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Bought a '96 850 Turbo last Fall with about 155 K on her, an upgrade from my previous 93 non turbo (290K) and have put some time and $ into it. For the most part it runs well, had to rebuild the ABS/Tracs
unit with Victor Rocha (excellent service) and some other worn out parts... but here's my question...
I am only getting about 19 miles per US gallon (or 12.1 liters per 100 kms) with this car. I have checked hoses from Turbo and they seem pretty fresh actually like they have already been replaced and I hear no hiss or have any oily mist or anything... also, when I want to accelerate quickly my turbo gauge needle will rise just to the white or 1/2 way line but will not go any higher which leads me to believe I am not getting the performance I should either. The car is responsive but i wouldn't say fast, and I thought they were supposed to be pretty quick. Am pretty sure my girlfriend's V6 '05 Camry would be faster off the line.
My check engine light comes on for a minute at start up then goes out but the Green triangle warning
is on at all times.
I have thought of replacing both upstream and downstream O2 sensors but wanted to see what you guys thought.
I am starting to get both dreaded flashing HVAC lights and also the dread flashing arrow (this is an intermittent occurrence and I can still drive the car ok)
I am obviously in for a DIY treat but Spring will be a better time.... I live in the Great White North.
First things first though... mileage sucks... any suggestions? Thanks
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I honestly think that you will never get your car running really well unless you use high test.
If you want better performance off the line, shut the TRACS off.
After you get done with your work on the car, try a couple of tanks of high test - I think that you might even get more boost.
Really, at todays prices, it is not that much more money.
You tell me what the computer does when is senses a knock.
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Thanks to Tom, Zack, James, Klaus and everyone else who contributed. Your generosity is appreciated.
Jaker
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Here's what has helped gas mileage on our 94' 850 Turbo (220k, owned 7 years since 140k):
- Always run premium fuel
- Check tire inflation every few weeks
- Remove the non OEM roof rack when not needed (we have one for skis)
- Plastic guard under engine present and intact
- Replace old 02 sensors
- K&N air filter, cleaned annually
- Full warmup each time car is driven (avoiding a bunch of short trips)
- Tuneup every 30k (cap/rotor/plugs, check wires)
- Italian tuneups (occasional hard accelerations and high RPM, leave in D3 for a few miles on the highway to get above 4k rpm)
- Cooling system (thermostat) to spec for fast warmups
- Mobil 1 10w30 synthetic every 4-5k
- Transmission flush every 50k
We have had our MPG range from 12mpg (stop and go in winter with bad o2 sensor) to about 30mpg (highway at 60mph cruise, summer). Usually it's in the 19-23 range for city only, 22-25 city and highway mixed, and 23-28 on the highway depending on average speed. We almost always use Shell 91 octane.
--
Zack Silver 83' 242Ti (230k)
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I had a 96 850 turbo. Great car! Put over 350K on it before I donated it.
PNP: The PNP switch isn't much of a job to replace. Just a lot of stuff to remove to get at it. Just position the new one the same as the old one and the alignment will be OK. The problem with them is the grease in them solidifies in the cold weather and prevents the contacts from working properly.As the weather warms up it will work OK until next winter.
No boost: One failure I had when I lost boost was the turbo bypass vacuum control(forgot the technical term) on the side of the turbo. It is controlled by the solenoid valve mounted on the air filter box. It can be tested using a vacuum pump. Could also be the vacuum hoses miss-connected. If you think the car is "responsive" now, wait wait until you get the boast fixed It's a rocket!
There should be a vacuum diagram sticker on the hood (passenger side near the hinge) I had to rake a picture of it and enlarge it to get any use from it. If you need it I can send you a copy.
Good luck with the car. Sometimes I would rather have the 96-850T than my 2012 S60. (except for the ignition improvements)
Good luck with it. Also do a tranny flush.
Tom
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If your car is not fully stage I, that is probably good mileage for winter.
Are you using high test? Many cars add extra fuel when they sense pre ignition.
At today's gas prices, the price difference is around 5 percent, at 19 MPG, one MPG increase is worth the extra 5 percent cost.
I now use Sunoco 260 - it is only 4 cents more here.
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Hi Guys... thanks for all the feedback. So the mileage seems ok but exhaust tells me its not quite right.
This winter, even after it was warmed up on a not so cold day I could see exhaust out the back when usually it decreases after a warm up... there's a certain smell too... like it is too rich.
It's still cold up here so this is where I'm at ... car has had a November tune up, oil, filter, changed out ATF 3 weeks ago), 336new tires (winter) and correct pressure (just checked), new plugs, brakes and callipers all around plus other stuff. I use regular fuel with (up to) 10% ethanol.
I have a code reader and the last time I used it (before changing out the rebuilt sensor with Victor) I got a lot of different readings (which unfortunately I cleared) but I did write them down. When I used the code reader yesterday it only gave me one code PO 440 Evaporative Emission System Fuel System CL-Fault. The "present picture" also included "Shrift 11 Short Term Fuel Trim Bank 1 Sensor"
This was the only code showing. Before when I read it there was a bunch of different codes that seemed to have "disappeared" since switching out the ABS control unit. PO 172 (too rich) headed the list then PO300, 302, 304, 310, 336 (CPS) and the same PO 440.
But they're all gone now except PO440. Thanks Klaus for your suggestions... I will vacuum the sensors as suggested. As far as the PNP switch is concerned... I checked this out and on Mathews (DIY) and it looked like a pretty heavy duty job... anyone done this? Any chance that it could be electrical... as it's intermittent? Will have to wait anyway but will shift as suggested.
I will research the Boost Controller... (accessible I hope) but would also like to check for vacuum leaks... can this be done relatively easily (DIY) or by mechanic? I did check out the "hidden" vacuum hose connector elbow and it "appears" to be quite new.
So I don't know if this makes things clearer or just muddy's the water but I really appreciate the input from everyone.
I do like this car... would like to get it running well... but there are limits.
Also ... one last thing... no speedo / odo ... is this common also ? never had it with my '93 and it had twice the mileage. Thanks
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We only see around 19 mpg on our '95 and I've already been through all the regular tune-up stuff + O2 sensors + any other maintenance items. What I mean is that ours is running as it should at 230,000 miles.
There is no question in my mind that the dismal fuel mileage is the fault of being forced to use ethanol blended fuel (E10 here in CT). It increases consumption around 15-20%. Bad for cars or any other power equipment, but great for politicians.
As for your power issue, perhaps the catalytic converter is clogged. That "can" happen if you have a bad O2 sensor.
What does the green triangle represent? That's not on our '95. Maybe because we're still OBDI?
--
"Differences of opinions should be tolerated, but not if they're too different' - Sharon Craig
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Canadians have a check engine light as well as a green triangle. The green triangle is for emissions errors. He probably has a SAS pump error or an EVAP leak.
Unfortunately, the 1996 and newer cars must use a scanner to get any codes, and then just the generic codes which do not go into detail as to what is really wrong.
Getting 19mpg around town in cold weather is 'normal' if the engine never heats up. Ethanol only inflates the price of corn, which inflates anything associated with corn, including the price of gasoline. I am with you on that, dumb politicians.
Still, a tune up, good tire pressure, fresh 5W30 oil, nice ATF, and occasionally runing the car longer than 30 minutes, should get the mpg to the low 20's.
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Klaus is right. 19 mpg isn't bad in the dead of winter, but it could be low 20's in town and high 20's on a long highway trip. That is what my 95 wagon gets. I've even broken 30 mpg on long highway trips in warm weather.
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I forgot... Replace the front O2 sensor for better gas mileage, it is over due.
Probably time to replace the spark plugs with copper core style, and get a new cap and rotor. Easy to do and will not hurt anything, like checking all of the vacuum lines. Especially the 'hidden' one under the #1 intake runner.
If you know anyone with a generic code reader, use it.
Klaus
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Last things first. The upshift arrow means that your PNP switch is starting to go and needs to be replaced. Hopefully when the weather gets a little warmer. Just 'row' the shifter from R to L about 20 times to help it last longer.
The HVAC blinking lights of death could be because there is dirt in the cabin temp sensors. One above each front door, behind the grab handles. Try vacuuming out the dirt and see if that helps. Look around for a 'home built' code reader that you can make with 3 wires and a LED light, then read the codes for the ECC. Do not erase them, just write them all down somewhere safe so that you can tackle the problems when it warms up.
Vacuum leaks will seldom make noise. You are not building any boost. This could be the boost controller hanging on the air cleaner box. Verify that the vacuum wires are routed correctly. Normally, when boost comes on, it will be enough to leave tire marks on the pavement in 1st gear!!
EDIT:
http://www.matthewsvolvosite.com/forums/viewtopic.php?f=1&t=48871
Also make sure all of the intercooler piping connections are tight.
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"This could be the boost controller hanging on the air cleaner box. Verify that the vacuum wires are routed correctly."
Addendum: Klaus C... is the location of the Boost Sensor / Controller actually in the air cleaner box ?
Is this box the engine air filter box or is there an air cleaner/filter box in the Turbo itself?
Is there any way of checking to see if the sensor is working before buying one... they're not cheap.. such as disconnecting so see if there is any reduction in performance or some other "test"?
Also you suggest replacing the front O2 sensor... is "front" the same as "upstream" ?
When i have the resources, should i consider replacing both upstream/downstream O2 sensors at the same time or is the front one simply more important for fuel saving etc.?
Is there a Vacuum wires route diagram/description available somewhere?
Thanks again.
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The boost control solenoid hangs on the outside of the engine air cleaner box. It has 3 vacuum lines and is reasonably small. Yes, they are not cheap, which is why you first need to check all of the clamps in the intercooler hoses and make sure they are snug. Easy to do, just grab the intercooler hose section and try to twist it, if it moves, tighten the clamp. Do this for all sections of hose. This includes the hose at the throttle body.
The front or 'upstream' O2 sensor has a reasonable service life of 110-120K miles. This O2 sensor determines fuel flow. The rear O2 sensor has a much longer life and its job is to verify that the front sensor is doing its job properly.
There is no perfect vacuum routing chart. It changes every year and is different between engine types and models, dependent on the emmisions which can vary between state and country.
Just look around for small hoses and elbows that look tired and cracked.
And read your codes.
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Thanks everyone for sharing your knowledge... it is greatly appreciated.
I will confirm success (I'm sure) at a later date.
Thanks again.
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