A defective cylinder head gasket is identified by one or more of the following symptoms.
- Power loss.
- Decreased coolant level. White exhaust gases when the engine is warm.
- Engine oil leaks.
- Coolant getting into engine oil. The engine oil level does not decrease, but rises. Gray engine oil, foam on the dipstick, thin oil.
- Engine oil in coolant.
- The coolant boils a lot.
- Low compression in two adjacent cylinders.
Removing
Attention: If the cylinder head is to be replaced, remove the plastic valve protectors just before installing the cylinder head. In addition, all coolant must be replaced.
The cylinder head gasket must be taken out of the package just before installation and must be handled with great care. Damage to the gasket will result in leaks. О With the ignition off, disconnect the negative cable from the battery.
Attention: This will erase the data from the electronic memory blocks. See instructions in chapter «electrical equipment».
Drain coolant.
Ford Fiesta/Mazda 121: loosen the intake pipe clamps on the air filter and intake manifold, remove the intake pipe.
Ford KA: remove the air filter.
Unhook the rope (cravings) drive «gas» from the throttle body and from the support, set it aside. О Remove the spark plug plugs, while pulling on the plugs, not on the high voltage wires. To eliminate errors during installation, you need to mark the high-voltage wires of the candles.
Pull the hose from the radiator to the thermostat housing (top of the cylinder head), for which loosen the clamp and slide it along the hose.
Pull the heater hose off the connector (tee) For coolant, to do this, squeeze the quick coupling by hand.
Pull or disconnect the electrical wires going to the engine. Cut the wire fastening tapes, having previously marked the wires:
- two plugs «engine» (1);
- plug connection for lambda probe (located in the exhaust manifold);
- connectors for the coolant temperature sensor, camshaft position sensor and oil pressure warning light switch on the cylinder block.
Pull off the vacuum hose (2) for the brake booster.
Remove vacuum hose (3) for activated carbon filter system. If necessary, cut the clips with clips, and during installation they must be replaced with screw clips.
Remove the engine oil filler cap. Remove the engine crankcase ventilation hoses from the neck. Put the cover back on.
Unscrew the oil dipstick from the cylinder head.
Pull the fuel supply and return hoses off the fuel distributor by compressing the quick coupling by hand. To ensure installation, mark fuel lines before removal.
Warning: The fuel system is under pressure! Before loosening the hose connections, cover them with a thick cloth - this will safely relieve pressure. Wear protective goggles when working.
Ford Fiesta/Mazda 121: remove the heat shield and catalyst from the exhaust manifold.
Ford KA: remove the wire guide on the bulkhead of the engine compartment at the cylinder head.
Attach the hoist chain or cable to the right side of the engine. If necessary, make lifting eyes and screw them into the corresponding threaded holes in the cylinder block. Attach the chains to the eyelets.
Raise the engine so that the right support (fastening) engine unloaded.
Loosen nuts and remove right engine mount.
Loosen four screws (1), remove washers. Remove valve cover. (2 - oil filler cap).
Loosen four screws (2) and remove the axle with rocker arms.
Remove the valve lifters (1).
Attention: The push rods must be placed in their original positions during installation. For this reason, the booms must be marked with adhesive tape or laid out so that they cannot be mixed up later.
Unscrew the cylinder head bolts in the reverse order shown in the figure, i.e. from number 10 to number 1, in turn by half a turn, and after the second pass, unscrew them.
Caution: Cylinder head bolts can only be reused once. Bolts that have already been used once must be marked, for example, with a center punch.
Check if all wires and hoses leading to the head are disconnected.
Raise your head (together with an assistant) and install it on two wooden bars.
Remove the cylinder head gasket.
Installation
Before installation, the head and cylinder block must be carefully cleaned with a suitable scraper from the remnants of the old gasket. Make sure that dirt does not get into the bores of the cylinder block. It is better to close the holes with rags.
Be careful not to create long scratches. If sandpaper is used, then its grain size should be of the order of 100 units. Carefully remove abrasive and grinding powder residues.
Check that the cylinder head bolt holes are free of oil and, if necessary, remove the oil. To do this, insert a clean rag into the hole and wipe off the oil.
Caution: Remaining oil in the bores can damage the cylinder block when tightening the bolts.
Check the deformation of the head with a steel ruler and flat feelers in several places. The deformation along the entire length should not exceed 0.25 mm.
The plane of the cylinder head must not be regrinded.
The cylinder block must have two guide bushings for centering the block head. Position the new cylinder head gasket without sealant so that none of the holes are blocked. The gasket must be handled very carefully. The smallest damage can lead to leaks. A new gasket should only be taken out of the packaging immediately before installation.
Install the head together with an assistant, without warping it.
Insert ten head bolts and tighten by hand.
Attention: These bolts can only be reused once. If it is not known how many times they have been unscrewed and twisted, then it is better to replace the bolts.
Attention: The tightening of the cylinder head bolts must be carried out very carefully. Before tightening, check the torque wrench for accuracy. The bolts must be tightened on a cold engine.
The block head bolts must be tightened in three steps. At each step, the bolts are tightened in the order shown.
- Stage 1: torque 30 Nm.
- Stage 2: Tighten all the bolts with a regular wrench by 90° (at once).
- Stage 3: Tighten all the bolts with a regular wrench by 90° (at once).
When tightening the block head bolts, you need to control the tightening angle with the wrench handle, turning the wrench a quarter turn at a time (90°).
Attention: Do not tighten the head bolts on a warm engine as part of maintenance or after repair.
Tighten new engine mount nuts to 70 Nm. О Remove the lifting device and engine lifting eyes.
Lubricate the pusher rods at both ends with engine oil and insert them into the pushrod stops.
Attention: Be sure to install the push rods in the same position as they were before removal.
Position the rocker shaft so that the adjusting bolts fit into the tappet stops. After that, first tighten the axle bolts by hand and then evenly tighten them to a torque of 45 Nm.
Adjust valve clearance.
Replace dented or damaged valve cover gasket. Install the valve cover and evenly tighten the bolts of its fastening with a small torque (6 Nm).
Screw the oil dipstick into the cylinder head.
Bolt the wire guide to the bulkhead of the engine compartment.
Connect all electrical wires to the engine. Fasten the wires with clamps (ribbons) at previously marked locations.
Put the high-voltage wires on the spark plugs in accordance with the marks made earlier and fix them in the holder on the valve cover.
Put on the vacuum hoses and, if necessary, secure them with clamps.
Push the fuel supply and return hoses onto the fuel distributor and secure them.
Attention: Do not confuse the fuel lines, pay attention to the labels.
Put on the hoses for the coolant going to the engine and to the heater, secure them with clamps.
Attach the crankcase ventilation hoses to the oil filler cap.
Ford KA: install the exhaust manifold with new gaskets and tighten the fastening nuts crosswise to a torque of 25 Nm.
Ford Fiesta/Mazda 121: Install the catalytic converter and heat shield on the exhaust manifold.
Attach cable «gas» to the throttle body and support and adjust it.
Attach the air inlet hose to the air filter and to the inlet pipe, secure it with clamps.
Check the engine oil level and top up if necessary.
Attention: If the head of the block was removed due to damage to the head gasket, it is recommended to change the oil and oil filter, as there may be coolant in the engine oil.
Top up with fresh coolant.
Start the engine and warm it up to operating temperature, which must be monitored by the coolant temperature gauge. Finally, you need to drive an additional 5 km to be sure that the engine oil has warmed up.
Check again the engine oil and coolant levels, as well as the tightness of the hose connections. О Connect the negative cable to the battery. Set clock and codes.