When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My 04 has 106,000 and had no record through the dealer of the timing belt being replaced. However I was looking and pretty sure these marks aren't factory... Can anyone advise thanks
They weren't on my 2000 Audi A6 4.2 either. Suggestion if you have it--put the cam lock bar on there and see if all the marks line up to some obvious reference points. If you don't have a bar, line up those holes on the plate underneath the cam bolts on both sides. Align it in one continuous straight line from one cam to the other. The bigger holes go toward the inside and the smaller toward the outside. You have to have #1 cylinder at TDC (firing) so may have to turn crank 360 degrees before it all lines up right. For this purpose of just evaluating those marks, that should retrace what they relate to.
A guess is either someone did the job total belt and suspenders and those marks were some double checks, OR that they maybe dynamited it... without the tools. How would I know that? Well, back in my younger days I did the 2.8 A6 that sort of way. But cam gears used to use cotter keys unlike on the 4.2's, so you really need the bar (and the crank lock bolt) to dial it in. But as Mister Bally says, look for the belt markings; without something like that you an't be sure that someone wasn't in there only to do the thermostat or water pump or some such without changing the timing belt.
Well I checked the timing belt itself and there's no marks or brands on the tops side of the belt which I thought for sure there would be but all the timing components are Audi oem and so is water pump. I also rotated cams so little holes were on the outside and big holes on inside lined up straight across from each other and I found more marks on cam bolts and sprockets. The orange marks I'm still not sure about... What do you think?
The paint across the cam bolts, the oblong plate and the toothed gear are factory I think, plus they look disturbed.
It's a judgment call, but my instinct if you can't see any markings on the belt is it has been on there a good amount of time. The rust in the whole area could be abrading markings more quickly though. Also, look at the pulley that is run off the tensioner--just to left and above the main crank pulley area in the picture furthest below. BTW if you don't know it has that allen head opening punched into it where when the time comes you would release the belt tension sticking an allen socket in there and slowly compressing the tensioner it acts on until you get the holding pin in. Anyway, notice all the rust around the inside of that specific lever arm pulley wheel. Very consistent with the well worn look of much else nearby--the crank main serp. pulley, the stud sticking out to the right, etc. In particular that does not really look like a part changed in the past several years where you would expect it to have been done in a thorough/complete belt job. I also see what may be a little nick on the front edge of the belt at about 11:00 on that same pulley; can't be sure in the pic but also look for any other evidence of wear like that may be.
You can snoop around more for decent signs of newer parts, but it isn't obvious to me in the pics.The one I point out tends to cut the other (no prior change) way. Could have been a prior thermostat change, water pump change, or a main or cam seal that forced a belt pull and replace but not overall job.
BTW, did serp belt show any signs of either being recent (markings still visible) or older--little cracks if you flex the belt for the grooved side curved sharply outwards. A 100K vs. 25K miles type belt delta you would have here might be discernible when I've seen/removed both parts of that spectrum of wear.
I saw the same marks on a 2005 A8L doing the timing belt on it for the first time. Digging through the records turned up a thermostat change at 55,000, which would have required removing the timing belt. Maybe yours had something similar.
From those pictures I would say that engine was not working for a long time.
Besides that, it is example how timing belt job should not be done. Paint marks and ripped belt are there because somebody used improper procedure to remove and install the belt. It is hard to say if the belt was replaced, but most certainly it was removed and it was done poorly. Good example for what even experienced mechanic can do to your A8 if he cuts corners or doesn't know better.
04-30-2015, 05:58 PM
Timing belt marks on cams and crank pulley
