'03 2.4T intermittent sputtering,CEL, no OBD codes

deadmerelda · Post by **deadmerelda** » 30 Aug 2016, 17:03

Most times this thing runs great. Fine when stone cold. After fully warm on the gauge it will begin sputtering at idle. Typically a little revving in neutral will clear it up enough to run normally. Sometimes it's bad enough the CEL flashes a few times then goes back to ON. No regular codes are set.
Sometimes this will go away for a long time, other times it presents frequently. Aside from the early warm up it's pretty unpredictable. I hate throwing parts at it without somewhere to go. Maybe I'll end up at the dealer but want to see if this sounds familiar.

First I replaced thermostat and sensor. Then well cleaned throttle body. Tried cleaning mas which really looked ok. It has a new fuel pump and filter. The other thing it rarely does on the highway is boom into limp mode. This is always when using cruise. A simple stop then restart always clears up the "reduced performance" light. New plugs a while back but I don't recall what brand frankly.

One person I asked suggested it was the dreadful pcv/separator box. But I don't have oil blowing or what I consider lots of positive pressure at the oil stick.

Any ideas really appreciated. Cheers. Ed

Post by **chrism** » 30 Aug 2016, 19:01

Sounds a lot like what our 05 2.5t was doing a few months back. The final fix was a trip to the local Volvo independent shop where they disconnected the ECM and plugged it back in. (It takes a special tool to unlock and fully relock the ECM back into its seat which I didn't have.) Apparently after 10+ years the connections get just enough oxidation on them that they fail when you add heat to the equation.

deadmerelda · Post by **deadmerelda** » 30 Aug 2016, 22:55

Ooh thanks that is interesting. I figured maybe an 02 sensor being slow or like that. But poor electrical contacts are definitely possible.

Post by **abscate** » 31 Aug 2016, 05:37

Do you get pending codes set?

How old are the ignition coils? They run do long on these cars we forget about them. The mantra to run a trouble free car is to replace them at 100k.

Misfires often don't set codes but will flash the CEL or message

Get a cheap code reader, or borrow one, and next time it limps read it out.

These cars are too complicated for diagnosis by symptom, especially after high miles.

How many miles on the beast?

deadmerelda · Post by **deadmerelda** » 31 Aug 2016, 06:12

abscate wrote:Do you get pending codes set?

How old are the ignition coils? They run do long on these cars we forget about them. The mantra to run a trouble free car is to replace them at 100k.

Misfires often don't set codes but will flash the CEL or message

Get a cheap code reader, or borrow one, and next time it limps read it out.

These cars are too complicated for diagnosis by symptom, especially after high miles.

How many miles on the beast?

Yes indeed all good points. Not sure what pending codes are. I've replaced 2 of the 5 coils as they failed solidly and set codes one at a time. I do dislike just throwing parts at an unknown issue, and so far my experience is that coils fail hard. I guess that's not a reasonable expectation and that partial breakdowns are possible.

The code reader on limp mode is a great idea. As bad as it's behaving I can probably expect to have that happen again soon. I didn't get one yet because this CEL I have now isn't setting codes I could read with it - didn't know that was possible. Actually the first OBD2 car I've ever owned. I'm pretty old school shade tree owner/mech. Worked on my girlfriends '01 2.4T before this and decided I liked it. Well, except for the ETM.

Interesting that keeping my foot into it seems to be the best thing. Cruising/coasting for a while is the only time it'll get freaky. Do folks mess with the TPS or whatever is inside the throttle control?

Bought it with 157K - now it's at 210. Really appreciate the reply!

Post by **abscate** » 31 Aug 2016, 11:40

Just to give you an idea, when I blew off a turbo induction hose a couple months back I got both a ECM-1300 MAF sensor intermittent fault and an ECM0981 Control Module Internal Fault.

All from a loose hose clamp.

IF the car is running like hell, the fault codes become useless at some point.

I even ordered a new MAF against my cheaper judgement even though I knew it wasnt the problem. From someone who re-uses coffee filters, that was my hell that month.

My sermon that Sunday was "You can't take it with you, but those mufflers you find on the highway sure weld in real nice and purdy"

deadmerelda · Post by **deadmerelda** » 31 Aug 2016, 11:58

abscate wrote:Just to give you an idea, when I blew off a turbo induction hose a couple months back I got both a ECM-1300 MAF sensor intermittent fault and an ECM0981 Control Module Internal Fault.

All from a loose hose clamp.

IF the car is running like hell, the fault codes become useless at some point.

I even ordered a new MAF against my cheaper judgement even though I knew it wasnt the problem. From someone who re-uses coffee filters, that was my hell that month.

My sermon that Sunday was "You can't take it with you, but those mufflers you find on the highway sure weld in real nice and purdy"

Lol, I'm with you. And yes boost plumbing has to be right. My other car is an 87 Conquest TSI with soft hoses that can easily slip off.

I've ordered a set of OEM coil packs to be here tomorrow since 3 are unknown age and 2 are of questionable origin (Advance). I'll post if this fixes the darn thing or not.

Post by **oragex** » 31 Aug 2016, 14:39

deadmerelda wrote:I hate throwing parts at it without somewhere to go.

Good thing. Many people think it's this or that and replace good parts. Not to mention the main dealer.

Aside the checks mentioned in the posts above, among the common issues was the FPS sensor as well as the PEM module. The later, on models with metal gas tank is located above the tank on the left side of the car and is prone to corrode inside.

deadmerelda · Post by **deadmerelda** » 31 Aug 2016, 16:29

oragex wrote:
deadmerelda wrote:I hate throwing parts at it without somewhere to go.

Good thing. Many people think it's this or that and replace good parts. Not to mention the main dealer.

Aside the checks mentioned in the posts above, among the common issues was the FPS sensor as well as the PEM module. The later, on models with metal gas tank is located above the tank on the left side of the car and is prone to corrode inside.

Thanks, fps must be fuel pressure. Power entry? Hmm, mine is a bit flaky. I have a plastic tank.

deadmerelda · Post by **deadmerelda** » 01 Sep 2016, 10:31

So PEM is the fuel module or something right? I don't think 03 has one.

I should have my coils this afternoon. I'm predicting that this will NOT fix it. I certainly hope so but think I'll be looking for something else.