Very rough idle - intermittent! - Volvo Forums - Volvo Enthusiasts Forum


Volvo 850 Made from 1993 to 1997, this Volvo line was available in both a wagon and a sedan, both with were graced with several trim levels.

Reply
 
 
 
Thread Tools Search this Thread
  #1  
Old 04-10-2018, 07:00 AM
Junior Member
Thread Starter
 
Join Date: Apr 2018
Posts: 9
Default Very rough idle - intermittent!

I purchased this 96 850 turbo wagen a week ago. Volvo service gave it a clean bill of health. But I'm having occasional very rough idle, engine struggles & sputters some but smooths out once up to speed. It was so severe twice it threw a check engine code twice. Both were "non-specific" codes. Fuel filter just replaced. I did put seafoam in the gas and washed under the hood, but the issue may have existed before. Car is 22 yesrs old, with 63000 miles. It just made a 1000 mile cross country trip. Not sure of plugs plug wire status. Any ideas where to stsrt? THANKS!
Reply With Quote
  #2  
Old 04-10-2018, 08:42 AM
Senior Member
 
Join Date: Nov 2006
Location: Birmingham AL
Posts: 540
Default

If you washed the engine then you probably got water down in the spark plug wells. The spark plug ends seal the tube pretty well and any water that turns to steam condenses again as the engine cools off.

I would warm the car up at idle, turn off the engine, then remove the spark plug leads and let it sit for a while to evaporate all of the water. I used to have to do this a lot when I cleaned the engine on those cars.
Reply With Quote
  #3  
Old 04-10-2018, 07:21 PM
Junior Member
Thread Starter
 
Join Date: Apr 2018
Posts: 9
Default

Thanks I will try that first! I'll be happy if it's that simple!
Reply With Quote
  #4  
Old 04-11-2018, 08:32 PM
Moderator
 
Join Date: Mar 2012
Location: Ridgefield, CT
Posts: 3,269
Default

considering the car is new to you, I would consider installing new wires, rotor, cap and plugs - there's a date code on the wires - if older than 5 years, time to replace. OEM or copper core plugs work best - don't spend xtra on iridiums/platinums. Not sure which codes you consider "non-specific" - what sometimes happens is the code readers give you a generic mapping but there are manufacturer guides and posts on the board which can help you interpret the codes. Once you have dry or new wires, if you still get a rough idle, then you can look for vacuum leaks or consider cleaning the idle air valve or MAF.
Reply With Quote
  #5  
Old 04-14-2018, 09:03 PM
Junior Member
Thread Starter
 
Join Date: Apr 2018
Posts: 9
Default Thanks

Plugs are dry. Service record shows new plugs 3000 miles ago. No record of plug wires, distributer cap or rotor in 63,000 and 22 years. That sounds like where to start. Any favorites? OEM, NGK, Bosh? I got an ICarSoft reader I hope it's not a waste but need to be able to deal with check engine light and trying to stall when on the road.

Last edited by TURBOLIZZY; 04-14-2018 at 09:06 PM.
Reply With Quote
  #6  
Old 04-15-2018, 10:10 AM
Moderator
 
Join Date: Mar 2012
Location: Ridgefield, CT
Posts: 3,269
Default

quality aftermarket brands should do fine - your cap/rotor will likely be Bosch which is probs the OEM. Wires can be Bosch or Bougicord and I'd bet NGK also makes them. FCP Euro and EEuro parts sell these brands at a fair price. I'd also suggest you check to see if your car has a cabin air filter - that was an add on kit (the cars didn't have them out of the factory for the earlier years) and check the intake air filter. Get the kit with the coil wire as well - I've seen them corrode from the inside under the insulator.
Reply With Quote
  #7  
Old 04-16-2018, 08:17 AM
Senior Member
 
Join Date: May 2012
Location: Kingsport, TN
Posts: 1,203
Default

Personally I don't find error codes all that useful. Better to pull actual data and think. Torque app is very popular for that, if you have an android phone, but I don't. You could also use something like a scangauge which is not all that expensive. I use an old scan tool. Real scan tools have sort of gone out of style due to the above options.
Reply With Quote
  #8  
Old 04-16-2018, 01:27 PM
Junior Member
Thread Starter
 
Join Date: Apr 2018
Posts: 9
Default

Thanks! Downloaded torque and ordered bluetooth transmitter. Cabin filter new, air filter new k&n, ordering wires cap and roter.
Reply With Quote
  #9  
Old 04-19-2018, 04:52 AM
Junior Member
Thread Starter
 
Join Date: Apr 2018
Posts: 9
Default

After running great for a couple days when I started it mid day yesterday, very rough idle and check engine cam right on. Was barely drivable felt like it was missing badly. Had to pull over and got this report out of Tourque. Seems like a great tool THANKS! Wires in transit.
Fault log report generated by Torque for Android
=================================================

Vehicle VIN: Not present
Vehicle Manufacturer: Unknown
Vehicle Calibration ID: Not present

Current Fault Log
------------------
P0300: Random/Multiple Cylinder Misfire Detected
P0303: Cylinder 3 Misfire Detected
P0305: Cylinder 5 Misfire Detected
P1310: [Chrysler] Ignition Coil 3 Primary Feedback Circuit
[Toyota] Igniter Circuit Fault (Bank #3)
[Lexus] Igniter Circuit Malfunction (No. 3)
[Dodge] Ignition Coil 3 Primary Feedback Circuit
[Jeep] Ignition Coil 3 Primary Feedback Circuit


Pending Fault Log
------------------
ECU reports no pending faults

Historic Fault Log
------------------
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
----------------------------------------------------
ECU reports no other fault codes logged

End of report.

Last edited by TURBOLIZZY; 04-19-2018 at 04:54 AM. Reason: Forgot to mention
Reply With Quote
  #10  
Old Today, 09:20 AM
Junior Member
Thread Starter
 
Join Date: Apr 2018
Posts: 9
Default

Now has new Bosh distributer cap and roter (they were worn) and new NGK plug wires (they were 1995), cleaned and gaped the volvo plugs that had 3000 miles. Runs smoother. Still has intermittent missing that will last for 30 seconds ir so at 65mph. I think the cpv system is clogged. I put a glove on the oil filler and it tries to inflate. Going to do a compression test just in case also.
Reply With Quote
  #11  
Old Today, 01:48 PM
Senior Member
 
Join Date: Nov 2006
Location: Birmingham AL
Posts: 540
Default

The excess pressure from the PCV will cause misfires as it dilutes the AF mixture.
Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Very Rough Idle / Wont Stay Started DOPExiAM Volvo 850 8 07-13-2012 10:20 AM
2000 Volvo S-80 rough (very) idle jbowl101 Volvo S80 4 10-10-2011 09:34 PM
Very rough idle after PCV service LoveMyWagon Volvo V70 5 03-23-2010 08:09 PM
help very rough idle jerryg951 Volvo 240, 740 & 940 8 10-28-2009 08:21 PM
very rough idle gberger1 Volvo S60 & V60 4 10-06-2008 09:08 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Advertising
Featured Sponsors
Vendor Directory

All times are GMT -5. The time now is 05:55 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.