Removal and Replacement

Removal:

Right Side of Engine:

Left Side of Engine:

1 Drain coolant of left or right crankcase.

CAUTION: The side crankshaft bearing cap bolts (arrows) must not be confused with the coolant drain plugs.

2 Remove fuel injection lines.
3 Unscrew brackets of injection nozzles.





4 Remove intake manifold.





5 Set engine to ignition TDC.





6 Mark relevant camshaft sprocket with sealing varnish together with timing chain (arrow).

NOTE: The timing chain is secured against rotating on the crankshaft sprocket once the oil sump is installed.





7 Loosen necked-down bolt of the camshaft sprocket while holding the camshaft with an open end wrench (arrow).





8 Remove camshaft sprocket.

Lefthand Cylinder Head (Steps 9-11 only apply for removal of left hand cylinder head.)
9 Unscrew power steering pump and set aside with piping connected.
10 Remove ignition distributor (only engine 116).





11 Remove inner sliding rail from lefthand cylinder head. To do so, pull out bearing pins by means of the impact puller.
First remove the camshaft sprocket, then the sliding rail.

Righthand Cylinder Head (Steps 12-14 only apply for removal of right hand cylinder head.)





12 Remove alternator with bracket.
13 Remove chain tensioner.
14 Remove inner sliding rail.

Righthand and/or Lefthand Cylinder Head(s) (The following steps apply for removal of either cylinder head.)
15 Unscrew exhaust manifold from exhaust pipe and cylinder head and remove. To do so, loosen engine mount (and engine shock absorber of engine 117.96) and raise slightly.

Tightening Diagram:

a = Bolts M 8

16 Unscrew cylinder head bolts in reverse order of tightening diagram.

Loosen the bolts M 8 (a) with screwdriver insert 116589030700.

NOTE: The following tools are required to loosen and tighten the cylinder head bolts:





Allen wrench 8 x 52 mm long





Screwdriver insert 116 589 00 13 00






17 To remove the righthand cylinder head, push the tension rail with the timing chain towards the center of the engine so that the tension rail is not in the way.
18 Lift out cylinder heads.


Installation:





NOTE: On ET (spare part) cylinder heads without air injection, the 4 holes for the air injection to the exhaust valves (arrow) must be closed by means of tapered aluminum plugs.

19 Insert aluminum tapered plug, Part no. 116 997 01 05 (7 mm dia.) with Loctite AVX 86 into the holes in the cylinder head.





Tapered aluminum plugs
Angle 0 ° 34'
A 6.90 mm
B 7.33 mm

20 Clean intake manifold sealing surface. To do so, cover the cylinder.
21 Clean mating surfaces of cylinder head and crankcase.

CAUTION! The light alloy crankcase mating surfaces must be treated very carefully to avoid scratches and score marks.

Clean threaded holes for the cylinder head bolts in the crankcase with compressed air.





11 Righthand cylinder head gasket
34 Lefthand cylinder head gasket

22 Fit new cylinder head gaskets by placing them over the two dowel sleeves on each cylinder bank.





CAUTION: The cylinder head bolt M 10 x 165 (arrow) at the rear camshaft bearing must be inserted prior to fitting the cylinder heads.
The respective exhaust manifold is only installed after the tightening of the cylinder head bolts has been completed.

23 Install cylinder heads.
Before installing the cylinder head bolts, the thread and the contact area of the cylinder head bolts and the washers must be coated with oil.

CAUTION: The cylinder head bolts M 10 x 165, M 10 x 90 and M 10 x 65 are 10 mm longer than those of the cast-iron engine 116.98 and 117.98.





24 Tighten cylinder head bolts in the sequence of the tightening diagram as follows:
- 1st stage with 30 Nm.
- 2nd stage with 60 Nm.
- 3rd stage after 10 minutes settling break with cold engine individually loosen cylinder head bolts slightly and retorque with 60 Nm.
25 Further installation takes place in the sequence vice versa to removal.