Checking the head gasket oil seals

Checking the head gasket oil seals
With the engine running, check for an oil leak at the cylinder-head gasket. This is a sign that the rocker shaft or camshaft oil-supply passage is leaking where it passes through the head gasket.
Oil may leak from the head gasket if the head nuts or bolts are loose, or if the head gasket, cylinder-head face or block face is faulty (See How to remove a cylinder head).
Oil-filter or pump adaptor
Tightening the pump adaptor bolts may cure a slight leak from the mounting flange.
Tightening the pump adaptor bolts may cure a slight leak from the mounting flange.
Depending on the position of the oil-filter or oil-pump adaptor on the engine, you may need to raise one end of the car on ramps and get underneath to see clearly. Apply the handbrake and chock the other wheels.Checking the head gasket oil seals .
With the engine running, a serious oil leak is clearly visible, streaming from the oil-filter seal or pump-adaptor housing on the side of the engine, which is where the oil is under more pressure than anywhere else in the system.
If the leak is serious, stop the engine immediately to prevent damage, and replace the gasket (See Replacing gaskets and oil seals). A slight seepage can sometimes be cured by checking the tightness of the filter or pump-adaptor fixings.
However, the best way of curing a leak is to remove the component and replace the gasket or seal.
The distributor flange
Tightening up a camshaft-mounted distributor and a crankcase-mounted distributor.
Tightening up a camshaft-mounted distributor and a crankcase-mounted distributor.
With the engine running, check carefully for leaks around the distributor mounting flange where it is attached to the crankcase or camshaft cover.Checking the head gasket oil seals .
On some engines there is a thin gasket between the mounting faces; on others there is an ‘0-ring rubber seal fitted over the distributor housing between the mounting faces.
Replacing the gasket or seal is the only cure for an oil leak there. You need to remove the distributor to do this (See Removing and refitting the distributor).
Fuel-pump mounting gasket
Fuel-pump gaskets are fitted only to mechanical fuel pumps that are mounted on the engine.mechanical seal.
Locate the pump, and with the engine running check for oil drips coming from the underside of its mounting flange or gasket.
On many engines there is a thick spacer plate sandwiched between two thin paper gaskets. valve seal.This thick plate may crack if the pump mounting nuts or bolts have been overtightened.
Check first that the pump mounting nuts or bolts are not loose, but take care not to overtighten them as this will distort the mounting flange and make the leak worse. If the leak persists, check the underside of the mounting and gasket with a mirror, looking for the exact source of the leak. Replace the gasket if necessary smeared with a non-setting sealant. Make sure that the pump flange face and the mounting face are both clean before fitting a new gasket.Checking the head gasket oil seals .
Note that the thick spacer plate (if fitted) also governs the distance the fuel-pump lever travels. If you fit a new plate, it must be the same thickness as the old one. Compare the new with the old before fitting, and use parts approved by the car manufacturer.Checking the head gasket oil seals .