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I bought my first Audi, -07 A6 avant quattro 3.2 fsi. Of course the upper chain skipped almost immediately. The car has done about 180 000km at the moment. After skipping tooth the engine still started, but ran poorly.
I read this thread throughout a couple of times plus some other threads before starting the repair. After gathering information I felt pretty confident with my average mechanic skills and bought the special tool set and a new pair of upper tensioners.
First I stripped down the old tensioners and put the engine back in time. I used the crankshaft locking pin to lock crankshaft in place and locked both camshafts on both sides with the locking tools from the special tool set. After getting the engine back on time I assembled it with new tensioners. I pre tensioned the chain lightly before tightening the camshaft adjusters. Then it was time to manually rotate the engine, I wanted to do 7 full rotations before trying to start it.
Well, at first time I got 1/2 rotations and the chain skipped. Then I did everything again from the start and I got about the same 1/2 rotations before chain skipped again. After getting pretty frustrated I read about getting oil to the tensioners piston. I depressed the check valve and compressed the piston fully and let it back to extend. Then I plugged the hole in the back of the tensioner and poured clean oil in to it (almost full). I put piston back in the housing and slowly compressed it and put the retaining pin back in place and took the plug out. I repeated this to the other tensioner also. When compressing the new piston with pressing the check valve, I noticed that it was totally dry and did not have any oil in it. Could this be the cause of all this failure? Should there be some "factory oil" in it?
After getting oil in the pistons I re assembled the engine with still pre tensioning the camshaft adjusters. I took locking pin out and unlocked the camshafts. Now it was time to rotate the engine again. I got almost 4 full rotations before drivers side chain skipped and jammed the motor. Again I stripped down the tensioners and re-compressed them with new oil. Re assembled everything and got 3 full rotations before drivers side skipped again.
At the moment I am in dead end and I don't know what I am doing wrong. Could my piston sealings be bad of all this recompressing? And why wasn't there any factory oil in the pistons to start with? If I buy new pair of tensioners, should I suck some new oil in them before installing?
Thank you for your replies,
Mika
you are doing well to keep doing it correctly even though it must really be annoying by now! I haven't actually done this job, and hope never to have to. But I definitely think you are on to something about 'pre-filling' the oil. keeping the tensioner extended so it can't jump time is the key! I do not know if there is a way to drive the oil pump without cranking the engine, but that would certainly help.
to digress slightly, when i used to build Ford V8s, I would always leave the distributor out and just before firing up a new build/overhaul i would spin the oil pump with a 5/16 drive until I had pumped at least a liter out of the pan. that way everything was pressurised when i hit the starter.
Last edited by FL C6.5 Avant; 08-01-2016 at 02:17 PM.
Reason: forgot something
Referring to my previous post I am going to buy a new pair of tensioners. I don't know what I possibly could be doing wrong so only option is to buy new parts. Maybe they were bad to start with, or I damaged them somehow.
Could someone who has done this repair succesfully point out a reliable seller with quality parts in Europe? Pm me if it is not allowed to advertise in public. I think these parts might be fairly expensive straight from the dealer.
When installing new tensioners have you pre filled the pistons with oil or do you just install them and after that take the locking pin out?
Referring to my previous post I am going to buy a new pair of tensioners. I don't know what I possibly could be doing wrong so only option is to buy new parts. Maybe they were bad to start with, or I damaged them somehow.
Could someone who has done this repair succesfully point out a reliable seller with quality parts in Europe? Pm me if it is not allowed to advertise in public. I think these parts might be fairly expensive straight from the dealer.
When installing new tensioners have you pre filled the pistons with oil or do you just install them and after that take the locking pin out?
Have you made progress & solved your timing/reassembly issue? Are you back "on the road" again?
Did pre-filling the tensioners work?
Let us know...I'm sure, we all hope so...
I have a new pair of tensioners now ready for install. I am just thinking maybe I should buy new bolts for the camshaft adjusters too. It takes couple days to get them from the dealer. I will attemp the repair with new oem tensioners in a week or two. First I will try without pre-filling and if they fail again when manually turning the engine - I will try with pre-filling. If they fail again, I might have to change more parts as chain etc..
Keep us informed of your progress....I think I'll be changing my drivers side upper tensioner in October. It's numbers are creeping up. It's gone from 7.1 to 7.9 over the last 10k miles. However, I have no rattle on start ups (yet).
Keep us informed of your progress....I think I'll be changing my drivers side upper tensioner in October. It's numbers are creeping up. It's gone from 7.1 to 7.9 over the last 10k miles. However, I have no rattle on start ups (yet).
Sorry noob on this topic. What are those 7.x numbers and how do you get them?!
Those are the "vcds" engine control module "measuring block 93" readings on my bank 2 (drivers side) camshaft variances, in degrees. There is an 8 degree service limit on the camshaft timing chain drive. Excessive variance will lead to engine failure. That occurs when the variance gets up over about 12 degrees or more. Actually, the yensioners aren't the typical cause for the increasing variance. The chain guides are what go, but you have to repace the upper tensioners to fix that.
I have a new pair of tensioners now ready for install. I am just thinking maybe I should buy new bolts for the camshaft adjusters too. It takes couple days to get them from the dealer. I will attemp the repair with new oem tensioners in a week or two. First I will try without pre-filling and if they fail again when manually turning the engine - I will try with pre-filling. If they fail again, I might have to change more parts as chain etc..
my suggestion would be to get as much oil as you can into the tensioner BEFORE pulling the grenade pin. that way, when the piston extends, it sucks some oil into the chamber with it. it won't be much, but maybe enuf?
if you try to do it after pulling the pin then you will have already had to force the piston back with no lube.....
Hi Guys,
Just replaced the upper driver's side tensioner after getting the cam position error codes and a horrid rattling noise.
Upon opening up both sides, the driver's side exhaust cam was misaligned by 20-30 degrees prior. Looks like skipped teeth on the cam gears. The passenger's side was all good - perfect alignment. I reassembled everything with good timing - both cams locked - and I have no compression in the 2 of the 3 drivers side cylinders. The passenger's side cylinders all have good compression.
Looks like the driver's valve are bent. Can someone point me to a DIY valve replacement thread?
I'd like to tackle the job myself. Can someone offer how long this will take and the tools I'm going to need?
09-07-2016, 03:03 PM
