How To Replace The Head Gasket On A Volvo 850 (page 5)


(This tutorial is written, sponsored, and hosted by TracysTrueSoaps. I make quality, pure, gentle soaps that are also great at removing grime after working on a vehicle. Please support my site by checking out my soaps. People of all ages LOVE 'em [especially ladies] and they make great gifts for almost any occasion. Thanks so much!)


Ignition Components, Cam Position Sensor, Engine Mounts Removal / Replacement




DISASSEMBLY - Disconnect the coil wire from the coil (left fenderwell) by grasping the entire upper portion of the boot and pulling firmly.
REASSEMBLY - Reconnect the coil wire to the coil, pushing firmly down until it seats.






DISASSEMBLY - Remove the spark plug wire leads from the plugs by grasping the entire upper portion of the boots and pulling firmly. Pull them out of the way, but keep these bundled together and leave them connected to the distributor cap for now.
REASSEMBLY - Replace the spark plug wire leads to the spark plugs, pushing firmly down until they seat on the plugs.






DISASSEMBLY - Remove the three screws and remove the distributor cap (leaving the wires still attached).
REASSEMBLY - Replace the distributor cap (FCP Groton Part #3501944), making sure it is in the correct position (that it was when removed). Also be sure to wiggle/manipulate it right in order to center the dust cap underneath into the proper position (as the distributor cap is all that holds it in place) and allow the distributor cap to engage the housing at all three anchor points.






DISASSEMBLY - If you want to install a new distributor cap, the first thing you should do is label the plug wires in some way before removing them. I numbered mine with dots of white-out before removing them. If your cap is like mine, you will have a black sleeve covering your cap that has numbering on it reflecting the cylinder numbers (a "3" can be seen near the "Bosch" on the top side of the cap in the picture above this one). It has all five numbers on it for all five cylinders (1 being the cylinder farthest from the cap and 5 the cylinder closest.) After making sure the wires are labeled for reassembly, disconnect them by grasping and pulling firmly. Once the plug wires are removed, the black sleeve (if you have one) can be removed from the old cap and placed on the new cap.
REASSEMBLY - Inspect your plug wires for any damage, cracks, or burnt spots. Resistance (if you want to check it) "should be between 1.5 and 4.5 ohms, depending on the length of the lead" (taken from the factory manual). Replace the plug wires on the cap in the positions they were originally in (using the info above if needed).






DISASSEMBLY - Remove the distributor dust cover. It should almost fall off, as it is held in position by the distributor cap that was just removed.
REASSEMBLY - Replace the distributor dust cover and hold it in place until the distributor cap is replaced over it.






DISASSEMBLY - Remove the distributor arm (rotor) by removing the three small bolts (3mm Allen) that secure it to the companion flange.
REASSEMBLY - Replace the distributor arm (FCP Groton Part #1367783) on the companion flange.






DISASSEMBLY - Remove the companion flange (10mm), noting how the depression around the bolt hole (yellow arrow) is positioned around 4 o'clock, and how the protrusions on the back of the flange line up in the slot on the camshaft.
REASSEMBLY - Replace the companion flange in the position described above.






DISASSEMBLY - Remove the two bolts (T40) that secure the cam position sensor and remove the sensor. It is a very snug fit and will require even pressure to remove (or replace) it. Be careful not to damage it.
REASSEMBLY - Replace the cam position sensor.






DISASSEMBLY - Remove the cam position sensor wiring anchor from the engine bracket by squeezing the tabs together and pulling it out of the hole its anchored in.
REASSEMBLY - Replace the cam position sensor wiring anchor to the engine bracket.






DISASSEMBLY - Press the locking wire in and disconnect the cam position sensor wiring. Put the sensor somewhere it will not get damaged.
REASSEMBLY - Press the locking wire in and reconnect the cam position sensor wiring






DISASSEMBLY - Remove the bolt (10mm) that secures the aperture in the cam position sensor housing, noting how the cutaway portion of the wall of the aperture runs from 8 o'clock to 2 o'clock, and how the protrusions on the back of the flange line up in the slot on the camshaft.
REASSEMBLY - Replace the aperture in the position described above.






DISASSEMBLY - Remove the upper engine steady bar from the engine bracket (15mm nut in red circle - 13mm bolt on other end), swing the bracket out of the way, and secure it (I used cable ties).
REASSEMBLY - Reattach the upper engine steady bar to the engine bracket and torque to 26 ft/lb.






DISASSEMBLY - Remove the supporting rod from the engine bracket (13mm) and the head (10mm).
REASSEMBLY - Reattach the supporting rod to the engine bracket (torque to 18 ft/lb) and the head (torque to 88 in/lb).






DISASSEMBLY - Remove the engine bracket lower bolts (red circles - 14mm). Disconnect the crank position sensor wiring connector (yellow circle) and the cam position sensor wiring (above the yellow circle) and remove the wiring from the wiring bracket so it can be removed with the engine bracket.

REASSEMBLY - Replace the engine bracket lower bolts and the wiring bracket and torque to 33 ft/lb. Reconnect the crank position sensor wiring connector (yellow circle) and cam position sensor wiring (above the yellow circle).





DISASSEMBLY - Disconnect the water pipe from the rear of the head (near the water pump - 10mm).
REASSEMBLY - This was (or should have) been done after replacing the head (when it was easier to get to).






DISASSEMBLY - Disconnect the wiring connector for the engine coolant temperature sensor (this is underneath the power steering fluid reservoir), so that the thermostat housing can be removed with the head (the easiest way).
REASSEMBLY - After reinstalling the head (with the thermostat housing attached), reconnect the wiring connector for the engine coolant temperature sensor.






DISASSEMBLY - Remove the spark plugs (5/8" deep well spark plug socket). The engine should be cold when you do this and you should remove them with gentle pressure, not a quick snap.

REASSEMBLY - Gap the spark plugs to 0.028" (with a wire gauge, not a "ramp" gauge). Mine were not pre-gapped out of the box (FCP Groton Part #4228). Apply an adequate coating of anti-seize to the threads of the spark plugs. Replace the spark plugs and torque to 18 ft/lb.





When you start reassembling the components on this page, start at the bottom of this page and work your way to the top in reverse order, using the "Reassembly" instructions.


1 2 3 4 Page 6 - Cylinder Head Removal 7 8 9 10



If this info has been helpful, please consider making a donation.
Even a dollar or so would be greatly appreciated, thanks!


(This tutorial is written, sponsored, and hosted by TracysTrueSoaps. I make quality, pure, gentle soaps that are also great at removing grime after working on a vehicle. Please support my site by checking out my soaps. People of all ages LOVE 'em [especially ladies] and they make great gifts for almost any occasion. Thanks so much!)