How To Replace The Head Gasket On A Volvo 850


(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!)


Intro, Miscellaneous & Fuel Rail Removal / Replacement




This is a tutorial on how to replace the head gasket (and the other components involved in the process) on a Volvo 850. The vehicle depicted is a non-turbo 1996 Volvo 850. On a turbo, there may be some things a little different. But this should still be of use to you and help you in performing this repair (or in deciding whether you want to do it yourself). The symptoms our car had that told me it was definitely a head gasket included: a small amount of coolant in the oil, loss of coolant in the reservoir with no visible place it was dripping from, burping of exhaust gases into the coolant reservoir, sweet-smelling white smoke from the exhaust (especially during acceleration), and a history of having been overheated a few weeks prior.

I didn't know how experienced some people doing (or researching) this repair might be, so I tried to show everything in detail. If you're an experienced gearhead, please don't be offended by this. If you're a novice who's never done more than change the oil, don't be intimidated by the magnitude of this job. A person who pays attention to detail, keeps track of how and where things go, and has the patience, time, and tools to do it can save themselves a LOT of money by doing home auto repairs themselves. If doing "only" the head gasket, you don't "have to" do some of the things shown. But to me, pretty much everything shown was necessary (or convenient to make more working room or enable you to clean the component or something) to do this repair right. This tutorial can also be useful if you are doing just one component like the timing belt or PCV system, etc. Here are a couple of useful things to remember (for me at least) when doing any car repair (especially one you've never done before). Label anything you think you may forget the location of (and refer to these pictures or pictures you may take yourself if your car is different). Keep components grouped together that "go together" on the car (taping screws to a component, etc). As much as I can, I also put fasteners back into the component they belong in/on when disassembling (like taking out a bolt that holds a bracket, then putting just the bolt back into the hole after I remove the bracket).

NOTES - When you see a braided, white, kind-of-translucent hose in any of these pictures, ignore it - you don't have one. I installed that to bypass the heater core when my daughter's heater core was found to be leaking. That hose is located on the rear of the engine underneath the cam position sensor area. You will also see that most of the pictures are of clean parts and new gaskets. This is due to me taking better (and more patient) pictures as I was putting everything back together, compared to the ones I took while dismantling the dirty, old stuff. I cleaned everything I could before reassembling, but specific cleaning instructions will not be given for "every" component, only some of the main ones. Torques I could find are listed; I labeled some torques with an asterisk * if I could not find one and I had to guess at it by comparing to the torque of a similar fastener or component. When reassembling several of the components, I mention or show the application of some grease or lube. This is important because it helps to keep bare metal parts from operating without any lubrication when you first start the vehicle after this repair, and I just use moly grease (like for wheel bearings) that comes in a tub. If the reassembly process is very similar to the disassembly process, I just put the instructions for both beside the same picture to save time and space. When reconnecting any electrical connector (plug wires, sensors, etc.), putting a small dab of petroleum jelly (Vaseline will do) in the female part of the connection (with a cotton swab if it is deep like a plug wire) will aid in reconnecting it smoothly, in conduction, and in preventing corrosion (battery terminals are a great example of how that can develop).

Here's the answer to what everyone will wonder, "How long did it take you?" I spent about 50-60 hours on this entire job (and saved myself about $3,000 according to the dealer estimate). While doing this repair, I was working outdoors (95 degrees or more) under the shade of either the hood or the overhang of a second-story deck I pulled under the edge of. This meant all of my tools had to be taken out and put back up whenever I started to work on it or had to stop (or evacuate for imminent rain). I also spent a lot of time to clean everything thoroughly, to stop and take numerous pictures from different angles, lighting, etc. (I took over 500 pictures) and to run to get a tool or something I needed. That said, I think I could have done this in a little more than half the time if I would have had a better workplace with cooler conditions and had not been photographing.

The following list is "most" of the tools I used for this job (but you may run into the need for something else too):

- Jack and jackstands
- 4-way lug wrench
- 7-17mm sockets (long and short, and in varying drive sizes)
- Short and long extensions in varying drive sizes
- Drive adapters for various drive sizes (ie 1/4" to 3/8", 3/8" to 1/2")
- 1/4" drive torque wrench that will read in in/lb
- 3/8" drive torque wrench that will read in ft/lb
- 1/2" drive torque wrench that will read up to 133 ft/lb
- Combination hand wrenches from 7-17mm
- 3mm and 8mm Allen wrenches (hex keys)
- 30mm axle nut socket (1/2" drive)
- 1/2" drive breaker bar (mine was 18" long)
- Flat head screwdrivers (regular size and a small one)
- Phillips head screwdriver
- Crescent wrench
- T25, T30, T40, and T45 sockets
- Needle-nose pliers
- Channel-lock pliers
- C-clamps or strong rachet bar clamps (4)
- Spanner tool for holding cam pulleys (or fabricate an equivalent tool)
- Small drill bit (or steel pin) about 2mm in diameter
- A torque angle gauge (looks like a 1/2" drive extension with a dial face around it)
- Harmonic balancer puller (Loan-a-tool at AutoZone) if doing oil seals, water pump, etc.
- An extendable magnet tool (PRICELESS when you drop something somewhere hard-to-reach!)
- Short length of steel stock (welding section of Lowe's, 1/8" thick x 1.25" wide)





You will notice that every (new) gasket you see in this tutorial is copper-colored. I used this product, "Permatex Copper Spray-A-Gasket High Temp Sealant," on both sides of every gasket that I replaced while doing this job (except for the black, rubbery side of the exhaust manifold gaskets, the head side). I have read excellent reviews on car forums about this product and a similar one (K&W "Copper Coat"). It is supposed to seal dry gaskets and make them impervious to water, oil, etc so they will last longer. I was told it was a good idea to spray a good coat of it on my head gasket too (both sides).






DISASSEMBLY - Disconnect the negative terminal of the battery (10mm) and position it so that it cannot accidentally make contact.
REASSEMBLY - Reconnect the negative terminal of the battery and make sure the connection is clean and tight.






DISASSEMBLY - Remove the coolant reservoir cap, open the radiator drain valve, and open the engine block drain (next picture) to drain the coolant from the engine and radiator (13mm). The radiator drain valve is located on the left side of the radiator. In this picture, the front clip that goes underneath the radiator/fan area has been removed for clarity. Also go ahead and drain the engine oil at this point.
REASSEMBLY - Refill the engine with oil. Close the radiator drain valve and fill the reservoir with distilled water (to flush with). Wait a few minutes until you can add more to the reservoir, then repeat. Keep doing this until you don't see the level in the reservoir drop after 5 minutes. After running the car for a few minutes to circulate it, shut it off, let it cool a while, then refill with 1 gallon of pure coolant (to get the ratio right) and top it off with distilled water using the same fill procedure. Check the level (while cool, before starting) every time you use the car until the reservoir stays at the full mark (when you're sure you have it all the way refilled). Always buy a gallon of the full strength coolant and mix it with a $1 gallon of distilled water to have two gallons of 50/50 mix for much less than what two gallons of the "premixed" coolant costs. It held close to 2 gallons.






DISASSEMBLY - Here is the engine block drain (13mm). It is located on the timing belt end of the engine, back side, down low on the block, protruding toward the rear of the car. If finding or reaching it is difficult, it can be opened later on in the repair without affecting anything. Just make sure to open this and drain the block at some point in this repair (to get out ALL of the old coolant that may have oil in it).
REASSEMBLY - Make sure the engine block drain is closed.






DISASSEMBLY - Break loose (but don't remove yet) all five lug bolts (maybe 1/4 turn) with a breaker bar or 4-way lug wrench (19mm).
REASSEMBLY - Torque all five lug bolts to 81 ft/lb, tightening every other one until all five are properly torqued.






DISASSEMBLY - Jack the car up (with the jack on a substantial portion of the underbody) and place heavy-duty jackstands under heavy portions of the frame that will support the weight of the car, then let the car slowly down onto the jackstands. I always try to rock the car after I have the jackstands in place to make sure it is stable.
A word of caution - PROPER JACKSTAND USE ON A FIRM, LEVEL SURFACE IS IMPERATIVE. As a paramedic, I once responded to a scene where a young man was trying to remove some exhaust components from underneath a car. He had only a scissor jack holding it up and was on a dirt surface. When we got to him, he had been pinned under the car for hours and had died some time prior. Safety first.
REASSEMBLY - Jack the car up (with the jack on a substantial portion of the underbody) and carefully remove the jackstands, then let the car slowly down onto the ground/driveway.






DISASSEMBLY - Finish removing the five lug bolts, then remove the tire/wheel. Now remove the wheelwell apron nut circled in red, fold the apron up along the crease, and secure it out of the way (I secured it with a small spring clamp). The whole apron looked like a big job to try and remove, so this seemed the best option.
REASSEMBLY - Replace the wheelwell apron in the position it goes and secure it with the nut circled in red. Replace the tire/wheel (noting there is a pin and hole that have to be positioned right for it to fit) and hand-tighten the five lug bolts.






DISASSEMBLY - Disconnect the coolant reservoir hose from the thermostat housing (T25).
REASSEMBLY - Reconnect the coolant reservoir hose to the thermostat housing.






DISASSEMBLY - Lift the coolant reservoir out of the fenderwell bracket. Press the locking wire in and disconnect the coolant reservoir electrical connection.
REASSEMBLY - Press the locking wire in and reconnect the coolant reservoir electrical connection. Place the coolant reservoir back into the fenderwell bracket.






DISASSEMBLY - Disconnect the hose on the bottom of the reservoir at the point where it connects to the water pipe at the back of the engine (Flat-head screwdriver). This is down behind the passenger side of the timing belt cover. The coolant reservoir should now be completely free from everything.
REASSEMBLY - Reconnect the hose that comes out of the bottom of the reservoir where it connects to the water pipe at the back of the engine.






DISASSEMBLY - Disconnect the plastic tube leading from the radiator shroud to the computer box (the one with an accordion segment in it). It just snaps into place at both ends. Remove the top radiator hose from the radiator and the thermostat housing (Flat-head screwdriver). Remove the top of the thermostat housing (T40 - and a 10mm bolt on mine). Also remove the thermostat and gasket.

REASSEMBLY - Replace the thermostat and gasket (FCP Groton Part #271664 for both). Replace the thermostat housing. Replace the top radiator hose (FCP Groton Part #1335433) at the radiator and the thermostat housing. Reconnect the plastic tube leading from the radiator shroud to the computer box.







DISASSEMBLY - Remove the six bolts (T30), then remove the cover from the top of the engine.
REASSEMBLY - Replace the cover on top of the engine and reattach it with the six bolts.






DISASSEMBLY - Disconnect the top PCV hose from the top of the engine and leave it to the side. Mine came off with just a little rotation and pulling. This will stay where it is for now.
REASSEMBLY - Reconnect the top PCV hose to the top of the engine. Mine went back on with just a little rotation and pushing, with the original clamp still in place.






DISASSEMBLY - With the bottom channel as the pivot point (red arrow), tilt the fuel injector cover back toward the front of the car and remove from the channel.
REASSEMBLY - Insert the fuel injector cover back into its channel (red arrow), and tilt toward the rear of the car to secure it in place.






DISASSEMBLY - Press the locking wires in, disconnect the wiring from all 5 fuel injectors (yellow in picture), and pull it back out of the way.
REASSEMBLY - Press the locking wires in and reconnect the wiring to all 5 fuel injectors (yellow in picture).






DISASSEMBLY - Remove the fuel lines from beneath the fuel line bracket (10mm). This is located at the back side of the engine near the firewall and can be found by tracing the fuel lines leading from the fuel rail. I saw some instructions about removing a second fuel line bracket somewhere on top of the engine near the top of the timing belt cover, but mine only had the one in back. I kept up with the bracket and bolt by reinstalling them after removing the fuel lines from underneath.
REASSEMBLY - Reinstall the fuel lines under the fuel line bracket.






DISASSEMBLY - Disconnect the fuel line from the fuel rail (17mm). There are remnants of some type of sealer "skin" at the bottom threads of this connection that I missed removing before taking this picture.
REASSEMBLY - Reconnect the fuel line to the fuel rail.






DISASSEMBLY - Remove the two bolts (circled in red) that secure the fuel rail onto the intake manifold (10mm). Using even pressure all along all 5 injectors, remove the fuel rail and injectors from the intake manifold. When I removed mine, all five injectors remained in the rail and came out of the holes they were in on the intake manifold. The injectors are held in the rail and the manifold by snug O-rings, with no fasteners to remove.
REASSEMBLY - Using even pressure all along all 5 injectors, reinstall the fuel rail and injectors to the intake manifold. Make sure that each injector nestles into the corresponding hole for it on the intake manifold, push in until it seats, and take care not to damage the ends of the injectors. Reinstall the two bolts (circled in red) that secure the fuel rail onto the intake manifold and torque them to 88 in/lb.






DISASSEMBLY - Disconnect the vacuum line from the fuel pressure regulator (red arrow). Then remove the regulator from the fuel rail (T25 - red circles). The fuel rail should now be completely free. Secure the fuel lines out of the way.
REASSEMBLY - Reattach the fuel pressure regulator to the fuel rail and reconnect the vacuum line to the fuel pressure regulator (red arrow). Make sure and reattach these in such a way that they will be positioned right when you twist the rail back over for installation into the intake manifold.






DISASSEMBLY - Carefully remove all 5 injectors from the rail, taking care not to damage them.
REASSEMBLY - Remove old fuel injector O-rings/spacers (taking care not to damage the injectors) and install both new O-rings (top and bottom - same size - 2 come in set, FCP Groton Part #30731375 need 5) and the spacer (bottom - larger than O-rings, FCP Groton Part #6842408 need 5). I also bought 5 of what was called an "upper spacer" (FCPGroton part #3528216) but could not find any place it would fit or any old part for it to replace, so it is in my "parts I might need later" collection. Insert fuel injectors into the fuel rail with a twist and a push until they bottom out in the fuel rail. You want the electrical connections facing the same side of the fuel rail as the fuel inlet nipple is. I applied a very light film of moly grease to the O-rings to aid in putting them on the injector and to lubricate them for insertion into the fuel rail and the intake manifold. I also applied a very light film to the ports of the fuel rail before inserting the injectors.






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.


Page 2 - Intake Components and Fan Removal / Replacement 3 4 5 6 7 8 9 10



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(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!)