colder plug options

[Ade]

My T5 seems to keep killing plugs!
I've so far run cheapo ones and fancy iridium ones.... both gave misfires after a thousand miles roughly.

Standard 850 T5 with a remap and DV.

Anyone got any advice or know the plug codes to ask for?

[nobananas]

Hotter and colder plugs aren't really related to the engine temp, a hotter plug has more of the core exposed to the flame front, too hot and the tip can burn away and/or cause detonation. Colder plugs have less core exposed to the flame front but run too cold and the deposits won't be burnt off the electrodes and the plug will start to fail and cause mis-firing. I've always used the NGK plug recommended without problems and many use genuine Volvo plugs without issue. What condition/colour are the plugs that you are removing and are you sure the problems are plug related and not lead/dizzy related that are only showing up when the plugs start to wear a little .
http://www.ngkpartfinder.co.uk/car_commercial_search.php?type=SPARK%2520PLUGS&manufact=VOLVO&model=850%2520SERIES&engine=2.3

[t5 stealth]

iv only ever fitted ngk to mine and havnt ever had a prob with plugs.....
as nobananas says...........are you sure its a plug issue and not something deeper........
i cant actualy remember ever having a fault with an ngk plug...and i fit hundreds of them !

[Ade]

Got a new cap and arm and leads recently.

Plugs come out pretty sooty, but not damaged looking.
Replacing last time instantly cured the misfire.

[Santa]

I thought "soot" covered plugs generally pointed to over rich fuel mixture? Not sure how this happens in a modern fuel injected car though. Maybe ECU being fooled by a dodgy MAF or Lambda sensor?

[nobananas]

Did they come out sooty after just being started or after a run ?

[Ade]

I only took them out after about a thousand miles...

[nobananas]

I only took them out after about a thousand miles...

Sorry buddy that's not quite what I meant. What I meant was when you took out the plugs and noticed that they were sooty had you just started the vehicle, then turned it off and had a look at the plugs ?. Reason being if the vehicle was still in cold start then the plugs would most likely be sooty as opposed to if you took them out after the vehicle has had a good run. If they are getting contaminated/sooty with normal use then it's more likely you may have an over-fueling problem somewhere. A faulty Lambda or duff maf may be the culprit, both can cause over-fueling and neither are likely to set off a MIL, providing they are both sending information (and the heater circuit isn't dead on the Lambda) then the ecu doesn't know that the information it's getting isn't correct. It's possible that you are using a plug that's too cold and not burning off the contaminants but far more likely that there is a problem elsewhere.

[leet5r]

use gen volvo

[Ade]

It was after a run.

The lambda light has been on since around the time I had the boost leaks sorted and fitted a DV. I just assumed the management didn't understand the DV hence the error light.
MPG didn't seem effected anyway.

[Volvostorm]

Get a code reader on it, they your know what the ecu is trying to tell you.

[Ade]

Is there a DIY code reading option on these?

[stu_850t5]

search on VOC for 'code reader for dummies' article written up by jodt5
very useful/helpful

stu


*edit here you go.....http://www.volvoforums.org.uk/showthread.php?t=83897&highlight=code+reader+dummies

[Tomcat]

If your car is an 'M' reg it may well have the built in code reader, look at the front left hand side of the engine bay(behind the headlight) for two small black boxes (about an 1 by 2 inches) side by side, if you have these then you have it built in. It's fairly easy to use, post back once you've had a look.

[Ade]

Nice one! I will investigate....

My car doesn't have a coin tray (an empty bluetooth sized slot instead!) so hopefully it has the self contained reader under the bonnet.

[Ade]

right.... My car's got a Diy reader under the bonnet!
Anyone got a link/info on how to work and interpet it?

[Volvostorm]

right.... My car's got a Diy reader under the bonnet!
Anyone got a link/info on how to work and interpet it?

http://www.volvoclub.org.uk/tech/service/850/TroubleshootingWithCodes-Turbo.pdf

I should noticed that yours was a M reg, mine is too

[Ade]

Nice one mate!

[Ade]

Got fault codes!

2-3-2 Lambda Adjustment

4-4-4 Acceleration sensor signal


Now what?! :D

[Ade]

What the hell is 'Acceleration sensor signal'?

[Ade]

Anyone got an idea on the fault code?

[Volvostorm]

Have a look at this for 2-3-2:

http://en.allexperts.com/q/Volvo-Repair-834/1995-850-Turbo-fault-1.htm

and this for 4-4-4:

http://www.matthewsvolvosite.com/forums/viewtopic.php?f=1&t=33288

Download the PDF file, it will explain what the sensor does.