1997 850 engine shaking and check engine light on

gallen · Post by **gallen** » 01 Nov 2003, 19:16

just bought a 1997 850 with 58K miles. Looked awesome and drove impecably. Immediatly after driving off the used car lot we filled it up with gas. Then right after starting the car there was a shaking from the engine that was not felt durring test drives. Check engine light also turned on. After continuing to drive 90 miles home the shaking decreased slowly till it became non-existent. Subsequent driving has revealed no more shaking for the most part (although it has reappeared briefly and rarely), although the check engine light remains on always. Service engine light is now on for the 1st 2 minutes every time we start the car. We checked the gas cap and it IS tight.
Could this be due to the gas filling up? Did we buy a lemon? Any advice? Thanks in advance.

Tsquared · Post by **Tsquared** » 01 Nov 2003, 20:35

May be a coincident. You can get the codes read at AutoZone for free. They should be able to tell you what the code means. Remember that the fault may be the result of something else that has failed and caused the computer to give you the code. Hopefully is is something that can just be reset or easily corrected. For more on the codes look at this thread:
https://www.matthewsvolvosite.com/chat/p ... c1394c0256

With 58K miles you need to see what maintenance has been done. There is a 60k maintenaince that is rather extensive as well as expensive. Going from memory: Rotor Cap, Plug wires, plugs, Air Filter, Fuel Filter, ?PCV Valve?, throtle body gasket, and transmission flush. Not sure about the PCV Valve and the trans flush needs to occur every 30K (I understand the need for regular maint on this as I just dropped $2700 on a new trans as I believed the manual, thinking the trans was a non-servisable item

). The maintenance should be documented in the maintenance records. The secret to keeping these cars going is the periodic maintenance and upkeep.

I highly recomend a K&N air filter for the maintenance. They are a little more expensive, but hey flow more air and are washable. Be sure to keep you old filter so that you can intall it when you wash the K&N and it is drying. I also recomend synthetic oil - from experiance, it is just better.

Good luck with the 850. I have enjoyed both of mine (the first was totaled after 18 monthes. I walked away with a bruise from the shoulder restraint). I used the insurance $$ to get my current 850 in late 96.

gallen · Post by **gallen** » 01 Nov 2003, 23:52

Tsquared, thanks so much for the info. I'll try to read the codes myself tommorow morning, although I'm not sure what the "flylead" is or where to find this code reading apparatus under the hood. If I cant do it myself I will go to an autozone.
Also, do you know any other weblinks for code keys (other than the A2 socket), since I do not have a haynes manual.

thanks again

gallen · Post by **gallen** » 02 Nov 2003, 00:14

After reading more posts I am wondering if I will need a codereader to determine the fault codes. See this post for my references:
https://www.matthewsvolvosite.com/chat/p ... c.php?t=91

If I do need the codereader I assume that this is what Autozone has and will use for me for free, rather than going to a mechanic and being charged for him to use it. Is this correct?

Guest · Post by **Guest** » 02 Nov 2003, 10:49

As of this morning the check engine light is not on! And the engine shaking is also gone. Sevice light still comes on, but it is near 60K so maybe thats what its about. Went to autozone to confirm and they do not read codes anymore in california, since they got sued a couple months ago. Anyhow, problem appears to have dissapeared so we can relax. Thanks so much for your help Tsquared!