SES light flashing... argh!

[scottydl]

On my way home from church Sunday morning, I noticed the idle was a little rough. Although it was subtle I could still feel it plainly, almost like a persistent twitching, especially thru the brake pedal when in Drive and braking at low RPMs. The tach needle barely showed the difference, but there was a small fluctuation with each revolution. About 5 minutes into my drive, and the SES light comes on. Another minute later (I'm still driving), the light starts flashing. DOH! I pulled over and put it in Park, and the light stayed on but quit flashing.

This became a pattern as I worked my way home (about 10 miles)... I'd start driving and make it 30-60 seconds before the light would start flashing again. As soon as I pulled over it would stop. I also found that I could shift into Neutral (while rolling) and the light would stop as well, so that's how I made it home. Drive until SES flashed, Neutral and coast until SES went solid again, back into Drive, etc.

Aside from the barely rough idling, I never felt/detected any other problems. Still had regular quick acceleration, and good RPMs at cruising speed. But I didn't want to chance any damage by driving on the flashing light, so my Aurora's in the shop as of 7:30am this morning. Hopefully whatever is wrong is covered by my extended warranty! I'm going to try and get the power antenna and my shifter backlighting fixed under my same deductible, while it's in there.

I'll post updates as they arrive. Any guesses in the meantime, based on those symptoms?

[JimW]

Hopefully its not tranny related, but it COULD be a throttle postioning problem...I dunno, never heard of it. Is it like a surging issue?

They'll lay down an OBDII scan and figure it out.

[scottydl]

There was no surging really, just a rough idle that I could feel pulling on the brake pedal ever-so-slightly (when I had it in gear, but stopped). Today when I drove it to the shop (1/2 mile) there was no rough idle or flashing lights to speak of, so I'm certainly hoping they can still figure it out.

[scottydl]

SES light was a misfire on cylinder #4, due to a non-working fuel injector I'm told.

Are fuel injectors convered by my warranty? Yes. BUT the company refuses to pay for a replacement until the injectors have been cleaned with some high-pressure chemical treatment, to see if that fixes the problem... and OF COURSE I have to pay for that, to the tune of $96.xx, plus the engine scan and labor time for diagnosing, somewhere around $75.

I almost hope the injector is bad, so at least someone else has to pay for something!

Oh yeah, and the mechanic told me that the engine scan showed 51 stored codes (!!!) compared to the usual 10-15 they might see for this kind of problem. Who knows what that means. There go my dreams of getting everything repaired for merely my $50 deductible!

[JimW]

Interesting

Keep us apprised of what goes down Scotty

*sigh* the joys of owning cars

[omegaic]

It could have been worse. Much worse.

[Letitroll98]

The proceedure is correct. The cleaning will usually fix this problem, a typical one for many GM engines. The price ranged from $59.95 at my local Xpress lube to $139.95 at my regular repair shop. The $75.00 for the code reading is also typical. You can get the codes read for free at Advance Auto and GM sells a fuel injector cleaner additive that's almost as good as the "pressure" systems. (Can't remember the name of it) With major league clogs you need to remove the injector and clean it by hand. By that time it's easier just to replace the fairly inexpensive part.

[Aurora95]

Just an f.y.i. to those without the benefit of a warrenty, you can change all the injectors and FPR for a decent price. The whole set with the regulator is available OEM on ebay for $145. This seems very reasonable considering cleaning costs. The auction I saw was number 7919810454. If this is a d.i.y. project just remember to relieve the pressure on the fuel rail to avoid a gasoline shower.

[scottydl]

Well it's done, I got my Aurora back last night, and I've had some time to cool down.

So far the injector cleaning seems to have worked. Mechanic said the misfire went away after 7 minutes of running the cleaning solution through the engine (total run time was 1 hour). The procedure included testing my spark plugs, ignition system, and cleaning the throttle body as well... a couple more things I don't have to worry about now. It test drove fine, and the mechanic said no codes returned after hooking it up one last time.

Even I have to admit that my 4.0 is running SILKY smooth after the procedure. Let's keep our fingers crossed that it stays that way... forever.

[JimW]

After what happened to the Bonne, you can be forgiven for a lil frustration regarding mechanical issues.

That being said, good thing its back to 100%, I would suggest a bottle of STP Fuel injector cleaner product once in a while, I have had excellent sucess with it in both cars over the years.

[scottydl]

JimW said:

After what happened to the Bonne, you can be forgiven for a lil frustration regarding mechanical issues.

Thanks for the consideration...

JimW said:

That being said, good thing its back to 100%, I would suggest a bottle of STP Fuel injector cleaner product once in a while,

...which brings up another question. The mechanic yesterday said that "stuff you dump into the tank" is essentially a waste of money. He claimed that all is does is clean the dirt out of the fuel tank, and deposit it in the engine. ??

I still can't believe I had an injector THAT bad off after 56k miles, but I've read numerous places now that GM's are known for it.

[JimW]

Sounds like it does what its supposed to do, breaks down deposits in the tank, and removes deposits in the engine...that may just avoid clogged injectors...but then I could be on crack...lol

At least its fixed!