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Dec 20, 2006 16:18:38 GMT
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Oy oy
My audi needs a new Knock Sensor (i think). At certain engine speeds/loads it thinks it has detonation and retards the ignition. It clearly isn't suffering from knock, as it only happens at 4000 rpm (regardless of load) and sometimes at 75mph in 5th even at practically no load (it goes away if you floor it at this speed). Also, this behaviour is unaffected by whatever petrol grade you put in. So my question is, is one Bosch knock sensor the same as another? They certainly all look the same. I know they are fundamentally a simple accelerometer which is 'excited' by engine vibes of a certain frequency, so maybe that frequency is similar for all in-line iron-block engines?
I'm sure a knock sensor purchased from Audi will cost about £47500, but there are some identical-looking Vectra ones on the bay for a fiver, which is more my kind of price. What do we think?
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1972 Fiat 130 1985 Talbot Alpine 1974 Lancia Beta Saloon 1975 + 1986 Mazda 929 Koop + Wagon 1982 Fiat Argenta 2.0 iniezione elettronica 1977 Toyota Carina TA14 BEST CAR EVER!!!!!!!! 1979 Datsun B310 Sunny 4-dr 1984 Audi 200 Quattro Turbo 1983 Honda Accord 1.6 DX GONE1989 Alfa 75 2.0 TS Mr T says: TREAT YO MOTHER RIGHT! |
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bstardchild
Club Retro Rides Member
Posts: 14,962
Club RR Member Number: 71
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KNOCK sensor Qbstardchild
@bstardchild
Club Retro Rides Member 71
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Dec 20, 2006 16:23:46 GMT
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Oy oy My audi needs a new Knock Sensor (i think). At certain engine speeds/loads it thinks it has detonation and retards the ignition. It clearly isn't suffering from knock, as it only happens at 4000 rpm (regardless of load) and sometimes at 75mph in 5th even at practically no load (it goes away if you floor it at this speed). Also, this behaviour is unaffected by whatever petrol grade you put in. So my question is, is one Bosch knock sensor the same as another? They certainly all look the same. I know they are fundamentally a simple accelerometer which is 'excited' by engine vibes of a certain frequency, so maybe that frequency is similar for all in-line iron-block engines? I'm sure a knock sensor purchased from Audi will cost about £47500, but there are some identical-looking Vectra ones on the bay for a fiver, which is more my kind of price. What do we think? Post a picture of it will ya Last count I had a box of known good Opel/Vauxhall 3.0 24V Iron block/alloy head knock sensors I can save you a few quid and an ebay purchase after all it's gonna cost cock all to send!!! |
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lebowski
Part of things
Hillman Avenger, Clan Clover
Posts: 488
Member is Online
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Dec 20, 2006 16:52:19 GMT
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I think the frequency of detonation is 6400Hz, regardless of engine.
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KNOCK sensor QBenzBoy
@benzboy
Club Retro Rides Member 7
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Dec 20, 2006 16:59:27 GMT
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You could always get the part number and cross-reference it. I've rang Bosch when looking for injector info and they've been really helpful.
Alternatively, I've also punched the part no. into Google in quotation marks and it's bore fruit surprisingly frequently!
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slater
Club Retro Rides Member
Posts: 6,390
Club RR Member Number: 78
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KNOCK sensor Qslater
@slater
Club Retro Rides Member 78
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Dec 20, 2006 17:48:21 GMT
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sounds like a suck it and see job.
only £5
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froggy
Posted a lot
Posts: 1,099
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Dec 20, 2006 19:26:47 GMT
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I'm with lebowski, i changed them on my old lotus carlton and the bosch ones are generic with a centre 6mm bolt normally
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bstardchild
Club Retro Rides Member
Posts: 14,962
Club RR Member Number: 71
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KNOCK sensor Qbstardchild
@bstardchild
Club Retro Rides Member 71
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Dec 20, 2006 21:51:08 GMT
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I'm with lebowski, I changed them on my old lotus carlton and the bosch ones are generic with a centre 6mm bolt normally LC one is not shared with 3.0 24V engines........ as it only has one not two |
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hmm, seems like there are a few different variants, recognisable by the colour of the wiring plug.
I haven't got a photo of mine as I haven't actually seen it yet, i will try and do some investigating this weekend.
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1972 Fiat 130 1985 Talbot Alpine 1974 Lancia Beta Saloon 1975 + 1986 Mazda 929 Koop + Wagon 1982 Fiat Argenta 2.0 iniezione elettronica 1977 Toyota Carina TA14 BEST CAR EVER!!!!!!!! 1979 Datsun B310 Sunny 4-dr 1984 Audi 200 Quattro Turbo 1983 Honda Accord 1.6 DX GONE1989 Alfa 75 2.0 TS Mr T says: TREAT YO MOTHER RIGHT! |
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