S60 Slow Acceleration

[Knullruffs]

I recently purchased a 2003 S60 2.5T AWD and it just seems slower than it should or struggles a bit during acceleration. I can feel the surge from the turbo so I don't think thats the issue. It seems slow off the line, like its missing torque - just low on power. I have no check engine lights and the car runs fine overall.

It also doesn't idle forward at stop lights like it should until I step on the gas which could be an unrelated problem with the old transmission. I was told by another past S60 owner that his was a pretty peppy car when he had it, but I have never driven another to compare myself.

The timing belt was changed by the previous owner about 40k miles ago, so I don't think that is the problem (unless the timing is off?). I thought about performing a tune-up, but since there are no miss-fires, and the previous owner changed the plugs when he replaced the belt, I think its likely something else.

Any advice would be appreciated. Thank you

[RickHaleParker]

Punch it and observe the RPM when the turbo kicks in. You may have a High Pressure turbo that does not kick in until ~3000 RPM.
The low pressure turbos are the ones that kick in at a lower RPM but peter out sooner.

[abscate]

The high pressure turbo lets you choose whichever side to pass them on up road a bit

Once it spools it’s good bye-M-W

[Knullruffs]

Thanks for the replies. I will check to see where the boost comes in on the rpm. To me it feels like the turbo side of things is fine, but the engine is just low power. There is a major lack of pedal response. I can put my foot into the pedal 1/4 of the way and there is almost no power difference than if I push it 3/4 of the way down. Once the rpms reach a certain rpm I can feel the turbo, but this car seems slower than I would have thought. I read that this car should have a 0-60 between 7-8sec but I would be surprised if I'm not over 10-11 sec 0-60. The car just feels bogged down somehow.

Could the timing be off from when the last owner changed the belt? Are there typical problems with this engine that I can cross off my list to see if it helps?

Thank you

[abscate]

Take a compression test and then look at your spark plugs while doing that

Remember the turbo won’t spool up on just rpms, it has to be loaded.

[vtl]

May I suggest replacing ATF? Hard acceleration happens with the torque converter not locked, so all of the engine torque is transferred through the ATF.

Idemitsu Type-TLS works well in this transmission.

[RickHaleParker]

The timing belt was changed by the previous owner about 40k miles ago, so I don't think that is the problem (unless the timing is off?). I thought about performing a tune-up, but since there are no miss-fires, and the previous owner changed the plugs when he replaced the belt, I think its likely something else.

40,000 miles on the plugs. You do want to pull them out and check them. The interval for spark plugs is 60,000 miles but do you know that he used OEM plugs, not plugs from the lowest bidder ....

[- Pete -]

^^^
All excellent places to start.

An inexpensive scan tool would possibly provide some answers as well. It may sound paranoid, but I keep a scan tool in every (running & insured) vehicle we own. They're like $10-15 and while they are extremely limited in their abilities with scanning P2's (& Volvo's in general), they can be very helpful in pointing you in the right direction. I have 3 Autel 300's and a couple Konwei bluetooth scanners. And all of them get used regularly!

How many miles are you at currently?
Do you know the previous owner? Well, good enough to ask if it's always been kind of a turd, or if it's performance decreased after the timing belt change.

It could be a total shot in the dark, but my most recent encounter with "turdiness" was after I had removed the transmission from one of our P2's (same engine/trans/rear driveline output as yours). After I had re-installed the trans & put the subframe back up I noticed it felt like driving your grandpa's late 80's Buick or Oldsmobile, maybe less impressive. Turned out when I put the subframe back up I neglected to plug back in the knock sensors (they both share a single plug). The plug is down low on the "front" of the block, slightly to the passenger side of middle. Without it plugged in the engine basically detunes itself significantly AND won't produce a CEL. Not saying this is definitively what's going on with yours, but it's a possibility. On mine it (knock sensors fault) showed up using a scan tool, then that info was interpreted here by smart guys like above.

Less recently was a turdiness symptom with an 01 2.5T. Turned out the dealer had timed the cams wrong doing a T-Belt job. It was off at least 2 teeth and I also ended up having to replace a VVT solenoid, ignition coil, spark plugs (amongst a couple other things). All turds removed in all situations though! And ALL thanks to the outstanding advice here.

Also, a cheap boost gauge can provide a good amount of info as well. Not just boost related, but vacuum also. Again, $10-15 and you will know if you're in the ballpark. I had one double-sided taped on my dash for a little while, then relocated it to the vacant pocket left of the radio. PS, they fit perfect in that little pocket up at the top, just gotta shove them in there, but they DO fit. I've learned a lot about turbo behavior on these since installing a couple of them on 2/4 of our P2's.

[Knullruffs]

Thanks for all the replies. The car has about 165k. I haven't checked the compression yet, but I never have to add oil or coolant so it seems like a pretty solid engine for the miles. I may pick up a boost gauge as well. Im curious to see what my boost is through the entire power-band.

I have a decent "Actron" code reader I had picked up at the Auto-zone a couple years ago. I have never used it to check anything other than for codes, but it may have functions to test more I would assume. Do you know what test I would run to see if all my connections are good?

I have a hunch that my issue may be related to the timing belt replacement that was done by the previous owner. There is no sticker displaying the miles when it was done, but it is written in marker, so I assume it was not done at a professional shop or at the very least, not done at a dealership. If my timing is off it there a way to tell for certain aside from really digging into the engine?

Thanks again.

[vtl]

VIDA+DiCE can tell that.