# Buying advice Audi S4 4.2L V8 B6 / B7 Problems and Common Errors - Warning Timing chain !!



## S4fanq (Dec 28, 2012)

*1. - Warning for Timing Chains on these engines (common problem).*

Otherwise a durable engine design that is spirited, strong and revving, has good throttle response and strong torque of the entire registry on both low and high revs using variable intake cam (VVT / VANOS) and variable length of the intake ducts in the intake manifold via a vacuum-controlled flap and advanced motor control.


*2. - Engine oil ** NOTE - Absolutely critical to run these engines with a good fully synthetic 10W-40 oil and not 0W- or 5W- oil, otherwise there is a large risk of engine failure due Low pressure in timing chain tensioners and abnormal wear at hte entire timing chain construction !!!*
And change the oil frequently with 10W oil every 10000-15000 km interval depending on driving style.

If you still run 0W- or 5W- the oil must be changed every 5000 km interval, since after 4000 km it is thin like "water" and low oil pressurer will fail to keep the timing chains fully stretched in certain situations with a high risk of a total engine breakdown as a result.
If the vehicle is serviced in accordance with VAG service intervals of VAG recommended oil you can expect abnormal wear ...

When the oil is to thin the engine can not handle to build up the oil pressure quickly enough and keep timing chains tense in certain situations, for example at rapid speed changes or sudden jolt at the "unsuccessful" downshifts and chain "Rap" over one teeth of the sprocket with a total engine failure as a result.
It is often preceded by a guide rail in composite shattered by the timing chain as too "slack" due wear on the entire construction and then becomes even more "slack" and chain "rap / teeth to the end of a tooth."

*Handles the car with especially frequent oil changes will keep the car in good condition and there is then no reason at all to be more worried about this engine design than other engines, it will be very durable ....*


** Note that the chain tensioner to the right bank (Bank 1) Art.Nr: 079 109 218 D sits at the end of the lubricating oilchain and has therefore an builtin oil pressure "accumulator" to "store" pressure and compensate for interim oil pressure situations, it seems like this construction at low oil pressure rather aggravate the problem instead of helping because it delays the reaction even further when the "accumulator" is empty and must be completed first before the chain tensioner can begin to tension the chain again.

Run the engine with low oil pressure increases the risk of engine failure many times...

It's usually in the right bank (passenger side), Bank 1 Wrecking with broken valves, cylinder heads and pistons total failure.

What happens is that the entire structure with timing chains wear down abnormally, especially guide rails and guide rails, and the middle chain (the longest) will be more and more "slack"and in combination with insufficient chain tension (lack of oil pressure) will lead to chain "punches" around and will end up with broken guide rail detail no. "24"or 
no. "25" (see path below) on the middle chain.
This means that the upper chains will be exposed to significantly more "stress/shock" than normal and in combination with less successful timing chain tensioner at Bank 1 leads to the right upper chain to the bank 1 "rap over one or more teth on the sprocket" and a extensive engine failure is a fact, may sometimes preceded by the guide rail also no. "36" (see path below) be broken before the accident or if it occurs at the wreckage, difficult to determine afterwards?

Note that with good oil pressure there is no risk or very little risk that this will happend, and with 10W oil the entire timing chain structure will be much better lubricated by far, and will last for a very long time without problems.

http://www.oemepc.com/audi/part_sin...ar/2003/drive_standart/249/hg_ug/109/subcateg

ory/109052/part_id/260910/lang/e#sec_25

(See the picture at the bottom Timing Chain tensioner (Bank 1): 079 109 218 D



*Buying Advice - Check the Timing Chains carefully before purchase - do this:*[/B]

1. - Function control of Timing chain and VVT / VANOS (Note. A short chain rattle and ticking for abaout Max 1/2 second is fully normal behavior when startup the engine, especially when engine is cold.
Make sure to start when the engine is cold, open the hood and listen to the engine's rear edge, it is completely normal to hear timing chain rattle an ticking from the oil pressure-controlled variable intake cam shafts (VVT / "VANOS") for about 1/4 to 1 second maximum.
Note however that the maximum 1 second !!, if it rattles longer time than 1 second, you shoud think twice, there is a chance to switch to a thicker 10W-40 oil and try again, if the problem persists after the oil change is all worn and everything needs to be replaced, walk away from there ....

Very expensive repair that requires the engine to be lifted out then the timing chains mounted in the rear of the engine and basically everything must be replaced, expect $5000 and upwards for labor and parts and special tools required ......
You must change the Timing chains, Chain tensioners, sliding rails and guide rails (composite).

http: ... //sv.realoem.me/Audi/RDW/A4Q/2005/454/R/1/109


*** Note, if suddenly constant rattling from the engine or the engine light is on, stop the car right away. !! ***


Does the car have the following error code and that the car lost power, engine light comes on (limp mode), drive the car to the nearest workshop.

17748 - Camshaft Position Sensor (G40) / Engine Speed ​​Sensor (G28)
P1340 - 002 - Incor. correlation


A good advice is to buy a car where the owner changed the oil frequently (max 5000-10000 km) between "service interval" and on good oil, or a car where everything is replaced and can be substantiated with receipts and example images (documented).
Otherwise, this engine really good and advanced engine design with low weight, high torque and lovely throttle response, popular motor at car projets when it is light and strong.

Give this car proper maintenance and if the engine do not have abnormal symptoms with chain rattle and noise it will last a long time and there is no reason to be more worried about this engine more than other engine designs.

Same thing with eg 5.2L V10 that has similar construction.



2. - Variable Intake - The vacuum-controlled flap in the intake manifold to switch the length of the intake channel, it enables high peak power while good low-end torque is maintained. - Often Sheaves

There is a vacuum bell in the front edge of the intake manifold with an arm attached to the flap, check the flap moves in speed of 4200 rpm, if not, try to press the arm (the metal arm that sits in the intake manifold, not the plastic arm of the vacuum clock) and see if it moves, if not you need to dismantled the intake manifold and lubricate the shaft proper.
If it moves when you press on it, but not move at the speed of 4200 rpm something else is wrong, the solenoid valve panels vacuum problems?



3. - Dowel pin - Warning the plastic dowel pin may lie in the intake ducts on top of the intake valves and eventually can cause engine failure.

There is a small conical "pointing stick" in plastic that is located under the intake manifold on the engine block to facilitate assembly of intake, the problem is that it has an M6 thread in plastic and very easy tp break without noticing it in the assembly of intake and then falls down and gets into the intake channel of either 1st cylinder or 8 cylinder (or both), it is there and "rattle" until it is so worn that it fits between the valve and the valve seat and the total engine failure is a fact.

It is not needed when there are also two dowel pins of steel.
Recommend to check this by loosening the intake and they remain on the intake manifold - Remove them!

Even 3.2L V6, have this fitted (not FSI)

This cone of plastic called "dowel pin" with Art.Nr 078103251
(See the picture at the bottom)



4.- Intake valve tubings "carbonisation" / back of soot and oil deposits (Note: does not apply to BBK, only newer FSI engines)
Keywords on Google - "Audi 4.2L FSI Intake Sludge" or "Cox"

FSI direct injection engine wherein fuel is injected directly into the combustion chamber under high pressure (about 100 bar) similar a diesel engine, on a standard injection engine fuel is injected into the intake above the valves and intake manifold and valves then purified continuously by the fuel that is injected and keep clean.

FSI engines have problems with the emergence of slag formation of soot deposits and "sludge / cox" in the intake ducts above the intake valves, sometimes so much that they lose power and go bad and need to be cleaned, the inlet must be dismantled and mechanical term process removes all deposits (there are threads about it), larger engines (V8, V10) seem to have more problems than the smaller engines but is only one opinion for what is written on the web?

In FSI engines, it is especially important that only drive motor on the synthetic oil only and the best quality. 

Otherwise you risk suction clogged with soot and oil deposits, among others.



5. - The oil pressure controlled variable intake camshafts "VVT" (Variable Valve Timing ") (" VANOS ")

They can be worn and they are very expensive, there is a locking pin with a spring that locks the position of intake camshaft when they are not controlled / variable controlled via the electrical solenoids, sometimes becomes the seat or hole where the pin will go into worn out, resulting in that it is not stuck without releases and locks on each other and then "ticking" and it sounds bad all the time idle.
These "Vanos" is expensive but you can buy just the sprocket alone (with the seat that worns)
"JHM (JHMotorsports.com)" Camshaft Adjuster Unit ".

Have not so far not seen any worn during disassembly, inspection and commissioning tests of function with compressed air (Must be done if you take them apart).
JHM has a good video on youtube showing how to make and also describes and illustrates the problem of the worn seat
locking pin, search for - "JHM B6 B7 S4 Mechanical Adjuster Repair Kit".

Is a good thread on Audizine.com that describes and illustrates the problems with photos, search - "B6 / B7 Timing Chain FAQ"



6. - Dual mass flywheel - They often go down, feel for abnormal vibrations in the car following the motor.
Recommend to mount single mass flywheels instead - Note that this will provide more vibration especially when accelerating.
Can also be a little rattle from the gearbox that disappears when you depress the clutch. = Comfort deterioration
(See picture on the single mass flywheel at the bottom)



7. - Multi belt (V belt) and idler at the front edge on the engine requires loosening the front a bit from the car to able to access, well if it is changed.



8. - The ignition coils can break, is not expensive but the engine runs poorly - Error codes show which cylinder is not working = Simple troubleshooting






Engine oil:

VAG standard for motor oil for gasoline engines 503.00, 503.01 for turbocharged petrol engines 506.00 for diesel engines.


1. Why do car manufactures recommend so thin motor oil?

Answer: Because they then protect against engine damage if customers start and drive the car hard direct at the severe cold, cold engine and engine oil, motor oil with higher viscosity (thicker), the hard driving directly when the engine is very cold could cause engine failure in severe cold due that the oil does not reach all lubrication points in small 
channels, the worst affected are con rod bearings (connecting rods to the crankshaft bearings), such a thin oil 5W means that the base oil is very thin and it is additives in the oil that makes it thicker when the oil is hot (30W), the problem is that the additives wear out after approximately 3000-5000 km because it takes a lot of additives to obtain a thin oil become thick as the range or "distance" of the base oil viscosity and 30W are much larger when compared to a 10W-40 oil (low viscosity of the base oil).
After 4000-5000 km is a 0W- or 5W- oil as thin as water constantly and the oil film then is so thin that it fails to lubricates timing chains, guide rails, slide rails enough and abnormal wear and often with engine damage as a result.

Another big reason is that with thin oil becomes less friction in the engine (easier), and draw slightly less fuel and then get something better exhaust values ​​(environmental classification and emission values).



2. Why do car manufacturers such long service intervals with so-called "Long Life Oil"?

Answer: Car manufactures want to get the car approved in a higher environmental class = selling point, most people who have knowledge of motors do not drive the car further than 10000 - 15000 km between oil changes if you also still run on light oil (as they recommend) you should never run more than the maximum of 5000 km and it lubricates still not enough, but is almost as "Water" when you drop out of it.
It is also about how the car is driven, long driving (commuting) keeps the oil longer, shorter distances, change frequently, hard driving, change frequently.
I recommend running on a good fully synthetic 10W-40 oil, for example, "Q8 SBK Racing 10W-40" and possibly run thinner oil only the coldest period of the year (minus degrees below -5), then run 10W-40 the rest of the year, but is absolutely not necessary if running easy or normal during the warm up.


3. Why you should never change the oil in the automatic transmission called "Lifetime oil"?
Answer: The same reason, to get the car approved in a higher environmental class, you should ideally change the oil after about 30000 km, or at least after 50000 mkm, especially the heavier stronger luxury cars or else wear the tranny out prematurely.





Description Oil film:

The main reason for most of the problems due to the recommended oil only manage to lubricate the engine's vital parts well enough that are pressurized with oil pressure (full film lubrication) with hydrostatic or hydrodynamic lubrication which means that the oil keeps moving parts separated from each other and it is the engine oil lubricating film which is really the "bearing".

The problem is that the oil is too thin viscosity (how "thick" or "viscous" oil is) is that the parts that are not pressurized but lubricated with "splash lubrication" such as Ktiming chains, slide rails, guide rails and similar structures where oil film building up because oil is sprinkled on the parts and is dependent on the so-called Boundary lubrication not lubricated enough good because the lubricating film is too thin / weak and under load from the gears, chains etc. fails to maintain lubricating film without "breaks through" the lubricating film and friction occurs when the metal makes contact against the metal with abnormally high wear as a consequence.

The "red thread" is short for excessive wear and if all motorists used the good synthetic motor oil with higher viscosity of the base oil 10W- instead 0W- or 5W- and shorter service intervals we would avoid many of the known problems with engine damage and damage to the engine and not have to be affected by the expensive engine repairs to 
damaged timing chains constructs with the drive and tensioner etc.

** Note that this is a general problem in many cars where some models affected more than others depending on construction **


Make automakers 'wrong' ?, - We can have many opinions about this but there is big money involved and they protect their interests and are controlled by the game rules of competitive bidding. 

The solution must be that we car owners themselves first of all become aware of the problem (take a position on it) and completely simply replace the oil ourself between car manufacturers established "Service Intervals", or better yet change oil i after 4000 km with 10W-40 oil, and after that by 10000 km interval so we avoid expensive and unnecessary repairs.

Think that all car owners have the right to be informed about the problems and can themselves decide it, and hope this means that in all cases, some car owners to be able to avoid unnecessary problems and costs.


Search Google - "VAG 503.00" or "VAG 503.00"


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