So 5 months ago I bought a 98 s70 t5(auto) with 152k miles. All my problems started around 3 months ago. At first my problems began with low mpg(about 14 city,18 hwy). Soon after that my boost began to fade, I went from getting put back in my seat( just a little:P) to hardly feeling anything from the turbo. Sometimes my car would boost strong, othertimes it would take several seconds for it to even start to accelerate then boost just a tad at the very most.

As of about 6 weeks ago my car began to vibrate at idle and is also sporadic in rpms about 200 in variation. When I pull out of my drive way it feels like my car lurches somewhat then smooths out once my speed picks up. Turbo is about the same as previously stated but I feel the overall acceleration is worse.

mpg is even worse now- 10 city 14-16 hwy.

I feel like I'm going through coolant too quickly. I'll top off my expansion tank and go threw half of that in a month. When I pull my dipstick there is fair amount of smoke coming out of it. the stick itself will have a very slight amount of sludge at the tip( cream color) and the top of the stick has white residue running along it.

engine will make ticking sound that increase with acceleration. this has only happened a few times, but still worries the hell out of me

I have no check engine light but my abs/ tracs off lights are on( think thats due to a bad abs module tho. For the most part my car runs pretty decent. starts up fairly quick and drives moderately smooth.

I have invested over 5 grand in repairs into this car. I love my volvo and am willing to do anything and everything to get her back in top shape! All help would greatly be appreciated in solving my problem. I cant afford any more mechanic repairs but can afford the parts!!

repairs- full tune up. spark plugs, plug wires, cap/rotor, coil wire, oil change and fuel filter
rear cam seal
mass air flow sensor
front o2 sensor
ignition switch, ignition lock
left and right cv shaft along with tie rods and a full set of tires
inner and outer boots
shifter **** and lever
upper motor mount bushing
both front control arms
oil cooler hoses
timing belt
radiator hose

After all these repair it leaves me thinking I've got a head gasket on its way out and clogged pcv and maybe my turbo is going. I cant think of anything else that would cause these problems. I am truly perplexed. If anyone can help point me in the right direction I'd be most grateful. thanks for your time!

 

To check for a head gasket, first look for any signs of oil in the coolant or coolant in the oil. Also note if you are losing any coolant with no external signs.. ie Any froth on the dip stick? oil in the coolant overflow? You can also get a test kit at Autozone etc with checks for exhaust gases in the coolant (sign of a cracked head/head gasket issue).

First test for the PCV is to try a "rubber glove" test to see if its pushing air out through the dip stick or oil fill cap. Check for any oil leaks (clogged PCVs can push oil out seals).

Have you had any episodes of black smoke? Bad turbo oil seals can push out black smoke and even clog the cat.

Ticking is not a healthy sound - could be oil starvation to the valves or just old valves that need adjustment. Any signs of oil pressure issues? Are you running the correct weight oil and using a quality oil filter? (some after market filters can restrict oil flow so best to use OEM and stay away from budget or "double filter action" stuff).

I'd personally be leaning towards something that controls the boost due to the intermittent nature of the problem - as simple as a vacuum line or a sensor. Tough to find without codes. Have you tried to put on a OBD2 reader to see if anything is stored?

 

The first thing I would do is test the PCV. If the oil is milky looking, you probably have a blown head gasket. I'm leaning toward the head gasket.
You'd probably have a bit of smoke if the turbo went out.

 

Thanks for the input guys. Ive been really busy with work trying to save money to get my car fixed, so i have not had much time to reply but I have the next few days off and will run some tests.

I'm thinking my head gasket is just startng to go out if it is at all. I only notice a very small amount of whitish residue on the very tip of the dipstick and do not seem to be go threw a lot of coolant. my engine does seem to be running very hot... I can see a very faint amount of steam or burn oil coming up from the hood after driving. also, I notice the smell of burnt oil coming through my vents when my heater is on but my temp gauge never goes past normal levels.

I tried the glove test buy it didnt inflate at all. which is bothersome considering im still getting 14 mpg even after a whole tune up kit along with a new front o2 sensor( hardly helped at all) and smell gas burning if i exceed speeds of 85 mph.

My questions are- what else could be causing my car to run this rich? Could my vibration at idle, low boost, and low mpg be caused by bad vac lines? Ive also read that o2 sensors should be replaced in pairs even if you're only getting a code for the front one???
Thanks for your time everyone! I'm planning on uploading a video so I can get more help with my problems

 

New problem. Went to start my car today( 37 degrees this morning) car started rough- rpms bouncing from 650-1050 for a few seconds then smoothed out. but a clunking sound started to come from the steering wheel area and stopped only when i moved the wheel in a certain direction(sound stopped once car warmed up. car also makes a clunking sound under light acceleration until i get into second gear or higher speeds then drives very smooth. Im thinking I need to redo my whole suspension due to it being all original with 160k miles.

I also notice my lights flicker. when I roll up the window my lights will dim. I.E. dash light, head lights ect... even in park the lights on my dash flicker very lightly. what could cause this problem? bad wiring ???

Mechanic has said my steering wheel is to the right causing my alignment to be off. would this contribute to low mpg and loss of power?

Once again, thank you all for you time and effort to help me solve my problems. I will continue to make updates on the progress and improvement of my vehicle.

 

The steering wheel being out of line could be causing low mpg, but not a loss engine power. Power to the ground, maybe. My aunt's Explorer has bad wheel hub bearings, and that has absolutely killed the mpg and has restricted a bit of power, so it's likely you're having the same problem due to the alignment.
As for a vacuum leak, it's possible. You'd have to have a smoke test done if you think it might be an issue.
Just out of curiosity, what octane gas are you using?

 

Thanks for the response. I always use the best gas i can get. either 91 or 93.... never ever anything less :P . I'm taking my car into a trusted mechanic tomorrow morning for a full diagnostics and a alignment . I will update you all once I know more.

 

Hey guys, just thought I'd post an update- Mechanic said my lower engine mount was completely blown out causing the clunking noises. They also said my mpg are fairly normal for a car of this age. according to them 16 mpg is what i should get in the city and 21 is what i should be getting on the highway( i'm now starting to get back up there for mpgs after resetting fuel trim. My car now drives much smoother and the vibration at idle is gone!

As for my turbo... It looks like its time for an upgrade it's starting to leak oil pretty bad and from what I know the cbv is starting to go which would explain the low boost.

Thank you everyone for your time.