This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your Porsche Boxster. The book contains 312 pages of full color projects detailing everything from performance mods to changing your brake pads. With more than 950+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any Boxster owner's collection. The book is currently available and in stock now. See The Official Book Website for more details.
The Boxster engine is not one of the easiest to perform repairs on. The tight enclosure of the engine compartment makes it pretty difficult to reach in and access a lot of the fuel injection components. There are indeed a lot of things that can be done with the engine in the car (fuel injection work, etc.), but many major operations need better access. In these cases, the only thing to do is to remove the engine: a task that many conceive to be very difficult. The reality is that the removal of the Boxster engine is not a difficult job: if you have the right tools and a little bit of the right knowledge, which I hope to provide here.
The car referenced in this project is my 2000 Boxster which I purchased with a broken engine. The engine was being dropped in preparation to install a brand new 996 3.4L Porsche factory engine in its place (see Pelican Technical Article: Boxster Engine Conversion Project). There were slight variations across the many years of Boxster production, but in general, the procedure for dropping the engine is almost the same for all the 911s. The following procedure checklist outlines what you need to do in order to drop the engine:
- Remove drivers seat (left side of the car, Pelican Technical Article: Sport Seat Installation / Seat Removal)
- Open the front and rear trunk lids
- Place the convertible top into service mode and remove the engine compartment cover (Pelican Technical Article: Air Filter / Pollen Filter Replacement)
- Disconnect the battery (Pelican Technical Article: Battery Disconnect Switch / Battery Buddy Installation)
- Remove access panel behind rear seats (Pelican Technical Article: Drive Belt Replacement)
Disconnect drive belt from A/C compressor (Pelican Technical Article: Drive Belt Replacement)
- Detach mass air flow sensor and loosen and remove the snorkel (Figure 1). Disconnect the air/oil separator hose from the intake and the separator if necessary (Pelican Technical Article: Air / Oil Separator).
- Disconnect the brake booster vacuum line (Figure 2)
- Unplug the A/C compressor electrical connection
- Remove A/C compressor mounting bolts (Figure 4)
- Disconnect electrical junction box (Figure 2)
- Remove power steering reservoir (Figure 2)
- Disconnect ground strap cable (Figure 3), remove gas cap and disconnect air injection hoses, and remove secondary air pump (Figure 3).
- Loosen oil filler neck and coolant hose clamps (Figure 3)
- In rear trunk, unplug engine harness from DME and other harness connectors (may require unbolting the DME from the firewall: Figure 5)
- Disconnect ground wire attached to the trunk wall (Figure 5)
- Pull dipstick out of reservoir tank holder (Pelican Technical Article: Coolant Tank Replacement)
- Push the grommet in and feed harnesses into the engine compartment (Figure 5)
Underneath the car:
- Remove transmission (Under trays, Support braces, O2 sensors and exhaust, Muffler, Pelican Technical Article: Transmission Removal)
- Remove safety cable (Figure 10)
- Empty coolant and remove all coolant hoses (Pelican Technical Article: Coolant Replacement / Coolant Flush)
- Disconnect power steering lines (Photo 8 and Figure 9)
- Remove power steering line from support bracket (Figure 9)
- Loosen power steering return line at junction in engine compartment (Figure 9)
- Remove accelerator cable linkage cover, disconnect cable and remove cable linkage assembly from chassis (1997-99 only, Figure 11)
- Detach both supply and return fuel lines (return line was used only on early cars, see Figure 6)
- Pull engine oil filler neck off (Pelican Technical Article: Coolant Tank Replacement)
- Position jack under engine, elevate
- Remove front motor mount (Pelican Technical Article: Replacing Motor Mounts)
- Begin to lower engine (Figure 13)
- Guide A/C compressor out of the way (Figure 12)
- Lower Engine Down (Figure 13)
- Lower Down onto Cart and Remove (Figure 14)
If you follow the procedure carefully, and check/double-check to make sure that everything is disconnected, the actual process of lowering the engine is not difficult. Different years will vary in what you need to disconnect, but in general, the procedure outlined above and in the photo series should give a clear indication of the steps that need to be followed. The general rule of thumb is to carefully inspect all the areas and components (lines, vacuum hoses, and electrical connections) that connect the engine with the rest of the car. Cars equipped with Tiptronic transmissions have a few extra lines and hoses to worry about.
With this particular engine drop procedure, the transmission is removed first. You need to make sure that you support the engine with a jack stand after the transmission is removed from the car. It is possible to remove the engine and transmission together. Although I typically find this a bit unwieldy, mating the transmission with the engine installed can be a bit more difficult than when they are both on the ground. Also, if you lower the engine and the transmission separately, you do not need to remove the center chassis support bar, which holds the whole rear suspension alignment together.
When lowering the engine, it is very wise to have an assistant on hand. Not only can this person provide emergency assistance in case something goes wrong, but it's also important to have an extra set of eyes that can watch and see if anything was overlooked during the entire process. Make sure that your assistant is watching the surface where the engine and the rear axle support bar meet to keep tabs on the progress. When the engine case passes the support bar, the engine will become slightly unstable on the jack, so make sure that you have a hand free to steady it.
Keep in mind that you may need to jack up the car higher than you expected in order to remove the engine from underneath the car. It is quite common to lower the engine all the way down to the ground, only to find that you need to raise the car much higher to pull it out from underneath. Use a high-lift jack on the rear axle support bar to raise the chassis higher. If you don't have enough clearance, you may need to remove the rear axle support bar and pull the engine out the back. It also may be useful to remove the rear bumper to gain additional clearance to pull the engine out from underneath. Either way, how much work is needed is a direct function of the equipment that you have on hand. Regardless of how you raise the car, always practice extreme safety: take your tires and wheels and stack them horizontally under the car just in case an emergency arises (the car will drop onto the tires and wheels).
Once you have the engine out of the car, it's really handy to have a furniture cart to place it on. Make sure that you don't crush any of the hoses, lines or fixtures when you place it on the cart, and try not to let the engine rest on the exhaust headers. Use blocks of wood to make sure that the engine case actually rests on the cart.
There are a few things that you might want to consider doing to the engine while it's out of the car. It's a very wise idea to spend a little money now, and do maintenance tasks that can only be performed when the engine is removed. Some of these include:
Replace intake manifold hoses and seals. On older cars these age and become brittle, which can then lead to vacuum leaks (Pelican Technical Article: Throttle Body Replacement / Cleaning Intake & Boots).
Replace the oil cooler seals. Although you can replace these with the engine still in the car, it is recommended that you tackle this job when access is much easier (Pelican Technical Article: Starter Replacement).
Update the intermediate shaft bearing and chain tensioners. The procedure for securing the camshafts and accessing the primary timing chain can be difficult with the engine installed. See Project 14 and Pelican Technical Article: Camshaft Upgrade / Chain Tensioner Replacement.
Replace the clutch and flywheel seal. I recommend that you inspect and replace the clutch disc when you have the engine out of the car. The flywheel seal, which can often leak, should be replaced as well (Pelican Technical Article: Clutch Replacement).
Replace the spark plugs. Although you can access them underneath the car, it's much easier to do so with the engine out (Pelican Technical Article: Replacing Spark Plugs and Coils).
Check the air / oil separator hoses. These are made out of hard plastic, and although I haven't seen too many leak lately, I suspect they will begin to cause vacuum leaks as they get older and brittle (Pelican Technical Article: Air / Oil Separator).
Disconnect the mass air flow sensor from the intake tube (yellow arrow), unplug it, and then place it off to the side in a plastic bag to prevent it from getting dirty. Disconnect the two hose clamps that hold on the intake tube (orange arrow) and then pull it back and remove it from the car.
This photo shows a variety of important items that need to be disconnected. The red arrow points to the electrical junction box. Snap up the black plastic cover (shown open here, blue arrow), and then disconnect the electrical cable underneath (red arrow). Make sure the battery is disconnected before you do this! The green arrow shows the power steering reservoir, which you need to disconnect and remove in order to maneuver the air conditioning hoses around the engine compartment. Pull off the cap and use a turkey baster or other suction device to siphon out the fluid in the reservoir. The inset photo (orange arrow) shows the thumbwheel on the lower part of the power steering reservoir: twist this counterclockwise to disconnect it and remove it from the engine. Believe it or not, the hose attached to the top of the reservoir doesn't actually connect to anything: it's an overflow hose that dumps excess fluid onto the top of the engine (I spent about two hours one day trying to research where this hose was supposed to plug into). Finally, the yellow arrow shows the power brake vacuum line: it's easiest to just remove the two screws and pull it off of the manifold.
Shown here is the secondary air injection pump. Disconnect the hose (green arrow), the electrical connection (blue arrow), and the bolts that mount it to its bracket. Remove it from the engine compartment. Also disconnect the engine ground strap (red arrow). It's also a good time to disconnect the oil filler neck (yellow arrow). Loosen the clamp (purple arrow) and you should be able to pull the filler neck out. You can remove it completely by disconnecting it in the rear trunk after you get the transmission out (see Pelican Technical Article: Coolant Tank Replacement).
Removing the air conditioning compressor is one of the more difficult tasks. Like on earlier Porsches, you leave the compressor in the car when removing the engine. This allows you to avoid emptying the system of A/C fluid, a task that requires specialized equipment. A- The compressor is held on by two bolts in the front, and one hidden in the rear (underneath the manifold). The orange arrow shows the right side compressor bolt. You can access and remove this bolt from the passenger compartment. B- The other bolt can be accessed by using a swivel socket (green arrow) through a gap in-between the intake manifold (inset photo C). D- Take some plastic wrap and lay it down in the back of your passenger compartment, and pull the compressor out of its mounting place on top of the engine. As the engine is lowered, you need to then route the hoses out of their channels and tuck them into the passenger compartment (see Figure 12).
Shown here is the rear trunk with the carpet removed (see Project 33 for instructions on removing the carpet). You need to disconnect the engine wire harness from the DME (green arrow) and the chassis harness (red arrows). Also disconnect the engine wire harness ground point from its mounting point on the rear fire wall (blue arrow). Finally, push in the big grommet and stuff the entire wire harness through the big hole in the firewall and place it neatly on top of the engine (purple arrow).
Shown here are the fuel line connections. Be sure to wear eye protection and have a small bucket handy when you unplug these. There may be a small amount of fuel still trapped in the system, and it will leak out onto you and your garage floor: be prepared. Disconnect these only when you have really good ventilation and are able to dissipate the fumes. The yellow arrow shows the power steering pressure line, which is lowered with the engine. The blue arrow shows the power steering return line, which is disconnected in the engine, just above the blue arrow (see Figure 9).
This photo shows the engine compartment with the engine removed. If you are having difficulty getting the car high enough to pull out the engine, then you can remove the chassis support brace shown by the yellow arrows. Be sure to reinstall this support brace if you put the car back down on its wheels at some point thereafter (with or without the engine installed). I would also recommend getting the car's alignment checked when it's back on the road, as this brace is an important rear suspension piece and may affect the alignment settings when removed and then reinstalled.
This photo shows the disconnection of the power steering pressure line (yellow arrow). You only need to disconnect the pressure line: the return line (green arrow) is disconnected further up inside the engine compartment (see Figure 9). Be very careful not to lose the small pieces that are integral to this connection (inset photo): the only way to replace them is to purchase a new line, which is expensive and difficult to install into the back of the power steering pump. Exercise caution, and remove the pieces carefully from the line and place them in a plastic bag. When I dropped the engine, I simply put a piece of tape over the end of the line, and the tape fell off months later, so I had to spend about 30 minutes scouring the garage floor for the small bits and pieces (which I found luckily). I also found it useful to disconnect the brake booster vacuum line here and remove it from the car (blue). A small plastic circlip near the white connector attaches it to the other line.
This photo shows two items that are a bit difficult to disconnect. The power steering return line has a rubber hose at this junction that mates into a barb attached to another hose. Remove the clamp and then pull off the hose. Do not cut this hose, as it is expensive and not easy to replace. If you can't get the hose off of the barb (it's very tight in there and you won't have much leverage), you can always disconnect the return line at the connection where you disconnected the supply line (see Photo E). The inset shows the fuel tank vent line connection, which is made underneath the manifold. This is also very difficult to get to: you'll have to reach in there and pull, or disconnect the line further upstream.
Even though it looks a little bit like one, this is not a ground strap. It's a safety strap that attaches the engine to the chassis support brace that spans the center of the car. Disconnect it from the engine by removing the bolt shown (yellow arrow). If you have a zip tie handy, you might want to zip it to the support brace so that it doesn't get in the way when lowering the engine.
On the 1999 and earlier cars, the throttle was controlled by an actual cable. Remove the outer cover by releasing the tabs (purple arrow) and rotating the cover downwards. Then release the throttle cable that is connected to the main body of the car (green arrow). Finally, remove the two nuts that hold the cover to the chassis (yellow arrow) and disconnect the housing from the body. The housing remains with the engine when you lower it.
As you drop the engine, take the air conditioning hoses out of the plastic channel (green arrow), and carefully route them off to the side. Take care when lowering that they don't get crush, scraped or damaged. You certainly don't want to be replacing the air conditioning hoses in your car because they accidentally got damaged during an engine drop. Also watch out for bad things happening, like in the inset photo. Here, one of the engine harness connectors is getting caught on the lip of the passenger compartment access hole as the engine is being lowered. If you don't check for items getting caught on the way down, then you will most likely damage something as the engine drops. Items getting caught happen almost 100% of the time: keep a close eye out for it.
This photo shows the engine about half-way out of the Boxster. The majority of the weight is supported by the floor jack: the jack stands are there for backup and for balancing (green arrows). In general, I don't suggest letting the engine weight rest entirely on the exhaust headers: the resulting force can put a lot of stress on the threads of the bolts that attach the headers to the cylinder head. To get the engine out, put the engine down on a furniture cart, then jacked up the car very high in the air, pulled the engine out, and then lowered the car back down to a workable level. Using this method, we did not have to remove the chassis support brace (yellow arrow).
After all that hard work, you can claim your success here! This photo shows the Boxster engine successfully removed from the car and sitting on the engine cart. If you have a low-clearance jack (see Pelican Technical Article: Jacking Up and Lifting the Boxster on Jack Stands), you can place your wooden furniture cart (yellow arrow). In this situation, we chose to simply drop the engine and exhaust together since the exhaust was filled with coolant and oil from this blown up motor. You will find that you have to jack the car up really high to get the engine to clear the rear bumper and/or the chassis support brace when removing it from underneath the car. If you find that you have clearance problems that you cannot overcome easily, then you can remove the chassis support brace (see Figure 7), and you can also remove the intake manifold, working with the engine underneath the car. Removing the rear bumper cover can also gain you a few extra inches of working room as well.