Check Engine Light is on

mellison0107 · Post by **mellison0107** » 06 Jul 2011, 11:14

Hi, all. I need some advice, here. I bought a 97 960 Sedan recently, and had no problems until last week. On Thusday, my check engine light came on briefly while driving to work. Once it blinked off, it stayed off. Upon leaving work, it cam on briefly just after starting, then went off again and stayed off. We went out of town for a few days, and it was not started or moved. Tuesday, the light came on at starting and stayed on for most of my 9-mile drive to work, blinking off periodically. Today, it did not come on at starting, but did come on shortly after. It stayed on briefly, then went off, coming back on periodically for very brief periods. I have all the maintenance records for this car - it was a one-owner, and they did all the recommended maintenance, including changing the timing belt. It seems to be running fine, with no stalling, hiccups or backfiring. Suggestions? I did see the post where taking it to Auto Zone for checking the codes was mentioned. Is that where I should start?
Thanks!

Post by **billofdurham** » 06 Jul 2011, 11:41

Welcome to Matthew's Volvo Site.

Go to Auto Zone and have the codes read. Be sure to make a note of them and post them here for more help.

Bill.

mellison0107 · Post by **mellison0107** » 06 Jul 2011, 12:55

Thanks for the welcome. I will do that. Thanks!

mellison0107 · Post by **mellison0107** » 06 Jul 2011, 19:08

Ok, so I get to the AutoZone, and guess what? The light goes out. A nice, very knowledgeable young man comes out to read the codes (now I know where to get them) and, of course, there is nothing to read. It says, "pass." Apparently, if the light isn't on, nothing bad is going on. So I leave to go home, and the light comes back on. As soon as I turn back into the AZ, it goes off again.
Suggestions for common ailments causing this to happen would be very helpful. Oxygen sensor? Dirty air filter? Clogged PCV valve? Loose vacuum hose? Old VWs I'm a whiz with. I've never owned a Volvo before.

Thanks for your help!

mellison0107 · Post by **mellison0107** » 07 Jul 2011, 10:12

I just had a thought. When I bought this car, I saw that there was a little oil coming out of the dipstick. The dipstick had the handle end broken off and didn't seal properly, hence the blowback.. I know it shouldn't do this. So now I have 2 questions - A) what would cause that to happen, and B) would needing oil make the light fluctuate like that? I mean, I'll check the oil level when I go out again, just because it dawned on me this morning on my way to work that I didn't see any oil on the valve cover like I had the day I bought it, so it could be low. Just say, "DUH, Marsha!"

Post by **billofdurham** » 07 Jul 2011, 11:20

"DUH, Marsha!" Check that oil ASAP and invest in a new/used dipstick. Our sponsor Erie Vo-Vo may be able to help with a used unit.

CEL - this is the technical answer:

The CEL can come on and go off because certain faults must happen in a certain number of consecutive drive cycles for the light to stay on, if the fault doesn't occur in those consecutive drive cycles the light will go out. The number of cycles required to make the light stay on varies with different problems.

As to the cause - is the fuel filler cap tightened properly? A cap that is not tightened down can cause intermittent CEL operation.

Bill.

mellison0107 · Post by **mellison0107** » 09 Jul 2011, 13:25

OK, checked oil - level is fine. Have a dipstick to replace the broken one with, no problem. I checked the fuel filler cap - it's tight. The light seems to come on more often when I accelerate, and go off when I decelerate. I also notice that there is a correlation with the A/C problem (I knew about that when I bought the car) - which is also stop and go. No problems with power, no unusual noises. Guess I'll see what happens in the coming week...
Thanks so much for your help!

JohnInFlorida · Post by **JohnInFlorida** » 09 Jul 2011, 15:21

I have a '98 S70 (my son drives) with 180k and a '00 S70 (my wife drives) with 220k and the check engine light has appeared a few times in the past 5 years. AZ reads it perfectly every time. I recommend to make sure all fluid levels are correct and regular maintenance is done. You will have to wait until the light stays on for a while to get a read.

By the way, the dipstick top was broken off on our '98 S70 and I picked up one from FCP Groton for about $20 only to notice that the dipstick didn't fit the holder. So, I bought another dipstick from the Volvo dealer and found that the holder is the problem. So I bought a holder for about $75 from FPC Groton and a mechanic friend replaced it for $25 for me.

Both Volvo's require oil changes every 5k to 7.5k (my manual says 7.5k and that is what I have been doing on the '00 S70 and it has 220k miles now) and regular maintenance about once/year and they are running fine now. Volvo's are strong cars with powerful engines, solid transmissions, and heavy metal bodies (tanks).

Good luck with everything!

Post by **bronxnativ** » 09 Jul 2011, 17:30

Invest in an OBDII reader/scanner for your Volvo. Autozone will check the codes, but will no longer clear them, that means that you will be driving around with a CEL on. I purchased my OBDII reader from Advance when it was on sale for $59.00. Best purchase I've made for this car.

We cannot predict what the problem is without codes (neither can you). Buy the code reader, when the light comes back on, check the code and post here. We will ALL have a clearer picture then.