2002vw jetta codeEPC misfire cylinders 2&3itwont start afterrunning fine for ays after replacing head gasket

Sounds like head gasket again, but may be more serious this time. Overheating is not something to take lightly.

Pull plugs. crank. Water come out of cylinders? Head gasket. Possible cracked block or head this time, too. I'd be looking at a replacement engine.

The codes mean the cylinders are not producing power, which could also be fuel injector problems, or something else.

Is it wet with gas or does it smell like coolant? If it's the latter you might need to replace the head gasket. If it's gas, did you also change the ignition coil pack?

Remove the spark plug of cylinder No. 3 and inspect it for any water or coolant traces on it. If water droplets are found, the gasket is at fault and need replacement. If not, the gasket is fine and does not need any replacement. It is recommended to check the valve clearance before entering into major repair.

REMOVAL & INSTALLATION

1C-LTC and 2CL-TC Engines
(see Figures 1 and 2)

1. Disconnect the negative battery cable. Remove and label all electrical wiring, connectors and vacuum hoses necessary to gain removal clearance.

Fig. 1: Loosen and remove the cylinder head cover retaining nuts

1. Disconnect the PCV hose.
2. Remove the six nuts and seal washers from the cylinder head cover. Loosen them in a crisscross pattern.
3. Remove the cylinder head cover and the cover gasket from the cylinder head. Discard the gasket and replace with a new one.
   

To install:

1. With a wire brush or gasket scraper, remove all the old gasket material from the cylinder head and the cylinder head cover gasket surfaces.
2. When the cylinder head surfaces are free and clean, apply beads of sealant to the cylinder head in the locations shown in the accompanying illustration.

Fig. 2: Be sure to apply sealant on the cylinder head prior to cover installation

1. Install the new gasket in the cover. Make sure that the gasket seats evenly.
2. Place the cover with the gasket onto the cylinder head.
3. Install the six nuts and seal washers. Tighten the nuts to 65 inch lbs. (8 Nm).
4. Connect the PCV hose. Connect all removed vacuum hoses, connectors and electrical wiring. Connect the negative battery cable.
5. Start the engine and inspect for oil leaks. Repair any leaks as necessary.

Hope this help (remember comment and rated this).

Misfire is a common driveability problem that may or may not be easy to diagnose, depending on the cause. A misfiring cylinder in a four-cylinder engine is, pardon the pun, hard to miss. The loss of 25% of the engine's power output is the equivalent of a horse trying to run on three legs. The engine may shake so badly at idle that it causes vibrations that can be felt in the steering wheel and throughout the vehicle. The engine also may be hard to start and may even stall at idle, depending on the accessory load (air conditioning, headlights and electric rear defroster, for example).

When misfire occurs, performance suffers along with fuel economy, emissions and idle quality. And, when a misfiring vehicle is subjected to an emissions test, it will usually fail because of the unusually high levels of hydrocarbons (HC) in the exhaust.

What causes a cylinder to misfire? Basically, it's one of three things: loss of spark; the air/fuel mixture is too far out of balance to ignite; or loss of compression. Loss of spark includes anything that prevents coil voltage from jumping the electrode gap at the end of the spark plug. Causes include worn, fouled or damaged spark plugs, bad spark plug wires or even a cracked distributor cap. A weak coil or excessive rotor gas inside a distributor would affect all cylinders, not just a single cylinder.

"Lean misfire" can occur when the air/fuel mixture is too lean (not enough gasoline in the mixture) to burn. This can be caused by a dirty, clogged or inoperative fuel injector; air leaks; or low fuel pressure because of a weak pump, restricted filter or leaky pressure regulator. Low fuel pressure would affect all cylinders rather than an individual cylinder, as would most air leaks. A leaky EGR valve can also have the same effect as an air leak.

Loss of compression means the cylinder loses most of its air/fuel mixture before it can be ignited. The most likely causes here are a leaky (burned) exhaust valve or a blown head gasket. If two adjacent cylinders are misfiring, it's likely the head gasket between them has failed. Also, if an engine is overheating or losing coolant, it's likely the head gasket is the culprit.

Intermittent misfires are the worst kind to diagnose because the misfire comes and goes depending on engine load or operating conditions. They seem to occur for no apparent reason. The engine may only misfire and run rough when cold but then smooth out as it warms up. Or, it may start and idle fine but then misfire or hesitate when it comes under load. Also, it may run fine most of the time but suddenly misfire or cut out for no apparent reason. Intermittent misfires can be a real challenge to diagnose, so let's start with a steady misfire in one cylinder before moving on to intermittent misfires.

Hope this help.

-It could be low compression due to blow head gasket, Burn valve. Bad injector (s). Low fuel presure


Good luck


Mai

When the coolant hose broke,did the engine overheat?If so,it seems through your description that the head gasket has blown.The most common cause of water/coolant in the cylinder is a blown head gasket.It will need to be replaced.Take the vehicle to your mechanic and explain to them what happened .This helps them to fix the problem, knowing what may need to be done and what to look for.Hope this helps.

Sound like an air / vacuum leak to me.
Re-check for an air leak on #2 cylinder inlet manifold.
Use a propane torch (unlit, of course) to flood propane gas around inlet manifold/head flange & gasket area.
If there is any change in idle speed during this test you have a vacuum leak.

The block sealer you used may have been too thick or too big. A leaking head gasket or cracked head is a rare cause for a cylinder misfire. Tryin putting a manufacture gasket back on and change the spark plugs. If that doesnt work, try checking your valves or pistons-- maybe you have worn valve guides or your cylinder wall is worn out.