High pressure pump ticking sound
Hi All,
My A3 recently starting making a ticking sound coming from the HPFP at low revs (below 2000 rpm), I guess at higher the sound is covered by the engine sound, also the sound only comes when the engine is warm.
Also the car drives fine as I do have any of symptoms such as loss of power, engine misfire etc...
I had the car diagnosed by garage specializing in diesel injection who told me they didn't really have an answer to give me as they were confused themselves as for what was causing the sound.
* They used the computer to check the pump's readings and they all match the manufacturer's values.
* They have removed the pump's head to inspect it (even with a microscope) and it was clean (no metal bits)
* The tried to disconnect the plug from the head and the sound was gone (which a I guess is a good sign as the pump being driven by the cambelt keeps rotating, meaning it doesn't seem to be anything wrong with the pump internal components rotating and obviously confirm there is no metal bits inside the pump), so they have replaced the head with a new one and the sound was back again... this what go them confused
* They only thing they have found faulty was that the fuel filter hasn't been changed since 2013, so I asked then to replace it thinking that could be the issue there causing the pump to work extra-hard but I have been driving a good 100 miles (city and motorway) and the sound is still there
So they told me I could either replace the pump but that would be an expensive bet (about £1200 as you need to replace the cambelt as well) as they couldn't guarantee it would fix the sound or I could go to have the car diagnosed by Audi to see of there is a software update (i.e. see if something needs to be done on how the head sensor and the fuel rail sensor communicate) but I am not really sure about that one as to me Audi will just tell you to change the pump and won't really bother investigating.
So here I am in a situation where either I change the pump, i go to get the car diagnosed by Audi or I just live with that sound, i mean the sound doesn't bother me at all I just want to make sure that ticking doesn't mean I will ending up having to change the whole injection system.
What do you think guys ? have you experienced that ticking sound with your car ? what did you do about it, live with it or replaced the pump ?
Thanks in advance for your replies.
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Re: High pressure pump ticking sound
We will only do this job with a genuine pump and cambelt kit because of the guarantee of quality and the back up of a 2 year dealer back parts and labour warranty. Unfortunately these two parts come to just under £1800 alone.
Re: High pressure pump ticking sound
Hi Crasher, thanks for your reply, but I was mainly asking if people have ever experienced the ticking sound and if a ticking necessarily means a failing pump as the car drives fine and nothing has been found in the pump (i.e. metal bits from a pump destroying itself from the inside)... The diagnostic didn't tell me my pump was failing but they couldn't find the reason of the ticking sound...
Re: High pressure pump ticking sound
The ticking is the solenoid valve struggling to deal with reduced delivery and this is not available as a spare part. On early CBAB engines I have known failure of the lift pump in the tank cause this noise but this is usually accompanied by a loud buzzing noise from the intermediate electric high pressure (Bosch 044 related) fuel pump indicating it is being starved as it is not designed to suck fuel, depending on a supply pump or immersion.
Re: High pressure pump ticking sound
What I don't get, if the pump had to deal with reduced delivery how come it didn't show up when the guy scanned the car, I mean he told me that all values were within margins of the manufacturer and there was no error code showing up also I don't seem to have any power delivery problem while driving the car.
Thanks again for your reply
Re: High pressure pump ticking sound
Re: High pressure pump ticking sound
I have had many a CRTDI where I can see the fuel pressure is low in measuring blocks but the ECU does not flag a fault code, depending purley on the ECU flagging a fault code shows poor diagnostic skills, they need to know how to read and interpret the live data. The other morning my car was extremely reluctant to start from cold but in the evening it was fine, the next day it was the same, later I asked my young trainee to do a code read and he said it was clear, I then asked him to see what the temperature was showing at the ECU in measuring blocks, when cold it showed 112 degrees C but the ECU did not flag it as an error. The other danger is what I call "barking at codes", seeing a code and then knee jerk reacting to it without thinking "WHY?"... VW do not sell that regulator separately for a good reason, it is usually the pump that fails and the regulator is just reacting to that low pressure, they need to study the fuel rail pressure sensor readings.
Re: High pressure pump ticking sound
Thanks again for your reply Crasher,
I have just phoned the diagnostic centre to ask them more details about the diagnostic and they told me that they did scan the car for error code but they also checked the live data from the pump and the injection rail and they confirmed me there was no sign of low pressure showing anywhere, also them guys are diesel injection specialists and they are Bosch aggregated to refurbish HPFP (the company name is Carwood, based in Birmingham) .
No I agree with you that the sound comes from the pressure valve, as disconnecting the valve makes the noise disappeared however they tried to fit a new valve for test purpose and the noise came back again, this why the diagnostic people got confused as they don't have an explanation for the "Why" of that sound, they can't find anything wrong the values provided by the different sensors, there is no metal in the pump and they can fault the car performance... it is just the noise that remains... this is just weird scenario
Re: High pressure pump ticking sound
Could you private message me your reg so I can get the VAG TPI list?
Re: High pressure pump ticking sound