2001 Volvo S40

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Hobbit91

My daughter owns a 2001 Volvo S40 4 cyl. L4 1.9 liter turbocharged
approximately 32,000 miles. The check engine light is on: following codes
noted: PO101 Mass Air Flow or Volume Air Flow Circuit Range/Performance
Problem. I have changed the air filter, checked the MAF sensor so here is my
guess: The engine is turbocharged thus increasing the intake volume of air
vs. a naturally aspirated engine. At times, the turbo can "overboost" the
engine causing the DTC I have recorded. Usually the turbo "wastegate" opens
and bleeds the excess air from the system before this can happen, but if the
wastegate is hanging up, this might be a likely culprit. Where is this waste
gate located on this particular engine and/or what does this wastegate look
like? Can anyone help?


Robert
 
Robert

Not sure if this helps but get some information regarding the turbo from
Mitsubishi (who make it) If you can get some diagrams, you can easily
see where the wastegate is. The wastegate is adjusted by a screw - may
just need an adjustment. Haven't done it on my T4 but know it is a
simple procedure...

Good luck - let me know how you go....
 
Hobbit91 said:
My daughter owns a 2001 Volvo S40 4 cyl. L4 1.9 liter turbocharged
approximately 32,000 miles. The check engine light is on: following codes
noted: PO101 Mass Air Flow or Volume Air Flow Circuit Range/Performance
Problem. I have changed the air filter, checked the MAF sensor so here is my
guess: The engine is turbocharged thus increasing the intake volume of air
vs. a naturally aspirated engine. At times, the turbo can "overboost" the
engine causing the DTC I have recorded. Usually the turbo "wastegate" opens
and bleeds the excess air from the system before this can happen, but if the
wastegate is hanging up, this might be a likely culprit. Where is this waste
gate located on this particular engine and/or what does this wastegate look
like? Can anyone help?

Robert
Click to expand...

Not likely. If the wastegate is stuck and the turbo is overboosting, a
different code is set - (I'm unsure of the number) usually with the
"boost pressure regulation" or similar in the description. In either
case, the boost will be limited to an lower initial value, so you should
notice a lack of power. With your scenario, you should notice lots of
extra power, followed by the engine cutting out suddenly as the
secondary protection cuts in.

My guess is you have a bad air mass meter or a vacuum leak.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)
 
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