How to remove and replace a Porsche 944 fuel tank (Square Dash Model)

THE WHY?

If you've ever asked yourself "Should I buy an early (square dash) or a late (oval dash) 944?" then this article may be the deal breaker. Having put my 944 in for a service my mechanic discovered a leak that appeared to be coming from the fuel tank. No big deal I thought, I'll buy a second hand one from a breakers or ebay. However upon further investigation it turns out Porsche significantly changed the material of which the fuel tank is made from between the early (square dash) and later (oval dash) 944. The square dash 944 (and 924) has a fuel tank made from steel, whereas the oval dash model has one made from plastic. More investigation reveals that the fuel tanks are also of different capacity (oval dash has the larger 80 litre capacity, compared to square dash's smaller 66 litre). Even more investigation finally concludes that the plastic fuel tank will not fit the early (square dash) 944's as the cross-member that supports the transmission is non-removable and therefore blocks the insertion of the larger plastic fuel tank.

So the options I had were:

a.) Buy a new steel fuel tank from Porsche for near £1500.00!
b.) Repair the old tank
c.) Buy a good 24 year old fuel tank from a breakers £40.00

I went for option 'C'.

For the record and from research on forums it seems the steel fuel tanks are susceptible to cracking due to the vacuum that causes the fuel tank to contract and expand. They are also susceptible to corrosion, externally and internally.


THE TASK


You'll need the following tools and a lot of patience and a spare pair of hands:

Socket set
Spanners
Couple of screwdrivers (flat and cross-head)
Container to empty petrol into
Clamp-able pliers
Trolley jack or two
Axle stands
Waxoyl (Spray version) - optional
3M Scotch Weld 80 Spray Adhesive - optional



THE HOW TO


(Amateur mechanic Job Time approx: 2-3 days)

You want to start by emptying the fuel tank as much as possible before you start. I did this by driving the car until the fuel light came on solidly on the dash.

The next thing to do is disconnect the battery, as fuel and sparks don't mix.

Now undo the fuel cap to release any vacuum or pressure in the fuel tank.

Next slide under the rear of the vehicle and locate the main hose between the lowest point of the fuel tank and the fuel pump. If you have a fuel clamp or a pair of clamp-able pliers then clamp the hose nearest the fuel pump and proceed to undo the jubilee clip that fastens the hose the fuel tank.

Below is a photo of the fuel pump with the main hose removed.

With the jubilee clip loosened get your empty container positioned below the tank to catch the remaining fuel. Wriggle the hose off the fuel tank and catch all the excess fuel until completely drained. You can now undo the much smaller hose that is also connected to the lowest part of the fuel tank.

Jack up the rear of the car as high as possible and set it on axle stands.

Now remove the rear section of the exhaust by undoing the 3 connecting bolts on the exhaust tube in the centre of the car and then unhook the rear box from its rubber hangers (shown below).

Next remove the four bolts that secure the exhaust heat shield (shown below) to the underside of the car.

Now remove the transmission (See this post for instructions)

Now it's time to get inside the car. Start by completely removing the carpet from the boot area.

Next pop out the rear quarter window on the fuel cap side and completely remove the interior panel of the same side (See this post for instructions)

Lay down the rear seat and un-clip and pull back the carpet from around the side of boot of same side to expose the fuel filler cover (Shown below)

Undo the surrounding screws, not forgetting the two small nuts at the base of the cover. Then as shown in the photo above position a screwdriver in behind the cover either side and pull towards you. The cover may resist at first because of the black goo it is secured with, but it will come away eventually to expose the filler hoses (shown below).

Undo the jubilee clips on all the hoses and pull off, with the exception of the largest hose which you can slide upwards to reveal the corner inlet of the fuel tank.

Now lift the large silver heat shield square located on the floor of the boot to expose the plastic cover for the fuel sender. Prise this up to in turn expose the sender wires. Make a note of what wire goes where and disconnect them all (shown below).

Get back underneath the car and locate the two large straps at either end of the fuel tank (shown below)

Undo the bolts and unhook the straps, the fuel tank is now only supported by the steel cross member it is wedged over.

Get your hands behind the rear most edge of the fuel tank and pull down. Keep wriggling the tank up and down checking that the fuel filler hoses aren't trapped. This part takes a lot of effort and patience as the tank is an extremely tight fit over the cross member and has probably never been removed before. Trust me the tank will eventually come free. You may need to unbolt the fuel pump from its rubber mounts if it gets in the way.

With the fuel tank removed we can now clearly see the fixed cross-member that stretches the width of the car underneath and the fuel filter bottom right (shown below).

As stated at the beginning of the post I decided to source a replacement tank from a breakers yard, it had a bit of dent in the side and some surface rust that I cleaned off. I then Waxoyled the whole tank to prevent further corrosion. I would also recommend you get them to pressure test the tank as I did. This helps prevent the problem of putting a tank back on that is the same or worse than the one that came off. It may also be worth checking the condition of the rubber hoses as they may have started to perish and go hard after 24 years of use and replacements would probably be a good idea.

Here are a few photos of the replacement non-leaking tank that I sourced from a breakers (note the expansion tank hanging off the bottom of the photograph and the fuel sender top left in the first photo).

Not shown in the photos is the large foam pad that sits around the fuel filler neck part of the tank. I carefully removed this before spraying the tank with Waxoyl. It was then finally put back on and stuck down with 3M Scotch Weld 80 spray adhesive before the tank was reinstalled.

Tank installation is the reverse of removal.

For more information on the steel fuel tank cracks and repair procedure if you can't source a replacement tank then follow this forum post. It also shows the differences in dimensions of the early and later 944 tanks side by side.

How to fit a short shift kit to a Porsche 944

THE WHY?

It has to be said that the 944 doesn't have the lightest gear shift you'll ever come across. So it makes sense to keep this part working as efficiently as possible. There are several ways this can be achieved. The first and by far the simplest is to make sure the transmission oil has been refreshed (A  job that only takes an hour, but can make your drive feel 100 times better). The second and third options involve replacing the shifter mechanism at either the gear stick end or the transmission end. Over time you'll find that wear and tear take their toll and the shift will not be as precise or as smooth as it should.

Since I had the transmission off the car and had noticed quite a bit of play in the plastic ball joint on the linkage I decided to replace it with and after market short shift kit.


THE TASK

This job is far easier if the transmission is off the car, however it is still do-able with it still attached. You'll need:

Socket set and/or ring spanners
Short shift kit (Bought mine off ebay, but you can also buy a really nice one from here)
Hammer

and maybe....

Hex rod and two rose joints (see foot of post)
Hacksaw (see foot of post)
Thread tapping set (see foot of post)



THE HOW TO

(Amateur mechanic Job Time approx: 1.5 hours (off the car) or 2+ hours (on the car)

Firstly identify the original shifter linkage and support arm attached to the gear box. If your transmission is still attached to the car the linkage sits on top of the transmission. You'll also need to slide back the rubber boot and undo the bolt that connects the linkage to the shift rod that runs through the car before you can continue.

Now remove the black rubber boot completely by sliding it off the linkage rod (you'll need to re-attach this to the new linkage later).

Next undo the nut and bolt at the top of the linkage where it joins the support arm. At this point the bolt on mine sheered as it was so old and rusted. If the same happens to you then you can either buy a replacement from Porsche or make you're own alternative support arm using some hex-rod and a couple of rose joints (See end of post for details on this).

Assuming you've not had problems undoing this nut and bolt you can then proceed to remove the small bolt that fastens the linkage to the shifting stub on the side of the transmission (Note: the flat side of the shifting stub that the bolt presses against). Having removed the bolt a small tap to the side of the linkage with a hammer should remove it from the stub and the transmission completely leaving only the support arm attached to the transmission at one end.

Here is a photo of the new linkage (left) beside the old one (right).

Installation of the new short shift linkage is the reversal of removal, taking care to line up the flat side of the shift stub as you slide on the linkage and do up the bolt. Then reconnect the support arm to the linkage and finally slide the rubber boot back on.

Here's what the finished article should look like.

Now for those of you that are interested in the support arm (The orange rod in the picture above). Having researched the short shift kit on the web before I attempted this modification there are several manufacturers all offering roughly the same piece of kit at varying prices. Some of the short shift kits come with a support arm similar to the one I made and some (like the one I went for) just make you use the original arm (and had the bolt not sheered then I would have reused the arm).

To make the arm you will need to source a length of hex-tube / hex-rod. In the UK this is easier said than done as most hardware stores don't stock it. Fortunately because I have been going Karting since the age of sixteen I happen to know that hex rods are used as the steering track arms on these vehicles. So a quick search on ebay for 'Kart track rods' brings up a number of results right away and at some very reasonable prices. The good news about buying them off ebay is that they usually come with the rose joints already attached at either end. If they don't then you'll need 1 x 8mm Left Hand Thread rose joint & 1 x 8mm Right Hand Thread rose joint (They are also known as 'track rod ends').

If you've bought your Kart track rod then you'll instantly notice that it has an 8mm thread cut into it at each end, one will be a left handed thread and the other will be right handed (Right handed threads are standard on virtually every screw you've ever come across). We need to make the rod shorter which means cutting off one of the ends. Leave the left hand threaded rose joint attached to the track rod and measure it up against the original support arm. Mark the length and use a hacksaw to cut off the standard right hand threaded end (we don't need this bit). You will now be left with left handed threaded length  and will need to re-tap an 8mm right hand thread into the sawn end. Once this is done attach the right handed rose joint and you'll have an adjustable support arm. By simply using a spanner to turn the rod you'll notice it'll pull the rose joints inwards and by turning the other way it will push them outwards.

Simply attach it in place of the original support arm using a couple of 8mm Allen bolts and some washers as shown in the photo above (Using Allen bolts instead of normal hexagonal bolts allows the rose joints to move more freely).

How to remove and replace the headliner on a Porsche 944

THE WHY?

If you've owned your 944 for a while and like me searched the internet to discover the pros and cons of owning one then you've probably discovered that the sun roof mechanism can become a little troublesome after 20 odd years of use. This often requires investigation of the gears and worm wheel mechanisms behind the rear headboard where the lifting arms are located. Unfortunately this also requires you to either peel back the headliner or cut holes in it so you can get at the mechanisms. Inevitably the headliner often tears leaving the inside of the car a little less than perfect (See below).

THE TASK

Philips screwdriver

Flat head screwdriver

Fat & thin rolls of double-sided sellotape

New headliner material

Lots of small bulldog clips (I used about 24!)

Scalpel (or craft knife)

Hair dryer or heat gun (optional)

THE HOW TO

(Amateur mechanic Job time: Approx. 1 day)

(Part 1 - Removing the headliner)

Start by picking a nice sunny break in the British weather and start as early in the day as you can, you'll need it to do a proper good job. It may be worth noting that if your sun-roof isn't working and you plan on fixing it then I'd do it before you install a new headliner. My sunroof repair guide will be up shortly.

Firstly completely remove the sun-roof from the car, this won't be going back on until the very end. Now unscrew the dozen screws that hold the rear headboard on and remove it.

Beneath it you should see headliner material stretching all the way to back window seal or like mine you will see the sunroof mechanism because the headliner had already been previously messed with.

Now turn your attention to the screws securing the sunvisors, remove all of them along with the sunvisors.

 

Next unclip the rear view mirror from the windscreen and prise out the cabin light that sits above where the rear view mirror was and disconnect the blade connectors and tape them up with insulation tape (We don't want any cabin fires). Tip: Use a flat-bladed screwdriver to prise the side out opposite to the switch first.

 

Now you're ready to remove the sun roof wind deflector. Start by prising out the microswitch button in the centre mount as shown in the photo below.

Here's the underside of the button once removed, you can see the two tabs at the longer end that hold it clipped in place.

Here's what the centre mount looks like with the button removed, note the screw in the centre and remove it.

Now you're ready to remove the mounts at either end of the wind deflector. Unscrew them and be careful to support the weight of the wind deflector as there are two fragile wires attached to the microswitch beneath the centre mount.

You should find that the only thing keeping the wind deflector attached to the car is now the two wires, either cut them and connect them back together later like I did or spend ages trying to prise the delicate microswitch out of it's housing. (Wind deflector completely removed below)

Now unscrew the two recessed mounts where the sun roof would usually clip into and you're ready to remove the front headboard.

To remove the front headboard get your fingers in along the edge that is closest to sun roof opening and gently but firmly pull down. It feels like you are going to break the headboard but it's just because it's been stuck there for 20 odd years. There is a little adhesive underneath it so you will just need to tug and wiggle it free. You may find it is really sticky along the the windscreen edge, just be careful and patient. (Photo below shows front headboard removed)

With the front headboard removed you can now carefully lift up the rubber trim that goes all the way around the hole left by the sun roof, being careful not to bend it.

After that it's time to remove the rear quarter windows. From the inside of the car start by getting a flat bladed screwdriver underneath the lower corner (nearest the rear of the car) of the rubber around the window. Once you have enough lifted to get your fingers underneath then do so. With your other hand begin to push that same corner outwards whilst peeling back the rubber further around the window. Once the window is half out move to the outside of the car where you can pull the window out. Be careful of the rubber running down the side of the doot pillar as it hooked over a lip of sorts on the outside of the car. 

Now go back inside the car and remove the little clothes hooks that are attached to the door pillars. You can also pull away the rubber seals around the edge of the door openings. You don't need to do the whole door, just enough so you can expose the edges of the headliner.

Now you just need to roll down the lining that is wrapped around the door pillar just enough expose the end of headliner, as we will be reusing this as it is not damaged.

Finally pull away the rubber seal around the top of the rear hatch opening.

You can now finally pull away all the old headlining from inside the car (Photos below show the headlining completely removed).

 

 

Depending on the condition of the headlining you may be able to salvage it and use the template to make your own headliner. Here's what the old headliner looked like once removed, pretty shabby.

And the now the new one I bought from ebay.

(Part 2 - Installing the new headliner)

Being the first headliner I've ever installed it was pretty much trial and error, but the end result was well worth it for the cosmetic difference it made to the inside of the car.

To begin with you will need to gather a suitable pile of bulldog clips (clothes pegs may even work), the more you have the easier it will be. Get 1 wide and 1 narrow roll of double-sided tape and a craft knife.

Step 1.

Start by loosely clipping the new headliner around the inside of the sun roof opening.

Step 2.

Make sure the parts of the headliner that go around the door pillars are sitting central on the pillar, remove and adjust the clips until you have got this spot on.

Step 3.
Remove the clips along one of the shorter edges of the roof opening and apply a strip of the narrow double sideed tape over the lip. Stick the headliner to it and re-clip. Repeat on the other side.

Step 4.
Now along the longer edges of the roof opening one at a time do the same as step 3 with the double-sided tape and re-clip. If the material doesn't seem to be fitting at the corners, don't cut or trim it just yet as you want to leave it until the last possible moment. You can always peel back the liner and re-adjust as you go along.

Step 5.
Stretch the headliner towards the back of the car around the rear hatch opening. Again clip it along the entire length until you are happy with the fit.

Step 6.
Move onto the liner around the door and quarter window. Depending on the material you have you may need to use a heat gun or hair dryer to get it to stretch around the door pillar.

Step 7.
We are going to leave the front section right until the end as it takes care of itself when the front headboard and fittings go back in place, so leave it for now. Instead concentrate on getting the fit and stretch right all the way around the rest of the car re-adjusting where necessary and adding double-sided tape as needed. Once you are satisfied with the outcome you can begin to trim some of the excess material away and reattach the rubber trims. Begin by re-applying the sun-roof rubber trim as everyything stretches away from it making sure you fold a little of the excess headliner over the trim lips and edges.

Step 8.
Re-apply the rear hatch rubber.

Step 9.
Roll up the lining on the pillars before re-fitting the quarter windows. Make sure the pillar edge of the window pushes in first starting with the bottom corner. Use a screwdriver to pull the rubber over the lip from inside the car (work your way around from pillar edge bottom corner to hatch bottom corner to top hatch corner and finally to pillar edge top corner) until the window is back in place.

Step 10.
Make two holes in the headlining so that the wires for the sun-roof switch and interior light can poke through.

Step 11.
Trim the headlining around the windscreen pillars and tuck behind the the trim on these where necessary. Now take the headboard and manouvre it into place. Take one of the sun visor clips and screw it into place. Do the same with the other. Re-attach the sun-visors completely.

Step 12.
Re-connect the wind deflector microswitch wires and re attach the wind deflector.

Step 13.
Re-attach the sun-roof clip housings.


Step 14.
Re-attach the clothes hooks to the door pillars.

Step 15.
Re-attach the rear headboard making sure you've trimmed enough of an opening for the sun-roof lifting arms to poke through the headlining.

And now the finished article.

How to change transmission oil on a Porsche 944

THE WHY?

If your 944 is 25 years old like mine with just over 120,000 miles on the clock then you may have noticed that the gear changes are not as smooth as they once were or maybe your gearbox is whining a bit. Then it's quite possible your gearbox / transmission needs some fresh lubricant.

THE TASK

Quite a simple one really. This is what you'll need.

17mm Hex bit
Torque wrench
Anti-seize thread lubricant
Swepco 201 gear oil (Approx £50) - You get 3.8 Litres in the bottle, the transmission needs 2 Litres
A large syringe
Bowl to catch old lubricant

THE HOW TO

(Amateur mecahnic Job Time approx: 1 hour)

If your transmission is still attached to the car then it's probably best to give it a 10-15 minute drive to warm the old oil up so that it flows out more easily. My transmission was already off the car so I just had to make sure it was on a level surface. The transmission is located under the rear of the car. Take an empty bowl and place it under the left hand-side of the transmission ready to catch the old oil. On the left side of the transmission you will find two identical oil drain plugs situated to the right and below the drive shaft mount.

Start by cleaning off any dirt or rust around the threads on both drain plugs, give them a spray of penetrating oil too. Remove the upper plug first (in case the lower one is seized then you haven't lost all your oil with no way of putting fresh oil back in). Then remove the lower plug using a 17mm hex key, the oil should then start to flow out. Once all the old oil has flowed out stick your finger in the hole and feel around checking for metallic particles left in the bottom of the transmission. If there are then your tranny may need a little more attention than just an oil change. Now is a good time to inspect the condition of the drain plugs. Mine were pretty old and roughed up so I decided to change them for new ones, only a couple of quid each from Porsche. Notice the tapered thread on the drain plugs.

Now apply a little anti-seize thread lubricant to one of the drain plugs and tighten it into the lower hole to a torque of 20Nm. Now fill the syringe with Swepco 201 gear lube which I bought from here and pump it into the upper right hand hole. Repeat until the oil comes level with the bottom of the hole you are putting the oil into. Once you're there apply the same anti-seize thread lubricant to the remaining drain plug and tighten to 20Nm. Job done.

How to install new bonnet / hood sound absorber on a Porsche 944

THE WHY?

The benefits of installing new sound absorber to the underside of your hood / bonnet are reduced noise. It also keeps the heat inside the engine compartment preventing damage to external paintwork and keeps the engine at the optimal operating temperature aswell as insulating it from the sun and snow.

THE TASK

Before you can start you will need to remove all the old sound absorbing material, see my other post for a how to. This is very important as poor preparation could end up costing you a lot of money.

You will then need the following items:

a. Methylated spirits
b.Wax paper or baking parchment
c. 3M Scotch Weld 80 Spray Adhesive (£15)
d. Scalpel
e. 2 x sound absorbing pads from Porsche or here (£30-40 per side)
f. Large sheet to cover engine bay
g. Masking tape
h. Old newspapers

 

 

THE HOW TO

(Amateur mechanic Job Time approx: 1-2 hours)

As stated above you should have completely cleaned the old sound absorbing material from the underside of the bonnet /hood. If not see here for a how to.

Now begin by covering the engine bay with a large sheet, this will prevent any glue getting on the engine. Next use newspaper and low-tac masking tape to mask off one of the sound absorbing areas as shown below.

Give the exposed area a quick wipe over with methylated spirits to remove any grease, allow a moment for the meths to evaporate. Now depending on what sound abosrbing material you've bought the process here may differ. If you've bought genuine Porche sound absorber I believe it has it's own adhesive backing. If like me you bought 3rd party sound absorber you will need to use a special heat tolerant spray adhesive called 3M Scotch Weld 80. Spray the exposed area giving it a generous coating, then tear off two large sheets of wax paper / baking parchment and stick these over the glued area (as shown below) making sure you leave about 2-3 inchs of exposed glue along the top edge.

Now pick up the corresponding sound absorbing pad and coat the back of the pad in the same 3M adhesive. Once you've done this take the top edge of the pad and carefully line it up in the correct position and stick it to the underside of the bonnet. This glue is not repositionable so precision is the key here. Once you are sure you've got it lined up correctly remove the upper most sheet of wax paper and carefully smooth down the pad making sure you massage any air pockets out to the edges. Then remove the lower sheet of wax paper and smooth the final piece down. You may find that the bottom edge overlaps the area, but before you trim it make sure you remove all the surrounding masking tape and newspaper. Now simply trim off any excess with a scapel and press down all the edges. If you've got any bubbles use a pin to make a smal hole in the centre of the bubble and massage out the trapped air.

 

Now mask up the other side and repeat the process.

Now the finshed article with transfers applied

 

Here is a link to the 3rd party manufacturers instructions in case you are still unsure or need further detail.