QuestionHi Ray, thanks for prompt reply to previous issue, what follows is actually two questions.
Q1. Starting: we've had continously poor starting on this vehicle for some time now (1/2 year) and highly experienced Volvo specilist cannot seem to find cause. Following have been replaced with no change- Fuel pressure valve; crank angle sensor. Engine runs well and with full power once started but can take up to 20 seconds of cranking to fire, then loads of smoke, smell and then often a 'staggerering'/ rough sort of start up and running. (within this question is another - what influence does the crank angle sensor have on gear changes in the auto? Changing this component seems to have cleared up the gear change issues - which reminds me, re the previous question on gearbox and light on dash, turns out the light on the dash at start up was due to a poor connection at the battery terminal. So poor in fact that in the end it melted the terminal clamp - due in part to extensive cranking times at startup).
Question 2. Car runs fine in the main in a straight line. Upon 'suburban' cornering (tight low speed corner) after a long run (50km or more) there is an terrible 'knock knock knock' that seems to come from the front centre of the vehicle. Also whilst straight running at 2200 revs there is a whine/buz coming more distinctly from the front left (passanger) side. No one can seem to isolate these either.
Thanks
Glenn
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Followup To
Question -
Hi Ray, I've had this vehicle for just over 2 years now and its been just one expense after another (averaging about 5 thou each year: try head gasket because the thermostate stuck in closed position. First sign: triangle engine warning light (the 'useless' light), temperature gauge reads fine, second sign: water light, temperature still reading fine. Final sign: switch off engine, temperature gauge goes screaming to top and fan kicks in at high. Now that's clever enginering for you).
Now I note that the auto gear box doesn't like to be played with on mountain runs. If I leave it in D I'm Ok, but if I 'play' and hold it down in 1st or 2nd then after about 15 to 20 minutes of this it just decides that its all too hard and picks any gear it feels like. I also note that of late when I start up the 'arrow' light stays on for about 10 - 20 seconds before fading out (it doesn't come on whilst driving - Oil level ok colour seems ok). Any thoughts?
Answer -
Glenn,
There is a high failure rate of the Gear Position sensors. The contacts wear and the control unit does not know what gear has been selected and gos into a "limp home" mode choosing a forward gear. See if there are any codes stored in the Trans control Unit. The fault code for the GPS is 313.
AnswerGlenn,
There should be a fault code in the control unit that may help to identify the failing part(s). I have seen a lot of Mass air flow sensors go bad and cause many problems, including smoking and stumbling. Read the fault codes and see if that helps.
Is there a way to run the car on a rack and listen to the nosie? I would say the front axles or hub bearing are going out. Axles tend to knock when they are bad, and the hub bearing make a rumbling noise.
