Hey all,

I am somewhat of lurker in these parts but recently purchased a 2001 Trans Am WS6 A4 from Sherman Texas, I actually drove it back home to Florida (just arrived this morning at 7am, long drive!) While she handled well, I did notice she ran a little rough (mileage is 29k), I have some very good recent service records from the previous owner (I put them in excel format and will copy paste them below). Question for you all? What are some of the things I should be looking out for and swap to make this a more smooth running car? It has door panel cracks which I expected and was disclosed prior to the sale (I had a mechanic I hired to check it out before I bought it). He gave it very good reviews both mechanically and cosmetically but did note it ran a little rough. The drivers side headlight seems like it gets stuck against the hood and won't come up, when I open the hood then turn on the lights it will opens and the lights work, I can then close the hood (when I turn off the lights they go down without issue or rubbing on anything).




I will post some better photos later, it's still raining out here. I've attached the maintenance records via excel.

 

I've noticed cars around this age, even with low miles, can have some stumbles. Fuel delivery and spark are usually the culprit.

It looks nice. Congrats.

 

Triple black? I assumed it was a convertible with that description, but I see it's a t-top model. One big issue will be the bubbling roof panel (sail panel behind the t-tops), unless it has already been replaced. There's a very comprehensive sticky about this in the Paint & Bodywork section, but the roof will eventually bubble (if it isn't already) unless it's never exposed to heat/sunlight, and the only permanent fix is to replace the whole panel. Sorry to be the bearer of bad news. With any luck, a prior owner may have already replaced it in the past.

I wasn't able to open the file so I don't know what maintenance has been done, but the rough running could be a number of things. Hard to tell if it's fuel or spark related without more data, but if you have a scanner that looks at misfires and fuel trims that would be helpful. Could be anything from a fuel filter to slightly clogged injectors (due to old fuel from sitting long periods) or even a dirty MAF (often due to a K&N style filter). Could also be spark related as mentioned above, but fuel issues would be more likely at that mileage. I assume the SES light isn't on (since your mechanic didn't note this), so there probably aren't any codes to read. Is the rough running worse at higher rpm or lower rpm/idle only? Does it fire up strong or stumble to life? Extended cranking times? Sputter when going WOT? Does it seem down on power in general? Any surging of the idle? Will the torque converter attain lock-up when cruising at higher speeds in 3rd or 4th gear?

My '98 has very low miles as well and doesn't see fresh gas very often, so I've always been careful about keeping the fuel treated (Stabil + Red Line SI-1). This has worked very well and prevented any stumbles/rough running over the years. But if you plan to drive the car more often, then old fuel shouldn't be a concern going forward.

 

Thank you! This is exactly what I was thinking too, I have some MSD wires coming along with the NGK Iridium IX spark plugs, they will be here Tuesday.

 

Apologies, I may have gotten the color code wrong, but it's black, ha.

I took a screenshot of the excel file I made for the maintenance, this will probably help others out if they can't open the excel.

 

 

Not much point in replacing the plugs and wires based on what's listed on the spreadsheet (thanks for attaching the image above). Looks like that was done about 1k miles ago (I realize that was a decade ago, but these items don't go bad from age alone). I see that injector cleaner was used at that time as well - wonder if the rough running was a problem starting back then, and the previous owner tried some of the same methods to fix it? Looks like another injector cleaning was done 800 miles later, again, probably for the same reason.

It's curious that the starter relay was replaced twice in the last 1200 miles (though ~8 years apart). Wonder if the issue was actually related to something else? It also seems that the bulk of the mileage was done in the first couple of years, after which it mostly sat. And apparently someone tried to adjust the problematic driver's side headlight before (sounds like they were unsuccessful).

There is no "normal" reason why a head gasket would ever need to be replaced on a 28k mile LS1 engine, so if that is in fact what was done (I know this is uncertain based on the spreadsheet comment) then it's concerning to think about what sort of event would have occurred to lead to this outcome. Perhaps some residual consequence of this event is the culprit for the current rough running condition. But, no point in going too far down that rabbit hole if the paperwork is unclear.

Overall, I think more in depth diagnostics needs to be done regarding the rough running. The questions I presented above are a good place to start, but a comprehensive scanner would also help (to watch fuel trims, O2 data, misfires, etc.). Since a plug & wire swap plus multiple injector cleanings have already been done within the last ~1k miles, I wouldn't toss more parts at it without doing some further evaluation and diagnostics first.

 

Congratulations 🎊👏 on the Black T/A WS6!

Sharp looking car! 😊


BTW - I agree with RPM, diagnosis before loading the parts cannon.

 

Thanks for your input, I do have an obdii reader I will throw on there. I did notice the CEL came on during the drive but went away (no abnormal events occurred or change in sounds or performance that I noticed) engine oil looked good and was changed prior to me picking up. I will run some more diagnostics as well, the insurance agent I have my policy from knows a few F-Body shops near me that will help me out (he has a 2002 Camaro SS) which he has work done from his recommendations. Worse case scenario, I bring it in to them and have them do a once over (in depth) and see what the outcome is.

Loving the car so far, my neighbors stopped by and admired it, the neighborhood kids call it the batmobile now, haha.

 

Fuel delivery would be my guess. Injector cleaner twice sounds like throwing it at a problem they knew exists but not knowing exactly where. The last vehicle I purchased sight unseen (yup, done it a few times) would start and run rough but no CEL. It would idle and then die. I found a few injectors were mostly clogged, one would stay open and cause the system to leak down, the FPR was shot, fuel pump was junk and the fuel filter was plugged. Every single important piece of the system needed addressed from sitting about three years.

​​​​​My guess is what you're experiencing isn't a big undertaking to get ironed out.

 

On the headlight jamming, you should be able to adjust the cover to eliminate the interference. Misalignment is about the only thing that could cause this unless there was body damage. The headlight pod itself bolts in and isn't adjustable.

 

Thanks all, it's in the shop right now getting a once over by my trusted local mechanics. I will report back what they find, I did give them a copy of the maintenance records so they can check those items to see if they are holding up.

 

So update all:

Knock sensors bad, misfire on cylinder 1 and 5. Everything else seems fine, fuel pump is good, injectors good. Fuel injectors were cleaned *** well.

So to replace the knock sensors they'll have to remove the intake manifold, they are also throwing in fluid flushes for all even the oil which was just changed.

Not too bad, I thought it could have been worse, thankfully I will get her back tomorrow and see how she goes! Will update more once I pick her up.

Total cost for me was $900 for everything which included flushing/filling all fluids.

 

What diagnoses did they provide to explain the cylinder #1 & #5 misfire?

 

The CEL was on, so they read the trouble codes, it went on and off a few times on my trip, it would occur on startup, then shut off a few minutes later. It only occurred 2 times and when I dropped the vehicle off the CEL was off, so it may have been a stored code.

 

Well, the rough running was likely due to whatever had caused the P0301 (cylinder 1) and P0305 (cylinder 5) misfires. I assume there was also a P0300 (random multiple misfire) code if there were cylinder specific codes present.

The knock sensor(s) shouldn't cause rough running, so I don't expect that to solve the issue. Someone needs to investigate the cause of those misfires, which is almost certainly the reason it was (or is) running rough.

 

Yep digging into it more with the mechanic who did the work, he said most of the spark plugs were loose and gasses were venting out (which was causing a noticeable ticking sound). I pick her up in an hour but he said she's running brand new now, night and day difference from when I dropped her off.

Now what caused them to come loose is anyone's guess but I may go with user error from the previous owners maintenance tech's

 

Gotta love the black WS6, what part of FL?

 

Clermont, not too far from Orlando

 

Oh yeah you are on the far west side