mike77

The hall sender on my 1990 S4 has a broken plug on the sender connection end. Also it looks like I have a leaking cam cover. I can't see exactly where it is coming from but it looks like oil is evaporating and collecting under the air intake tube on top of the cam cover and also along the engine brace. So looks like I need to do the cam cover gaskets and at the same time get the hall sensor swapped. So far my shopping list looks like this.

928 104 447 09 Gasket x1 (Main cam cover gasket)
928 104 443 08 Sealing ring x4 (Spark plug gasket)
944 606 170 02 Hall Sender x1
999 170 156 90 spark plug x 8

I see there are also pan head bolts and related thrust ring, thrust washer and sealing rings. Should I replace all this stuff out too or can some be reused?

Also there is some plumbing on top of the cam cover that looks like it needs to be removed to get the cover off. 2 rubber pipes and one metal, are these fuel related? Would this be a good time to replace them?

Also is there anything else I should be thinking about replacing while I'm at it?

Not sure if I want to tackle this myself or not. Looks like it could be fiddly and the posts I've read appear to agree.

FredR

Mike,

Removing and replacing the cam cover is generally an easy job to do. The trick is to use a non hardening sealant to bed the gasket and the spark plug seals into the cover - not the sealing face itself. I use silicon RTV to do this - others have recommended different sealants. If you have not done this before and do not know the age of the current seals better to replace them. The only place I use a little sealant is on the 90 degree stepped corners. On mine with relatively new seals I have had them on and off 3 times now with the same seals- not saying this is good just that it has not let me down. I take the view point that if the gaskets are still very elastic they should work- but if there is any doubt just sling them. Remember there is no pressure feed on these joints they just need to prevent oil from dribbling out of the cover.

I would take some advice on the Hall trigger- apparently that can be a bit awkward to replace and the items I have read on it suggest it is easier to do when the cam wheels are off.

As I am aware there are no obvious "while you are at its" for the cam covers unless you need to do something inside the cover itself. A good time to take a look at your cam lobes and the chain tensioner for signs of wear?

The fuel supply line crosses over the UK driver side 1/4 cam cover and the two rubber pipes that vent the cover are part of the 90 S4 breather system. I pulled my 1/4 cover off a few weeks ago to modify the breather system vent and I seem to remember I id not have to remove the fuel line.

The fiddly one is the 5/8 cover. You need to get the throttle cable harness out of the way and the venturi pipes. There is a power steering line [I think] that runs along the edge of the 5/8 cover that sort of gets in the way but it is not too difficult to manipulate and a couple of the cover holding down bolts are awkward. You should also consider purchasing a set of the rubber crush washers that sit under the collars on all the holding down bolts- just note that there are two bolt lengths- usually obvious what fits where.

Rgds

Fred

Rob Edwards

The Hall sender plug can be replaced for cheap, Roger sells the plug end. DIY writeup here:

https://rennlist.com/forums/928-foru...ing-wiait.html

Speedtoys

Might be a proper time to look at the intake refresh too.

If the covers are leaking...so is vacuum in the intake...

John Speake

Hi Mike
I stock the 3 pin plugs and sockets .....

mike77

Thanks Fred you're making this sound not as hard I thought so I think I'll get stuck in.

I'm having a hard time working out which are the rubber crush washers. Listed in that area are:

thrust ring 928 104 115 02
thrust washer 928 104 116 00
sealing rings 900 124 144 30

Looking at pics online I think it is thrust ring 928 104 115 02 but it lists 26 for the car, half that (13) sounds too many

Rob thanks for the link. Looks like this will save some cash. I'm in the UK so John you'll be getting an email from me about the connector.

Afraid not! Want to drive the car this summer. At my snail pace I would be off the road until next summer. I'm also at risk of losing the garage I rent at fairly short notice. Need to keep the car mostly in one piece at the minute just in case. It's on my todo list.

Mike

Speedtoys

This can be greatly simplified, by calling roger and saying "cam cover refresh kit please".

mike77

Yeah I know but the only problem is that I'm in the UK. Means import tax and having to go collect from the depot. I've got a porsche centre just up the road from me. I've had a few parts from the US, eg pktensioner from Roger.

ROG100

Mike - my master list on the way to you - use it as a reference for the numbers you need.
Also a really good tutorial.

Speedtoys

It's called "spare parts, $10" Roger..on his invoice to customs.

mike77

Found dwaynes guide for this and it confirms 13 is correct. All parts now ordered.

Saved some money on the plugs for the hall sender so bought a performance chip from John as well. Will fix the sensor first and see if I notice a performance improvement, then add the chip later.

Also wondering if I should change oil after replacing the cam cover gaskets? My oil has less than 200 miles on it but am wondering about contamination risk.

mike77

Attempting to get this cam cover off. I've had to remove what I think is the diverter for the air pump. As I've removed the cats can I leave this off when I reinstall the cover and block the hole up on the base of the air filter housing?

There is one small tube that attaches to the top of this diverter which I don't know what it does. Other than that it it just looks like it connects from the pump, air filter housing and down to the cats

Rob Edwards

Yes, just plug the bottom of the airbox. The small tube on top of the diverter valve is a vacuum line that is connected to the intake- you need to plug that vacuum line with a golf tee, a short M6 bolt, or a factory plug specific for the task, 900 312 012 02.

mike77

Thanks Rob. Good info. Less for me to put back together.

Rob Edwards

Yes, getting that diverter bracket mounted on the cylinder head with all the other junk in there is a bit of a pain in the ****.

Have you removed the air pump as well?