Volvo AWD 850 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 2/2011 850 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

850 Blue smoke/mileage/trip computer problems??? 850 1996

posted by  potkettle on  Sun Dec 13 13:39 CST 2009
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Mon Sep 26 10:39 CST 2011
[RELATED]

OK, I've had this 1996 855 Platinum since June. 216K miles. Runs powerfully and smooth as can be. Turbo spools up nicely. A nicely maintained car as the person I bought it from was another Volvo guy. About a month ago I noticed it started blowing some blue smoke out of the exhaust at idle. Doesn't seem to blow any smoke when the car is moving no matter how hard I accelerate.... or if its smoking at all it is not noticeable in motion. The previous owner replaced the whole PCV system last year. So, before getting into the PCV system I decided to take apart the PTC valve and clean everything out. It was quite dirty and plugged up.

Here's where it gets kind of weird....

The blue smoke seems to still be there... maybe a little bit less. But I noticed that the trip computer was acting strangely afterwards. Not sure if its coincidence or not. The MPG at idle goes down 1/10 about every 8 seconds. I thought it was because I forgot to connect a vaccuum hose or my seals weren't tight- but I double checked everything (twice) and it all looks good. Actual MPG while driving still reads normally- I still get about 19-22 city depending on the amount of stop and go. Yet the computer still drops about 1/10 every 8 seconds at idle. Also, the computer will start reading outside temperature even though the dial is still on MPG. If I turn the dial to the temp setting and switch back it will go back to MPG... but eventually it starts to read temp again in that position. Coincidence?? I know I'm asking a few different questions here.... any help is very welcome. There are no oil leaks, no smoke coming out of the dipstick and engine performance is excellent. There didn't seem to be any play at all in the turbo either.








  •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

    850 Blue smoke/mileage/trip computer problems??? 850 1996

    posted by  jablackburn on  Mon Dec 14 02:29 CST 2009
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Thu Jan 20 10:56 CST 2011
    [RELATED]

    Did you see a lot of oil in the turbo hoses?

    If you only see blue smoke at idle, it's possible that you just have a leaky valve seal. They are pretty easy to fix, but really not a huge deal. My car smokes a little bit at start-up and runs a little rough if I leave it sitting for a couple days, but then immediately smooths out and runs fine, and doesn't burn any significant amount of oil.

    As far as the trip computer problems, if you just reset the gas mileage by chance, it will drop as you're idling as it's calculating an average based on only a few miles of driving. Keep an eye on your gas mileage for the whole tank and if you notice any significant differences, then you should start looking for problems with something you did. The switching randomly to other things is a common problem - the trip computer knob often goes bad. ratchet it between settings a few times really fast and attempt to clear the contacts; otherwise, you can just replace the INFO switch.








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      850 Blue smoke/mileage/trip computer problems??? 850 1996

      posted by  jadnhm on  Mon Dec 14 04:13 CST 2009
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Tue May 22 18:03 CST 2012
      [RELATED]

      Why not pull the info switch apart and actually put some contact cleaner in there? I don't know what the switch looks like or how you'd pull it apart, but it might be possible to get in there and sand the contacts a bit to clean them up. It's worth a look.

      One thing folks often forget to look into is oil collection in the intercooler. The onset of colder weather has a drastic effect on how much oil is condensing in the intercooler and PCV system lines.

      Take the car for a good drive and get the intake system good and hot, then get a catch pan and put it under the lower intercooler hose, and pull the clamp and hose off the intercooler and let the oil drain out. A fair bit of oil can collect in there over the years, and it will seriously affect the breathing of the car.

      Is it possible you could be pulling oil out of the intercooler into the rest of your intake and burning it off?

      It'd be worth it to give it a good drain whether it helps your problem or not.
      --
      1998 V70 AWD Turbo 195k+








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      850 Blue smoke/mileage/trip computer problems??? 850 1996

      posted by  potkettle on  Mon Dec 14 03:43 CST 2009
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Mon Sep 26 10:39 CST 2011
      [RELATED]

      There was a bit of oil in the large metal hose coming from the top of the turbo. Nothing that would really seem out of the ordinary. There was no shaft play. The car doesn't really smoke at start up either and the idle is smooth as can be even when the engine is cold. Leaky valve seals does seem to be a possibility for the blow by. I guess I'll have to look into the PCV when I get some more time.

      As for the trip computer- I just filled up a tank and will do the math on the MPGs on the next fillup. The fact that the MPGs go down so significantly at idle concerns me. I understand the MPGs will go down as obviously the engine is using fuel at idle, but this is definitely not normal. I can literally just watch it drop considerably at a 30 second stoplight. The OBDII is throwing NO codes at all. I'll try to ratchet the dial as you suggested to clean out the contacts.








      •   REPLY TO THIS MESSAGE    PRINT   SAVE 

        850 Blue smoke/mileage/trip computer problems??? 850 1996

        posted by  db on  Tue Dec 15 05:48 CST 2009
        Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
        last visit: Thu Aug 19 14:50 CST 2010
        [RELATED]

        Are you sure it is blue smoke and not black? Blue suggests oil and black suggests fuel.

        If its black, I would check your fuel pressure regulator on the injection rail. If the membrane in this gets ruptured (even a slight tear), your fuel pressure can be off and it could be running rich at idle...and you computer could be trying to correct for it, but it is out of range.

        If not that, try doing an Auto-RX treatment in the oil. It does some wonders on cleaning out deposits in engines over the life of an oil change. It is a bit pricey ($20) and only available online, but it is one of the few engine products which has a strong following that works. It certainly couldn't hurt.







<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.