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 > Technical Articles: / BMW E36 3-Series (1992-1999) >
BMW Head Gasket Replacement
 
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Pelican Technical Article:

BMW Head Gasket Replacement

Time:

8-16 hours

Tab:

$600-$700

Talent:

*****

Tools:

32mm socket, camshaft alignment tool with TDC pin, E12 Torx headbolt tool, rigid chain tensioner, VANOS tuning tool, valve pliers, valve spring compressor, homemade protractor for torque stages 2 & 3, zip ties, Kim wipes, isopropyl alcohol, brake cleaner, set of metric sockets and ratchet

Applicable Models:

 
BMW E30 325i Coupe/Conv (1987-93)
BMW E30 325i/iX Sedan (1987-93)
BMW E30 325is/iX Coupe (1987-93)
BMW E34 525i Sedan/Wagon (1989-95)
BMW E36 323i Convertible (1998-99)
BMW E36 323is Coupe (1998-99)
BMW E36 325i Convertible (1992-95)
BMW E36 325i Sedan (1992-95)
BMW E36 325is Coupe (1992-95)
BMW E36 328i Convertible (1996-99)
BMW E36 328i Sedan (1996-99)
BMW E36 328is Coupe (1996-99)
BMW E36 M3 Coupe (1995)
BMW E36 Z3 Convertible (1997-02)
BMW E36 Z3 Coupe (1999-02)
BMW E39 525i Sedan/Wagon (2001-03)
BMW E39 528i Sedan/Wagon (1997-00)
BMW E39 530i Sedan (2001-03)
BMW E46 323Ci Coupe/Conv (1999-00)
BMW E46 323i Sedan/Wagon (1999-00)
BMW E46 325Ci Coupe/Conv (2001-06)
BMW E46 325i/xi Sedan/Wagon (2001-06)
BMW E46 328Ci Coupe (1999-00)
BMW E46 328i Sedan (1999-00)
BMW E46 330Ci Coupe/Conv (2001-06)
BMW E46 330i/xi Sedan (2001-06)

Parts Required:

Head gasket set, cylinder head bolt set, copper lock nut exhaust flange, nut for exhaust manifold to cylinder head, coolant, distilled water, Mobil 1 oil, oil filter

Performance Gain:

Saved the engine and restored performance to your BMW

Complementary Modification:

Use 0.3-millimeter-thicker gasket to compensate for reduced material thickness on the head (decked head)
101 Performance Projects for Your BMW 3 Series

This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your BMW 3 Series. The book contains 272 pages of full color projects detailing everything from performance mods to timing the camshafts. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any 3 Series owner's collection. The book was released in August 2006, and is available for ordering now. See The Official Book Website for more details.

BMW engines are known for weak cooling systems. It is not uncommon to have a water pump fail or a thermostat get stuck, which can result in engine overheating. The car typically runs fine for a few hundred miles after overheating, but it eventually begins to leak coolant and ultimately requires a complex head gasket replacement.

This project incorporates steps and procedures from many other projects. Here are the tasks that you need to perform prior to the specific steps outlined below:

Jack up the car: Raise the front of the car to gain access to the coolant drain plug on the engine block, as well as the engine oil drain plug.

Empty engine oil: Drain out the oil that has been contaminated with engine coolant.

Remove coolant: Empty the coolant from the system prior to removing the cylinder head.

Remove radiator and fan: Remove the fan to gain access to the front of the engine. Also, remove and flush the radiator, and replace the hoses.

Remove drive belts: You will need to remove the belts in order to gain access to the water pump.

Remove water pump: You should remove the water pump in order to clean it out or replace it with an upgraded unit.

Spark plugs: Remove the ignition coils from the head, and remove the spark plugs.

Valve cover gasket: Remove the valve cover to access the head bolts.

Camshaft removal: It is possible to replace the head gasket without removing the camshafts. However, you should have the head resurfaced by a machine shop, and this process requires that you remove the camshafts.

Intake manifold removal: The intake manifold covers a lot of items in the engine compartment and is attached to the cylinder head, so it needs to be removed.

VANOS installation/cam timing: To remove the cylinder head, you must first remove the VANOS unit. To reinstall the head, you need to retime the camshafts and properly adjust the VANOS unit.

Cam sensor replacement: Remove this sensor from the cylinder head and have a new one handy.

Crankshaft sensor replacement: This sensor is only accessible with the intake manifold off, so it might be a good time to replace it.

Tensioner update: Remove the lower chain tensioner to loosen the chain on the camshafts and upgrade to the new style if applicable.

VANOS oil line replacement: Disconnect the VANOS oil line prior to removal of the head.

Machine shop 101: Send your cylinder head out to a machine shop that will resurface it and check for cracks.

The remainder of this project is presented step-by-step in the accompanying photos and captions.

If you would like to see more technical articles like this one, please continue to support Pelican Parts with all your parts needs. If you like what you see here, then please visit our online BMW catalog and help support the collection and creating of new and informative technical articles like this one. Your continued support directly affects the expansion and existence of this site and technical articles like this one. As always, if you have any questions or comments about this helpful article, please drop us a line.

CLICK HERE FOR REPAIR PARTS FOR THIS ARTICLE: 

CLICK HERE FOR BMW E30 PARTS:

CLICK HERE FOR BMW E36 PARTS:

Figure
Figure 1

If you see this kind of mess with your car, you know you aÂÂÂÂÂÂÂÂÂÂÂÂÂ're in trouble. This is a perfect example of oil mixed with coolant due to a head gasket leak. The light-colored milky texture of contaminated oil is a sure sign of head gasket problems. For a quick analysis, remove the oil filler cap and compare it to the photo (upper left). Also take note if steam comes out of your tailpipe. Some condensation is normal upon startup, but if it continues well after the car is warmed up, you have a problem. Of course, the first clue is that your low coolant warning lamp will turn on, even after filling the reservoir multiple times.

Figure
Figure 2

More carnage can be seen under the valve covers. The underside of the valve cover is coated with a mixture of coolant and oil. At this point, we haÂÂÂÂÂÂÂÂÂÂÂÂÂ've emptied the oil and coolant, and removed the fan, radiator, drive belts, water pump, spark plugs, and valve cover.

Figure
Figure 3

Before you remove the cylinder head, lock the engine at top dead center (TDC) for cylinder number 1 to accurately time the camshafts when you reassemble the engine. There is a special tool that needs to be inserted into a hole in the engine block, which then mates with a corresponding hole in the flywheel. The intake manifold has been removed in this photo (see our intake manifold removal article), and the yellow arrow indicates the general area where the tool needs to be inserted (see also Photo 4). You can rotate the engine'ÂÂÂÂÂÂÂÂÂÂÂÂÂ's crankshaft by placing a 22-millimeter deep socket on the front pulley and rotating clockwise (photo inset). Install the camshaft alignment tool (see our article on Camshaft Timing and Vanos Unit Installation). If your camshaft alignment tool doesn'ÂÂÂÂÂÂÂÂÂÂÂÂÂ't seem to fit, your car may have had the camshaft timing tweaked as part of a BMW service campaign to correct an uneven idle (affected engines built up to August 1992). Loosen the tool to allow it to fit in this situation.

Figure
Figure 4

Here iÂÂÂÂÂÂÂÂÂÂÂÂÂ's a close-up of the spot in the engine case where you insert the flywheel locking tool. Your car should have a small blue plug that covers the hole (inset photo). The flywheel locking tool itself is a long, thin rod with a smaller insert tip on its end (inset, lower right). Insert this tool into the engine block and rotate the crankshaft pulley until the pin fits into the matching hole on the back side of the flywheel.

Figure
Figure 5

At TDC for cylinder number 1, the exhaust camshaft sprocket should have a small arrow that points upward, perpendicular to the plane of the head gasket. Double-check this if you aÂÂÂÂÂÂÂÂÂÂÂÂÂ're trying to find TDC when you aÂÂÂÂÂÂÂÂÂÂÂÂÂ're turning the engine over by hand.

Figure
Figure 6

Also check the front crankshaft pulley itself. The line by the yellow arrow will match up with the boss in the engine block (blue arrow) when the engine is at TDC for cylinder number 1 and cylinder number 6. Check the arrow on the exhaust camshaft sprocket shown in Photo 5--ÂÂÂÂÂÂÂÂÂÂÂÂÂ--it should only pointing upward, not downward, when the engine is at TDC for cylinder number 1.

Figure
Figure 7

Shown here is the front of the VANOS unit prior to removal. The VANOS unit advances the camshaft timing at higher rpm, which translates into better engine performance while driving. Undo the nuts that attach the unit to the cylinder head. The cable for the crankshaft sensor (see also Project 15) is integrated with a small plastic cable guide that ties into the studs that also hold the thermostat housing and the VANOS housing (yellow arrows). Remove the thermostat in order to remove the VANOS unit.

Figure
Figure 8

With everything disconnected, you can now remove the front VANOS unit. Disconnect the VANOS oil line (blue arrow), and disconnect the electrical connection to the VANOS solenoid, as indicated by the green arrow (see our article on VANOS Oil Line & Solenoid Replacement). Remove the unit from the front of the cylinder head and place it aside on your workbench. Push the upper VANOS chain tensioner down and lock it in place with small pins (red arrow). You can use a small Allen key as shown, or even large paper clips will do.

Figure
Figure 9

Remove the sprocket assemblies from the front of each camshaft (see our article on Camshaft Timing and Vanos Unit Installation). Use a zip tie or some wire to secure the timing chain (blue arrow) ÂÂÂÂÂÂÂÂÂÂÂÂÂ--you don'ÂÂÂÂÂÂÂÂÂÂÂÂÂ't want this to fall into the recesses of the engine when you remove the cylinder head.

Figure
Figure 10

Remove the cylinder head bolts with a special BMW Torx deep socket tool (11-2-250). The bolts will be tight and difficult to remove, but if your tool is in good condition, you should have no problems removing all of them (14 total for six-cylinder engines). The bolts are hidden underneath the camshafts, so you will have to maneuver your tool past the camshafts to reach them.

Figure
Figure 11

Remove the camshaft position sensor (see photos in Project 14) and disconnect the last remaining connections to the cylinder head. The small electrical connections pull out after releasing the small spring wire retainer. Don'ÂÂÂÂÂÂÂÂÂÂÂÂÂ't forget the hose attached to the rear of the cylinder head that supplies the heater core (inset). Also disconnect and loosen the exhaust manifold (see our Exhaust Manifold Replacement article).

Figure
Figure 12

With everything disconnected, the cylinder head should be loose on the engine block. Tap it with a rubber mallet and it should start to lift off of the block. If it doesn'ÂÂÂÂÂÂÂÂÂÂÂÂÂ't budge, then chances are that you forgot to disconnect something that is holding it down. ItÂÂÂÂÂÂÂÂÂÂÂÂÂ' is not uncommon to forget to remove a cylinder head bolt. Count the cylinder head bolts and make sure that you have 14 of them prior to your removal attempt (six-cylinder engines). As the head begins to lift off of the engine block, tilt it slightly toward the exhaust manifold and grab the timing chain. Tie off the timing chain with some wire or a zip tie so it will not fall into the recesses of the engine block.

Figure
Figure 13

Shown here is the head is coming off of the engine. Untie the timing chain from the top of the head, and secure it at the top of the engine block (blue arrow). Triple-check that everything attached to the head is now disconnected. The cylinder head is very heavy, and the angle for lifting while you're standing in front of it is very challenging. I do not recommend lifting the head off the car by yourself--ÂÂÂÂÂÂÂÂÂÂÂÂÂ--get someone to help you lift the rearmost part of the head. If you attempt to lift the head off of the engine and something catches on your way up, it will be difficult to put it back down again without crushing or potentially damaging something.

Figure
Figure 14

Since you are removing the cylinder head from the engine, I recommend that you take it to a machine shop for evaluation and reconditioning (see Photo 17). Prior to taking it to the shop, you can remove the camshafts. Most machine shops won'ÂÂÂÂÂÂÃÂÂÂ�