Steves_TR6 Posted February 17, 2018 Report Share Posted February 17, 2018 So, i think i can hear a slight knocking noise from the engine of my tr6, ive been noticing it for a couple of weeks. Its only audiable with the bonnet up and seems to be proportional to revs. Its a loud tap/clonk, seems to be low down in the engine rather than top end but hard to isolate. Engine is running perfectly, pulling as hard as ever, no water in oil or smoke etc. As regulars will know my engine is a mongrel, i understand it to have +60th forged pistons built late 80s and i saw 145bhp at the weels at enginuity a couple of years ago, but i dont have full details. . As i dont have any kind of lift i was thinking of taking the car to Rees Bros or Enginuity to have the sump off for a quick check over, unless someone has a better idea? Steve Quote Link to post Share on other sites
Mike C Posted February 17, 2018 Report Share Posted February 17, 2018 Can you hear/feel anything if you rock the crankshaft back and forth with a spanner? Quote Link to post Share on other sites
Steves_TR6 Posted February 18, 2018 Author Report Share Posted February 18, 2018 Hi Mike I rotated the crank with a ratchet and it felt smooth, perhaps heard a slight tap but could have been imaginary! Would i be better with a sold breaker bar ? I’ve not delved into the bottom end of a TR engine before so its new territoty for me. Steve Quote Link to post Share on other sites
RogerH Posted February 18, 2018 Report Share Posted February 18, 2018 Hi Steve, have you used a stethoscope to try and locate the apprx area. Long screwdriver - with extra steel bar to extend the access My dodgy cam suggested the front end, towards the nearside. Not dizzy drive, water pump, or timing chain. It was the cam lobes # 1&2 so fairly accurate. Roger Quote Link to post Share on other sites
Steves_TR6 Posted February 18, 2018 Author Report Share Posted February 18, 2018 Thanks Roger, good idea but im not sure i’m competent to diagnose this! Steve Quote Link to post Share on other sites
97fm Posted February 18, 2018 Report Share Posted February 18, 2018 Hi Steve Sorry to hear your woes. I had similar symptoms with my 6, could also hear the noise inside the car, even dropped the sump and examined bottom end and crankshaft float to no avail. Eventually traced the problem to gearbox bearings. Recon box and all is well. Frank Quote Link to post Share on other sites
Motorsport Mickey Posted February 18, 2018 Report Share Posted February 18, 2018 Steve, More info needed, Is the noise there from cold ? Is the noise then proportional ? If you leave it on tickover or does it disappear if you put a couple of thousand revs on and hold it there. Mick Richards Quote Link to post Share on other sites
barkerwilliams Posted February 18, 2018 Report Share Posted February 18, 2018 Steve, Engineers stethoscope as per Roger above, about £8 on Ebay. They are so simple to use do not worry about competence. Put on any part of a running engine and you can clearly hear all sorts and rumblings. Move along a few inches and some rumblings die away and some get louder. Move towards the knocking you are tracking down, it really is that easy to track down any external device on the engine that is the source of noise. Internals are a little more awkward as you need to be aware of the internal construction of the engine. Only two caveats, always look at where the probe is and keep it away from the moving belts, and at the risk of personal pain, and a new hair syle avoid the coil /plug leads and dizzy cap. Alan Quote Link to post Share on other sites
Steves_TR6 Posted February 18, 2018 Author Report Share Posted February 18, 2018 Thanks for the input Frank and Mick So, i’ve just been out to test from cold start, yes the noise is there and it does seem to change / quieten with a couple of thousand revs. Experimenting with long screwdriver/stethoscope i can hear lots of wiring noises bot not the knock On the inlet/exhaust side of the engine the knock is very pronounced with my ear to the plenum chamber’s open end , air tube and filter are off at the moment. Reinstall air tube and filter , original casing with k&n insert and couple of extra big holes cut in it........noise moves to front of car. So is that it? I imagined engine wear/damage when the ‘knock’ is actually air pulsing from the open plenum? I’ve never run the engine without the filter, but did so when checking the new damper was all secure and have given myself a fright. Thoughts? (apart from what an idiot!) Steve Quote Link to post Share on other sites
Z320 Posted February 18, 2018 Report Share Posted February 18, 2018 I would take of the fan belt to be shure it's not the water pump or generator. Ciao Marco Quote Link to post Share on other sites
Steves_TR6 Posted February 18, 2018 Author Report Share Posted February 18, 2018 I would take of the fan belt to be shure it's not the water pump or generator. Ciao Marco Thanks Marco, i did this test and there was no difference. Steve Quote Link to post Share on other sites
MostEasterlySteve Posted February 18, 2018 Report Share Posted February 18, 2018 Just a thought as you say it's a 'mongrel'....does it have a viscous fan by any chance? When on the way out they can effectively imitate the sounds of some very serious mechanical problems. Quote Link to post Share on other sites
Steves_TR6 Posted February 18, 2018 Author Report Share Posted February 18, 2018 Just a thought as you say it's a 'mongrel'....does it have a viscous fan by any chance? When on the way out they can effectively imitate the sounds of some very serious mechanical problems. Thanks Steve, no viscous fan. Has a 1980’s electric fan which i thought about replacing but its still working so left it. I’m increasingy confident that there is no engine problem, and the ‘knock’ was just a noise from the induction system that i’ve not heard before as never run engine without air filtering. I’ll still have the sump off i think to check bearings, thrust washers etc. Steve Quote Link to post Share on other sites
MostEasterlySteve Posted February 18, 2018 Report Share Posted February 18, 2018 Fingers crossed for you! Quote Link to post Share on other sites
Blue cedar Posted February 18, 2018 Report Share Posted February 18, 2018 Steve, whilst you are there why not replace the big, main and thrust washers. I think back in the day changing the bearings was expected at intervals to extend the life of the engine. I replaced the originals bearings on my car, they had done 100k. It sweetened the engine sound. Peter Quote Link to post Share on other sites
graeme Posted February 18, 2018 Report Share Posted February 18, 2018 On the inlet/exhaust side of the engine the knock is very pronounced with my ear to the plenum chamber’s open end , air tube and filter are off at the moment. Steve Steve, What you are hearing could very well be an exhaust manifold leak where it fastens to the head. This is usually heard as a tap and the noise softens higher in the rev range. You could try nipping up the manifold nuts and see if it makes a difference. Good Luck Graeme Quote Link to post Share on other sites
Z320 Posted February 18, 2018 Report Share Posted February 18, 2018 Tappets clearance? Quote Link to post Share on other sites
jerrytr5 Posted February 18, 2018 Report Share Posted February 18, 2018 Does the noise stop when you have your foot on the clutch? If so, could indicate either thrust washer issues or gearbox layshaft on the way out (gearbox layshaft still turning in neutral don't forget). Jerry Quote Link to post Share on other sites
Steves_TR6 Posted February 18, 2018 Author Report Share Posted February 18, 2018 Thanks guys, the exhaust leak sounds likely Doesnt sount like tappets, i used a big screwdriver as a stethoscope on the rocker box amongst other places Havent tried the clutch, as the noise is only really audiable over the exhaust from next to the engine. Plan is to dti the end float then have the sump off, its about time i had a look at the bottom end! Thanks for the support! Steve Quote Link to post Share on other sites
Mike C Posted February 18, 2018 Report Share Posted February 18, 2018 It doesn't sound like an urgent fix is required. I'd take it to a Register meeting and ask for other member's opinions. Quote Link to post Share on other sites
Alec Pringle Posted February 18, 2018 Report Share Posted February 18, 2018 Hi Steve, I'd check out the exhaust and induction for issues first . . . . . Anything resembling a meaningful bottom end problem is usually a pretty hefty noise, and you know something is adrift without needing to resort to stethoscopes for further advice . . . . There's no merit in dropping the sump unless you really have to, as the old adage goes "if it ain't broke, don't fix it . . . . " Cheers Alec Quote Link to post Share on other sites
Mike C Posted February 18, 2018 Report Share Posted February 18, 2018 +1 "if it ain't broke, don't fix it . . . . " Quote Link to post Share on other sites
Steves_TR6 Posted February 19, 2018 Author Report Share Posted February 19, 2018 (edited) +1 "if it ain't broke, don't fix it . . . . "Yes, i think that is the best advice ! Thanks Alec and Mike Im busy for a couple of weekends, so going to do nothing and see what i think next time im out in the TR Steve Edited February 19, 2018 by SDerbyshire Quote Link to post Share on other sites
ShaunC Posted February 19, 2018 Report Share Posted February 19, 2018 Piston slap? Quote Link to post Share on other sites
Steves_TR6 Posted February 19, 2018 Author Report Share Posted February 19, 2018 Piston slap? PistNBroke more likely :-) Quote Link to post Share on other sites
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