T5 (0-60mph) with approx 140,000 miles.
 

To get as close to stage 0 as possible for my higher mileage S40 T5, I have done the following:

- Cleaned MAF Sensor with CRC MAF sensor cleaner.
- Cleaned the MAP Sensor (found on the intercooler coupling, drivers side) with CRC MAF sensor cleaner.
- Replaced the Pierberg TCV (Turbo Control Valve) which is accessible via the drivers side wheel arch. - approx £30 for this sensor - Boost Pressure Control Valve PIERBURG 7.28197.16.0
- Replaced the 'Turbo Check Valve' (or sometimes refered to as the "Crankcase breather valve). This valve is accessible from the top of the engine, where the turbo pipe connects to the turbo - approx £30 - Volvo PN: 30677524

My T5 is approaching 140,000 miles and it's top end performance in 3rd gear was crap. Of the above changes, the biggest improvement to 70-90mph 3rd gear performance came with cleaning the MAP Sensor. Probably needs replacing but cleaning it was sufficent stop the ECU from holding back boost at the top end.

As metioned, the top end performance used to be crap, whereas now, I can feel the engine hit peak power at 5000rpm.

Hope this helps someone.

Here is my current acceleration on my stock S40 T5 after doing all of the above. Car is supposed to do 0-60 in 6.3 seconds, and it looks like I'm getting very close to that:

+ YouTube Video

Cool. I'm not far behind you in mileage in my new (to me) T5.

I'm busy changing the suspension & exhaust (because they're shot) then I'll be on to the stage 0 stuff + plugs, leads, coil packs, etc. (I've never been as poor since I bought this car).

A couple of questions if I may:
I'm not familiar with the T5 but I was surprised when you mentioned cleaning the MAP sensor. Any chance you could post up a guide ?
Also you changed gear at ~5800rpm - is that where the turbo runs out of puff ??

I'll post up something similar when I get mine back on the road.

Nice one !
I second to your experience with cleaning&replacing all above to freshen up the car, in fact just week ago I changed the same TCV and CBV valves after about 40k miles done on them and I can feel car pulling better after that. Those parts do wear down and it would be good practice to replace them ever so often just to keep car breathing fully.
I also clean MAF regularly but MAP sensor itself was just replaced it year ago and kinda forgot "that its there" - might be good idea to clean it ocasionally, thanks for tip. How did yours look? is that sensor subject to dirt&clogs or it was just preventitive? My MAF for example always look spotless.

I would just add "cleaning throttle body" to your list above - sometimes those are left neglected for years and buildup of nasty stuff can affect performance, and cleaning of intake snorkel (from front grille to airbox) as that can really get dirty and I bet it can affect airflow just a little bit.

I cant properly test acceleration on mine to compare, as with my gear changing issues I always loose second or more, but your result looks great for stock car - almost like from factory.
If you feel like testing the 37-85mph acceleration test it may provide some interesting comparison and is more torque&boost oriented rather than pure acceleration.

Damn you LOB - Just re-read that thread and it's made my heart ache for a T4 again :D

Interesting points on the MAP sensor, I'll give it a clean, also need to do the throttle body.

Mine is on 104k now and AFAIK on all original bits so is probably in need of a refresh.

Heh, good ol times when focusing on shaving tenths of second from various times vs constant battle with CEM and other gremlins? :} I think I know what you mean ;)
btw - if your TCV and CBV are 104k miles / 10 years or so, yea - replacing them might make those few extra horses to wake up.

My CEM is fine now :) It was just those pesky connectors, gave them a good clean and no issues for a few weeks now. Issues were frequent before so I think that's case closed!

I'm not going to be replacing the throttle body, no point since it's not broken, but I'll certainly take it off and give it a blast of intake cleaner as I expect it's pretty gunked up.

No, replacing it is pointless indeed (not sure if its after my suggestion but if so you misread it :P) unless you upgrade it to Porshe TB with all priper piping. But as for cleaning it, not sure if intake cleaner is sufficient though, the buildup in TB you may experience is really something and you may need some proper brake or carb cleaner and toothbrush to get it nice. Took me a while to make it nice and shiny, defo not as easy as MAF cleaning.

If you have a pre-face lift car, I believe you can get to the MAP sensor by removing the front-left foglight trim. Mine is post facelift and the foglight covers are different. No room to reach MAP sensor so have to remove the bumper to get to it:

- Remove headlights
- remove the 4 or 5 torx screws in both front wheel arches (turn the steering wheel to make access easier)
- remove the 4 torx screws underneath the bumper.
- pull headlight washers out and unclip the washer covers (take care not to break the retention clip)
- push in the 5-6 plastic push-pin rivets along the top edge of the bumper (where the bonnet latch is) then pull them out with a thin flat edge screwdriver.
- unscrew the 2x torx bolts either side of the plastic push-pin rivets.
- pull the bumper away from the top corner edges underneath the headlamps
- seperate the bottom of the bumper from the retaining section underneath.
- disconnect foglight connector plugs.
- unscrew torx screw from map sensor (left hand side of intercooler) and remove from sensor from the intercooler.
- spray vigirously with MAF sensor cleaner (or electrical contact cleaner). Let sensor dry for 5-10mins then refit.

Bumper removal really isn't that difficult, quite an enjoyable job. Even quicker if you dont have headlamp washers.

It's probably worth doing an ECU reset after this as well by leaving the battery disconnected for 30 mins.

Full BHP is acheived at 5000rpm in these, power starts to tail off higher than this, though I think I could have got a slightly better 0-60 had I used the full rev range.

Mine looked only slightly dirty, especially compared with some of these diesel MAP sensors you see that are absolutely caked in crud. However despite the minimal dirt, cleaning it made a massive difference as the boost pressure at high RPM was clearly lacking...70mph-90mph in 3rd felt outright slow, whereas afterwards the car is whizzing through that speed range.

Good shout, I bet mine is filthy given the mileage. I wanted to do this to my previous S60 2.0T but never got round to it before I sold it. Much easier to access the throttle on the S40 than the S60, which is a bonus.


Posted! I did around 8.5seconds for 35 to 85mph in 3rd:

+ YouTube Video

Was that only after cleaning MAP or also after tcv/cbv replacemebnt combined? Damn, if map cleaning itself could do that, I can see myself doing it asap :P


vid - cool, looks like it pulls like a train :) Im always astounded how FWD cars are geared compared to mine, you are on Manual tranny right? I can barely reach 85Mph before redline where it doesnt want to pull anymore.

edit - technical question, how did you manage to stabilise the screen so much? GoPro or some phone holder? all my tries with phone looks like Im driving over potholes :P