2.5T (S60) Observation regarding engine vibration Topic is solved

[mrbrian200]

MAF is on my "list". Unplugged it just now/this morning on a cold start letting it warm up before I take off for coffee. I have noticed since this all started it is taking much longer to warm up, and often isn't up to temp after 5 minutes in the driveway + two miles into town. Initial results (started, stalled, unplugged MAF, restarted and seemed a-ok) encouraging, but going to leave it like that a day or two and see how it acts before I plunge into ordering the part. Says "Bosch" every car I've owned in the last 30 years ends up having much of their branded stuff replaced sooner or later. The notable exception being a Cressida from ~1990 used a MAF I suspect Toyota either made in house or contracted out at a very high spec. Had 200k miles on it I don't think I ever messed/replaced any of the management controls it was all original. I don't hold Bosch to any particular high regard like many (mostly younger?) people do. Cars designed around their systems have always been "troublesome" in my experience.

[mrbrian200]

Guys, am I wrong, or is that idle speed hinky? (that's a technical term: hinky )

Hey that's a legitimate diagnostic term in my book. If it seems minor/not making you upset, mr. hinky (or his little brother winky) come knocking.

Regarding the idle speed, I suspect it's never been updated. Dealer printed out the full history (5 pages) I didn't see any Volvo dealer entries on it anywhere. I could have taken it but in the excitement of writing the check and signing various docs I forgot to stuff that report in my briefcase.
Owner 1 Florida 0~20k (rental company/auctioned)
Owner 2 North Corolina 20k~70k (traded in)
Owner 3 Chicago 70-80k Chicago (repo/auctioned)
I'm owner 4.
--No major accidents (at least not reported). I have seen nothing to contradict that (door/panel alignment, behind the bumper cover etc) Wire loom or two seem routed a little hinky up around the headlights/RH computer box I do suspect the drivetrain was pulled or the harness was replaced at some point, or maybe a fender bender.
Owner 3 sort of let things go/ probably couldn't afford repairs (likely got something else/ stopped making payments), Address on the title (south/southwest City of Chicago neighborhood) isn't the first place I'd think to go just for a joyride. Genuinely poor neighborhood sort of a war zone at the moment.

[mrbrian200]

Had to make a trip to the larger hardware store just now for home repair item (about 40 miles round trip)
With the MAF disconnected: best it's run in the last week or so, highway mileage ticked up from around 28->32. A little sluggish (somewhat like "wet mode") but overall ran good. Consistantly started up to a good/smooth idle, no surging during acceleration/crusing etc.
I did notice hesitation from a stop sometimes, 1/4-1/2 second (but not every time). Would this be expected with the MAF off line or might this point me back towards the ETA? New car for me I don't know how it should act with the MAF disconnected assuming nothing else is wrong.

[mrbrian200]

I'm getting my head wrapped around the engine management system a little better. I'm a firm believer in understanding how it's all supposed to work. Beyond being my first Turbo car ever owned, it is also my first car equipped with an electronic (drive by wire) throttle body.

1. erratic fuel pressure reading though diag tool (sometimes 0 with engine running): FPS, already fixed
2. Rough Idle, surging, stalling, poor econ at very cold temps: Bad MAF, symptoms disappear with MAF disconnected
3. With MAF off-line sluggish part throttle performance: Expected behavior. ME 7.1 scales back some advanced throttle plate/torque request handling that normally hides the nature of turbo boost from the driver.
4. With MAF off-line occasional hesitation from a stop, one or a combination of: worn plugs below their optimal heat range at idle (check, re-gap, replace), ETA internal DC motor developing mechanical resistance (from brush dust) and cannot perform quick throttle plate angle changes, with a direct relation to temperature (mechanical resistance increases as temperature drops). Engine begins to flood momentarily until plate angle catches up (opens) as appropriate for fuel delivery, or, computer senses slow throttle plate response and scales back fuel delivery. With a functional MAF fuel delivery would react more quickly, possibly hiding issues from the driver until the plate gets "really bad" or just plumb stuck...

The 15 miles of "clarity" coming out of a heated garage: warm ETA working properly, MAF working. The effects of worn (but not "really bad") plugs normally hidden from driver by engine management. ME has more than one limp home mode. It gives the driver best it can (minimizing risk of engine/catalyst damage) dependent on which systems/sensors are still working.

[JudgeRat]

I don't know what the others think of it, and I don't know if it is your only issue, but I do think from your description of what you've done and how the vehicle has responded that you definitely need to clean/replace the MAF (others more knowledgeable should chime in here).

Since these cars are essentially like driving a computer with wheels attached (they are over-engineered to a fault in my opinion), there are literally dozens of sensors that could be contributing in some small part to your issues. This site has loaded actual Service Manuals and is a pretty good starting reference for every system in most Volvos: http://workshop-manuals.com/volvo/

Also, even though you've replaced the Fuel Pressure Sensor on the rail, if I'm not mistaken, there is a Fuel Tank Pressure Sensor back either on or near the tank that you might want to check. I believe both are monitored by the ECM and might affect how it compensates for any faults it sees. Actually, now that I think about it a little more, if I remember correctly from what I've seen out on YouTube, that tank sensor would probably cause your tachometer to jump erratically while starting if it were experiencing difficulties, and you didn't mention seeing that particular symptom.

I just had another brain-fart as well: how many tanks of fuel have you run through this thing since you got it? Is it possible that you have some "old" fuel? Perhaps a small amount of moisture in the mix? Maybe adding some fuel cleaner/octane boost to the tank or filling up with 93 octane would help alleviate any concerns in that respect. I just know that these things are very picky about their fuel/octane.

[JRL]

First... clean the throttle body, this is necessary every 100K miles or so
If that doesn't help you need a new MAF sensor. (Don't clean the MAF, people have tried but it usually doesn't work out that well!)

[mrbrian200]

4 tankfulls (premium/93). 2nd fill up Lucas + Oil (full syn) + filters. Fuel filter + FPS on current tank. Tried cleaning MAF no change, symptoms have progressed (all the time/not cold dependent). Disconnected MAF yesterday leaving it that way until new one arrives. Will wait for that and re-evaluate at that time.

On a side rant...
I plugged the part number into google (in this case 0280218088) just to see what pops up. Interesting. I wouldn't discount the idea that the "bits" are fabricated in China and Bosch assembles, tests and calibrates in Germany. Cheap "knockoff MAFs" could quite possibly be built from the same OE parts sourced from the same factory Bosch gets them (some claim as such)...but unit-to-unit variance calibration I would expect to be an epic failure at a total cost of $30-$50. "Branded fakes" sold at full MSRP are a problem with purses costing half as much as these MAFs if Bosch has a problem with this (and I bet they do!) it's their own fault for not maintaining a trusted supply chain with at least a handful of retailers and disclosing as such.

[mrbrian200]

Are memory seat position buttons (M-1-2-3) suppose to light up at night or did the product design team all call in sick that day? Considering the seat doesn't retain power 24/7 anyway, If there isn't a bulb/LED to check I might have to use one of those 12v stick on LEDs and do just that (to seat power). Have a couple floating around pulled from previous cars (to light up cubbyholes/cupholders/ashtrays etc).

[JudgeRat]

Are memory seat position buttons (M-1-2-3) suppose to light up at night

You know, that's a really good question...I've never looked; I've always done it by feel.

[abscate]

I found idle speed spec of 720rpm on the web, no tolerance given. +- 50 is probably reasonable

I wouldn't waste time chasing engine management demons until you have new plugs, evaluated coils, compression cold/hot/wet on all 5.

People often jump to the engine mangement systems as faults way too early.