cjhillman
Posted a lot
1979 Capri (Rolling Project) 1985 Escort mk3 (Daily)
Posts: 1,580
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May 19, 2021 18:47:05 GMT
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Hey all, I have a strange noise on my Capri that I thought was pre detention/pinging but I let a garage friend drive it (for another reason) and when I mentioned that he didnt know what it was either but said its not pinging.
It only happens on light Acceleration and not all the time. If you floor it, it seems to go away which is why its annoying around town as every gear it mostly does it... then it wont do it for a while. I tried topping up the gearbox oil and I cant really remember if it did anything if i'm honest.
Its quite loud in person, the camera doesnt pick it up that well. Heres a mashup from one drive recently.
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spiny
Club Retro Rides Member
Wiki Admin
I am abivalent towards car electrics ...
Posts: 1,330
Club RR Member Number: 167
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May 20, 2021 10:24:08 GMT
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I can't hear anything odd in the vid, but that might just be my ears. I'm guessing Pinto engine ? My 2.0 Cortina used to make odd noises which I traced to the viscous fan not 'visc-ing' properly. It never got up to temp to lock on, something broekn internally I guess, but it made odd noises - which were drowned out at high revs. Just a guess though  |
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cjhillman
Posted a lot
1979 Capri (Rolling Project) 1985 Escort mk3 (Daily)
Posts: 1,580
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May 20, 2021 10:34:30 GMT
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Fair enough, its just a weird rattle. its quite loud in the Car but the camera doesnt really pick it up. The noise happens at 0.3 seconds and 0.8 at its loudest .
How did you check the fan? someone once told me you should be able to stop a viscous fan with your hand but I don't fancy that haha. I've never really looked at it but guess its driven off the water pump?
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spiny
Club Retro Rides Member
Wiki Admin
I am abivalent towards car electrics ...
Posts: 1,330
Club RR Member Number: 167
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May 20, 2021 10:37:53 GMT
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Fair enough, its just a weird rattle. its quite loud in the Car but the camera doesnt really pick it up. The noise happens at 0.3 seconds and 0.8 at its loudest . How did you check the fan? someone once told me you should be able to stop a viscous fan with your hand but I don't fancy that haha. I've never really looked at it but guess its driven off the water pump? Yes, it's mounted on the water pump. From memory, it should freely spin when cold , so when the engine is not up to temp the fan shouldn't provide any airflow - check with the engine off and when the engine warms up the fan should 'lock' so that it it works like a fan. Easiest way to check is go for a run, get the car up to temp, then turn the engine off and check the fan, it should be much harder to turn than when the engine is cold. |
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May 21, 2021 15:26:22 GMT
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Maybe a bearing failing in one of the engine ancillaries.
You can do the 'screwdriver trick' - although I've found other metal shafts like jack handles also work.
Put one end of the metal shaft on the housing of a component such as a water pump or alternator and press your ear against the other end.
If you find one of the components running off the drive belts has significantly louder sound feeding back to your ear then it may have a faulty bearing.
Needless to say... when messing around with spinning pulleys and straight metal bars in the engine bay the two should not mix in order to maintain optimum comfort, particular when your ear is pressed against one end.
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May 21, 2021 16:39:04 GMT
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difficult to tell , but sounds like an exhaust baffle rattling  |
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cjhillman
Posted a lot
1979 Capri (Rolling Project) 1985 Escort mk3 (Daily)
Posts: 1,580
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May 21, 2021 22:14:39 GMT
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I'll check out the screwdriver technique . I slackend the fan belt off the other month and the alternator seemed to spin ok (it doesnt charge very well so was looking into that).
I'm wondering if its an exhaust baffle. It seems to resonate down the exhaust and driving past other parked cars with the window down, it sounds quite loud. I noticed when I went out in it before pulling off the drive it sounded like the exhaust catches the ground but I think its the angle/vibration.
I gave it a little rev using the throttle linkage and you cant replicate it unless the engine is under load. Just sounds like an normal engine
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cjhillman
Posted a lot
1979 Capri (Rolling Project) 1985 Escort mk3 (Daily)
Posts: 1,580
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Right... without getting too Spielberg on this ... I tied my Go pro under the bonnet  I thought this way I could get a better listen to it... turns out its a lower noise most of the time (under bonnet) and sounds really high pitched outside the Car. Its pretty much every gear change after about 2 mins of driving and if your in 4th and plant your foot you can generally hear it for longer... I made this video of the few times you can hear it inside the car and under the bonnet with the word "Noise" over the point its doing it... I'm probably going a bit mad with this and its weirdly loud in real life compared to any footage, just trying to track it down as the Car sounds/ drives nice now. Any ideas I'm all ears. Its odd revving the engine doesnt seem to do it, it seems it needs to be under load. I tried the viscous fan while it was cold (although its hot out) and it nearly chewed up my haynes manual trying to stop it. It doesnt wobble side to side though. I know the one of my dads spitfire did when it was going. I've had headphones on while editing this and it is a bit harder to hear just on laptop speaker. |
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I thought this way I could get a better listen to it... turns out its a lower noise most of the time (under bonnet) and sounds really high pitched outside the Car. Its pretty much every gear change after about 2 mins of driving and if your in 4th and plant your foot you can generally hear it for longer...