Which sensors to replace to help car run better?

[-Neil- 0]

so, i have running issues that when i drive and my car is under load, it splutters and revs die, then shoot back up, then die, the car has no power at all, and i come to a halt.

 

i searched and found people suggest cleaning the MFa, ill do this 2morow, also the Blue temp sensor, and others suggest the Knock sensors.

 

Now the knock sensors have me intrigued, coz i have no idea what or where they are, or how to change them or how much the parts are or anything?

 

the temp sensors i can change myself, the MFA i can clean myself, but the knocks, no idea!

 

can anyone help, or show me pics please?

 

Neil

[zak 0]

theres two knock sensors on a vr6 one for each bank of cylinders. They push in to the front and the back of the block and secure with a small bolt. You cant miss them as they have a lead coming of them.

[-Neil- 0]

thanks for the quick reply, are they easy to replace, and how do i go about this?

 

and any idea how much they are?

[zak 0]

Very simple to replace, i've only ever removed them when ive had the engine out so as long as there is enough access it should be quite straight forward.

[Roger Blassberg 0]

In situ, they are not easy to get at (or at least that was the justification my garage gave for a large bill a few years ago!!). I was getting horrible pinking under load which actually turned out to be due to incorrect spark plugs.

 

Your symptoms do not point to faulty knock sensors, in my opinion. Are you hearing pinking/knocking under load or at high speed? If not, Ithink you should look elsewhere. A faulty sensor will ignore the pinking and allow ignition advance to continue which will not reduce power significantly, if at all. Cutting the power, to the extent that you come to a halt , is unlikely to be caused by the knock sensor(s).

 

If you do decide to change them, be very careful to do up the mounting bolt to the exact torque of 15 lb.ft. Too loose and they won't detect the onset of pinking in time, too tight and they will be crushed and rendered useless.

 

Best wishes

 

RB

[-Neil- 0]

thank you for youur reply, i had a look today for the sensors and see that it will not be a easy job to do, i hope to god it is not them that need replacing.

 

i drove today to work this morning and drove very gently and no hard acceleration. i did not encounter any problems.

 

i have just cleaned the ISV, MFA and throttle.

 

i did disconnect the wire on the front of the engine on the right just under where the HT leads clip into that plastic runner bit. The engine died a tiny bit then ran like normal, then i kept connecting it and disconnecting it the only change was the sound of the engine, i can only discribe it as the air inside the enigne got quieter when i disconnected.

 

is this wire the Temp sensor people are on about? it wasnt blue, it was black.

[-Neil- 0]

can anyone please give me the parts numbers or what i need to ask for and from where, eg, VW dealers or GSF of any sensors i could replace to help my car run better.

 

ie the blue temp sensor...

 

Thanks, neil

[KipVR 1]

You're best off taking it to a reputable garage to diagnose it rather than blindly replacing bits!

[tonedef 8]

You're best off taking it to a reputable garage to diagnose it rather than blindly replacing bits!

+1 I read your posts yesterday Neil and thought the same, you've been having these troubles off and on for the last few years. Think I'd be letting somebody diagnose what the fault is and fix it, might cost a few quid getting it done but maybe it'll save keep stabbing in the dark?

 

There's nobody I know of in Sheffield but I do know a guy in Chessie who's pretty hot on problems like this if you're interested?

[-Neil- 0]

well after cleaning mfa and isv n throttle last night i went for a drive for about an hour, encountered no porblems, will wait and see if the the problem persists, then that guy in chessie can help me :) cheers tonedef