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Enes
Enes, Volvo Master Technician
Category: Volvo
Satisfied Customers: 5477
Experience:  18 yrs+. experience as Volvo & ASE Certified Master Technician.
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my s40 2.0 diesel has rough idle. injector replacment?

Resolved Question:

my s40 2.0 diesel has rough idle. i tried to clean up throttle body and mas sensor, but still same. i then disconnected each fuel injector seperatly and 3 of them resulted in a further drop in revs, however the 4th when disconnected, did not alter the idle, is this a sign that the 4th injector is needing replaced? forgot to say that when car idling, it wont rev above 1100 revs,( i think car is in "limp home mode") will this correct itself if new injector is fitted? Car is a 2005 volvo s40 2.0d. (Also there is no warning lights / engine diagnostic lights come on on the dash.)

Submitted: 3 years ago.
Category: Volvo
Expert:  Enes replied 3 years ago.

Enes :

Hello and welcome to our web page here my name isXXXXX a Certified Volvo Car Expert Mechanic.I'm going to try today to answer your question.

Enes :

yes fuel injector can be bad or clogged up

Enes :

but you must first read error codes with scanner to make sure there is no electrical sensor going bad

Enes :

I would not replace injectors now until you test first and hook up scanner you will be going to Volvo garage to run those test

Customer:

have just noticed couple of air bubbles in fuel line just before fuel filter. could this be cause, and just need fuel system primed to remove bubbles?

Enes : No I don't think is air
Enes : Most important is to get for right the test of check engine light
Enes : When you get that engine diagnostic code that create all problems and make also injector not fire correct
Enes : before you spend money on injectors to guess you must run that diagnostic scanner test at volvo garage it will help a lot to what part is causing it
Customer:

can a normal garage do the diagnostic test? want to try avoid main dealer prices. what could have caused air in fuel? had no prob previously.

Enes : Any garage can do it who has good diagnostic scanner
Enes : well it can air from cracked fuel line somewhere sucking air
Enes : But you will not know until you see thr fault codes
Customer:

Ok. cheers XXXXX XXXXX help. thanks again.

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