worldwidewebs Posted June 7, 2013 Posted June 7, 2013 Right, I have a problem and I'm at the end of my tether so I need some help... I had a Piper 421 fitteda year or so back and straight away I started getting a tizzing noise around 4000rpm. Cutting a long story short, I replaced the Piper with. 2bular manifold and sports cat - the tizz disappeared for a while but came back after a month or so but this time it was a bit quieter. The noise gradually got louder until recently when I decided it was the back box so I bought a Hangar 111 Signature exhaust to replace it. I fitted this today and when taking the old one off I noticed a few issues with it so was happy that I'd got round to replacing it. Then I started the car up. The bloody tizz is back, just louder this time! So has anyone got any ideas? I've had a few people look at the car but no one can find the issue and it's really spoiling the enjoyment of my car
Martin R Posted June 7, 2013 Posted June 7, 2013 Check all the heatshields are not close or touching anything.
worldwidewebs Posted June 7, 2013 Author Posted June 7, 2013 I've removed the heat shields around the manifold when I first experienced the tizz and it made no difference, although I have refitted them since. I've tried revving the engine whilst manipulating the heat shield but nothing changes so I'm not sure it's this unfortunately It's not the under tray as this is currently sat in the garage!
Martin R Posted June 7, 2013 Posted June 7, 2013 You can buy a mechanics stethoscope ( spelling? ) Funny enough similar to a doctors. Try it on various bits and see if you can pin point it? Edit, you can get one for less than a fiver on ebay.
Elise+Imp Posted June 7, 2013 Posted June 7, 2013 A large screwdriver placed on various items with your ear on the handle works very well to amplify sounds and trace faults. Sounds like the tizz is in part of the system you've not changed, perhaps the cat element is loose? Brian
worldwidewebs Posted June 7, 2013 Author Posted June 7, 2013 The cat has been changed - from the std one to the 2bular sports cat. I'll do the stethoscope thing and see where I go. Having changed most things yet still having the problem must point to something "obvious"
richbk Posted June 9, 2013 Posted June 9, 2013 my fixed section of middle undertray vibrated on my s2. it didnt appear to be removable to fix / tighten, so i scientifically found the vibration whilst it was up on a set of ramps at a garage and applied a large knocking stick (hammer) to the area, which caused a small dent but also tightened up the tray immidiately stopping the vibration / tizz. not sure if this is case on s1, but might be worth a look / richbk
worldwidewebs Posted June 12, 2013 Author Posted June 12, 2013 my fixed section of middle undertray vibrated on my s2. it didnt appear to be removable to fix / tighten, so i scientifically found the vibration whilst it was up on a set of ramps at a garage and applied a large knocking stick (hammer) to the area, which caused a small dent but also tightened up the tray immidiately stopping the vibration / tizz. not sure if this is case on s1, but might be worth a look / richbk Well it's worth a go - thanks for the idea
P4N Lotus Posted June 16, 2013 Posted June 16, 2013 Ask a fellow 111s owner , I don't recall and tizz sounds , usually they are reverberations , mine had alsorts - under tray - bracket holding exhaust on - rear grill - engine cover lid - exhaust vibrating on the grill holes sometimes aftermarket exhausts vibrate on it and might give that tizz sound Jamie on here has a 111s might be able add feedback too
worldwidewebs Posted June 17, 2013 Author Posted June 17, 2013 Well I looked at the undertrays etc and am pretty sure their not the culprit. I am wondering though whether it could be the heat shield this time. Originally with the Piper manifold, I removed the heat shield so I knew it wasn't that and did trace it to the manifold itself which is why I replaced it. Now with the 2bular manifold the heat shield is back on and after having another dig around this weekend it does look close, if not touching. So I removed the top bolt holding the heat shield on but left the bottom one in place (time and patience issues!) and pushed it away from the manifold. The tizz was still there but it didn't seem quite the same so I'm guessing that this time it could be the issue. I need to remove it totally to confirm but will wait until I have the time to remove AND replace it before having ago. Lesson learned from a while back! I'll update when I've tested my theory
worldwidewebs Posted June 30, 2013 Author Posted June 30, 2013 Well, it's not the heat shield. Bugger. I knew I should have left it alone when it was perfect!
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