2003 S40

Been having an issue for about 10 days now. Having trouble isolating and diagnosing the cause.

I started to notice a sluggish response when I would accelerate at low speeds (around town, stop lights, side streets etc.) However, if I would punch it everything seemed normal. During acceleration a slight growling noise can be heard, maybe before turbo kicks in. It also seems to need a little more pressure on the accelerator pedal (may just be my imagination??)

I then noticed that my mpg was going down in the trip computer display. I was averaging about 34.8-35.2mpg and now I am 29.8-31.4mpg.

At idle there seems to be a slight strain or laboring sound, almost like a continuous rubbing/wearing sound (slight).

I have replaced the plugs and air filter, checked for any loose vacuum lines and given a once over for any obvious indicating factors. I just changed the oil after this issue had started. I always use Mobil 1 full synthetic 5w-30. There are no codes being shown.

Recently, I had washed the engine area (couple of weeks ago). When doing that water got into the plug cavities and caused a misfire. Maybe drove 1 mi. with 2 cylinders misfiring to get back to my garage. Blew out the water, dried the plugs and everything ran fine. Following that, the motor ran fine for another 750mi or so. (not sure if there is any correlation or not)

Today I decided to do an induction cleaning with Seafoam. Applied it through a vacuum line as normal. It is expected to see white smoke out of the exhaust when applying. However, I noticed white smoke coming up from behind the motor near the manifold/turbo area. Could this indicate an exhaust leak, which further is impacting the performance of the turbo resulting in the list of symptoms stated above????

224,000 miles. 95% highway miles, I commute 160mi per day. 2nd timing belt/pulleys in real near future also. Did the last one at 123,000. Starting to hear the bearings in the pulleys begin to labor as well.

What’s your thoughts. THANKS

 

Change that timing belt and pulleys asap (water pump too while your there). Volvo says 105k miles but I'd do no more than 100k. My 2001 started leaking oil from the CVVT at 175k and slipped the timing belt right soon after causing 8 bent exhaust valves.

Do you hear the classic sewing machine sound when first started? When mine does that it's a loose nut on the exhaust manifold stud above the turbo. I've since put a lock nut on and it hasn't backed off since July.

And mine has an exhaust leak right below the turbo on the cat converter. It seems to be at a poor weld and not a crack. I can feel it with my hand when the car is first started. (not sticking my hand there when hot...) Take your heat shield off and you can see things much better.

For the sluggish response I'd give the brakes and bearings a quick once over. Maybe jack up the back and spin the tires to check for rubbing brake pads or bearings going bad, etc. Same for the front with trans in neutral. Just listening for something dragging. Just trying to eliminate the easy stuff before worrying about the TCV or trans or other more expensive stuff.

 

what kind of fuel u put in the car?? octane??

 

Always 93oct!

Replaced the timing belt, tensioner, idler and water pump, as well as serp. belt and tesioner. (water pump bearing let go while trying to figure out this other issue)

Everything in that dept. is good, purrs like a kitten.

However, this other issue is still bothering me. Seem sluggish when accelerating and fuel economy is still down to an average of 30mpg or so. (about 4-5mpg off its norm).
Can this be turbo related? Winter fuel blend related? Maybe plug/coil related. Have not put new coils on, did replace plugs couple hundred miles ago. But, parts store only had ACDelco or other cheapies. Put in the Delcos. Might be the issue?? I normally use an NGK Iridium plug.

Thoughts?

 

don't know the post date...but what did u think or got averg MPG...I thought Hwy rated is 32. You seem to indicate like u got 34 mpg...?n

 

yes, per the trip computer I would average 34.9mpg and 45 mph over a 1500mi period. Since I started noticing the laboring feel to the car I paid attention to the trip computer after every commute. I am now averaging 30.1mpg and 46mph over a 950mi period.

I am not stressing over the lossed fuel mileage, but using as an indicater of a possible larger issue. Car doesnt feel right + noticable loss of fuel economy (seemingly overnight) = something wrong.

While I was doing the timing belt had the car in the air so I checked the wheels for any brake drag. Nothing real concerning, very slight warp in the two rear rotors but certainly not anything which would be noticable to this capacity.

 

Reset the trip computer.The readings are average and always moving around a lot if you hit trafic then the fuel consumption goes out the window but only seemingly.

 

Has the sluggishness gotten worse? Maybe the lower gas mileage is because you are goosing it because you feel it's sluggish? Vicious circle there.

I wouldn't worry about the coils until you feel a miss when accelerating. As long as you gapped those plugs correctly you should be ok. The iridiums are to minimize knock potential but you are using premium and it's winter time so even the delcos should work.

Your cold air snorkel still intact from under the air cleaner box to the front of the car? If that thing collapses it could starve the engine for air or suck in hot underhood air.

A potential problem would be a poor winter gas blend causing knock which causes the ECM to retard the timing which causes a loss in power. The test would be to try 115 octane racing fuel or 100 octane low lead aviation fuel. Expensive but it'll answer your fuel question.

 

Replaced the Delco plugs with NGK Iridium's, world of difference!!!

I did notice while replacing the plugs that when removing the plastic cover to access the coils there was a little oil collected on top of the head, mostly in the center. My though was the gasket for the oil cap or the PCV (I'm assuming that is the hose coming from the top of the head)...?????

 

have tough time believing the delco will fire that poorly compared to NGK, to affect the combustion quality.

I had champions in the V40/2000 I bought with 85k, when changed to NGK, thought to see 'some' diff but none.

I ve also seen oil seep near the neck of oil fill, but NOT related to the spill while fill...and not being able to pinpoint the source, even when intake manifold was taken off to replace the PCV parafernillia.

I did notice that a hose [formed], comes from black pcv cannister to the top...which I suspect to be bringing uncondensed oil vapors to the top area.