Audi A4 Revised 3 Port Intake Manifold

Disclosure: This post may contain chapter links, significant when you click the links and make a purchase, we receive a commission.

Audi'due south 4.2L V8 40v engine was released in 2003 in the Audi S4. It is a quad cam, 90-degree V8 with 5 valves per cylinder, totaling twoscore valves. The block and heads are made of cast aluminum with a forged steel crank. The engine was used by Audi until 2010, although it had begun being phased out in favor of the iii.0L Supercharged V6 FSI engine as early equally 2008.

The 4.2 V8 won Ward's 10 All-time Engines ii years in a row, in 2004 and 2005. Despite the success of the engine, the large V8 footprint and associated poor gas mileage led to the engine being phased out in favor of a smaller, more fuel efficient V6 coupled with forced consecration.

Audi's that use the 4.2 V8

• 2003-2005 Audi B6 S4
• 2004-2008 Audi B7 S4
• 2002-2005 Audi C5 A6
• 2004-2006 Audi C6 A6
• 2002-2010 Audi D3 A8
• 2003-2010 Volkswagen Phaeton

Audi 4.two V8 40v vs. 32v FSI

In 2005 Audi built a revised, 32-valve version of the 4.2L V8. While the 32v was built off of the 40v platform, it received numerous upgrades including a new crankshaft, rods and pistons, cylinder heads, oil cooler system, intake and exhaust system, and ECU. The 32v version was used in premium cars such as the R8, RS4, Q7, and A6 and A8 models from 2005 through 2011.

To confuse matters more, Audi produced a predecessor 40v V8 from 1999 until 2002. While all these engines are like in design they are very dissimilar engines.

The common problems we mention in this post are applicative to the 40v version of the iv.2 V8 that are fitted into the cars mentioned above.

Audi 4.2 V8 Engine Problems

• Timing Concatenation Failure
• Carbon Buildup
• VVT/Vanos Solenoid Failure
• Ignition Coil Failure
• Intake Manifold Linkage Arms

1. 4.2 V8 Timing Chain Failure

The timing chain connects the crankshaft and camshaft together and controls the opening and closing of the engines intake and frazzle valves. In improver to the concatenation itself, this system likewise uses guides to keep the concatenation in place and a hydraulic tensioner to go along slack out of the concatenation. The chain is protected inside a timing concatenation cover that bolts up to the block to protect it from road dirt and to lubricate it with oil.

The 4.2 V8 timing chains fail for a number of reasons. Showtime off, the chains naturally stretch over time and need to exist replaced. While they mostly should last the life of the auto, exceptional oil changes and engine overheating can cause the chain to stretch more than apace than normal.

The concatenation guides are made of plastic. Because they are right upwardly nigh the block they are discipline to abiding vibration and high temperatures. This tin can cause the plastic guides to break. Additionally, the tensioners can neglect which causes slack in the chains which can atomic number 82 them to leap teeth.

Timing chains on the 4.2 V8 oft fail before the 100,000 mile marker and have failed as early every bit 50,000 miles.

4.2 V8 Timing Chain Failure Symptoms

• Cylinder misfires
• P1340, 17748 engine codes
• Rattling from the engine
• Limp mode

For more details, you can bank check out this guide on diagnosing timing chain failure. Timing chains don't unremarkably fail immediately. They usually start to stretch a minor amount and continue to stretch over time. All the same, guides and tensioners breaking can cause more imminent failure.

When the timing concatenation "fails" it ordinarily starts jumping teeth on the cam and crank gears. This throws off engine timing and will pb to a lot of misfires. If the chains jump likewise many teeth it can send the valves crashing into the pistons causing catastrophic internal engine damage.

Timing Concatenation Replacement Options

The Audi four.ii V8 gets a very bad rap for reliability considering of timing chain failure. While this is a very mutual problem, it's only part of the reason the engine has a bad reputation.

While most cars have their timing concatenation mounted on the forepart of the engine block, the Audi 4.2 V8 actually has it located on the back side of the engine. Therefore, to supercede the timing chain you accept to pull the whole engine, resulting in dozens of hours of labor.

Additionally, the parts themselves are not cheap, with a full timing concatenation repair kit costing over $four,000. In one case you lot tack on labor y'all are looking at an $eight,000+ replacement task.

To foreclose timing chain failure brand certain you change your oil ofttimes. We recommend doing it every 5,000 miles regardless of the factory oil change intervals.

2. four.ii V8 Carbon Buildup

The four.ii V8 is a direct-injected engine. Direct injection engines apply fuel injectors to spray fuel directly into the combustion sleeping accommodation. The culling to straight injection is port injection. With port injection the fuel is sprayed into the intake manifold and then travels through the intake manifold and valves into the combustion chamber.

When you lot employ port injection, the fuel traveling through the manifold and valves helps clean them from congenital up gunk. However, when you utilise straight injection, the fuel is sprayed directly into the combustion chamber so no highly pressurized gasoline is passing through the manifold and valves to aid clean them out.

The issue is the valves and intake manifold getting coated in gunk, chosen carbon buildup. These left over carbon deposits will slowly clog up the intake system and valves. This restricts air catamenia and can lead to various operation issues.

Carbon Buildup Symptoms

• Cylinder misfires
• Rough idling
• Poor overall performance
• Sluggish acceleration
• Hard starts
• Worse gas mileage

Removing Carbon Buildup

Carbon buildup happens over fourth dimension. These symptoms a lot of times aren't noticeable (except misfires and crude idling) since the performance tends to deteriorate slowly over time. While carbon buildup isn't going to cause whatsoever serious engine problems we still recommend cleaning the valves and intake ports every 80,000-100,00 miles.

By the fourth dimension you lot hit this mileage in that location volition exist a adept corporeality of buildup on the valves and ports. Cleaning them will definitely bring the car back to life a scrap from a performance perspective and get rid of any sluggish operation.

The best route for removing carbon buildup is through a process called walnut blasting. Walnut blasting uses a shop vac to blow a agglomeration of small walnut shells through the valves and intake ports to clean abroad all of the buildup.

Preventing Carbon Buildup – Audi 4.2 V8

While at that place is no way to completely remove carbon buildup, yous can prevent some buildup and slow down how apace information technology accumulates.

• Modify your oil and filter every v,000 miles
• Install an oil catch can
• Utilize ethanol fuel injector cleaner
• Use 93 octane fuel or higher only
• Drive on the highway at high rpm's for 20-xxx minutes from time to time

3. 4.2 V8 Variable Valve Timing Failure

Audi's V8 engines use variable valve timing technology, commonly referred to as VVT or Vanos. The organisation variable alters the position of the camshaft, assuasive for more precise intake and exhaust valve timing.

The arrangement uses a VVT Solenoid which is actuated via oil pressures to command the camshaft timing. These solenoids frequently get clogged or gunked upward which tin crusade them to fail and atomic number 82 to performance and timing related engine problems.

VVT Solenoid Failure Symptoms

• Rough idling
• Loss of depression range ability
• Frequent misfires
• Decreased gas mileage
• Cold kickoff issues
• Engine goes into limp way during dispatch

Solenoid Replacement Options

Replacement VVT Solenoid

While you can simply pull your solenoids and make clean them, this is usually a bandaid fix. Solenoids will typically go bad every seventy,000-eighty,000 miles and volition need to be changed for optimal performance. Yous can drive on bad solenoids for a period of time but the solenoids volition eventually become too gunked up and result in very decreased driveability.

4. Ignition Coil Failure – Audi four.2L

For spark plugs to burn down and create combustion, they need electricity. The electricity they get comes from ignition coils. Ignition coils mount onto the height of the spark plug and connect to the cars battery system. The ignition coils transfer the electrical current from the battery to the spark plugs, allowing the plugs to fire and create combustion.

Because the ignition coils sit within the cylinder of the iv.2 V8, they are field of study to a lot of heat. Heat and electric components do non usually go well together. The oestrus from the engine wears the coils down over time and causes them to fail. This is mutual for pretty much whatsoever engine that uses ignition coils.

Coils tend to fail every 50,000-seventy,000 miles. If you lot are tuned or running bolt-on modifications, and so they usually neglect a bit more frequently. Unfortunately, there really is no style to prevent failure. Fortunately, they do not tend to neglect all at once but rather fail individually. Therefore, when they do fail you tin replace them one at a time instead of having to purchase a brand new set every fourth dimension.

Ignition Gyre Failure Symptoms

• Cylinder misfires
• Check engine lite
• Decreased power
• Difficult starts
• Rough idling
• Lack of acceleration

Ignition Whorl Replacement

DIY replacement is pretty easy on the iv.2 V8. The ignition coils themselves are pretty cheap, although that adds up when you lot demand to supersede all 8 of them. A lot of people prefer to supercede all of them at the same time to ensure that the car is performing at optimal levels.

These parts wear down naturally over time so running a scattering of make new coils with a handful of former coils can potentially create some noticeable performance issues. For less than $250 you can get all 8 ignition coils AND spark plugs so we by and large recommend replacing them all together.

Audi 4.two V8 Ignition Coil Replacements

five. iv.2 V8 Intake Manifold Linkage Arm Failure

The 4.2L V8 has a variable intake manifold. While a traditional manifold just distributes air through 1 passageway to the cylinders, a variable manifold has 2 passages. There is a long passage and a brusque passage and an actuator that controls a flap that delivers air to either one of the passages.

The flap is held on by ii manifold linkage arms. These linkage artillery were manufactured out of plastic from the factory. They are very poorly manufactured and therefore snap and break very easily. When the linkage arms break, the actuator flap no longer functions properly which leads to various operation problems.

Linkage Arm Failure Symptoms

• Misfires
• Sluggish functioning
• Hesitation during acceleration
• Worse fuel economic system

Linkage Arm Replacement Options

Do not replace the linkage arms with OEM artillery. Commencement of all, the dealership will only sell you lot a "full" kit instead of only the linkage arms which is $400+. When the arms intermission you can simply buy replacement arms and bandy them out without having to change the actuator and everything else.

Upgrade to metal linkage arms, such every bit the Gruven Linkage Arms, which are manufactured from steel and will never break.

Audi 4.two V8 Reliability

Audi's four.2L V8 gets a bad reputation for reliability primarily considering of the commonality of timing chain failure as well equally the toll to supervene upon the timing chain components. While these timing chains are a serious business concern, nearly of the problems associated with them tin can be mitigated by always using the proper oil, making sure oil levels don't get too low, and changing the oil every 5,000 miles instead of at the recommended interval levels.

Outside of the timing chain problems, the 4.2 V8 doesn't many issues that can atomic number 82 to catastrophic engine failure. Virtually of the other common problems are less expensive general maintenance items that can be taken care of easily and cheaply. Nonetheless, one other noteworthy problem that isn't engine related is transmission failure. The transmissions that go along with the four.2L V8 usually start to become problematic around the 120,000 mile mark.

A lot of the S4's and other Audi's with the 4.2L V8 are pretty inexpensive nowadays. Don't think you are getting a banging deal on a V8 Audi unless you can afford and are willing to pay for timing chain replacement. While it might exist less of a concern on a depression-mileage and very well maintained Audi, the chances of the timing chain declining are higher and higher equally the mileage on these engines goes up.

Overall, the iv.2L V8 is an expensive machine to maintain. I wouldn't expect much more than 120k miles out of one earlier you have to start breaking out big dollars on repairs.

DOWNLOAD HERE

Audi A4 Revised 3 Port Intake Manifold

Posted by: figueroasilleal.blogspot.com

Share this post