This afternoon my 2004 s60 2.5T suddenly felt sluggish and I noticed that I do not hear the 'vacuum cleaner' characteristic sound of the turbo anymore. I believe the turbo does not kick in anymore for some reason. I have no engine light on. Yesterday I replaced a faulty coil and the car was working great again until this afternoon. Could the fact that the turbo does not work anymore right after replacing the faulty coil be just a coincidence or could it be linked? Could I have disconnected anything while working on the coil? I am thinking a faulty turbo boost pressure solenoid may be but any suggestion will be welcome.
Thanks
Al

 

IM guessing you do not have a boost gauge. This is the only way to can see what going on with boost pressure/turbo. I would install one It really helps trouble shooting issues .My guess is the turbo is still working but could be a few thing Turbo control valve. This is connected to the Air box. Also check all the lines from this .The Over the engine(Charge Pipe) make sure everything is tight at the couplers.Check for rips or worn elbows.When turbo fells sluggish it usually comes down to Vac lines and TCV. But seeing boost would help. GL

 

Thanks MYS6T. I checked the lines and they look good. I sprayed MAF sensor cleaner over the lines and no change in RPM so it looks like there is no leak from what I can see anyway. I ordered a new TCV online, should get it by Tuesday. Will see if that fixes the problem. You are right, I dont have a boost gauge. I will probably order one from IPD. Is it easy to install?

 

Yes it is Very easy to install 20mins .
When you replaced the Coil did you take the charge pipe off? If yes i would check the Vac lines at the Turbo itself and give the OTE pipe a wiggle and make sure it good and tight. Other than that Tcv is a good place to start. What did you use to clean MAF and did you take it out of the car??

 

Today I got a the engine light and the code says P0234. I did not remove the charge pipe of when I replaced the coil and it looks like everything is tight. The charge pipe TCV may be the culprit then. Will know for sure once I receive the one I ordered over the internet.

 

I would also check if you have not already the Plug for the TCV. Also you did not remove any of the vac lines from the TCV for anything did you. This code is common when the red and blue i believe are switched.GL and i hope that the new TCV fis issue. Try resetting the codes and see if it comes back with that or anything else.

 

Today the turbo came back a few times. Sometime it worked and sometime it did so it may indeed be the TCV valve.

 

I would check the couplers that the charge pipe connect to the turbo and the inter-cooler. When I changed my plugs the first time, I didn't seat the coupler back on the turbo tight enough and it was loose causing loss of turbo. Even if you didn't take it off, moving it could have loosened it enough to come off during acceleration.

 

Well I changed the TCV today and I thought I had fixed the problem because when I test drove the car the Turbo kicked in at every hard acceleration and I could hear the very characteristic vacuum cleaner noise from the turbo. Unfortunately that only last for a little while and when the car got warmer then no kick in the *** sensation anymore . So back to square one. The charge pipe seams to be tied. This coming week end I will check every single hose and pipe that get to the turbo. May be it is the turbo itself. I don't know

 

9 times out of 10 it's not the turbo, turbos tend to fail....catastrophically its one of those things that you don't have any doubt of
all your neighbors know it
everyone on the road knows it
its painful

get a turbo gauge like a cheapo 20-30 bucks on eBay hook it up to your boost line and test it that's rly the only way.

 

Today I checked all the hoses that go to and come from the turbo and did not find any issue with them. So I decided to try to drive the car hard, put the geartronic on manual and drove for about 12 miles pushing the engine to redline limit as often as possible. Well, that did something because since then the Turbo boost is back working normally. I drove more than 50 miles after that and the turbo kept working perfectly fine. The engine light that was on with the p0234 code even disappeared on its own. What's up with that? Could it be a clogged vacuum lineline?
I had been driving for about a week with no turbo and now that the turbo is back working properly the car is transformed.

 

Nevermind

 

Well almost 350 miles later now of mixed highway and city driving and the turbo still works like a charm. The hard driving did the trick. High RPMs may have unclogged a vacuum lines or something. Anyway it is good to get the car back. I love this turbo sound zzzzeeee!

 

Same thing happened to my s60 i found out it was the flapper thing(yes i know really technical) on my wastegate, fixed it and runs great

 

Its called the CBV (Compressor by pass valve). Looks like this Mitsubishi CBV Upgrade Kit - ViVA Performance This is possible. Its just a small plunger with paper edges that is control by a spring. They have been know to fail. But this usually cause Boost spikes not a dead Turbo. Did you ever mess whit the waste-gate rod and or make any adjustments ??