So i picked up my car from the mechanic's this afternoon after having two cam leaks and the rear main seal fixed. A couple hours later, noticed that when accelerating, the CEL will briefly flash and it feels sort of "jerky" as it moves through the hiccup and accelerates. this was not happening before the visit to the mechanic.

And it's Friday, 9:40 p.m. of Christmas weekend. So the earliest i could get it in is next wednesday.

After scouring online for answers, it seems it could be O2 sensors or ~shuddering~ compression issues.

a) Are the current and former issues possibly related?
b) Is it remotely safe for me to drive and do the final bits of Christmas shopping or will I potentially kill my engine?

 

Don't want to toss stones but it's a good "chance", chance they may have missed something or they have a connection that isn't fully clipped together.

Compression wouldn't be something they could have damaged or changed and you likely have the same now as before the repair. Very small chance the timing belt jumped which would change valve timing and would affect compression but it's not worth considering at this point.

I'd drive it as little as possible until you let the mechanic check out his work. If you can, I'd try to see if it's recorded a trouble code that could be very helpful in figuring out what's up.

That, and do a good under hood exam and just try to push any electrical connector you see together to see if one feels loose or has some play and snaps together. Depends on what they took apart to get to that rear main seal.

 

Ran across this post, it's not an 850 but similar problem.

Swedespeed Forums - Check engine light flashing

 

a flashing CEL usually means there is a misfire that can damage your cat-converter. does your car feel like it "bucks"?

 

Yes. It jerks a little bit when the light flashes (almost as if about to stall), then resumes acceleration.

It's sitting quietly in the driveway, thinking about what it's done, until i can get it back to my mechanic.

I am crossing my fingers something didn't get attached correctly. I thought about looking under the hood and seeing if i could see something amiss, but since i know absolutely nothing about cars, figured nothing would jump out at me unless there was a big sign that said "messed up here!"

Sometimes i curse my much loved, dearly departed mechanic father for not teaching me how to fix cars.

I'll take a look at the link. Thankfully, my boyfriend has two cars and i'm borrowing his wagon until i can get it back from Munich West.

Thanks for responding! I'm glad you confirmed my instinct to sit tight until it can be checked out.

 

Misfires are bad, raw fuel goes into the Cat which then blows in there and can miss things up. you may just have a loose sparkplug wire or a bad coil. Very VERY rarely, built up moisture inside a distributor cap will cause an engine to misfire and act strangely, but water has to get in there to start with.

Hope it isnt anything serious. Luck !

 

I would retrieve possible fault code(s) from the ECU. If your 850 is '93-'95, you can pull codes by yourself without any equipment. If '96/'97, you need an OBD-II scanner/Volvo tester.

Some models are equipped with both OBD-I & OBD-II. If you do not have OBD-I, I would visit a nearby Autozone for free OBD-II code reading services (if they still do that).

JPN

 

The rest of them.

JPN

 

What year is your vehicle ?

 

It is a '94.

Talked to the mechanic. He says it was a faulty cam sensor that they are eplacing at no charged. Picking up tomorrow. Will report back on how it works out.

 

When you get it back you should check to see if you have this panel under the hood.

In the future it can come in handy for finding out what might be wrong with your car.
http://www.matthewsvolvosite.com/read-codes-volvo-850

 

so picked up my car and it's working great. guess it was the cam sensor!

Thank you so much for those codes and the images of the diagnostic panel. very helpful. bookmarked for future reference!