Static timing randomly went retarded, lumpy idle out of no where?

Giberish33

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1997 Jetta TDi 1z
Hey guys, fairy new to TDI's but I've owned my jetta for over 2 years now and have gotten familiar with vagcom and have been doing plenty of reading. About 3 days ago now on my way home from work coming up the last hill to my house I noticed that the car was making a louder than normal "ticking" noise, sounded like injector on a cold morning. The noise was a constant pace and only seemed "loud" when above 2500ish rpm. My I initial thoughts were possibly a sticking injector or just getting worn out (245,xxxkms on original bodies and nozzles).

Today I finally got around to hooking up vagcom to see what was wrong. The car drove normally if a little slugish but the main thing was the idle was lumpy to the point of shaking the car like it was running on 3 cyl. Seemingly from one day to the next my timing in basic settings has gone from dead on center to just slightly above red line retarded. IQ voltage is also jumping around like mad.

Sorry I dont have any screenshots right now but injection balance hduring the summer was not great with cyl 1 = 1.38 cyl2 = 1.18 cyl 3 = 0.33.

Now the balance is at cyl 1 = 2.07 cyl 2 = 1.30 cyl 3 = -0.98

fuel filter + oil filter + oil + air filter all have about ~4000kms on them
timing belt has maybe 30000-40000kms

the car starts fine and actually runs better / smoother when cold (im assuming ECU is adding timing) but by the time I get home from work and everything is warmed up its a lumpy idle that can be heard at the tailpipe as well. Anything in particular to look for? How could timing jump from middle to almost bottom of the graph seemingly overnight?
 

Vince Waldon

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2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
There's a couple possibilities, but the first thing I'd recommend is looking very carefully at the harmonic dampener while the engine is running to see if there's any visible wobble.

If so, the car should be parked, crank bolt removed, and crank snout and sprocket checked for damage... the bolt may have worked loose.

Loose timing belt that has jumped would be the next suspect.

Worn IP a distant third, perhaps, but that would tend to cause a gradual shift in timing. A sudden shift, particularly on an older engine, is generally the crank bolt letting the sprocket shift back and forth. If it is allowed to persist valves can meet pistons. :)
 
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Mongler98

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Ok, so there are a few things here that are an immediate thing to investigate.

Timing being the obvious and that "ticking sound"

Get her to TDC and check to make sure the IP lock out pin is still in perfect alignment as well as the cam and so on. Ok if you’re good on that part, you can move onto what Vince Said. While cold engine, check the tensioner for the timing belt is dead on. If it’s not, adjust it with the tool and put a drop of blue lock tight on the threads for the nut and torque it down to 10ftlb I think, check that one for me before you do. Now make sure that the crank bolt is not loose, now check the tightness of the bolts on the top cover and body of the IP, like if you’re doing a hammer mod. If all those things check out ok, you can start the car. Once you start the car, watch your QA on the IQ You need to be somewhere around 3ish, when its bucking or hard idle issue and your IQ is right, move on, if it somehow jumps to something like 1.4 or less then here is your issue. I’m my 1z it has a very rough idle the lower the IQ goes. I have mine at 1.2-1.4 as I’m trying to get as much fuel as I can, don’t do as I do, OK. Now on to that tensioner, while it’s warm and doing its rough idle, make sure it’s not that tensioner. A faulty one will give a bit of slack here and there as it’s not adjusting properly anymore and can cause this issue as well. You’re right to think it’s a timing issue. If that looks good, make sure your 3rd injector is plugged in. Also check to see if the big round wire harness bit by the end of the head over top of the Trans is plugged in all the way and free of water contamination within. Also MAKE SURE THAT IS GORUNDED. I had this exact issue but it never stopped, all the time, the grounding screw on its frame part was snapped off. It must be grounded. Now if you have check everything here that I have said so far and nothing is working or correcting it or wrong, move on to running a purge of liquid diesel molly injector cleaner, with a can, a bit of hose, a inline filter and go to town, consume the entire bottle, it takes a while. In a nut shell, put 2 hose lines into the bottle, one to the IP intake and the other to the IP return and have a cheap clear filter inline on the IP intake.

If that don’t work I highly suggest you start investigating the IP. They do go bad but all the other things I just mentioned are much more likely.
 

Giberish33

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Montreal, Qc
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1997 Jetta TDi 1z
Thanks for the input guys. Ill check what I can tomorrow as there is supposed to be a snow storm coming my way and I don't have a garage to work in. Would it be possible for the IP pressure relief valve (maybe not correct term) part of the reason? In reading about what it does when its "not together" sounds sort of like what I experienced where there is not enough pressure in the IP case at idle / low rpm causing the timing issue then when on the throttle the ECU takes over and there is more pressure in the IP to supply more timing advance. I guess its easy enough to remove that valve and see if the parts have worked their way free, then jam them back together to see if that is a possible cause. Harmonic balancer as well as A/C pulley etc are not wobbling at all I already checked that out, also Alternator pully was changed just before the winter. I have yet to check the timing belt tensioner. I don't think the noise is valves touching anything, it seems entirely fuel related as there is only noise when accelerating, decel there is nothing so not cv clicking and not valves and not lifters. I can replicate the knocking / ticking sitting stationary in neutral(5 speed car if that makes a diff).

Another possible cause I read about is IP bolts working their way loose and allowing the timing to drift off? Possibility? I have new non stretch type bolts and a torque wrench so I could adjust the pump timing if needed.
 

iluvmydiesels

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uuuh, vinces advice come 1st to check. crank bolt being loose is a real possibility. like he posts check harmonic-pulley for wobble, even then the crank gear may be loose. if it gets 'out of play' valves may cross pistons. may have happened, for you.
for ip bolts working their way loose, a 'micro-torque' wrench is used, a 3/8" wrench. ip base bolts about 18ft-lbs, add some more for tightness, not much more. for a 'micro torque wrench' convert inch-lbs to foot-lbs. its 12inch-lbs to a foot lb.
 

KLXD

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The thing is that the pump pin won't be in perfect alignment at TDC on a 1Z or AHU since the pump lock pin is removed when the belt is tensioned and the sprocket will move. So don't expect it to be.

The cam should be.
 

Mongler98

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98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
The thing is that the pump pin won't be in perfect alignment at TDC on a 1Z or AHU since the pump lock pin is removed when the belt is tensioned and the sprocket will move. So don't expect it to be.

The cam should be.
yea i guess it wont be EXACT but it should be very close, a tooth or more off and the holes wont even come close to aligning.
 

Giberish33

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IP pressure relief valve was together as it should be so I guess im going to check the IP sproket bolts next. Any kind of real danger running with very retarded IP timing except for more smoke or poor fuel economy. The car has started just fine and drives fine its just at idle where things get funky. Ill check it out and report back.
 

Giberish33

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Cracked open each injector one by one, each of them made the engine stumble so I guess things are looking ok for the injectors, I bumped the IQ a little from mid 5's to high 3's seems to have smoothed it out a little, I havent experienced the idle stumble / 3 cyl shake. The one thing still puzzling me is how the IP timing drifted off to within spec but retarded when a few months ago it was dead on in the center of the graph. I guess its possible it has been retarding slowly and I only now realized. Any one have any clue after what time period / mileage the "timing belt stretch" comes into effect. I've heard that it is normal for the timing belt to stretch somewhat over its life and slowly retard the timing so its usually best to set the timing slightly advanced to compensate for the stretch. Currently a snow storm with possible ice rain tomorrow were I live so I'll see if I'm able to adjust the IP timing or wait for better weather. Thanks again for all suggestions guys!
 

Vince Waldon

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If timing belts stretch at all it is a very very very tiny amount. :) :)

If your timing was good and then suddenly changed something else is going on.

If you're not sure it suddenly changed perhaps reset and monitor is all you can do at the moment.

Unfortunately, on an older TDI like a 1Z, my money's on the crank snout interface. :( :) The harmonic damper will wobble when it's really in bad shape, but it starts with things sliding around in line.
 

Giberish33

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Damn ok, thanks Vince. I guess I over estimated the amount of timing can be offset by any stretch. Like I said the last time I checked timing it was mid 40's reading dead on in vagcom, now timing is in the mid to low 30's given the same fuel and coolant temps. Pretty much my plan at this point is to reset the timing and monitor it. I can't seem to see any kind of wobble in the harmonic balancer, should I be looking at first start up when things are cold or when the motor is already warmed up / doesn't even matter there would be wobble at all times?

Also weird to me is that cyl 3 (I know this is really cyl 4 in comparison to cyl 3) is showing negative numbers for injection deviation, this summer all cyl were in the positives. Again all of this could have been progressive and I only realized now but I'm just worried that something is actually not ok. I take great care of her otherwise, consistent oil changes, filters, diesel additive and taking the bi-weekly WOT run onto the highway.

*side note: have not had the same lumpy idle since I tightened down the injector retaining clamps and bumped the IQ a little, maybe unrelated but as of now I'm only trying to figure out the reason / correct the drop to retarded IP timing from dead on center*
 
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Mongler98

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98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
lets put it this way, i did a timing belt on a car with 280K on the clock on the ORIGIONAL belt, i marked the teeth on the sprockets and counted them against a new belt, the stretch was only half a tooth off over the top of the cam sprocket to the top of the IP sprocket and the bottom of the crank in that direction. So yea, minimal to say the least.
Unless you verify that the physical timing is correct, your ricking even starting it up. there are a hand full of things to check before you turn that key. Your risking big $$$ to repair a simple check over. the IP bolts just dont back out randomly, if they were worked on before, maybe over a few hundred or thousand miles, i can see that but of the 4 times i have adjusted my IP timing on my 1z its never backed out or changed.

Vince is 100% on point and this is the most likely option of what happened.
Bring it to TDC and make sure your on time.
 

whitedog

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I didn't not know the MkIII well - just what I have read and I know that the crank snout is a common problem. But something in the OPs last post caught my eye. He said that last summer all three readings were positive. Well, from my understanding, there should be some negative and some positive and if you add them together, they should equal zero, or just about.

So that makes me wonder if there is a problem with the #3 injector sensing. Yes, the crank sprocket is most common, but if that's tight, would it be worth looking into the #3 injector? Maybe even swapping it out with a know good?
 

Vince Waldon

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Yup, don't get me wrong... there's other possible explanations to a sudden shift in timing.

Just thinking that if nothing else obvious becomes apparent for the cost of a new bolt and some time spent building/borrowing a crank lock it might make sense to inspect the snout, if only to eliminate it as a suspect... and sleep better at night? :)

Issues with the pump or needle sensor are non-terminal to the engine.... the crank snout unfortunately not so much. :) :)
 

Giberish33

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1997 Jetta TDi 1z
I'm not going to ignore that fact that many vets here are suggesting the crank sprocket as the issue and in doing some reading it seems possible, however I don't see any wobbling on the harmonic balancer and the car has no starting issues even in -15c not plugged in after work. The timing graph starts off dead on when cold starting as I observed yesterday in vagcom and progressively drops off. Wouldn't things be more constant if the crank sprocket bolt did loosen up and things had slipped timing(ie. always retarded timing even when cold starting). As of now I only experienced the very rough idle / stumble once. I don't have the tools or space to do it myself, is there anything I can check by hand or with a socket wrench & cheater bar?

I also read that if the crank sprocket is loose the timing wouldn't stick so do I trying to advance the IP timing and see if it drops off again or just call my local vw/audi shop and ask them to take a look at the crank snout/ harmonic and repair?
 
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Abacus

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A common issue on these engines is the crank sprocket moving, and it will create the problem you describe. Checking the static timing is easy and doesn't even require any special tools, although they are good to have. All you have to do is pull the top timing belt cover and the valve cover. Make sure the timing belt tensioner is close to the slot, it won't be exact since it's temperature compensating, so don't bother adjusting it and DO NOT use loctite on it.

Pull the transmission flywheel inspection plug and get the mark in the slot, then check the injection pump hole and the cam slot, to make sure it's even with the top of the head. If the crank sprocket is moving even a little they won't line up.

There is no way to 'check' the crank sprocket bolt, so don't bother. The only way to check it is to remove it and if you're removing it, you might as well replace it. I would not take it to a garage for this unless you can handle a big bill for the labor.

Check the static timing when cold and when it's warm and messing up. If they're in alignment each time, move on to the injection pump. Any air bubbles in the line by chance?

It could also be an electrical short, from two wires that only make contact when the engine is warm, which allow things to move around more. I've seen a fair amount of this in the past.
 

iluvmydiesels

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(1:)Make sure the timing belt tensioner is close to the slot,

There is no way to 'check' the crank sprocket bolt, so don't bother. The only way to check it is to remove it and if you're removing it, (<2>:)you might as well replace it. I would not take it to a garage for this unless you can handle a big bill for the labor.
1:the timing belt tensioner, while checking static timing, like abacus recommends, check, it has a mark and a slot they are supposed to line up or be close. do not loosen the tensioner, 1:you need the tool, 2:you need timing experience.
2:if you loosen crank bolt you need replacement. its a one-time use bolt. you can get them for ~$4.

another thing VW dealers arent the most adept, either your own garage, or a good private shop is most times much more consistent, and dealers are price gougers, they will add up that bill, both on paper, and tell you, you need this much(more and unnecessary)work, and if they get you in the shop. a private shop will be hard to find to know our 'tricks'. they can be good for certain things, but i doubt many are very well knowledgeable of such tricks as problem crank snout timing problems. if you have a good shop, ask him to look at it, and give other relative info for him to check.
 

Vince Waldon

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The timing graph starts off dead on when cold starting as I observed yesterday in vagcom and progressively drops off.
Ah... perhaps we're misunderstanding your symptoms. Are you saying every morning the timing starts off perfect... but after the car has been run for a while the timing drops?

If so, here's the thing: the timing is adjusted for temperature (both fuel and coolant) and you should in fact be getting warnings from VCDS if either are too cool for accurate checking... in particular, if the engine (aka coolant) is too cool.

Is this the case? IIRC the coolant has to be a minimum of 80C to accurately check the timing (which is why I do my tuneups in the summer... hard to get to 80C in Edmonton in the winter :) )
 
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Giberish33

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Check the static timing when cold and when it's warm and messing up. If they're in alignment each time, move on to the injection pump. Any air bubbles in the line by chance?

It could also be an electrical short, from two wires that only make contact when the engine is warm, which allow things to move around more. I've seen a fair amount of this in the past.
What do you mean by "in alignment each time"? Like I get repeatable scenario where the static timing is dead on when cold and then drops off to retarded each time? The day I had the weird lumpy idle it did sound like most of the noise was up front closer to the IP, I have observed some bubbles going though the clear line to the IP but nothing substantial, maybe a few medium sized bubbles for a split second and then no bubbles for a while. I've always had some small amount of air but no streams and no constant air.

I dont have the ability to get under the car or do any of the TDC verification your asking about right now, its ****ting snow in canada and I have no place to work on my car. The garage I'm talking about is not a vw dealer its a local vw/audi guy that is well known liked here in montreal, people have nothing but good things to say about him (good prices and honest). He is actually the guy who did my timing belt about 30000kms ago and who resealed my IP about 1.5years ago. I would normally be willing to do the work myself and learn but I dont have the work space to do it right now, if it was summer it would be a different story.
 

Giberish33

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Yes Vince, that seems to be exactly what is going on, yesterday morning I had the car plugged in for about 1 hour or so and started the car up with my laptop and vdcs hooked up. I know normally timing is checked with coolant above 80c and that timing will be dependent on fuel temp. coolant was about 26c when I started the car and I let it idle for a minute or 2 while i checked out IQ , dynamic timing and coolant/fuel/ambient temps. I went into basic settings then tdi timing graph and observed the timing lining up with the blue line although towards the left of the graph because fuel wasn't up to temp yet. I drove the car around my area at low speeds for a little to get everything up to temp, got back home fuel sitting at ~39c, coolant at ~91c and again checking the timing graph it was reading mid 30's (timing number was mid-high 40's when last observers in the summer fiy)

As a side note, I changed the fuel temp sensor just before the winter becuase it was reading like almost 20c too high(was reading like mid 60's in the summer yet the fuel filter was just warm to the touch), after changing the temp sensor temps were more realistic and timing graph went up a few points.

Everything about driving the car feels and sounds normal to me except when checking vdcs where I see the timing graph is now half way between the middle and bottom red line. IQ is normal, dynamic timing normal (0.9btdc when warm, 2-3btcd when cold), no cold start issues (normal crank time and no abnormal smoke when starting), no stumbling or hesitation when driving (smooth acceleration and pulls fine in boost). Even if I nit pick and say the idle is slightly more vibration than before its nothing new as my injection deviation values arn't great and I know im due to change the nozzles /have them calibrated. If the crank snout is getting mangled and timing did slip wouldn't there be some sort of constant drivability issue with things not lining up to tdc? Cold start issues? missing or noticeable issues though the rev range? Not trying to stick my head in the sand but it just doesn't seem like anything is significantly wrong.

Anyone know what kind of cost would be associated with having the crank sprocket and harmonic balancer changed at an independent vw/audi shop? The car has great sentimental value to me so I doubt the cost will be too much.
 
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Vince Waldon

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Well, this no longer sounds like a crank sprocket issue, since it's a predictable change in timing rather than a sudden, permanent shift.

I'm still not super-clear on your symptoms... are you saying;

- the coolant temperature is always over 80 whenever you check the timing
- you're always in basic settings (ie ECU control of timing disabled) whenever you check the timing
- and yet somehow the timing changes dramatically between when you first get the engine over 80 C and later in the day?
 

Giberish33

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1. Normally I would check the timing graph when the coolant is over 80c, but in this case I checked the timing graph very soon after cold start so coolant "hot" yet.
2. Yes I am always checking the timing graph by going Measuring blocks>000>go>switch to basic settings>TDI-Timing. Unless this is not the correct method?
3. No. Timing is changing from following the blue line(dead on) soon after cold start to halfway between blue and red lines (slightly retarded). This shift occurs after a period of driving to get all temperatures up. I just got back from a drive to confirm this is the exact same behavior as I saw yesterday under the same circumstances of cold start timing is up but after driving (coolant and fuel up to temp) timing is retarded.

Something else I noted is that my injection deviation/balance rates for cyl 3 are starting off positive when cold starting but then end up being in the negatives when things are up to temp. Seems that there is some similarity between timing and injection deviation. Something IP related? QA starting to fail?

Here is a some pics and a video of my harmonic balancer right after cold start. Sorry I forgot a pic of the timing graph when warm but fuel was just above 100 and timing jumping a little between high 30's low 40's you will see that those 2 line up about halfway between blue and red.
Video:
https://drive.google.com/open?id=1SjdlETvMpGH8hrgSI7l8OURBSvb53f_i

Timing graph after cold start:
https://drive.google.com/open?id=15rgc1C_l_RNSG1ieGhJTnq2a2GmUg93t

Injection deviation after cold start:
https://drive.google.com/open?id=1wgNdW1nIVhfeBWlyIokYsEofeAufyFnn

Injection deviation when warm:
https://drive.google.com/open?id=1JI3GDO1nkeYNYsMSVjUiRPqpIl5bAhem
 

Vince Waldon

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Sorry for being so dense... it's hard over the internet... but in essence you're saying the static timing shown on the timing graph is different when the engine coolant is warmed up to 80 C than it is with the engine stone cold?
 

Giberish33

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No worries man, partly my fault for just spewing info lol. But I can see how my initial post could sound like the crank sprocket was at fault. I hadn't had a chance to check vagcom when the car was stone cold or find a pattern / repeatable symptoms.

Yeah timing is about 10 points higher when stone cold than when coolant/fuel are up to temperature. Possible that the injector balance going from positive to negative value lines up with the timing being different from stone cold to fully warmed up?
 

Vince Waldon

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No worries.

Unfortunately I'm now at a loss... I dunno that the static timing values/graph have any diagnostic meaning if the coolant is not at full operating temperature.

Ross-Tech might know?
 

Giberish33

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I guess the question now becomes "what could cause timing to drift as the car warms up"?

What other sensors / parts are responsible for adjusting timing depending on temp? CTS, fuel temp sensor maybe timing belt tensioner as its supposed to adjust depending on temperature? Either way thanks for the info Vince :)
 

iluvmydiesels

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yea but whats drifting, as far as timing. mechanical timing? mechanical timing can change, well some as an engine warms up, this in later models is compensated for with a tensioner that has a warming motor 'adjustment'. <mechanical in nature. the injection VCDS timing changing makes little sense, for one the engineers at VW made this, its their adjustment. when coolant reaches operating temps and we hook up and get VCDS reading we then go form the measuring block screen and look up timing graph and select the correct engine set up, and get a reading @idle, and adjust(if necessary). as far as changing in timing, which variable would you choose? any will apply, lo-engine temp, yea at idle as our motor heats up there will/should be timing change. this is inconsequential its programmed in. get accurate timing with coolant at or about temp.
 

Vince Waldon

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I guess the question now becomes "what could cause timing to drift as the car warms up"?
...and I guess what I'm wondering if it's even abnormal for it to drift until operating temperature is reached ?

I don't know one way or the other... hopefully smarter people will weigh in.

VCDS *is* pretty picky about warning that the engine needs to be fully warm before checking/adjusting timing... that may mean that the numbers are meaningless until then.

Or not. :) :)
 

Giberish33

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I get that timing does normally shift when the car is warming up, a few months ago however the timing was dead on with everything up to operating temp. Now tiiming is more retarted given the same engine temp, so I'm trying to figure out what could allow for the IP timing to shift down on its own. All hypothetical right now I will have to see what happens a when I adjust the ip timing back to where it's suppsed to be. If it drops into the retarded area again or stays put. I know from the OP till now might be confusing as the symptoms in my OP could have been for a different problem. Its been several months since I hooked up vagcom and the only reason I thought something might be wrong is because I noticed slight differences in driving the same route with the same conditions. My timing when warm is lower than it was in the summer and maybe i only noticed it now by some fluke but I would like to find out what things can cause this, or if it is normal for the ip timing to drift to the retarded area over time on its own.
 

Giberish33

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get accurate timing with coolant at or about temp.
I did and it seems the static timing has shifted down by about 10 points @ same coolant & fuel temp. I was noticing that my idle was decently more shaky and after running some powerservice and getting through most of my tank it had not changed yet so I checked out timing in vagcom. The last time I checked the static timing graph was over the summer so several months ago.
 
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