1997 Volvo 850 - CO2 buildup - pulled over to safety

Post by **xHeart** » 16 Jan 2015, 08:36

Without common sense it would have been a terrible drive last night.
Please read http://www.engr.ucr.edu/~heejung/publications/2013-CO2-exp.pdf

How to go about solving this problem?

Post by **mecheng** » 16 Jan 2015, 09:44

I didn't read the whole article but reviewed the graphs and conclusion.

These Volvo's are perfect at controlling both particulates and CO2. First, you have an air filter, if not install one.

The other feature these cars have is "Air Mix" knob in the top vent on the center of the dash. You can specify how much pure outside air you want even if you have it in Recirc. You can have lets say 10% fresh air and the remainder re-circ. I only use Recirc, in the summer when its hot but I keep the air mix at about 30% fresh air.

Post by **cn90** » 16 Jan 2015, 09:49

Don't use "recirc" if you don't have to. The only time I use recirc is when stuck in traffic behind a diesel truck exhaust!

Open windows on and off to flush out the old air.

Post by **precopster** » 16 Jan 2015, 10:31

I must read our P2 XC70 owners manual. I don't quite understand how you can have fresh or recirc at varying amounts on P2s...

Post by **xHeart** » 16 Jan 2015, 11:53

Our 850 is MCC.
Recently replaced Volvo cabin air filter, blower fan resistor, and a new Behr blower fan. All working great. Heat temps at 2 O'clock, fan setting 2 is adequate.

Once dizzy, I switched ON recirc, which accelerated impairing. Rolled down all four windows.
Quickly decided to exit to shoulder, two lanes away. Rush hour traffic, nighttime driving but not wet, motorists would not yield.

It was hard to stay alert. Once at the shoulder turned ON the trouble, but did not turn off the engine, let it idle... and sat at the shoulder for a while for heartbeat to normalize and vision to recover.

Lucky me it was 30º outside.
I was off the road in minutes, terrifying moments.

Post by **kahl** » 16 Jan 2015, 12:02

It appears you had a bout of carbon monoxide poisoning. Is this the same car you did some exhaust work on? In recip aircraft we had a stick um which had a disc that would change color in the presence of CO2. Most airports have these for sale.

Post by **FLXC90** » 16 Jan 2015, 13:14

I don't know about P80s, Bu the ECC on my 04XC90 will only run recirc for 15 mins. in auto, then it purges and repeats to prevent such situations. On a manual control car I guess you would have to use the vent knob next to the center dash vent. Sucks when it's cold

Also, since filter was recently changed, verify good seal at cowl. And as mentioned, check for exhaust leaks into cabin

Post by **FLXC90** » 16 Jan 2015, 13:18

By the way,
#1 Glad you are safe
2 Thanks for the warning and heads-up

Post by **xHeart** » 16 Jan 2015, 13:31

kahl wrote:It appears you had a bout of carbon monoxide poisoning. Is this the same car you did some exhaust work on? In recip aircraft we had a stick um which had a disc that would change color in the presence of CO2. Most airports have these for sale.

I now know for sure how CO2 feels, kahl.
Yes. Exhaust manif by Estonia Dec 2013, and the complete exhaust pipe in one piece by Volvo from CAT to tail-tip July 2014.

Do I look for leaks at these replacements?

Post by **FLXC90** » 16 Jan 2015, 14:00

yes, check for any cracks in manifold, check all flanges. Was the downpipe w/flex joint changed? joint could be a major candidate, hidden under braided sheath.