2007 Aero 2.8t engine skipping/bucking
Hi all, first post here.
Starting last year, my 2.8 started to slightly buck sometimes when driving. Brought it to Saab, and they told me to wait until it throws a code. One year later, it is getting much more serious, and is bucking very hard at idle and between 2,000, and 2,500 RPMs. One thing I've noticed is it generally only skips when the engine is warmed up, or when it is above 72 degrees (Fahrenheit). No CEL on the dash. Brought it to advanced auto to put on the scanner, no codes whatsoever. Coil packs are stock, but have a suspicion it could be one of the O2 sensors. Read other posts, but it seems like everybody with the problem is throwing a code. Anybody know the problem or have a similar experience?
Starting last year, my 2.8 started to slightly buck sometimes when driving. Brought it to Saab, and they told me to wait until it throws a code. One year later, it is getting much more serious, and is bucking very hard at idle and between 2,000, and 2,500 RPMs. One thing I've noticed is it generally only skips when the engine is warmed up, or when it is above 72 degrees (Fahrenheit). No CEL on the dash. Brought it to advanced auto to put on the scanner, no codes whatsoever. Coil packs are stock, but have a suspicion it could be one of the O2 sensors. Read other posts, but it seems like everybody with the problem is throwing a code. Anybody know the problem or have a similar experience?
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101,000 miles.
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5,545 Posts
When were spark plugs last replaced? If it has been awhile I would do both spark plugs and coils to start. Since the rear bank of engine is such a pain to get to it makes sense to do both and at that point you're only either three plugs or coils from doing everything anyway. 100K miles on original coils sounds like you got your moneys worth out of them;ol;.
Would you be able to do the work yourself or do you always use a shop?
Would you be able to do the work yourself or do you always use a shop?
Yes my money is on the Coils. Just replace them and all the spark plugs all 6 at the same time...don't try and find just the one or two that are not working properly as the same thing will happen again to you. Make sure you buy the Bosch 112 Coils, I would recommend RockAuto that's where I just bought mine for the lowest price anywhere I could find. Even my Saab only mechanic being careful broke the vacuum line but he almost expected it anyway and had a new one ready to install, good luck!
I was getting misfires with my Vtune stage 0. Spoke with Brian and diagnosed it to be the issue at the time. Replaced them with the Airtex 5C1551 coils...
I am looking at the ENA coils on Amazon to replace mine. $79 for complete kit is enticing. I couldn't find any discussion of ENA here. Any thoughts?
https://www.amazon.com/gp/aw/d/B017...--1-6-5-8139-1649-1-1---1-0&keywords=coilpack
I just had the same problem, car would hesitate at high acceleration in 4,5 and 6th...
Changed all the spark plugs and back 3 coils and it solved my problem (car has 63k)...Than I changed the front ones too just in case...
I used Bosch ones from eeuroparts for $45 a piece...Not cheap but since you are doing this job that can be PITA I would spend little more money and not worry about if for at least few years...
Changed all the spark plugs and back 3 coils and it solved my problem (car has 63k)...Than I changed the front ones too just in case...
I used Bosch ones from eeuroparts for $45 a piece...Not cheap but since you are doing this job that can be PITA I would spend little more money and not worry about if for at least few years...
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1,937 Posts
The latest Bosch coils are an updated version so worth going with them, got mine from Rockauto.
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1,271 Posts
Mine misfired under acceleration and never triggering a CEL. After a spark plug and coil change, the misfires went away and hasn't come back...
if you know someone with tech2win and a mongoose cable, this is a reliable method to actually determine WHICH coil is failing:
http://www.saabcentral.com/forums/showthread.php?p=4966130&highlight=coils#post4966130
using this technique i was able to return to service some of the shotgun-replaced coils i had pulled the FIRST time i had misfires (and, much to the chagrin of my wife, kept in a box in the garage).
hth
ken
http://www.saabcentral.com/forums/showthread.php?p=4966130&highlight=coils#post4966130
using this technique i was able to return to service some of the shotgun-replaced coils i had pulled the FIRST time i had misfires (and, much to the chagrin of my wife, kept in a box in the garage).
hth
ken
Hey guys,
So I replaced the front three coils and plugs a few days ago and the skipping stopped. Also, yesterday I replaced them for cylinder 1, 3 and 5 in the back. Car runs great now! It drives like new. Luckily, the vacuum lines didn't seem to be very brittle and moved out of the way so I could replace coil #5. I used the OEM NGK platinum plugs gapped to .375, and Bosch coils from Rock Auto. Thanks everyone.
So I replaced the front three coils and plugs a few days ago and the skipping stopped. Also, yesterday I replaced them for cylinder 1, 3 and 5 in the back. Car runs great now! It drives like new. Luckily, the vacuum lines didn't seem to be very brittle and moved out of the way so I could replace coil #5. I used the OEM NGK platinum plugs gapped to .375, and Bosch coils from Rock Auto. Thanks everyone.
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