Quack Posted March 25, 2022 Report Share Posted March 25, 2022 I was just going down the motorway in my Herald 13/60 and all of a sudden a very loud knocking sound came out of nowhere, it then continued any time I go above 60mph. It’s extremely loud, I can’t tell where abouts it’s coming from in the car, any clues? Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 25, 2022 Report Share Posted March 25, 2022 start with the easy loose wheel nuts ?? exhaust fouling chassis somewhere when under power ??? does it change drive overun or out of gear ??? Pete Link to comment Share on other sites More sharing options...
Quack Posted March 25, 2022 Author Report Share Posted March 25, 2022 Noticed engine is also very jumpy…going up and down revs on idle Link to comment Share on other sites More sharing options...
dougbgt6 Posted March 25, 2022 Report Share Posted March 25, 2022 Rhythmic knocking or random? Worse when accelerating? Do you have an oil gauge? Doug Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 25, 2022 Report Share Posted March 25, 2022 some how we need to isolate is this engine /transmission/ exhaust/driveline/ body related knocking Pete Link to comment Share on other sites More sharing options...
Quack Posted March 25, 2022 Author Report Share Posted March 25, 2022 Probably best to look when I’m home, at another services now. Hopefully it’s just something below the bonnet knocking like the heater lead, or even under the dashboard. It’s hard to tell of course cause I can only test it going 79mph down the m1 which isn’t the greatest idea! Link to comment Share on other sites More sharing options...
PeteH Posted March 26, 2022 Report Share Posted March 26, 2022 Have you got Eccles locked in the boot?, Sorry couldnt resist it, been on the other thread. 🤣 "Blonde Moments". Pete Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 26, 2022 Report Share Posted March 26, 2022 23 hours ago, Quack said: 79mph down the m1 earlier you quoted 60 mph so is the frequency getting worse !!! ha when it comes to noises and vibrations its a case of sorting out what can this be engine is normally rev related gearbox and diff run at engine speeds drive shafts and wheels run 4 times slower intermittent , what changes it ?? speed only or how agressive you drive one very often ignored banshee rattle is a loose number plate Pete Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 26, 2022 Report Share Posted March 26, 2022 as the blonde thread has re awakend you have had a look to make sure tony hancock isnt driving and kenneth williams is outside ??? hanging on Pete 1 Link to comment Share on other sites More sharing options...
paul fosh Posted March 26, 2022 Report Share Posted March 26, 2022 personally i would not be driving the car at 60mph with out finding out if its safety related , u j wheel nuts engine mounts gearbox mounts who knows , Link to comment Share on other sites More sharing options...
ahebron Posted March 27, 2022 Report Share Posted March 27, 2022 Many many years ago when my my Vitesse 6 was on the road I would drive rapidly round a 90 degree bend then floor the accelerator. The throttle would jam open and the engine would move forward with the metal fan blades hitting the lip on the lower radiator tank making a hell of a noise. Turn the key off wiggle the accelerator pedal and all good till the next time. To stop it happening I took the car apart nearly 40 years ago. Still got it and its restoration is being over taken by glaciers. Link to comment Share on other sites More sharing options...
NonMember Posted March 27, 2022 Report Share Posted March 27, 2022 3 hours ago, ahebron said: metal fan blades hitting the lip on the lower radiator tank making a hell of a noise. Many years ago my brother, driving what is now my Spitfire, turned right at a junction and heard a deafening BANG followed by persistent (and loud) dugga dugga at engine speed. Thinking the worst, he stopped the car, opened the bonnet, and couldn't see anything because it was dark. He was a mile or two from mum's house so he locked the car, hitch-hiked, and returned with mum's car and a tow rope. In the mean time some ratbag had smashed the driver's door window (with a wooden block that had been in the boot). The terminal fault? Well, it had air horns and the compressor was mounted on the radiator frame. The bolt had come loose and the compressor had hit the fan. Link to comment Share on other sites More sharing options...
Peter Truman Posted March 27, 2022 Report Share Posted March 27, 2022 I had a strange noise just last week in the Sprint a tap tap at low revs but it went as the engine revved. I changed the Alternator but noise was still there I couldn’t locate any rotational cause eg cam shaft, water pump, pistons, etc so I removed the rocker cover and eventually found the problem the bracket used to lock the overhead cam when removing the head had broken off due to fatigue whilst it shouldn’t be in contact with anything in normal operation just sit there clear of the cam sprocket springing forward of the camshaft sprocket but during a previous rebuilt 20 plus years ago appears it hadn’t been set up correctly was fouling the bolt used to lock the cam sprocket thereby working back and forward hence fatigue. luckily I located the failure before any real damage was done and removed the broken bracket all good engine now back to normal but no bracket so any future rebuild could be tricky! Link to comment Share on other sites More sharing options...
ahebron Posted March 27, 2022 Report Share Posted March 27, 2022 This has all just reminded me when I was in a mates TR6 3 cars behind a Spitfire driving down the road when we heard and felt a loud bang. Thinking the TR6 had a problem we stopped as did the other cars. It turned out the Spitfire had blown its diff which probably was due to the Daimler 250 motor that powered it. Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 27, 2022 Report Share Posted March 27, 2022 we need to isolate mechanical rythmic to body unsympathetic noises Pete Link to comment Share on other sites More sharing options...
PeteH Posted March 28, 2022 Report Share Posted March 28, 2022 On 25/03/2022 at 10:10, Quack said: I was just going down the motorway in my Herald 13/60 and all of a sudden a very loud knocking sound came out of nowhere, it then continued any time I go above 60mph. It’s extremely loud, I can’t tell where abouts it’s coming from in the car, any clues? Is it only in Top?. Or can you get it to occur at lower speeds in lower gears?. Pete Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 28, 2022 Report Share Posted March 28, 2022 do check the number plate is secure its a classic speed related clatter same on moderns with a flapping undertray Pete Link to comment Share on other sites More sharing options...
Quack Posted April 10, 2022 Author Report Share Posted April 10, 2022 Finally got round to taking a look and I’m rather shocked to have found out that the problem was as seen in the picture attached. Somehow my alternator mounting bolt had sliced clean off mid drive, and the nut was rattling around in the chassis?!! I’m not even sure how this could possibly have happened! Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 10, 2022 Report Share Posted April 10, 2022 looks like a straight forward shrear due to over tighening at some time in its life Pete Link to comment Share on other sites More sharing options...
NonMember Posted April 10, 2022 Report Share Posted April 10, 2022 That's not unlike a certain member's recent "catastrophic engine failure" (judging from the horrendous noise) that turned out the be a sheared water pump shaft. Link to comment Share on other sites More sharing options...
PeteH Posted April 11, 2022 Report Share Posted April 11, 2022 Look close at first pic;. Small discoloured "notch" at the bottom of the thread?. Probably from where the failure propagated?. Unusual for rolled threads, not uncommon on Cut one`s though. Over-torquing would not help. Uncle Pete`s "Gorrilla Paws".😁 Pete Link to comment Share on other sites More sharing options...
Peter Truman Posted April 11, 2022 Report Share Posted April 11, 2022 Thats some serious effort as it's a free bolt so you would have to hold a ring spanner on one end and socket on the other not easy to input that amount of torque to shear that bolt I'd assume the bolt was faulty! Link to comment Share on other sites More sharing options...
cliff.b Posted April 11, 2022 Report Share Posted April 11, 2022 On 10/04/2022 at 12:03, Quack said: Finally got round to taking a look and I’m rather shocked to have found out that the problem was as seen in the picture attached. Somehow my alternator mounting bolt had sliced clean off mid drive, and the nut was rattling around in the chassis?!! I’m not even sure how this could possibly have happened! Was there not a sheared off bit still in the nut? If not, I'm wondering if it sheared previously and someone has just got the the nut to bite on a thread or two of what's left. Could explain what happened, maybe 🤔 Link to comment Share on other sites More sharing options...
Quack Posted April 11, 2022 Author Report Share Posted April 11, 2022 Nope, couldn’t find that bit anywhere. Also the bolt and nut were brand new as I fitted them myself with the alternator conversion kit. Very weird Link to comment Share on other sites More sharing options...
cliff.b Posted April 11, 2022 Report Share Posted April 11, 2022 32 minutes ago, Quack said: Nope, couldn’t find that bit anywhere. Also the bolt and nut were brand new as I fitted them myself with the alternator conversion kit. Very weird That is a mystery, unless the one that sheared is on the road somewhere and what you found was some other random nut from somewhere else 🤔 Link to comment Share on other sites More sharing options...
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