Guest yurir Posted March 24, 2004 Report Posted March 24, 2004 Wonder if anyone might have any ideas as to this symptom. Once the engine has warmed up, it has a very pronounced throb during idle. It's almost like how one might rev up the engine at the lights (when we younger of course <_< ), raring to go, but the frequency is greater than once per second.You have to keep a firm foot on the brake (its got an autobox) and even then, the whole car rocks. It was doing this before it's last service (about a month ago) and one of the things they changed was the lambda sensor. Is it likely that the sensor has gone again ? Are they known to have a poor reliability ?Could it be a wiring problem ? Should it show up in the fault codes ?How does the oxygen sensor work anyway; anyone know ? Many thanks,Yuri. Quote
charles Posted March 24, 2004 Report Posted March 24, 2004 the lambda sensor cannot be wrong if it is replaced. it last more than 100K and the heated 4-wire sensor (like yours) even longer. Maybe there is a broken wire/bad connection.a ECM-diagnoses could tell which sensor is in default. Quote
Guest yurir Posted March 26, 2004 Report Posted March 26, 2004 For anyone who's interested, I've found some useful info on the lambda sensor: A Lambda sensor is a device that measures the amount of oxygen in the exhaust gases. The sensing elements are usually made of cobalt monoxide or zirconia, who resistance is greatly affected by small levels of gaseous oxygen. They are also "poisoned" by carbon, sulphur, lead or silicon. Which is why a defective engine management system which is running rich will also lead to a demise of the sensor. The sensor is usually implemented as part a resistance bridge, such that the output varies by about 1V, between no oxygen and a little oxygen. The resistance of the narrow band sensors changes over it's full range, with only a small change in O2 levels. When used to control the air/fuel mixture on an engine, due to the lag in engine control system, the mixture control can be fairly unstable. The resistance change of the sensors is seen to "switch" as the engine management tries to apply control. Translating the voltage signal into something visible can be done by a voltage meter. However, analogue meters can damage the sensor because they draw too much current through the sensing element (becasue of the bridge connection). Digital voltage meters are usually too slow to react to the switching signal changes. Therefore most of the time a specially designed meter is used. Thre are a number of types of sensors:1 wireThe wire is the signal output. This sensor is unheated and will take longer to give a signal, and have unstable performnce during idling 2 wireThis is the same as above, but with separate ground wire. 3 wireThis is a heated sensor. 2 wires are for heating the sensor. The 3rd wire is the signal output, usually a different color compared to the other 2. 4 wireThis is a heated sensor with additional ground. 5 wireThis is a wide band sensor i.e. it output changes over a much large range of O2 levels. There is only one make available on the market as the patent is held by Honda. It's made by NGK/NTK/BOSCH (all the same sensor) Now according to the Haynes mnual, the Galaxy has an oxygen sensor heater relay, controlled by the ECM.And what I've noticed is that as the engine is gradually reved up, a relay can be heard clicking, and clicking back as the revs drop back. Is it likely that this is the O2 heating relay, and it's not actually heating up the sensor, or only partially heating it, so that it's behaving badly when it cools during idle ? Many thanks,Yuri. Quote
HJT Posted March 26, 2004 Report Posted March 26, 2004 Not sure what the cause is but I would get it into a garage fairly quickly. The car rocking like that is going to do the auto box and transmission no good at all. Howard Quote
Guest martyn locke Posted April 13, 2007 Report Posted April 13, 2007 Had same problem mate. Changed the Lamda sensor and temp switch and still the car rocked on idle in D. Changed the plugs Had it plugged in and had all faults resset and corrected and still it had same fault. Changed the Head Gasket and CURED !!!!! I didn't want to do it but good friend of mine checked water and oil and even though to me it looked fine, he told me that the head gasket had gone. Hard to do but worth it. Quote
mumble_bee Posted April 13, 2007 Report Posted April 13, 2007 (edited) how are your spark plug leads ? edit: lol so did I.. ur fault m04 Edited April 13, 2007 by mumble_bee Quote
Guest martyn locke Posted April 13, 2007 Report Posted April 13, 2007 Yes I know that i replied to an old thread but that means that if anyone else has the same problem they can see that Head gasket was a possible solution. Just trying to help future readers cause I had the problem for ages and when i looked on this site, i found no answers. This is my solution and i hope it helps others. Quote
mumof4 Posted April 13, 2007 Report Posted April 13, 2007 As a newbie it would be good if you intro yourself in the intro section..i posted a thread about it today..no disrespect meant..but you are vague in your car details. Quote
Guest martyn locke Posted April 13, 2007 Report Posted April 13, 2007 Ok Fair enough. Galaxy 2.3 Zetec Auto Ghia 1998 Quote
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