Lambda sensors

johnjp · Feb 15th, 2006, 15:25

I have been reading about Lambda sensor problems, the Lambda on my 1997 945 came on recently after I was topping up the cooling system with the cap off and engine running. I thought I would find the sensor attached to the exhaust in front of the cat but it`s not there! Where can it be? Also does anyone near to me, Brighton area, do OBD?

ivor940 · Feb 15th, 2006, 15:58

Hi, If your 940 is a Turbo, the Lambda sensor is fitted to the underneath of the exhaust just aft of the 3 nut clamp. It is not visable from top, but you can feel it ( when the exhaust is cold). I think a 7/8 spanner will undo it. On the turbo, the wire for it is routed near the distributer to keep away from the exhaust.

ivor940

bogart · Feb 18th, 2006, 10:18

I have a 94 940 turbo estate and I cannot find the sensor either. It is definitely not just after the 3 bolt connection as in this piccy. And out of interest is the exhaust system from a 90 model suitable for mine, at least the cat bit anyway? Thanks

ivor940 · Feb 18th, 2006, 22:32

Hi, sorry but I meant the 3 nut clamp at the exhaust manifold. If you follow the pipe forwards and up from the cat, the sensor should be above the oil filter. The wire for the sensor usually sits on top of the oil filter. It is visable easier from below the car, looking aft of the steering rack.

ivor940

bogart · Feb 19th, 2006, 11:01

Found it now, obvious when you know where. Last question, honest. All this talk re PCV stuff where on a B200FT do I check for blocked pipes and gunge etc?
Regards

ivor940 · Feb 19th, 2006, 11:42

Hi, on B200FT, the pipes to check are as follows:

The over engine 1/2" dia hard plastic pipe with insulation --- This pipe can block completely or have a restricted internal diameter due to cokeing. It can also get cracked / broken inside the insulation. ( can be temp fixed using 1/2" heater pipe. It is not dear from Volvo, and is difficult to clean out hard coke deposits due to its shape

The "flame trap" white plastic junction at the inlet manifold. It does not have a grill in Turbos . It can be brittle and the small pipe can snap off.

The Breather Box above the starter, below the inlet monifold. Can be cleaned, but best to replace. Can be purchased from non Volvo suppliers. Do replace the green O ring at its base.

The flexible 1/2" pipes above and below the "Flame Trap" are easy to clean. Only replace if they are deteriorated.

The small diameter pipe connecting the "Flame Trap" to the inlet manifold. Easy to clean out. Don't forget to clean out nipple on manifold with small diameter wire.

Inspect the Duct from Air Filter to the Turbo for softness due to oil just below where the over engine 1/2" dia pipe joins the Duct.

When all these Items are done, the engine should have fewer oil leaks, but more importantly for the Turbo, oil can return to the sump easier. This can reduce oil getting from the turbo into the inlet system. This leads to dirty deposits in the Throttle Body and plumes of blue skoke occasionally on acceleration. George Holmer has posted info on Turbo Breather Systems as well.

ivor940

94 940 2.0 SE Turbo Est 5 spd 166.5k

VOC member

neil stevenson · Feb 19th, 2006, 11:45

Perhaps someone here could also explain what to clean and degunge on a B230FT please.
Sorry to hijack your thread but I find lambada issues all very confusing. The dash warning light on my 940 SE B230FT engine lights up every now and again, the car runs lumpy and the revs (more when cold) dont aways settle down to a steady tick over when stopped at trafic lights etc.
Cheers.

RollingThunder · Feb 19th, 2006, 11:46

Couldn't have put it better myself Ivor

RollingThunder · Feb 19th, 2006, 11:51

Quote:

Originally Posted by neil stevenson

Perhaps someone here could also explain what to clean and degunge on a B230FT please.
Sorry to hijack your thread but I find lambada issues all very confusing. The dash warning light on my 940 SE B230FT engine lights up every now and again, the car runs lumpy and the revs (more when cold) dont aways settle down to a steady tick over when stopped at trafic lights etc.
Cheers.

Neil, I'd pull the codes and see what the ECU is complaining about. As an initial step, I'd check the various sensor electrical connections to ensure they're clean and secure. My number 1 suspicion would be the air mass meter (on top of the air filter housing). I left this off when I was rebuilding my engine and it (obviously) triggered the lambda light, and the engine didn't idle very well or have any power as it went into limp home mode.

neil stevenson · Feb 19th, 2006, 12:17

I have undone some of the electrical plugs and checked them and replaced them. How can the air flow meter be checked?
The lambada light is off at present so I will check the codes when it comes back on. Where can I find a list of the codes and how to read them?
Thats what I like about this site, ask a question and someone is bound to know the answer or where to find it.
cheers.

Feb 15th, 2006, 15:25	#1
johnjp Master Member Last Online: Jan 30th, 2019 22:56 Join Date: Nov 2004 Location: Heathfield, East Sussex View Photos By: johnjp	Lambda sensors I have been reading about Lambda sensor problems, the Lambda on my 1997 945 came on recently after I was topping up the cooling system with the cap off and engine running. I thought I would find the sensor attached to the exhaust in front of the cat but it`s not there! Where can it be? Also does anyone near to me, Brighton area, do OBD?

Feb 19th, 2006, 11:45	#7
neil stevenson Senior Member Last Online: Jun 6th, 2017 14:09 Join Date: Oct 2000 Location: Carrowdore	Perhaps someone here could also explain what to clean and degunge on a B230FT please. Sorry to hijack your thread but I find lambada issues all very confusing. The dash warning light on my 940 SE B230FT engine lights up every now and again, the car runs lumpy and the revs (more when cold) dont aways settle down to a steady tick over when stopped at trafic lights etc. Cheers. __________________ Neil Stevenson 2000 S40 1600cc. 940 SE Turbo Estate.(sold).

Feb 19th, 2006, 11:46	#8
RollingThunder Grumpy Old Git Last Online: Apr 19th, 2024 09:16 Join Date: Dec 2004 Location: South Yorkshire View Photos By: RollingThunder	You beat me to it... Couldn't have put it better myself Ivor __________________ S40 2.4i '07 Japanese import '96 850R - https://www.volvoforums.org.uk/showthread.php?t=312484 Ex Danish Embassy '96 940 GLE LPT - https://www.volvoforums.org.uk/showthread.php?t=326071

Feb 19th, 2006, 12:17	#10
neil stevenson Senior Member Last Online: Jun 6th, 2017 14:09 Join Date: Oct 2000 Location: Carrowdore	I have undone some of the electrical plugs and checked them and replaced them. How can the air flow meter be checked? The lambada light is off at present so I will check the codes when it comes back on. Where can I find a list of the codes and how to read them? Thats what I like about this site, ask a question and someone is bound to know the answer or where to find it. cheers. __________________ Neil Stevenson 2000 S40 1600cc. 940 SE Turbo Estate.(sold).

Feb 15th, 2006, 15:58	#2
ivor940 Master Member Last Online: Sep 16th, 2013 07:55 Join Date: Dec 2003 Location: Malahide View Photos By: ivor940	Hi, If your 940 is a Turbo, the Lambda sensor is fitted to the underneath of the exhaust just aft of the 3 nut clamp. It is not visable from top, but you can feel it ( when the exhaust is cold). I think a 7/8 spanner will undo it. On the turbo, the wire for it is routed near the distributer to keep away from the exhaust. ivor940

Feb 18th, 2006, 22:32	#4
ivor940 Master Member Last Online: Sep 16th, 2013 07:55 Join Date: Dec 2003 Location: Malahide View Photos By: ivor940	Hi, sorry but I meant the 3 nut clamp at the exhaust manifold. If you follow the pipe forwards and up from the cat, the sensor should be above the oil filter. The wire for the sensor usually sits on top of the oil filter. It is visable easier from below the car, looking aft of the steering rack. ivor940

Feb 19th, 2006, 11:01	#5
bogart Master Member Last Online: Jan 31st, 2023 09:51 Join Date: Nov 2003 Location: Languedoc Roussillion	Found it now, obvious when you know where. Last question, honest. All this talk re PCV stuff where on a B200FT do I check for blocked pipes and gunge etc? Regards

Feb 19th, 2006, 11:42	#6
ivor940 Master Member Last Online: Sep 16th, 2013 07:55 Join Date: Dec 2003 Location: Malahide View Photos By: ivor940	Hi, on B200FT, the pipes to check are as follows: The over engine 1/2" dia hard plastic pipe with insulation --- This pipe can block completely or have a restricted internal diameter due to cokeing. It can also get cracked / broken inside the insulation. ( can be temp fixed using 1/2" heater pipe. It is not dear from Volvo, and is difficult to clean out hard coke deposits due to its shape The "flame trap" white plastic junction at the inlet manifold. It does not have a grill in Turbos . It can be brittle and the small pipe can snap off. The Breather Box above the starter, below the inlet monifold. Can be cleaned, but best to replace. Can be purchased from non Volvo suppliers. Do replace the green O ring at its base. The flexible 1/2" pipes above and below the "Flame Trap" are easy to clean. Only replace if they are deteriorated. The small diameter pipe connecting the "Flame Trap" to the inlet manifold. Easy to clean out. Don't forget to clean out nipple on manifold with small diameter wire. Inspect the Duct from Air Filter to the Turbo for softness due to oil just below where the over engine 1/2" dia pipe joins the Duct. When all these Items are done, the engine should have fewer oil leaks, but more importantly for the Turbo, oil can return to the sump easier. This can reduce oil getting from the turbo into the inlet system. This leads to dirty deposits in the Throttle Body and plumes of blue skoke occasionally on acceleration. George Holmer has posted info on Turbo Breather Systems as well. ivor940 94 940 2.0 SE Turbo Est 5 spd 166.5k VOC member

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