V50 1.8 Hesitation
 

Hi, I have a V50 1.8 2006, with 82k on the clock. The vehicle has developed an annoying intermittent hesitation and lack of power on acceleration. This issue normally appears after the vehicle has been driven for a number of miles and has reached full running temperature, and is more noticeable at higher speeds. There are no eml codes or warn lights on, but have also noticed that the engine sounds a bit rough/vibration if I rev it in neutral between 2000 -2500 rpm. Not sure if the two are linked. I have started with some simple fixes checking for vacuum air leaks (none found), changed spark plugs and a full set of new coil packs, but none have made the slightest change to the symptoms. Has anyone experienced the same and found the cause?

Hi,

On my older v40 i had similar sounding issues which in the end was the MAF. Hesitiant and no fault codes. Could be worth an investigate.

back in 2006 there was a mod to fix a loose throttle housing plug .
if you try to wiggle the black plastic plug it should be very firm ...

Thanks for the response. Yesterday I removed the throttle body housing and whilst having better access, I removed the MAF too. The throttle body was quite clean considering age/mileage, but I gave it a clean anyway. The MAF was dirty with oil/grease so I gave that a good clean with electrical connector cleaner and reinstalled both. I took it for a spin and it performed much better with only the slightest hint of hesitation. However, I have driven the car again today and the hesitation is progressively returning. Could the MAF be soiled again already or failing? Or I wonder if one of these components has a poor electrical connection or break and during my investigations it helped repair it, although only momentarily?!

Thanks - Interesting suggestion. I had the throttle body off yesterday along with the MAF and cleaned and reinstalled both. The car was running so much better, but the hesitation has returned again today. So whilst I had the throttle body off, reinstallation may have improved this connection for a short time.

was there any looseness at all in the throttle housing plug?

Air mass meters do not get dirty , for one they are fed with clean filtered air and also they clean themselves when you turn the ignition off . The number of £350 air mass meters i have seen destroyed by cleaning in my career is astonishing .

I have rechecked the throttle housing plug and it appears to be firm with only the slightest wriggle. Its feels very firm to disconnect and reconnect and the plug looks clean and dry inside.

My MAF was soiled with oil/grease, so I do not know why this would occur when you say it is only supplied by clean air. Theres lots online about clean MAF and throttle valves, so whats causing that black carbon like a deposit?
My airbox and filter is clean as a whistle. Why are MAF £350? A Bosch replacement on mine is circa £25 and took about 40mins to remove and install.

the breather goes up into the air filter housing , I bet your foam oil separator is missing from the little square compartment in the air filter housing .

NO one does an air mass meter for £25 ! They are £350 from volvo you get what you pay for ...

My foam separator was present and reasonably clean. I think the car has been well looked after in its past. A new Bosch sensor 1s7a-9f479-ab is £27 on AUTODOC excluding delivery. Is Bosch no longer decent quality brand?

IT was always the very best ,and even better as volvo gave Bosch their own specification to make their parts .. hence the extra cost ..
Not many use Bosch these days , they closed an alternator factory down in south wales in the 1990's as The cheaper brands were preferred by most f the manufacturers