Flashing CEL and rough idle for appx 20 seconds

catera00 · #1 (**permalink**) 02-26-07, 11:24 PM

I have a Check engine light, Dont know the code yet but I think its the P0411 returning. I got that code and had it reset at Autozone a week ago. I found a vacume hose near the brake booster w/ a slice in it and taped it up. Car was fine till yesterday. Now when I start the Car from a cold start, it idles rough, the rpms fluctuate from 1,000-1,200(ish) RPMs and the CEL flashes for about 20 seconds. Then the idle and RPMS smooth out and the CEL light stays on constant. The car is going to the dealer tomorrow but I wondered if anyone knew what that might be caused by. Thanks guys

9BlackN*Black6 · #2 (**permalink**) 02-27-07, 01:55 AM

a flashing CEL is a missfire condition and usually sets a PO300, need a tune up? Over 100k miles?

Marks DTM Calib · #3 (**permalink**) 02-27-07, 03:38 AM

Check your hose repair first....the tape has probably come off when the engine got hot.....
Note, the ECU one this power plant cant detect a missfire....

PEETYZ · #4 (**permalink**) 02-27-07, 12:52 PM

my 98 catera manual in the U.S says when a check engine light is flashing a misfire in occuring and to shut car off and to see a dealer immediately is that not true?

catera00 · #5 (**permalink**) 03-01-07, 01:29 AM

You guys are right, Misfire...

okay, I took it to the dealer and my pass. side valve cover gasket was leaking oil into one or more cylinders (Typical prob for these cars I'm finding out) The repair was done free of charge since I just bought the car. The car still runs rough and lacks some power. After I got home, I went to the store and the check engine light came on again. Went to Autozone and read the codes. P0300, P0304, P0306- Misfires in cylinder 4 and 6

4 and 6 are on the drivers side so I pulled those spark plugs and #6 was full of oil. Looks like the drivers side valve cover gasket is bad too. I cleaned the oil off the plugs and scuffed them with a wire brush. The car runs smooth now.
So back to the shop it will be going. Thankfully I have a warranty that covers gaskets and seals. The dealer charges $396 to replace the covers. Yowza! They shoulda checked the other side while the plenum was off. Now they get to do it again.

So the wierd thing is that when the engine ran crappy, it sounded like I had an exauhst leak. As soon as I cleaned the plugs, the sound went away.

My car has 65K miles on it. How often do the valve cover gaskets go bad?

Warez · #6 (**permalink**) 03-01-07, 02:39 PM

Quote:

Originally Posted by Marks DTM Calib

Check your hose repair first....the tape has probably come off when the engine got hot.....
Note, the ECU one this power plant cant detect a missfire....

They can indeed, and a flashing CEL spcifically indicates a misfire.

catera00 · #7 (**permalink**) 03-09-07, 02:42 AM

Update**
My issue continues.

>>A little back ground: I just bought this car 3 weeks ago with 60k miles on it. I originally brought the car in to the dealer I bought it from because of the rough idle after cold start and check engine light. The found the passenger side valve cover was leaking oil. They fixed it free.. I got the car home and the next time I started it I had the rough idle and CEL again. I took it back in.<<

The dealer replaced the coil pack. As Soon as I started the car, it ran rough and the check engine light came on again!!. Gave them the keys. They said it ran and started fine in the warm shop. Maybe the cold outdoors effect this prob.

The car stayed for another day (3 days now)
They had to get a fuel injector tester. They found on injector to be bad so they replaced it. Its fixed!!

Until I got home and started it again later. Runs rough and guess what's blinking on the dash board... CHECK ENGINE!!

Its going back on Monday.
Is this a MAF prob? The technician mentioned there was a "stored code" mentioning the MAF. A lot of posts here with these exact symptoms, even the fact that other peoples cateras did this when it was cold and not when it was warm outside.

If its the MAF, shouldn't they be seeing that when they are hooking the car up to their scanning machines?

Thank goodness I've only paid for the coil pack so far.

**Update**

Went to Autozone and read the codes.
I am getting the exact same codes, multiple missfire on cylinders 4 and 6
Takin her back to the dealer Monday. I'll report back with more info. Any opinions on the MAF? Would that cause a misfire on specific cylinders? Its always 4 and 6

catera00 · #8 (**permalink**) 03-10-07, 02:30 PM

I bought some CRC Mass Air Flow sensor cleaner. Using that made no difference. Dont think its the MAF. Any ideas?

todd2fst4u · #9 (**permalink**) 03-11-07, 04:11 AM

Quote:

Originally Posted by catera00

I bought some CRC Mass Air Flow sensor cleaner. Using that made no difference. Dont think its the MAF. Any ideas?

if the MAF is faulty the cleaner isnt going to do anything anyway

catera00 · #10 (**permalink**) 03-12-07, 01:09 AM

I went to the auto parts store to buy some coolant cause for some reason I am low. The coolant light came on yesterday. I have been noticing an odor coming from the car every time I park it. Its a kind of, hot smell. I assumed it was from the new valve cover gasket and other stuff they recently installed just getting hot and settling in so to speak. But the guy at the parts store said he smelled coolant. So we looked around and found no leaks. No puddles in my garage. He suggested maybe a head gasket is leaking into the #4 & 6 cylinders. I bet that would cause a misfire. I'll have the dealer do a compression test on the cylinders to check for a leaky head gasket.
I'll have them test the MAF also.

bengsxr · #11 (**permalink**) 03-12-07, 03:35 PM

well you can always just unplug the mass air flow sensor to test it.

catera00 · #12 (**permalink**) 03-14-07, 01:51 AM

Quote:

Originally Posted by bengsxr

well you can always just unplug the mass air flow sensor to test it.

I did and it made no difference.

catera00 · #13 (**permalink**) 03-14-07, 01:55 AM

I spoke to the dealer and they have no idea why its having this problem. I was affraid of that. Now that the weather has warmed up here the car is working good and the check engine light went away.

I do have an exhaust leak at the exhaust donut. They suggested maybe it threw a false code because of that. (I doubt it)

They are going to do a carbon cleaning on it. They are gonna (I assume) run something through the engine (Probably a fuel injector cleaner) in the hopes that theres a piece of carbon stuc somewhere. Sounds like they are grasping at straws at this point

catera00 · #14 (**permalink**) 03-15-07, 03:26 PM

ok, heres the newest from the dealer:

Compression test came back ok. No leaks.
They are now getting an O2 sensor error

I posted awhile back about a broken stud & bolt I found in the engine compartment:
>>It has a triangle on the end of the stud

Heres the back

Side

Looks like someone cross threaded it

Heres where I found it. On the Pass. side

Closer shot

>>

Well it seems that two of the studs that connect the header to the block broke. They say this is causing extra air enter the engine and cause the o2 sensor (Which is located after the header) to adjust the fuel mixture richer.

So they are going to change the exhaust donut and replace the broken studs

Holy crap man. Still havent made my first car payment! Hope this fixes it.
Any thoughts?

catera00 · #15 (**permalink**) 03-17-07, 10:25 PM

Well they finished with the exhaust leak and header studs. I went to pick it up. They test drove it 5 times that day. Then, just before I got there, the Service manager test drove it and guess what?
Check engine light!!

Left the there. Seriously, what the heck? Should I be concidering a different car? What could the problem be? The technician was going to test drive it with the scan tool connected. Who knows whats wrong with it....