round, it's loose or flywheel bolts can catch it. Rich Yes Rich, If the plate is mounted reversed the flywheel bolts can hit it. Cheers Graeme Quote Link to post Share on other sites
2long Posted March 31, 2018 Report Share Posted March 31, 2018 Isn't rattling sometimes caused by a worn distributor drive shaft? Dan Quote Link to post Share on other sites
Chris Hubball Posted March 31, 2018 Report Share Posted March 31, 2018 Hi Dick Are the nuts holding the two eared clamps that secure the exhaust manifold to the inlet manifold situated under the carburetters tight, sometimes they run out of thread before they grip the clamps. Cheers Chris. Quote Link to post Share on other sites
Den T Posted March 31, 2018 Report Share Posted March 31, 2018 (edited) Gearbox cover plate, bottom of the bell housing Edited March 31, 2018 by Den T Quote Link to post Share on other sites
Motorsport Mickey Posted March 31, 2018 Report Share Posted March 31, 2018 Gearbox cover plate, bottom of the bell housing Hi Neil, I wondered that but it was quoted "Engaging and disengaging the clutch does not alter the noise" which in my experience is one of the pointers to it being on incorrectly. Mick Richards Quote Link to post Share on other sites
Graham Harris Posted April 1, 2018 Report Share Posted April 1, 2018 I think I would take that cover plate off and check for scratch marks,I fitted it upside down the first time and it does make a lot of noise. Graham Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.