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850 turbo 1994 check engine light

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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Ozark Lee
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Re: 850 turbo 1994 check engine light

Post by Ozark Lee »

My bet is that the knock sensors are OK. They are really just microphones and they rarely fail.

I think if I were working on the car I would clear all of the codes and see which ones come back. For the MAF sensor double check the connector, it may also be a legacy code from some time when the car was started with it unplugged.

The PCV on these cars is a "system" rather than a standard PCV valve. It consists of an oil trap and several oil and vapor lines. There are a number of writeups in the database on how to service the system. FCP Groton sells PCV "kits" that have all of the parts you need except the EGR valve gasket. The kits come with Oetiker style crimp on clamps that require a crimp tool. Unless you get a real fancy (expensive) tool there are some of the clamps that can't really be crimped. For those I just buy a variety pack of small worm gear type hose clamps at the local auto parts store.

For spark plugs I have great luck with plain old - Dollar a Holler - Bosch coppers. They used to be FR7DC but Bosch changed the numbering system. They only last for 30,000 miles or so but for 5 bucks, who cares. They can be a bit hard to find but NAPA usually has them. The gap is critical, 0.028". They come out of the box closer to 0.040".

...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

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misha
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Year and Model: '97 850 2.5 20v
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Post by misha »

shynepo419 wrote: What is the PCV and how do i go bout servicing that.
Here's the write up with pictures:
http://lakesidedp.com/uploadpics/pcv/

Enjoy!
'97 850 2.5 20v / fully equipped / Motronic 4.4 from the factory / upgraded with S,V,C,XC70 instrument cluster / polar white wagon
History of Volvos in the family:
'71 144 S
'73 144 De Luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

shynepo419
Posts: 17
Joined: 13 April 2009
Year and Model: 850 turbo, 1994
Location: Morgantown,WV

Post by shynepo419 »

Thanks again Lee. And Misha thanks for the link that's kool. The reason i asked concerning the knock sensor is cos my car does this funny thing when you start it....... she cant stay idle by herself. you have to rev it up till the car's temp is in the middle(most times) before she can stay idle by herself. and some guy said it was the knock sensor. but i didn't believe him. what do you guys think?

shynepo419
Posts: 17
Joined: 13 April 2009
Year and Model: 850 turbo, 1994
Location: Morgantown,WV

Post by shynepo419 »

Wow i wish i found this site a long time ago. You guys have bin so helpful

Ozark Lee
MVS Moderator
Posts: 14798
Joined: 7 September 2006
Year and Model: Many Volvos
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Post by Ozark Lee »

A bad MAF sensor will cause the car to not idle properly. It will set another code but just unplug it and see if the idle smooths out.

...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

shynepo419
Posts: 17
Joined: 13 April 2009
Year and Model: 850 turbo, 1994
Location: Morgantown,WV

Post by shynepo419 »

I feel like we should go have a couple beers and i can pick your brain concerning my car lol. So far the check engine light hasnt come back, i drove it all day yesterday and today. So what does that say? i guess it might just need servicing cos the service light still comes on, or maybe i should give a few more days. thanks again Lee

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misha
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Year and Model: '97 850 2.5 20v
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Post by misha »

shynepo419 wrote:...i guess it might just need servicing cos the service light still comes on, or maybe i should give a few more days.
Service light is JUST a reminder for oil change interval.
'97 850 2.5 20v / fully equipped / Motronic 4.4 from the factory / upgraded with S,V,C,XC70 instrument cluster / polar white wagon
History of Volvos in the family:
'71 144 S
'73 144 De Luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

Ozark Lee
MVS Moderator
Posts: 14798
Joined: 7 September 2006
Year and Model: Many Volvos
Location: USA Midwest
Has thanked: 4 times
Been thanked: 76 times

Post by Ozark Lee »

4 shots of 151 Rum will fix the service light.

Flywire to port A-7.

Press the button 4 times. - the LED will light.

Press the button once and the LED will light again.

Press the button 5 times and the LED will light again.

Press the button one more time.

The service light should reset.

If it doesn't 4 shots of 151 rum will make you no longer care.

...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

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