ferrocene

I think I may have a clue, but I thought I'd ask you smarties.

I have a '04 AT with 56k. Plugs and oil recently replaced. Haven't checked air filter (K&N) in awhile.

Since about a week ago, every time I start it up, warm or cold, the engine turns over 3-4 times before starting. Before, it would start after 1-2 turns every single time (here I'm assuming "turning over" is the wuh wuh wuh" sound before ignition).

After it starts up, I have lower power up to 4-5k RPM. To really exacerbate the problem, if I start off in 2nd gear (on the automatic), I can literally watch each number on the speedometer crawl by - 1...2...3...4...5...etc. It's bad. Please save the slushbox jokes...but something is off. After the first (and only) set of ports open around 5.5k it pulls pretty well up to 8k.

I've also noticed a distinct rough/grinding sound/feeling. It's hard to describe, but the smoothness while accelerating from idle to 3k is gone. Just a slow and rough sounding acceleration.

I'll do more thread searching, but I hope someone has some ideas. I think it may not be getting enough fuel...maybe? Or the cat's clogged. Those are my only two ideas. I've been getting a CEL for about a year regarding evap code (bad gas cap, even with an autozone replacement one), and oddly enough the CEL is gone.

I've driven this car daily for over 5 years and no engine problems at all other than the dealership-performed flashes/recalls.

Edit - while reading other threads, I haven't replaced the tranny fluid, well, ever. Not sure how to check the fluid level. Perhaps its time? Also, the dealer told me not to replace the tranny fluid until 50k anyways.

I have never replaced the wires or coils. In fact, the only thing that's been replaced is the air/oil filters, plugs, and of course oil.

It has been dealer maintained up to about 35k miles. Got new motor mounts to fix a rough idle/reverse issue.

I have the racing beat exhaust and K&N drop in filter, the other mods are suspension and visual.

ferrocene

OK quick reply. Tonight I did a quick "cat check" as recommended in other threads and I got the pulsating back pressure.

I rolled down both windows and from a rolling start in 2nd gear (to give me more time in the lower RPM range), acceleration sounds like my old 5cyl Audi. This car sounds like it has cylinders, lol. I also have a ticking sound under the hood at idle. It seemed louder before I replaced the plugs, but it's still there.

Again, after 3k RPM it seems to accelerate like normal.

Also, do I have this correct: if I replace the coils with BHR coils, that will void the engine warranty? 'Cause I'm sure not going to do that if I need a new engine.

Dealing with my dealership is a PITA. God help me.

VOODOO8

Negative on voiding the warranty with BHR coils. Dealer would have to prove the coils caused the damage to use them as an excuse to void and that just ain't gonna happen.

If you want to play it perfectly safe, keep the old coils and swap em back if you ever have to go to a stealership for major warranty work.

I've had BHR coils for a couple of years now - love em. Betting weak coils is probably the source of your issue.

DavidR

Might be reviving a semi old thread, but this seems identical to the problem I am having now. If OP has found the solution let me know

ferrocene

Just to give an update, I found the problem and it (kinda) fixed itself.

Today while going up a semi-steep hill in 2nd gear (70mph, 7k rpm), I lost like 1/2 power. Car dropped to 52mph. Then a thick foul smell filled the car.

After I got to my destination and started it up again, it fired up on the first crank. It was so fast, I was startled. It usually took 5 cranks. Then this grey foul smelling smoke started blowing out of the exhaust.

I believe my cat was clogged, which caused the slow cranking, poor gas mileage and sluggish acceleration.

It then "fixed" itself by breaking the cat up. The car hasn't felt this fast in a long time.

It's still probably under warranty so I should have the dealer check it out/replace if necessary. But hot damn is it quick now!

Mazurfer

FYI...........Cat warranty is 8 years 80k miles.

xexok

I know this was a few months ago, but you mentioned that you had not checked your k&n filter in a while, thats something that gets dirty FAST. With the way it filters the longer you wait to clean it the worse it performs. So you may want to clean that up when you can and recharge it with oil.