Mj17

Hi, As I said in an earlier thread I started getting a mechanical noise around 3500RPM on the way back from the Le Mans 24hrs the other week and finally managed to get through my list of other niggles and fit an oil pressure gauge last night, so today I took it for a run... Yes... Cold pressure was OK, between 50 and 75 lb/ft or 5 kg/cm. Warm oil pressure wasn't quite so pretty, down to 1 kg/cm or 15 to 20 lb/ft. I know it's impossible to say without seeing but the car still seems to run and pull fine, with the noise still not kicking in until 3500RPM but I'm off to France for a week on the 25th (2 and a bit weeks time).  Am I likely to get away with just replacing the bearings (will check with a friend tomorrow but don't think there's any crank movement so thrust washers OK), or would I be better off dropping it in to a garage, so they have time to get anything else fixed? I'm off to have a little cry now :(

2396 wrote:Ha Ha! Noise Paranoia! I suffer terribly with it! (clap) My worst attack was when this deep, rythmic thudding noise suddenly started.  Turned out my passenger was tapping his foot against the firewall in time to the music...

Is the battery new?  If the car's been sat for a few years it could be duff now and so not holding charge. If it's new/known good and on the grounds a picture paints a thousand words try either of these to test the alternator: http://easyautodiagnostics.com/alternator_tests/alternator_diagnostic_tests_1.php http://www.wikihow.com/Check-an-Alternator

Base on your replies I'm starting to think it's NOT the bottom end then.  The only time I see the oil pressure warning light is when starting up, never while the engine's running (though idle is at 1000RPM so never goes THAT low).  Noise is definitely RPM and not load-related and no noticeable loss of power.  Was happy to pull up/coast down the hills on the M20 in o/d 4th provided I kept it even just under 70mph. My imagination/its always been like that is an option but I guess something gearbox is also there.  It does sound a bit like gears running together - not in a bad, metal on metal way, just a more a Victorian steam-powered vehicle way than a Triumph way.  Oh and while the gearbox does leak a little oil from the overdrive sump plate it was topped up before Le Mans and the overdrive was still switching in/out at a flick of the switch (it's been like that for years and I'm used to when the oil's low engagement gets slower and it's time to top-up). Travelling for work at the moment but should be able to get the small jobs fixed, oil pressure gauge fitted and some test driving in this weekend.

Hi, If your big ends start to knock how far are you likely to get if you keep driving? I ask because I think I started getting a noise on the way back from Le Mans (24hrs).  It started at the toll pay booth on the A16, so 40 miles from the tunnel and seemed to kick in at 130kph but be fine at 120, so I did 120.  Back in the UK for the 70 miles to home it seemed to happen at 70mph, so I did 68/69.  The noise seemed to be the same the whole way home, not getting any worse/louder.  The noise is related to RPM and comes in at the same point (between 3000-3500) in both 4th and o/d 4th. If the big ends were going would the noise have just stayed the same?  Can you usually avoid the noise if you're just under a certain RPM?  Would you be able to drive over 100 miles without things getting any worse? The reason I ask is because it's also 100% possible nothing's changed and I just had that sudden noise paranoia.  You know, the one where you suddenly hear a noise that's always been there but talk yourself in to it being something new, usually terminal and expensive - and often goes away when you switch the stereo off and realise it's just part of the song that's playing. Does it sound like paranoia, or a problem.  And if it's a big-end problem can you change them with the engine in on a Spitfire?

ajp wrote:Bottom ball joints are not to bad to do James -use a grinder to get the old one out slice the bottom off it and twat the f**ker ,refiting reversal of removal without the grinder! Or if you have a friendly garage with a press that you can get to without your 2000, drop the lower wishbones and winder down.  Five minutes later you will be heading home with two nice new balljoints in your wishbones.

Yes, using the flywheel is more accurate than using a degree wheel - but it's nothing like as accurate or as easy as using a dial gauge on the 7/8 rocker arms! Again from memory but I believe it's... 1) If it's a running engine, skip to step 2, otherwise set the cam up as the Haynes book. 2) Find TDC and set up an accurate mark. 3) Set up dial gauge on #7 rocker arm and zero it. 4) Rock engine back from TDC until #7 is off-cam. 5) Read off the dial gauge to see how far open #7 is actually at TDC. 6) Repeat 1-4 on #8. 7) Change the cam timing based on the dial gauge number (i.e. if #8 is more open than #7 at TDC, turn cam to correct and either flip cam toothed-wheel or fiddle with your vernier wheel for the best match to that position). 8) Repeat 1-5 to check you've got it right/gone the right way. There you have it - a perfectly (standard) times cam, regardless of overlap/duration, symmetrical/asymmetrical profiles, etc.  If you want to tweak the cam timing for performance then you'll need a lot of money or a rolling road in your garage!  (even then you use the same logic to adjust the timing by the desired amount, just aiming for a specific difference between the opening of #7 and #8 valves rather than an identical one).

Yes, using the flywheel is more accurate than using a degree wheel - but it's nothing like as accurate or as easy as using a dial gauge on the 7/8 rocker arms! Again from memory but I believe it's... 1) If it's a running engine, skip to step 2, otherwise set the cam up as the Haynes book. 2) Find TDC and set up an accurate mark. 3) Set up dial gauge on #7 rocker arm and zero it. 4) Rock engine back from TDC until #7 is off-cam. 5) Read off the dial gauge to see how far open #7 is actually at TDC. 6) Repeat 1-4 on #8. 7) Change the cam timing based on the dial gauge number (i.e. if #8 is more open than #7 at TDC, turn cam to correct and either flip cam toothed-wheel or fiddle with your vernier wheel for the best match to that position). 8) Repeat 1-5 to check you've got it right/gone the right way. There you have it - a perfectly (standard) times cam, regardless of overlap/duration, symmetrical/asymmetrical profiles, etc.  If you want to tweak the cam timing for performance then you'll need a lot of money or a rolling road in your garage!  (even then you use the same logic to adjust the timing by the desired amount, just aiming for a specific difference between the opening of #7 and #8 valves rather than an identical one).

Two options come to mind. 1) Buy a Haynes book and follow the instructions (don't remember it being too tricky). 2) Buy a dial gauge, set #1 to TDC then use the gauge to find the point #4 cylinders inlet and exhaust valves are equally open.  That's the point you want the cam with the crank at TDC. Note: #2 is from memory and should be checked! :)

Two options come to mind. 1) Buy a Haynes book and follow the instructions (don't remember it being too tricky). 2) Buy a dial gauge, set #1 to TDC then use the gauge to find the point #4 cylinders inlet and exhaust valves are equally open.  That's the point you want the cam with the crank at TDC. Note: #2 is from memory and should be checked! :)