Saturday, June 1, 2013

3.0L Dodge Chrysler Plymouth Engine Removing Front Cylinder Head

  My Caravan had been idling roughly for a long time and dying sometimes, especially when hot. It was happening more often and it was time to fix it. With the engine idling, one by one I pulled off the spark plug wires. Only #2 did not effect the engine idle.I listened to the fuel injectors with a long screwdriver and all  were clicking away nicely. Compression tests on each cylinder revealed that #2 had only 45lbs of pressure. The others were at least 146 lbs. This indicates valve trouble, a head gasket or a cracked head. The front head was going to have to come off. First of all, lets take a look a look at the rockers, valve spring assemblies and camshaft.
  1) Remove air filter assembly
  2) Disconnect breather hose from valve cover and remove the valve cover (2 bolts of different lengths).
     Examination of these components can now be done. Everything was in order, so the head would have to come off.
  3) In order to remove the camshaft sprocket the timing belt will have to be removed.

The 3.0 liter engine

                                          Removing Timing Belt


1) Disconnect the negative lead of the battery.
2) Drain the coolant from the engine.
3) Jack up the front end, put on jack stands and remove the passenger side right tire.
4) Remove the wheel well splash guard to allow easier access to the belts and covers that need removal.
5) Remove the radiator side upper timing belt cover. (3 bolts, the lower bolt holds wiring in place).
6) Position the engine at top dead center for cylinder 1. Manually move the crankshaft clockwise by turning the crankshaft bolt with a socket on a breaker bar. The open wheel well provides good access for this. Top dead center for cylinder 1 is at the point where the timing mark on the front camshaft sprocket will align with a mark, now visible, on the inner timing belt cover. Also confirm that the distributor rotor points to spark plug #1. Turn over the cap to check this, as the external positions of the plug wires are skewed from the electrical contacts inside. A third alignment point is the “0” degree mark on the timing plate above the crankshaft pulley. It will align with a notch mark on the pulley.
7) Remove the air conditioning belt by loosening the pulley bolt and turning the tension nut above it counterclockwise.
8) Remove the serpentine belt. Put a 15mm socket on the tensioner and pull it forward, holding it there until the belt can be removed.
9) To do this job the engine mounts have to be unbolted and removed. Support the oil pan with a floor jack. Put a piece of wood between the jack and the pan. It’s not a bad idea to put some planks under the engine for additional support.
10) Unbolt the front engine mount by removing the long bolt and then the under bolt. Then remove the mount bracket from above the passenger side wheel well.
11) Remove the idler pulley.
12) Remove the big black engine mount plate. Keep track of where each of the 5 bolts go as they vary in length.
13) Remove the air conditioning idler pulley assembly. (3 long bolts).
14) Remove the air conditioning compressor mounting torx bolts and 13mm nuts and move the compressor out of the way and support it with a hanger. It isn’t possible to get it very far out of the way.
15) Remove the air conditioning mount bracket. It’s held on by three 15mm bolts and the middle one is exceptionally hard to take out and even harder to refasten.
16) Loosen and move the power steering pump out of the way by loosening the nut behind it.  This is necessary to remove the rear engine support bracket.
17) Remove the rear engine support bracket. This is held on by five bolts. The two small ones under the power steering pulley are the most difficult to remove.
18) Remove the firewall side upper timing belt cover. (two 10mm bolts).
19) Remove the crankshaft pulley and damper. Go ahead and try. It is super hard to remove. What I do is slip the lower timing belt cover over it. This lower (and largest) timing belt cover is mounted with three different length bolts. Keep track of the positions. Pull it carefully over the pulley. It is likely to crack a bit. Touch up the crack with some silicone sealant on reassembly.
20) Confirm all timing positions and loosen the timing belt tensioner bolt. Completely remove the spring from the timing belt tensioner.  Then the belt will come off easily.
21) Remove the timing belt. Inspect it for wear. This would be an excellent time to replace it if old or worn.

                                           Front Cylinder Head Removal

1) With the valve cover already off, remove throttle cable bracket. I took the cables off also, but this may be unnecessary.
2) Move the Idle speed control motor wiring and the Throttle Position Sensor wiring out of the way.
3) Remove the air intake plenum.
4) Relieve fuel pressure by applying 12V and ground to either connection on any fuel injector  and activating for short bursts.
5) Discconnect fuel rail gas lines using quick disconnects near the left wheel well. Disconnect injector wiring harness.
6) Remove three fuel rail hold down bolts.
7) Remove fuel rail. A front to rear rocking motion did not help. I put a drop of oil around each injector seal and pried up on one injector at a time from right to left and front to back to get the stubborn things out. Make sure you vacuum and clean up this area as best you can.
8) Remove bracket for MAP sensor from the left rear corner of the intake manifold.
9) Remove intake manifold (8 bolts). Manifold comes off rather easily with with rocking motion.
10) Remove distributor cap with all wires attached.\
11) Make a mark on the bottom of the distributor bottom where the rotor points at TDC for #1 cylinder.
12)Unbolt the distributor. The only bolt is the one for the adjustment plate. Remove it.
13) Remove the camshaft sprocket. I inserted a bolt and nut through a hole in the sprocket and a slot in the upper timing belt cover. Tighten this greatly. Remove camshaft sprocket bolt. It is torqued to 70 ft lbs.
14) Unbolt the exhaust manifold from the front crossover pipe. Do not unbolt from the cylinder head at this time.
15) Unbolt the cylinder head along with the exhaust manifold
16) Remove distributor adapter (3 bolts).
17) Remove heat shield and exhaust manifold.
18) Remove rocker arms and shafts as an assembly, being careful not to lose hydraulic lash adjusters. Replace adjusters if they are don't move freely. Cylinder 2 turned out to have a burned valve. I wonder if the stuck adjuster on that valve may have led to the damage. I had a machine shop repair the head.
19) Reassemble in reverse order, being careful to correctly torque all bolts.

3 comments:

  1. This is an astounding post I seen because of offer it. It is truly what I needed to see trust in future you will proceed in sharing such a great post. Tractor Sleeve

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  2. Really,this is amazing information admin :) i really appreciate your efforts Bunch oh thanks Edelbrock 4.0 jeep cylinder head

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  3. one thing I have read is to loosen aluminum cylinder head bolts 1/4 turn all in sequence as if in tightening them . Possible warp damage if not done , so ,,,

    ReplyDelete