Changing the battery and low rpm when starting the engine?

2001 Volvo V40 diesel engine, high-pitched jet engine sound when accelerating?

• Thanks for the opportunity to post. I’m a single mom with an old Volvo V40 diesel (170,000 km/106,000 miles), living in Switzerland where everything is expensive, and trying to do everything in my poor French. Don’t know much about cars and just need some advice to help me have a safe, decent way to get myself and my son around town. Let me provide some background: Last February may car starting making a very loud ticking/rattling noise in the engine, mostly when in neutral/low gears. I took the car to the dealer who insisted that I needed $3,500 of work done, including a new power steering pump that was supposedly making the noise. Then I took it to the nearest chain repair store—they had a completely different diagnosis (related to belts or pulley or idler)—much less expensive but I didn’t feel confident. Finally went to a recommended local garage that a friend has used many times. They diagnosed the ALTERNATOR and changed that and the TIMING BELT (suggested doing it why they were at it) and checked all other belts. It was expensive ($1,500 or so) and was on top of several other repairs before inspection related to suspension and brakes (+ new battery and new tires). Following the repair, I noticed the engine was still noisier than before, but the loud tick/rattle was gone and I thought it was just the cold winter weather. About a month ago the service light went on (goes off after a while) and I started noticing a LOUD-PITCHED WHIRRING SOUND when I accelerate/just before I change gears. It sounds like a jet engine revving up or front-load washing machine on spin cycle. It gets louder/higher-pitched until I change gears. It seems worse when changing lower gears and by the time I’m in 5th gear on the highway, I don’t even notice it. Or, if I’m driving slowly in 2nd or 3rd gear and not accelerating, I barely notice it. It doesn’t seem better or worse with the air-conditioner on. I took it back to the garage that repaired the alternator. When I called to get an estimate, I was told that they replaced the alternator again (it was “simply defective”, but luckily under warranty) and they had given me an oil change (gas, oil, air filters). All this for $400 (it is Switzerland, after all…). As I drove away, I noticed nothing had changed with the high-pitched sound. Immediately went back. The owner of the garage said he replaced the alternator because it was making a sound (unclear what kind). He asked me to reproduce the high-pitched sound by pushing on the accelerator in neutral, but that doesn’t do anything. So, he came into the car with me, I drove fast, shifting gears and he heard the sound. He immediately said it had nothing to do with the alternator and was due to the TURBO getting old. He said that it had probably been making the noise for quite some time and that I just now noticed it. He also said that it probably wouldn’t get worse and was not dangerous and it would be expensive to fix and probably not worth it. I suspect I am super sensitive about the noise (have pointed it out to several people who said they wouldn’t have noticed it, but when they do hear it they say it sounds very bad). I don’t want to sink more unnecessary $$ into this car if it’s going to be one expensive repair after another. But I do love my old Volvo and would like to keep it for another year or two. I would appreciate any thoughts you might have and suggestions about possible causes, what I should look out for if I take it to another garage, etc. Thanks!

• Answer:

  o.k. there are several possibilities for this symptom [please bear in mind that, while we do not get this version in north america, turbo system symptoms related above are common to any charged engine regardless of make and are not always going to be expensive to repair.] 1. first inspect the rubber/plastic air piping connections. check these from the air filter housing to aluminium turbo housing inlet [compressor side of turbo] now check the connections from outlet side of turbo to intake manifold [in between thes connections should be a few devices i will touch on later]. if all is found in good shape and hose clamps are tight move on to next. 2. most likely this car makes use of an inter-cooler this probably is mounted in front of the radiator but behind the air conditioning condenser. it will be of aluminium construction with plastic inlet and outlet manifolds that are pinch clamped to the aluminium core. i have found stress cracks Develop at these pinch points and have also seen both inlet and outlet bungs crack because someone overtightened the hose clamps resulting in massive air leaks. there is no acceptable repair possible for these it is a replace only part, further if you choose to visit a salvage yard for this part you may wind up with one that has debris in it that could ruin your engine [even if it was flushed out] 3. pop off valve/recirculator valve: this has two jobs. first it can limit overall boost by opening and letting a portion of the compressed and cooled air back into the inlet side of the turbo. second job is to kill the boost immediately when the throttle is released, these sometimes stick open or improperly commanded open resulting in a turbine over speed condition with low or no boost pressure developed [continued use in this condition can damage the turbo] if found bad, this is also a replace only part. 4. exhaust gas recirculation valve [some engines do NOT have this] this is supposed to let a metered amount of burnt gases back into the intake system, this allows injection timing to be further advanced for more performance and reduces oxides of nitrogen if this valve sticks open or leaks it will typically cook the pop off/recirculator valve in very short order. 5. waste gate valve and or actuator, this is a device similar in operation to the pop off valve but works on the [HOT] exhaust side of the turbine one that is stuck closed can once again cause excessive turbine speed and noise with an improvement in performance until over boost occurs, serious engine damage occurs rapidly at this point. 6. of course you could actually have a failing turbo, at the mileage indicated, if oil change schedules and proper shutdown proceedures have been followed this would be rare in both fact and deed. i hope to have shed some light ,and wish that your trouble[s] are less expensive than turbo replacement.