26/10/2010

Power Steering Location on a Porsche 944

THE WHY

If your gut feeling tells you it doesn't look right then it usually isn't.

When I first got my 944 the previous owner told me that he'd had the power steering unit fitted several years previous because his wife found the car difficult to drive (early 944's like my 1984 had optional power steering), and this was confirmed with the receipts in the service history. The first time I noticed something wasn't quite right was when I removed the floor pan and noticed one of the power steering lines on the outside of the sway bar mount. This made me suspect that the location of some of the other parts weren't correct either and so I got to researching where they should be. This proved more difficult than I had anticipated as both the Porsche service manual and Haynes manual have no diagrams and very very poor photographs. Fortunately after posting some photographs on the Pelican Parts forums I found some very excellent members who helped me out.

THE TASK

I was only relocating the cooling coil which required the following:

10mm socket
10mm spanner
Socket extension bar
Socket Wrench
Dexron II Automatic Transmission/Power Steering Fluid (Approx. £5-£7)
Flat bladed screwdriver
Cross-head screwdriver

THE HOW TO

(Amateur mechanic job time Approx. 2 hours)

Half the battle with this particular job was establishing right from wrong and making sure I had the correct parts and brackets. It is also worth noting that there are two versions of the power steering oil cooler, fortunately the more common coiled version fits later and early models with the correct bracket.

Early (Square Dash) long cooler coil - quite rare I think

Later (Oval Dash) looped cooler coil


THE WRONG WAY TO MOUNT THE COOLER COIL

So here's how the cooler was wrongly mounted and why I couldn't just leave it where it was. The picture below shows it mounted incorrectly in the engine bay on the radiator between the fan and the lower radiator hose.


The coil is very rusty and has been twisted to fit the location. Look how close the lower part of the coil is to the power steering belt! And has also been zip-tied to the power steering pump belt adjuster arm.





Longer arrow below shows just a single clip attaching the coil to the lower right hand corner of the radiator



Arrow below shows a kink in the rubber hose due to it being routed incorrectly




THE RIGHT WAY TO MOUNT THE COOLER COIL

To get an idea of just how wrong the location was take a look at the photo below which shows the coil correctly mounted ahead of the right front wheel and NOT in the engine bay or near the radiator at all.


So here's how I set about mounting mine after a purchased a good 2nd hand coil off ebay with the correct mounting bracket. I set the car up on axle stands and began by draining out the existing power steering fluid by simply detaching the hose from the lower end of the old coil. Do not reuse the old oil when you come to bleed the system at the end. I then removed the hose that secures the coil to the power steering bottle and detached the coil from the mount on the radiator. I then set about locating the mounting position using the photos form the Pelican Parts forum.

The photo below show where the bracket will attach directly below the washer bottle.


Now with bracket attached


Flip the headlights up to make threading the solid metal part of the coil around the front of the washer bottle easier.


Arrow below shows the headlights up and where the tube should appear


Arrow below shows the same tube but with the headlights down making sure it doesn't affect the headlight mechanism.


Photo below shows how the coil clips into the bracket


First arrow on left shows the end of the coil being held by the second bracket (attached to the corner of the raidiator bracket) and hose fed along engine bay towards steering rack.


Continuation of above picture showing hose going to steering rack.



Having securely connected up all the hoses I then proceeded to bleed the system. Whilst the car is still up on axle stands fill up the power steering bottle with new fluid to the correct level, then turn the steering wheel all the way from left to right several times whilst topping up the fluid to the correct level as it will drop on the cap dipstick as the air in the system is forced out. When the level appears not to drop anymore then you may run the engine and repeat moving the wheel from extreme left to right and vice versa making sure the fluid level doesn't drop and topping up if necessary, also check for leaks on any hoses too.

If your power steering rack needs replacing see my other how to here

11/10/2010

Erratic Idle Problem Porsche 944 (Square Dash Model)

THE WHY

The words idle, problem, Porsche and 944 seem to appear more times together on any forum than any other niggle to do with the car. The reason they appear so frequently is that there are a number of situations and/or combination of situations that can cause the idle speed of your 944 to behave erratically as the following clip of my own car shows.




You will find a lot of posts talk about the cause being vacuum leaks or something known as the 'Idle Control Valve' or 'ICV' as it is often abbreviated (the Porsche parts catalogue calls it the 'Idle Speed Adjuster'). What is not often clear is that the ICV only appears on the Oval Dash models of the 944. The difference in configuration between the Square Dash and Oval Dash models can be seen in the two diagrams below.


Square Dash configuration

Part 9 - Auxiliary Air Regulator (944 606 103 00)
Part 16 - Electric Air Valve (944 606 215 00)




Oval Dash configuration

Part 18 - Idle Speed Adjuster (930 606 161 00) ... aka ICV




I have no idea why Porsche changed the design but if you are an oval dash owner you may want to check out this post if you want to test your ICV. If you're a square dash owner then read on.


THE HOW TO


(Amateur mechanic job time approx. 30 mins)


Fortunately the fix for my 1984 square dash model didn't require checking for vacuum leaks. The problem was actually dirty electrical contacts on the Auxiliary Air Regulator and Water Temperature sensor on the radiator. This occurs due to the constant heating and moisture that the engine bay is subjected to.


Auxiliary Air Regulator




Water Temperature Sensor (located top corner of radiator on the air box side) - Top view




Water Temperature Sensor (located top corner of radiator on the air box side) - Bottom view




To clean the contacts simply pull the connectors off their plugs, spray the contacts with some electrical switch cleaner and before reattaching apply some switch grease to the contacts to prevent moisture from corroding them in future.





12/07/2010

How to repair sunroof on a Porsche 944 (Square Dash model)

THE WHY

Before I bought my 944 I did a fair amount of research on the net to find out about the things to look out for when purchasing a car of such an age. Amongst some of its well know weaknesses the sunroof lifting mechanism happens to be one of them. There also happens to be TWO versions of the 944 sunroof lifting mechanism, one for the earlier Square Dash model and one for the later Oval Dash model. A lot of the forums and tutorials on the web will often cover the Oval Dash model only which has a habit of stripping the white plastic gears (two gears, one in each lifting arm), and a simple fix for it can be found here. The Square Dash model does NOT have these gears and uses a different method to lift the roof. A good tutorial for fixing both versions exists in the official Porsche Workshop manual (contained in this tutorial) and here at Clarks Garage. I used both of these sources to help understand and fix the sunroof on my Square Dash 944 and have therefore provided more detailed pictures to supplement these existing guides.

THE TASK

You'll need the following:

Philips cross-head screwdriver
Flat-head screwdriver
Cleaning wipes/cloth
Degreaser

THE HOW TO

(Amateur mechanic job time: Approx. 1-3 hours)


Having taken the complete mechanism apart I discovered several faults on mine, these were as follows:

1. Broken drive dog (Shown further down post)
2. White transfer box mounting holes disintegrating


3. Both black lifting arm boxes mounting holes disintegrating


4. Main drive coil and left lifting arm coil missing several coils where it engages white transfer box



Luckily I managed to source items 2-3 in one 2nd-hand lot on ebay, and item 1. I was easily able to get from Porsche.


Tips for reassembly:

Once all the new parts arrived I cleaned out all 3 drive tubes using pipe cleaners and degreaser, then degreased all the coils themselves. I also cleaned all the accumulated dirt from the drive motor and slide rail too.

I then re-greased the drive tubes and coils as well as the lifting arms themselves.

The next step involved attaching the the new drive dog (white plastic square in photo below) to the new main coil I'd received. Luckily the new coil I received had the modified screw-in connection (upper picture) for the drive dog as opposed the old crimp style version (lower picture) on the broken coil.


Once the drive dog was attached I then threaded the coil into the drive tube in the boot (shown by right-hand orange arrow) so that went all the way back into the car. Left-hand arrow is the power connection for sunroof motor.


The drive dog was then slid into the rail on the motor assembly with the correct length of coil (305mm).


The motor assembly was then mounted back in position


Next I moved back inside the car to assemble the lifting arms and attach them to the transfer box. I made a slight modification the lifting arm boxes by securing them with zip ties after they had been secured together. I did this because the fixing holes on the previous pair had disintegrated where the screws had either been over tightened or the pressure of the arms had made the boxes explode. The zip ties therefore help spread the strain the screws come under.


Now finally, the transfer box is quite a tricky part to piece together with one pair of hands especially as all 3 drive tubes and their coils have to be lined up correctly. To make up for the lack of an extra pair of hands I used a 3 zip ties to hold the two drive tubes (that are attached to the lifting arms) in place in the transfer box before I inserted the drive gear and then finally the main drive tube (in the space shown by the orange arrows).





Once the whole mechanism was assembled and secured it took a bit of trial an error lining the lifting arm boxes up with the insertion point in the roof. This was achieved by packing them out with a few large shilling washers (shown by orange arrow).


The last piece in the jigsaw involved setting the limiter on the microswitches back on the motor assembly (shown by orange arrow).