The 1997 to 2004 Porsche 996 has a reputation for suffering catastrophic engine failure from a faulty Intermediate Shaft bearing (IMS). While there certainly have been a larger number of engine failures in the M96 engine than in previous Porsche motors, no one seems to know, or are willing to admit, exactly how many motors suffered from this problem.
If you are worried about the health of the IMS in your engine, but do not want to go through all the work to replace the bearing, there is now another option. The IMS Guardian allows constant engine monitoring through its dash interface. The IMS Guardian couples technology originally created for military aircraft to a specially designed sensor and wiring package. This system was originated with the sole purpose of detecting imminent IMS Bearing failures prior to their occurrence.
The system relies on Magnetic Chip Detection (MCD) technology for monitoring the metal content in engine oil. The sensor consists of two strong, opposing-poles, permanent magnets with an insulated gap of air in between. Each magnet is connected, by a wire, to the wiring harness, comprising an open electrical circuit. The wired magnet unit itself is mounted in a modified oil drain plug replacing the stock drain plug.
As oil circulates throughout the engine, the magnets will attract the smallest metal debris caused by deterioration within the engine and circulated within the engine oil. As the ferrous metal debris is captured in the center of the magnets, it will quickly build up to the point that it will bridge the gap in between the magnets allowing the conduction of electricity, and will close the electrical circuit. Closure of the electrical circuit causes a warning light, installed in your dashboard, to illuminate and an audible alert will buzz. When the IMS Guardian alerts, the driver of the vehicle should turn off the engine as quickly as possible and call the IMS Hotline number provided with your purchase.
I installed the IMS Guardian in our 1999 996 Cabriolet project car. While the kit comes with a DVD tutorial as well as a printable set of instructions I will describe the process, problems and short cuts I used during installation.
Begin by disconnecting the battery. You are going to be working around the cars electronics and it never hurts to be safe. Now you need to drain the oil by removing the 8mm Hex bolt in the sump plate. Once the sump has drained you will want to remove the sump plate itself. It is held in place by thirteen 10mm bolts. When removing it, it is a good idea to leave two of the bolts partially threaded so the cover will not fall on you when it lets loose.
There is no gasket between the plate and engine case as a seam of Loctite 5900 is used to make the seal, meaning you may have to tug on, or pry the case and cover apart. Porsche provides a place to pry them on the passenger front side of the cover. Never try and stick a screwdriver between the case and cover, as this can potentially damage the surfaces and make for a poor seal.
With the sump plate off the car you will need to clean it very well. You must get all of the metal out and off of the plate. I was able to just use some rags, but if you are going to use a solvent make sure you do not get it on the rubber oil control baffles.
Inspect the sump body, oil pick up tube and the two anti foamers in the lower part of the engine case.
A word of advice here. A small amount of ferrous metal is common to most engines, but, if you find a large amount of metal or any bits, there is a very good chance your engine is on it’s way to destructing. It would be best not to drive the car and either remove and inspect the IMS bearing yourself or have a professional look at it.
Install the new Magnetic Chip detector (MCD) into the sump plate, using the crush washer; like you would the normal drain plug and hand tighten. It does not matter which way the magnets are oriented in the bottom of the sump plate. Apply a bead of Loctite 5900 to the clean sump plate surface and re-install the cover. Make sure you tighten the bolts in a crisscross pattern and torque to spec. Do not over tighten the bolts.
Once the plate has been installed you will need to do the final tighten on the MCD plug. The plug is designed to be hand tightened and then given a further ¼ turn with a 26mm or adjustable wrench.
If you where due for a new oil filter now would be a good time to change it as well.
Now fill your engine with new oil. If you did not change the filter you will need between 7-9 quarts and if you did, you will need between 8-10.
Next you will want to locate where you are going to run the harness from the “dry zone” inside the cabin, to the “wet zone” outside in the engine compartment. Here is really the only complaint I had with the system. I watched the DVD which demonstrated running the plug and harness through a lower body plug. I made all the arrangements to do so and when I went to install the plug through the hole it was too large to pass through. The plug has been reengineered to better handle the elements and will no longer fit through a standard Porsche body plug. Make sure you check for clearance on the plug hole you plan on using. I ended up having to remove almost the entire rear seats and interior to find a body through hole that would accept the plug. On the 1999 996 there is a plug under the passenger rear seat that will accept the wiring and harness. This ended up working out well as the wiring enter the engine compartment above the transmission and there was lots of room to work, but added a few extra hours to get all the interior out and reinstalled.
Once you have established where you are going to run your wiring, move to the dash and begin installing the Dash Interface. There are six places for switches on the dash of our 996, three on either side of the climate control unit. You will need to pull power from one of the existing switches. On our car there was a functioning switch on the drivers side of the dash that we could pull power from, otherwise you will need to run the wires behind the dash to get power from the passenger side.
Remove the switch plate using your trim removal tools. Remove the electrical connection from the working switch and then remove the blank from the space you wish to place the IMS switch. The switches and blanks just pop right out. Install the IMS switch in the blank space.
Start to route the main wiring harness into the dash. It helps if you temporarily tape the main power lead (red wire) to the thick large black wires. If you are working alone, place a shop light on the floor by the pedals and point it up towards the inside of the dash. This will help you find the best pass through hole to use inside the dash board. Pass the bulk of the wiring through, leaving yourself enough room to work with the other wires.
You will need to route the orange wire to an existing switch. On the back of the powered switch from the dash, open the harness and remove the number 3 connector. You will need a small jeweler’s screwdriver to remove the spade connector. Take the wire from the number 3 connector and plug it in to the white connector coupler that comes with the kit. Make sure it locks in place by giving it a little tug. Insert the white connector into the black plug on the harness. Install the orange wire from the IMS harness into the number 3 connector in the original powered switch (the same spot that you just removed the wire that is now in the white connector from).
Reconnect the powered switch harness to the switch you removed it from, and connect the IMS harness to the new IMS switch you installed in the dash.
With everything connected, place the black circuit box and buzzer inside the dash console. You will to feed all of the wires into the dash and reconnect the switch panel back onto the dash. It just snaps into place.
Under the dash find your main power lead (red wire) and route it out of every things way over to the fuse panel. Locate one of the accessory fuses (7.5amp) that is only powered when the key is switched on. Remove this fuse from the panel, and using the IMS adapter install the 7.5 amp fuse into the first slot in the adapter beside the fuse supplied by IMS Guardian. Now plug the adapter with the two fuses in it back into the spot where you took the 7.5 amp fuse from.
Next, you will need to route the wiring harness through the car and out to the engine compartment. The only body plug that I found on our cabriolet that would accommodate the plug was located under the rear passenger seat. I removed the lower center tunnel cover, ran the wires under the center console and into the back seat. It became a little more complicated as I had to remove the rear seats, seat belts, driver side rear panel and the rear carpet to get access to the plug. If you have to cut the plug to get the wiring through, make sure you seal it back up with some silicone.
Run your wiring harness back to the MCD. Make sure you route it in a manner that will keep it away from any moving parts and so it does not hang down below the engine. Use the supplied zip ties to secure it. I used a few additional zip ties to tidy everything up.
Connect the wiring harness to the MCD. Make sure you get a full connection ensuring that it is sealed from the elements.
With everything done, you should now check the system for operation. Turn the key on, but do not start the engine. The IMS Alert Warning Indicator Switch should be illuminated in an amber color. This indicates the system is armed. Press the IMS Alert Switch (lighted portion) to test for operation. The light should illuminate to a red color and an audible alarm should be heard. This indicates a fully functional system.
Congratulations you have installed the IMS Guardian. Now, just button everything back up and you are done.
After disconnecting the battery drain the oil from your sump. Remove the sump plug with an 8mm Hex
After the oil has drained remove the sump cover. There are thirteen 10mm bolts holding the plate to the engine. I recommend leaving 2 bolts slightly threaded (red arrows) so when you remove the cover it does not fall on you. You will probably need to pry the cover off. Use the pry area (yellow arrow) by the oil filter. Never pry by trying to jam a screwdriver between the cover and engine case this can damage the mounting surfaces and cause a leaky seal.
Install the Magnetic Chip Detector (MCD) in the sump plate in the drain plug hole. Make sure you use the crush washer provided. Fully hand tighten the MCD. It does not matter which way the magnets are oriented (insert upper left).
After thoroughly cleaning both surfaces of the engine and cover, apply a bead of sealant (I like to use Loctite 5900). Install the cover and torque the thirteen bolts (red arrows) down in a crisscross pattern. Do not over torque these bolts. Once the case is torqued down you should see a small bead of Loctite between the case and cover (green arrow). Now move to the MCD. You should have already hand tightened the plug, if not double check it now. The MCD is designed to be hand tightened, and then tightened another ¼ turn with a wrench (yellow arrow).
You will need to pull power from one of the dash switches. I pulled power from the traction control switch, but if you do not have any powered switches on the drivers side of the dash, you can pull power from a switch on the passenger side by running the harness through the hole behind the vents. Remove the dash switch plate with your trim removal tool (red arrows).
Open the connector for the traction control using a small screwdriver and remove the number 3 connector (red arrow). You will need use a small screwdriver to unlock the spade connection inside the connector.
Install the IMS switch into the blank space and install the IMS harness to the switch (green arrow). Plug the traction control connector back into the switch (red arrow). Now pass all of the wires and control box into the dash through the opening and reinstall the dash plate.
Safely run the red wire down to the fuse panel. You can remove the carpet around the panel and pass the wire behind it, to give a cleaner look. Remove a 7.5 amp fuse from the panel and plug it into the fuse adaptor. Pulg the fuse adapter into the space on the panel for the fuse you just removed. Make sure you pick a fuse that is for the accessories and is only powered when the key is in the on position.
Run the main harness back towards the rear of the car, to the area where it is going to pass into the engine compartment. Remove the center console panel (green arrow), tuck the wire up under the center console (red arrow) and inside the parking brake area. I removed the seat to give you a betterPicture. Both the parking brake handle and center console panel just pull straight off.
On our cabriolet I ran the wires up and under the rear passenger seat. The harness enters from the center tunnel area (green arrow), runs along the existing wiring loom (yellow arrow) and out through the body plug under the seat (red arrow). Make sure to seal up the plug with silicone after the wiring has passed through.
Route the MCD wire safely back to the connector to the harness (red arrow) and connect the two pieces. Make sure they click together insuring them of being weather tight. Be sure to use enough zip ties to securely fasten the wiring harness.
I will be so free to ask You for some help to determinate what kind of IMS bearing is in my Boxster which engine has a number that starts with M96/22-652...
Thank You in advance...
June 1, 2016
Followup from the Pelican Staff: I would need to know the year and model. That method is faster to figure it out. - Nick at Pelican Parts
Comments: Owning 2 Porsches with no need to worry about an IMS problem is great. But if I add a boxster to my garage and the engine does go, I will just do an engine swap with a Subaru Sti motor. Flat four , turbo charged just like the new Spyder.At least it's still a boxer engine and not a Renegade chevy swap kit. At least I'll know it's reliable! who wants to play Russian roulette with detonation?
May 4, 2016
Followup from the Pelican Staff: Thanks for the input on this one. We appreciate it.
- Nick at Pelican Parts
Comments: Does anybody know what the orange cable is supposed to do? The wire which gets removed and looped back through the orange leads is switched and if on another bearly visible LED in the IMS Guardian Switch comes on... that is all? As soon as you release the TC or PSM Switch the power on the orange cable is off. So please can ynone explain to me why I should connect the orange cable at all?
November 24, 2014
Followup from the Pelican Staff: I don't have any experience installing this item. I would give the folks at the IMS guardian a call. - Nick at Pelican Parts
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