98 A4 B5 1.8t AEB oil pump replacement by MrSnickelsnizer

By diyauto
( 3 )

17 minute read

98 A4 B5 1.8t AEB oil pump replacement

Compliments of MrSnickelsnizer @ www.audiforums.com

All right so here is my attempt at explaining the nitty gritty that comes along with replacing the oil pump on this motor. First there should probably be some background as to why you would ever want to or have to perform this procedure on your car. The 1.8t motor is known for collecting an unnecessary amount of crud in the pick up tube portion of the pump, this sits farthest down in the oil pan and sucks up oil for the pump. When this clogs it can lead to a multitude of problems such as low oil pressure, the infamous beep of the oil warning light on the dash, hard cold starts leading to a moment of ticking noise from lack of oil, and more wear on the internal parts of your motor. Our cars do not come pre installed with a oil pressure gauge that you can read to confirm whether you have a proper pressure or not. Instead they have a oil pressure sender unit, that when senses low oil pressure triggers the warning light to come on your middle dash cluster. Some people like myself only triggered the warning when cruising in a high gear at a low rpm, or when pulling to a stop from some highway cruising. The engine is not working enough at those moments or rpm's, to push the necessary amount of oil through the clogged pick up tube. There are differences in the years of this motor that led to a design change, going from a shaft driven pump to a chain driven pump. They are different and coincide with your motor code. AEB's are shaft driven. Some years also do not use an oil pan gasket but instead use a bunch of oil pan sealant, like a permatex or loctite product designed for oil pans, usually colored black. A common thing that has been discussed is not using any sealant with the engines that use an oil pan gasket. I will tell you to apply a small amount with or without the use of an oil pan gasket, according to what my Audi A4 B5 Bentley manual says. So what do you need to have on hand to perform a oil pump swap? Your best bet is to go to ECS Tuning and order their oil pump kit. It gives you oil, brand new pump with pickup tube, a much bigger updated oil filter, wrong fitting oil pan drain plug for older models, an oil pan gasket, and in some versions of the kit oil pan sealant. If the kit you order does not include sealant go to your local car shop and buy some, 5-9$ usually. One last note before we head into it, the bigger oil filter which comes with the kit is something you should already be running. The oil filters on these car have been recommended by Audi to be changed to the much larger filter that you will receive. With the addition of this filter your oil capacity should be right around 4liter's. Also this is not supposed to be done with the motor still in the car but it is completely possible 

-Tools needed for front clip/Bumper removal-

T-30 star point socket

T-45 star point socket

Flat head screwdriver- (For radiator hose clips & intake hose clamps, and lower body pan removal, etc..)

6mm Allen Head/Hex Bit- (For two bumper retaining bolts)

- Tools you will need for oil pump job-

1/2 socket wrench

3/8 socket wrench

3/8 torque wrench- ft'lb's

1/4 torque wrench- in/lb's- (Purchased through Harbor freight)

1/4 to 3/8 adapter head- (For 1/4 torque wrench

5mm long allen head/Hex Bit drives- (Purchased through harbor freight)

5mm short allen head/Hex Bit drives-(Purchased through harbor freight)

10mm wrench 

Set of 3/8 mm deep socket's

Set of 1/2 mm deep sockets

19mm 12 point socket- (For crankshaft)

1/2 drive socket extension 5"

3/8 drive socket extension's- (17in's worth, two 6", two 3", perfect amount)

3/8 drive swivel joint

16mm open end wrench

16mm or 5/8" stubby open end wrench- (5/8 & 16mm are the same size)

1/2 drive 18mm deep or short socket- (For Front Subframe Bolts)

Disposable Latex Gloves- (You will appreciate them a ton)

Clean oil for for bolts- ( Bolts must be oiled prior to install or torquing) 

A hydraulic floor jack

Some jack stands

So now that you have a massive list of tools to say oh my gosh! at, I should now say I will not be covering the procedure for removing the front clip or bumper. I will tell you a couple things about it though. I removed my front clip completely, drained my coolant out (filtered it and reused it), and set the a/c condenser to the side (don't unscrew the lines!!), removed headlights, and all that jazz. I did not take as many pictures as I should have but there are a couple sites/ threads, I will reference at the end of this that aided me with their previous experiences and pictures. I felt I would attempt to fill the missing blanks, that I believe they missed. This is a fairly extensive procedure that you can perform in your own driveway or garage. I would say it is a 5-6 out of 10 in difficulty. (I am not liable for any damage you inflict on your car if you mess up)

First remove front clip & bumper. Make it look like this. Also drain oil and remove old filter (self explanatory). 

Click the image to open in full size.

Second remove the A/C compressor tensior iddler pulley deal. Remove belt as well. 

Click the image to open in full size.

Third remove the snub mount bracket plate. Their is a hidden hex bit bolt behind the tensior pulley. There are also two stability bars on each side that just need to have their bolt heads unscrewed, along with the washers. Should look this when snub plate is removed.

Click the image to open in full size.

Fourth you need to unscrew the bottom bolt's off of the motor mounts, 13mm deep socket. Mark these with nail polish or a paint pen before unscrewing, to remember exactly where they tighten down. The motor mounts will move around on you, and need to be put back exactly where they first were. The driver side mount will need to come out all the way. Connect all your 3/8 drive extensions and put a 13mm deep socket on it. Feed it through from the top of the motor, right next to your oil dipstick and wiggle it down onto the top of your motor mount nut. When the mount is completely free leave it alone, you will be able to wiggle it out when the subframe is loosened. Remember the position of the way the motor mount goes on. There is only two ways possible due to alignment bumps, so just get it right.

Fifth place a hydraulic jack under the A/C compressor and lift up. If needed put some blocks of wood on the jack then place it on the A/C compressor bracket. Make sure that the jack is fitted as best as you can get it!! If this slips you will have a very very bad day. You can lift the motor up quite a bit at this point. I actually lifted mine till the back of motor hit the firewall. Not recommended to go that far but proves you can do that without breaking anything. There is a small indent on my firewall now fyi  I am going to reuse a picture I used before already but it should look like this. 

Click the image to open in full size.

Sixth unscrew the three front subframe bolts on both sides of the motor, 18mm. These are very tight! Unscrew the two bolts you see in the picture first, not all the way but almost to where they are almost completely out, then unscrew the big bolt behind those two, again not all the way. Do this both sides. You may need a cheater bar on the end of your 1/2 drive wrench. A 3/8 wrench will definitely break on these bolts. No need to unscrew the rear ones, If I am not mistaken when loosened those can mess with your camber or something. Just don't unscrew them. You can also now remove the driver side motor mount.

Click the image to open in full size.

Seventh you should have plenty of room between the subframe and oil pan to remove the oil pan and oil pump. So start unscrewing all the bolts from the oil pan. If you have too draw a diagram on a piece of paper and place the bolts you remove on it where you took them out from. There are quite a bit of bolts so try to keep them organized. You should definitely seperate the transmission to oil pan bolts from the engine to oil pan bolts. On the passenger side there is a bigger bolt which goes through one of those metal bars, which connected to the snub mount plate. Remove that. Behind that bolt going towards the transmission there is another bolt that needs to be unscrewed. Due to it's length, you cannot fully remove this bolt till all others are out and you are removing the oil pan, so just fully unscrew it. Also remove the two 10mm bolts that hold the turbo return line to the oil pan. Remove the tube's gasket and set aside. On the drivers side their are two bigger bolts which need to come out, 16mm I believe for all these larger bolts. All the rest of the bolts are small 5mm hex bit bolts. Some are more hidden than others. So feel around for them or look at my oil pan picture to get a general location where you might have missed one. There are two very hidden 5mm hex bit bolts that you can only access through two small holes between the oil pan and transmission. You have to place the 19mm 12 point socket on the crank and turn it while looking through one hole at a time to line up the access indentation on the flywheel to correspond with each hole. Can be turned by one person while still under vehicle, not that hard to do. You can turn crank clockwise and counter clockwise, does not affect anything. You will need the lengthy 5mm hex bit socket with a 3" extension on it to get to these bolts. The other bolts are the transmission to oil pan bolts and these are all 16mm. I unscrewed the majority of these by combining all 3/8 extensions with a swivel joint at the end connected to a 16mm socket, then going straight from the front of the car under the oil pan onto the bolts. The last bolt is on the upper side of these on the driver side. It is a bolt that runs from the rear of the car to the front. It a 16mm on both sides of it. Can be unscrewed by using two 16mm or 5/8" open end wrench's. One of them needs to be a stubby open end wrench. So now your oil pan should be falling out, if not "lightly" tap it with a rubber mallet. If it does not come out make sure you removed all bolts.

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.

Eigth your oil pan is out! Clean oil pan and lightly sand down the mating sealing surface with high grit sandpaper. Also remove your plastic oil baffle plate and set aside. The next part requires disassembly of the oil pump to get it out and the new one in. It is very lengthy in design. Unscrew the bottom of the oil pump. Two 5mm hex bolts hold it together. It will fall apart but no biggie. The pump is composed of two gears in the inside, one is connected for life to the drive shaft rod. The other is a free bird and needs more attention so you don't drop the gear and scuff it. That is it. Nothing special. So once the cap, which has the dirty harlot of a pick up tube connected to it, is out continue to unscrew the other two hex bit bolts which hold it to the motor. Once out the pump can be wiggled free. 

Click the image to open in full size.

Click the image to open in full size.

Ninth install the new oil pump in the opposite manner of how you removed the last one. Make sure when fitting the bottom to the top of the oil pump that you keep the internal gears together and you don't drop that silly free bird one. The torque for the reassembly of the oil pump is 7ft/lbs or 84 in/lb's. Make sure you dip the two bolts that hold the oil pump to the motor in clean oil before torquing to 18ft/lb's or 216in/lb's. 

Tenth you need to clean the mating surfaces of both the oil pan and motor. Next you need to coat the front and back of oil pan (and same for the motor) with a thin coating of sealant. This is the most important thing I will stress, I missed this the first time around myself. Remember that long bolt on the passenger side towards the rear, oil it and then put it in through the hole before attempting to put the oil pan in position. The bolt will hit the subframe and not go in no matter how hard you try if you keep it out. Reinstall the plastic baffle plate before the oil pan. In my case it would not fit unless i broke off the rear most plastic clip on the plate that holds it against the side wall of the motor. Has not affected anything at all, so if you run into the same fitment issue just do it. The plastic cross piece on the baffle plate sits in the side of the oil pump. Now put the oil pan gasket on the oil pan and fit it back onto motor. Screw in the long bolt if you want first or let it drop and hit subframe, it will just sit there. You want to reinstall all the 5mm bolts hand tight with the add of the socket wrench, don't forget the two in the transmission. Now install all of the transmission to oil pan bolts to the spec of 33ft/lbs. Next tighten all the bigger bolts from the oil pan to the motor to the spec of 33ft/lb's. Remember the one closest to the front on the passenger side has that stability bar, which connects to the front snub mount plate. Finally go back and retighten all the 5mm bolts to 7ft/lbs or 84in/lb's, including the two hidden one's. Reconnect the oil drain line for turbo hand tight with new or cleaned used gasket. Remember to dip all these bolts in oil before torquing them. Allows proper torquing.

Click the image to open in full size.

Click the image to open in full size.

Eleventh reinstall the motor mount you removed, tighten up the three subframe bolts on each side to 18ft/lb's. I just tightened them till I felt they were solid. Now lower the motor back down and make sure the motor mount bolts go back through the holes where they belong. Tighten the motor mount bolts down back where they are supposed to be tightened, remember they can move around on you. Reconnect the front snub plate mount to the motor, hand tight will do fine, oil these bolts as well. Reinstall the tensioner pulley for the A/C with belt

Twelth put the front of your car back on. Make sure new oil filter is installed along with drain plug 37ft/lbs. Fill with clean new synthetic oil. Fill car with new or strained old coolant, G12 red/purple only. You could at this point when car is ready to be started perform a throttle body adaption but may not be necessary. Double check everything, make sure everything is tight, all fluids are topped off, nothing is missing, cross fingers and start car. Might make a rough start up noise but will go away in seconds.

So now you probably have dropped quite a bit of bad words and feel completely stress free, (if nothing blew up that is). This solved all of my oil pressure issues, no more clicks, no more ticks, just good old funness. The car's engine oil temperature even went down a little. It is anything but fun to do by yourself, so do it on a weekend with some friends and start early in the day. This is my attempt at making a walk through for everyone who wants to do this. It is a very long article but I tried my best to be as precise as I could. I will pay my respects to the following people and websites for giving me some visual aid and proper technical information. 

1.8T Sludge issues!! Can it be done without taking the engine out? Yes



Here are some final pictures from my Bentley Book for your viewing pleasure.

Click the image to open in full size.

Click the image to open in full size.

So good luck if you attempt this. Remember your screw up is not my fault.