How to remove and replace the headliner on a Porsche 944


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).


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)


(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


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.


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


(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 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.


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



(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.

How to repair heater control valve on a Porsche 944 (Square Dash Model)


One of the good things about the 944 is that it doesn't take long for the engine to warm up, which is great in the winter when you need to de-mist the inside of the windscreen and heat the passenger compartment. However it's not so good in the summer if like mine your heater is always giving out hot air even when the heater slider is set as far over to the left handside (the cold setting) as possible. This is caused by usually one of two possible problems. Either the hot/cold slider has a broken cable or the heater control valve (HCV) is faulty. It is usually the heater control valve (HCV).


It is important to note here that the HCV and heater mechanism are completely different on the square dash 944 model to the oval dash 944 model. Oval dash owners should look here and here as this guide is only for square dash owners.

This job is relatively simple (if a little fiddly) and should only take an hour or two.

You will need the following:

Long & small flat bladed screwdrivers
Long-nose pliers
Heater Control Valve (approx £20 from Porsche main dealer)


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

Firstly it's important to know what the HCV actually does. The HCV is basically a tap that allows hot water from the engine to enter the heater matrix. When you set your heater to hot the tap opens and lets hot water into the matrix and when you set it to cold the tap closes stops the hot water entering the heater matrix.

It's also important to understand how the heater controls work on a square dash 944 as I've seen alot of confusion over this on some forums. There are 4 controls for the heater. This is what they do:

Upper left slider controls the direction of heat (footwell & centre)
Upper right slider controls the direction of heat (centre & windscreen)
Lower slider controls the hot or cold setting
Dial to the left of the sliders controls the fan speed (Off & speeds 1,2,3)

To begin with it's important to make sure the cable that goes from the hot/cold slider to the HCV is not the fault. Start with the lower hot/cold slider all the way over to the cold setting as shown below.

Now open the bonnet and locate the heater control valve which sits tucked down at the back of the engine smack bang in the centre. Below is a picture of the heater control valve.

Because the heater slider is set to cold the heater control valve should have its white arm all the way over to the left hand side (as shown below). You can even see the cable extended.

Now go back inside the car and move the hot/cold slider all the way towards the hot setting. Go back and look at the HCV and you will now see the white arm has moved all the way over to the right (as shown below).

If the white arm of the HCV is not moving then your problem is with the cable. Either the cable has become disconnected at the HCV end or at the hot/cold slider end. Or the cable has broken in the middle somewhere. If the arm is moving you now know that it is very likely that the HCV is the fault.

To remove the HCV you will first need to remove a small metal clip that locks the black outer of cable to the HCV. Do this with your fingers or a pair of long nose pliers. DO NOT LOSE THE CLIP otherwise the cable will not be able to work the HCV. Now unhook the inner cable from the small hole at the end of the white arm on the HCV. Next you will need to undo the 2 hose clips that help secure the 2 hoses to either side of the HCV. Once this is done twist and wriggle the HCV loose from the hoses. Do not be alarmed if water comes out of either hose whilst doing this, just make sure you don't allow the lower of the two hoses to hang down once you have removed the HCV as water will go all over your clutch, just wedge it so that it's upright.

Below is an image of my new HCV (left) against the old HCV (right). Note the washer in the middle that appears to have come loose inside in the old HCV.

You are now ready to install your new HCV. Installation is the reverse of removal. By far the hardest and most important part is re-attaching the metal clip around the black outer of the cable, it took me several attempts and you might be advised to familiarise yourself with how the clip works with the HCV before you attach the hoses to the new one.

One last important thing is that you may or may not have to top up your coolant level as some will be lost when you removed the HCV.