Boxofbits Posted September 27, 2023 Share Posted September 27, 2023 Hi all Well, as I’m doing the RBRR this year, I’ve been doing all those jobs that wouldn’t normally get done, like Brake Master seal kit, new brake fluid, steering rack inner rack joint shim, tracking and wheel balancing. Today I decided to back flush the rad/engine and fill with fresh antifreeze, just to keep the temperature normal…hopefully. When warming the engine up afterwards, I noticed quite a loud ‘clattering’ noise which comes in at about 3,000 RPM. This is with the car stationary so not under load. Oil pressure and temperature look normal and neither wildly fluctuate, so I’ve tentatively ruled out big ends or mains, for the moment, though still could be but I do hope not as I can’t see I can take the engine out and rebuild it before next week! I haven’t ruled out a load of other things like timing chain tensioner, cam followers etc. Does this engine have a ‘known’ weakness which might cause this? Your thoughts please! Kevin Quote Link to comment Share on other sites More sharing options...
thescrapman Posted September 27, 2023 Share Posted September 27, 2023 Time to get the big screwdriver out, put it against your ear and then against the engine to listen and hopefully narrow down the source. or just buy some earplugs 🙂 Quote Link to comment Share on other sites More sharing options...
Boxofbits Posted September 27, 2023 Author Share Posted September 27, 2023 22 minutes ago, thescrapman said: Time to get the big screwdriver out, put it against your ear and then against the engine to listen and hopefully narrow down the source. or just buy some earplugs 🙂 Thanks. Tomorrow I will try to narrow it down. Hoping I don’t hear a very loud noise in the sump! Quote Link to comment Share on other sites More sharing options...
Wendy Dawes Posted September 27, 2023 Share Posted September 27, 2023 Maybe a video recording so everyone could hear the noise may help with suggestions of a diagnosis Quote Link to comment Share on other sites More sharing options...
Boxofbits Posted September 27, 2023 Author Share Posted September 27, 2023 23 minutes ago, Wendy Dawes said: Maybe a video recording so everyone could hear the noise may help with suggestions of a diagnosis Thanks Wendy I’ll TRy that tomorrow. 1 Quote Link to comment Share on other sites More sharing options...
Dannyb Posted September 28, 2023 Share Posted September 28, 2023 For peace of mind. Why not remove sump and check big end bearings. If they are worn then order new bearings. I did the same with my Spit. No4 was well gone and suspect the crank has gone oval. Changed them and running the car while the original engine which was stored in my garage is now with the machine shop. Danny Quote Link to comment Share on other sites More sharing options...
glang Posted September 28, 2023 Share Posted September 28, 2023 12 hours ago, Boxofbits said: When warming the engine up afterwards, I noticed quite a loud ‘clattering’ noise which comes in at about 3,000 RPM. This is with the car stationary so not under load. Oil pressure and temperature look normal and neither wildly fluctuate, so I’ve tentatively ruled out big ends or mains, for the moment, though still could be but I do hope not as I can’t see I can take the engine out and rebuild it before next week! I haven’t ruled out a load of other things like timing chain tensioner, cam followers etc. Does this engine have a ‘known’ weakness which might cause this? Your thoughts please! Kevin Not sure what your is but all our engines have bearings which dont have a reputation for longetivity. The sixes are worse and I read a recommendation years ago that if big ends were changed in time every 40k and mains at 70k the cranks could last indefinitely. However once theres loud knocking the crank is worn and will need regrinding. The good news is that once they reach this level normally the oil pressure drops off considerably because the tolerances have opened up so in your case still having good oil pressure should indicate the problem lies elsewhere.... Have a good look round the engine to make sure nothing is in contact - fan, exhaust etc 2 Quote Link to comment Share on other sites More sharing options...
Boxofbits Posted September 28, 2023 Author Share Posted September 28, 2023 Today I decided on rocking the crank to and fro by hand using the original metal fan blades, just to see if there was any free play in relation to the rear of the crankshaft which might be causing the clattering noise coming in around 3000 rpm, suspecting a broken crank but which didn’t really stack up tbh as the oil pressure was good, but apparently these 4 pots have an appetite for crankshafts. Rocking the engine, I noticed the fan assembly moving slightly on the hub, so somehow the 4 bolts retaining the fan had loosened over a period of time. I was relieved to find tightening these another turn each resolved the issue and noise gone. Which makes me think the rubbers might have perished slightly maybe over the years and led to some free movement. It sounded like a piston was just about to let go tbh, so definitely worth checking out these bolts and others on the engine before the run and definitely before stripping it! Thanks everyone for your suggestions. 3 Quote Link to comment Share on other sites More sharing options...
thescrapman Posted September 28, 2023 Share Posted September 28, 2023 I would have thought there would be lock tabs on the fan bolts, certainly is on the 6-cal cars. Quote Link to comment Share on other sites More sharing options...
Boxofbits Posted September 28, 2023 Author Share Posted September 28, 2023 2 hours ago, thescrapman said: I would have thought there would be lock tabs on the fan bolts, certainly is on the 6-cal cars. There was and they were locked over. Possible that the rubber bushings are perishing, causing the bolts to appear loose? Quote Link to comment Share on other sites More sharing options...
glang Posted September 29, 2023 Share Posted September 29, 2023 Which car is this as I thought all the four cylinder models had there fans attached to the water pump and not the crank? As such they dont have the rubber bushes cos the dampening effect isnt required. Have you got some sort of hybrid? With the rubber bushes on the six cylinder cars there should be short metal tubes inside which the fixing bolts tighten up against so although they can perish causing the fan to be loose tightening the bolts usually achieves nothing. Has someone removed the tubes in an attempt to compensate for knackered rubber bushes? If so it needs to remedied or youll lose the dampening effect... Quote Link to comment Share on other sites More sharing options...
glang Posted September 29, 2023 Share Posted September 29, 2023 Ahhh Ive worked out its a Tr4 now so yes the fan is on the crank and with rubber bushes so the second part of my previous post applies. You can even get poly bushes now for the fans and although expensive you know they arent going to fall apart in six months like many rubber components available these days.... Quote Link to comment Share on other sites More sharing options...
yorkshire_spam Posted September 29, 2023 Share Posted September 29, 2023 18 hours ago, Boxofbits said: Rocking the engine, I noticed the fan assembly moving slightly on the hub, so somehow the 4 bolts retaining the fan had loosened over a period of time. I was relieved to find tightening these another turn each resolved the issue and noise gone. I had a slightly similar experience today when I started to panic about the wheel bearings on the Spitfire... until I realised I hadn't done the wheel nuts up properly yet. Time for a checklist for me! 2 Quote Link to comment Share on other sites More sharing options...
Tim Hunt Posted September 29, 2023 Share Posted September 29, 2023 18 hours ago, Boxofbits said: Today I decided on rocking the crank to and fro by hand using the original metal fan blades, just to see if there was any free play in relation to the rear of the crankshaft which might be causing the clattering noise coming in around 3000 rpm, suspecting a broken crank but which didn’t really stack up tbh as the oil pressure was good, but apparently these 4 pots have an appetite for crankshafts. Rocking the engine, I noticed the fan assembly moving slightly on the hub, so somehow the 4 bolts retaining the fan had loosened over a period of time. I was relieved to find tightening these another turn each resolved the issue and noise gone. Which makes me think the rubbers might have perished slightly maybe over the years and led to some free movement. It sounded like a piston was just about to let go tbh, so definitely worth checking out these bolts and others on the engine before the run and definitely before stripping it! Thanks everyone for your suggestions. Really glad you got it sorted Kevin. A good watch out for some others but not me - I binned the mechanical fan and hub extension when I fitted a Kenlowe over 40 years ago. A side bonus is it makes a fan belt change a breeze. No need to jack the engine up to give clearance between the hub extension and steering rack! Best of luck for the RBRR. Tim Quote Link to comment Share on other sites More sharing options...
Boxofbits Posted October 2, 2023 Author Share Posted October 2, 2023 On 29/09/2023 at 14:03, glang said: Ahhh Ive worked out its a Tr4 now so yes the fan is on the crank and with rubber bushes so the second part of my previous post applies. You can even get poly bushes now for the fans and although expensive you know they arent going to fall apart in six months like many rubber components available these days.... That’s an answer - they were tightened when I rebuilt the engine, but maybe the rubber damper bushings aren’t quite the same quality as the originals (surprise surprise )! The TR4 and 4a ( maybe 5/6 too) have the fan running off the crankshaft hub, so being more of a direct drive it might be more susceptible to noise if it works loose. Quote Link to comment Share on other sites More sharing options...
Boxofbits Posted October 2, 2023 Author Share Posted October 2, 2023 On 29/09/2023 at 15:39, Tim Hunt said: Really glad you got it sorted Kevin. A good watch out for some others but not me - I binned the mechanical fan and hub extension when I fitted a Kenlowe over 40 years ago. A side bonus is it makes a fan belt change a breeze. No need to jack the engine up to give clearance between the hub extension and steering rack! Best of luck for the RBRR. Tim Many thanks Tim. BIG sigh of relief there! I may well change to an electric fan as it possibly drags a few horses too. I’ve just got around to finishing the crop of jobs I had on my list for the RBRR -and some..I’ve just finished fitting a rear screen heater from Holden. Fiddly, but hope it works. I’ve wired in a 10 minute timer relay with a momentary switch. It sounds like the relay is coming on which is a good start, along with a period ‘jewel’ orange warning light… so looks very good, but I just hope that’s not the only part that works! Usually get some condensation on the run so hopefully it will. I hope your ‘Smiths’ unit is still working. Kevin Quote Link to comment Share on other sites More sharing options...
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