View Full Version : Surging while accelerating

11-07-2012, 05:53 PM
Just recently purchased what I thought was a solid car for my son,but it has been anything but that after about 1000 miles of driving. Shortly after the purchase check engine light came on for an 02 sensor, fixed that, then air bag light came on right after and got a vag con to reset it, found out it was a faulty connection under passenger seat. Then put four brand new tires on her with allignment,wasnt cheap. After that put new tie rods in the front end since the boot on the passengers side looked ripped. Then the heater core was shot, spent a hell of a lot of time doing that since this was the first Audi I have worked on. Got the heater core in and realized that the car was running real rich when we went to change the plugs, turned out the coolant temp sensor was faulty causing it to run this way. Then I decided to put in a new t stat and the one I purchased was faulty and this car began to overheat. At this point with help from this forum I checked the water pump and it had no broken fins and seemed to be solid. So I then decided to just put in a new one and everything is right where it should be. I thought my problems were solved untill today when I was on the free way. As I accelerated to pass I felt the car surging and shuddering slightly while I would accelerate. As I continued to drive stepping on the pedal it seemed to do it more and more. This has the tiptronic trans but was recently serviced at audi dealership couple thousand miles before I bought the car, they changed the fluid. When it surges it makes a slight thud noise and it seems like it is coming from the rear end and not the trans. Could a bad cv axle cause this? What is a good way to check all of the cv axles? Visually the boots are not riped. What about the rear differential ? Drive shaft? U joints? The car shifts nice when I drive it like a pussy and it and goes through all the gears smoothly. Any suggestions on where I should start to diagnose this next issue? This is a 2000 1.8t Quattro with 116k. Beautiful car but afraid it could bankrupt me!

11-07-2012, 10:46 PM
Stock turbo? If so, the stock turbo is way too small to result in surging while you're accelerating. I can't comment on the transmission, mounts, or suspension, but I can tell you that your turbo isn't surging unless the inlet pipe totally collapses.

Avant Nate
11-08-2012, 07:16 AM
I almost bought an Audi with a very similar problem. Upon little acceleration it felt normal. But if you gave it a little more it would thud, thud , thud. The more gas, the stonger the thud. I was told it needed a new center driveshaft, but from my research you can fix it with thishttp://www.034motorsport.com/chassis-components-audi-a4s4a6s6-driveshaft-support-b5-audi-chassis-p-13696.html

ECS Tuning-Audi
11-08-2012, 11:09 AM
When its doing this "surging" as you say is the check engine light coming on or flashing at all?

If so this could be a misfire, when coil packs go back they can cause misfires that will really cause the car to fall on its face.

Even if it doesn't throw the check engine light a misfire code should pop up in vag-com. I'd rescan and see what's going on.


11-08-2012, 11:35 AM
the check engine light came on shortly after I noticed the shudder. it almost feels like someone lightly stomping on the floorboard. The only code I can pull with my cheap made in china vag com was a P0113 which is Intake Air Temp Sensor High. I just cleaned my MAF sensor the day before. I don't think this is the issue though. I did back up on some ramps and inspect sway bar links, cv axles and everything looks real good except there is some oil build up around where the rear passenger side cv axle enters the rear dif. I am going to check the fluid level and possibly be changing out the axle even though there are no tears in the boot and no excess play in the axle, at least that I can see or feel. I did just change and gap all plugs when I cleaned the maf sensor. No codes for a miss fire so the coil packs should be ok, right? The driveshaft support could be what I need, but how can i tell if the drive shaft is failing?

ECS Tuning-Audi
11-08-2012, 11:42 AM
I highly doubt its drive train related. Seams more like a misfire - you mentioned you changed the gap on the plugs, what did u gap them at?

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11-08-2012, 09:02 PM
I gaped at .32 since what i know about the vehicle is that it is stock. I used the copper ngk bkr6e's. I think thats what they are. I did a lot of research on the plugs and gaping. Do you think the gap is to big? The only aftermarket add ons are the borola exhaust and the spectre air filter intake kit as far as I know. The check engine light did not come on while the car started the shuddering, but came on while driving at normal speeds and stayed on till i just cleared it. I wish I could make it 30 miles without the check engine light coming on and giving me a new code. That is eight different codes within a couple weeks, I new these cars take a little work but wow, I must have bought a lemon. I have to much into this to turn back now, so I appreciate all the help. Any way that the P0113 could cause this?

11-08-2012, 10:13 PM
Lol high intake air temp makes sense with your aftermarket filter. Put the OEM air box back on. If you have no other codes, then I'd look closely at the suspension and transmission.

11-08-2012, 10:18 PM
wish i had stock air box, but bought it this way.

11-08-2012, 10:23 PM
No worries. I'm sure that you can find one floating around...

Look closer at your suspension and transmission.

ECS Tuning-Audi
11-09-2012, 07:15 AM
Any way that the P0113 could cause this?

Here's some more info on the P0113 code.

Click HERE (http://www.obd-codes.com/p0113)

Gap seams about normal but I would stay away from copper plugs - they are inexpensive but at the rate they need replacing its almost better to spend a little more on a Platinum or Iridium plug since copper plugs life span is very short.

I would also go ahead and list all the codes you are getting so we can see if there's anything really obvious.