Eric5412

I have a 2006 4.2 approaching 95K and I'm starting to get concerned about the timing chains, tensioners, and guides.

I've read that you can get a good idea what's going on inside be checking measuring blocks 91, 92, 93. I just don't completely understand how to interpret the values.

I'm getting -8 and -4 for measuring block 93. From what I understand there is a tolerance of +/-6. What I don't understand, is that a DIFFERENCE between the banks or a limit for EACH bank ? For example, I have a difference of 4 which would be within spec but one bank is -8 degrees off.

LarryJa

In vcds, there are 4 readings in measuring block93. The sum of the intake & exhaust reading for bank 1 or bank 2 are the full "deviation" for that bank. The acceptable tolerance for each bank is 8 degrees.
As an example, my bank 1 is about 3 degrees total, from idle, up to 3000rpm. Meanwhile, my bank 2 runs 6-7.5 degrees.
My C6 3.2 has 160,000 miles on it, & I'll be changing the bank 2 upper timing chain tensioner in October, to bring it back down.

raaaudi

I'm sorry if reviving this old thread is the wrong protocol but I have exactly the same concern as the original poster. In my case, the VCDS output does not seem to match the other examples that I have seen. Any help/advice would be much appreciated. Thanks!

2005 A6 4.2, 120,000 miles





By the way, I've benefited tremendously from this forum but haven't added anything because I didn't feel that I had much to add other than 'thanks--I tried this and it worked'. (Yes, I realize that could be useful, but I strive to be a person of few words. Maybe I can change.)

09mazda6

raaudi - I'm in the same boat as you - I have an 11 A6 avant with 3.0tfsi and 6 sp Automatic transmission - on start up in block 93 I only get the first two measurements you show as well and both mine are below 3 so I'm a little at a loss to determine if I have an issue. Now I need to check some other blocks to see if the other measurements are on another block with my engine vs the 3.2 that LarryJa has.

das60

Is there an accepted standard for measuring Block 93 values in terms of engine temp and rpm? I have been doing them at warm idle for the past 50k miles at each oil change.

Bank 1 usually sums to -1.1kw with a variation of 0.4kw and no trend, yesterday it was -0.4kw (a big jump)
Bank 2 usually sums to 3.7kw with about the same variation and no trend, yesterday it was 4.1kw

Typically each time a change registers, it goes back to the old value at the next oil change

Usually the exhausts are at near 0kw and any deviation from zero is on the intake side.

I had a disturbing touch of what I assumed what chain rattle about 1,000 miles ago on cold start after sitting a day or two. In my passenger headlight ordeal I noticed an oil leak on the passenger side exhaust VVT Solenoid and immediately replaced the o-rings. Timing chain noice is gone except just after Thanksgiving when the car sat for a week in the garage. The oil is always Castrol 0w-40 from Wally world. The car, of late, has no major oil leaks and for the last 3 changes I have gotten out 6.5 of 6.5 liters per my oil extractor. Yesterday I got out 6.7 which I attribute to the VVT leaking.

Relevant history is the entire timing chain system was re-done under warranty by Audi at under 10k miles (engine out). The cars sits at 183k miles now.

I am about to have to let the engine sit for another week, should I be worried about anything?

My sense is it is in fairly good shape.

A6Gary

If the sum of the intake and exhaust values for each bank are essentially the same value over time, and less than -8 degrees, then I wouldn't worry about the upper chain tensioners. Also. since you stated that the entire chain assemblies, i.e., chains, guides, and tensioners, were replaced, then chain drive system should be good for the life of the engine. On my '06 A6 Avant with 108K miles, the Block 93 values had remained the same since I started checking them over many years. Re: the Castrol 0W-40 oil - does that oil meet the std VW 502 000 or VW 505 000? If not, you should use only oil meeting the VW standard. Additionally, you didn't state the oil service (oil, filter) mileage interval you're using for you A6. The correct oil and the interval between oil service has a huge effect on the camshaft chain drive system (as well as the other moving engine parts).

das60

Sorry, I use the Castrol Euro Spec from Walmart as it is cheap, brewed in Belgium and meets VW 502/505. The car has always be on a on a 5,000 mile OCI. Filters are generally Mahle.

I use an extractor. This cycle I lost 0.2l which I attribute to the o-ring at the solenoid. So far, it has leaked oil at all the common locations but I have no evidence it burns oil.