Paddcomp

I've read the threads on water bridge removal with the intake in place which is deemed possible. I did the obligatory rounding of the rear left bolt due to poor access between the bridge and intake, resulting in drilling off the head. I'd tried various options first, such as hammering a torx bit in, but without success.
Drilling gave the result required and the stud was then easy to unscrew with little effort.



Now removing the bridge was a wrestling match, with lots of doubt regarding the room available under the oil filler neck. Ended with the use of a 3ft pry bar, which didn't seem right on a Porsche 928.

Question is how will I get it back in with new seals, as I will need to take care of the new seals. Any tips, photos, recommendations appreciated.

For your amusement see a photo of my front knock sensor, which passed inspection in my 928 garage, with the comment knock sensor faults are due to using cheap fuel!



I'm planning a full intake refresh when I've more time, other than the knock sensor and a water leak, no need currently.

Brian
'88 S4 auto UK

Speedtoys

Considering the age-related issues you are tackling right now, it's a mistake to NOT pull the intake manifold and manage the ones that exist there as well...right now.

Captain_Slow

+1 I'll be doing the same this summer.

Paddcomp

I know what you mean and I'm not disagreeing with you, but I've check the TPS, and flappy actuator. The rear knock doesn't exhibit the same issues as the front. I do intend to do more work as time permits, but the weather window in the UK is so small these days I only have 12 sunny days to enjoy the 928 to the full.
Other than the issues the knock creates the car doesn't have any other issues.

Speedtoys

Well..if you're that picky about the 12 days you'll drive it, be pickier about maintenance.

Without making things pretty, you can do that intake refresh in a day, off & on with the only special bits being replacing the throttle and flappy plate bearings..which are four nice vacuum leaks as it sits right now. If the flappy works at all.

Your other issues are vacuum leaks, and "that rubber hose that will split open tomorrow".

Not to mention the vacuum leak you have now from loosening that one intake manifold nut..because..you cant 'snug it down' farther than the hardware will let you, which is where the rubber grommet has already collapsed to.

Chalkboss

If you're not going to go big, just get the waterbridge seals and o rings. They go on with no sealant, make sure the side seals for the water bridge are secure upon installing bridge. Replace inner seal and thermostat. Oil filler neck likes to leak. Use sealant here plus gasket. I would also replace the bridge bolts, and use ptfe thread compound on the threads.

Paddcomp

Hi and thanks,
I've seen a TSB that the bridge should now have paper gaskets, to stop leaks which I didn't have before but will have if I don't follow the TSB. There's also a recommendation that the oil filler neck in later cars should be fitted with the paper gasket from earlier cars. I already have the o rings for all the above, and have added the PCV hose and gaskets to another parts list.

It was such a struggle to remove the bridge I'm just wondering if it will be just as hard to replace, and what effect this will have on the new seals / gaskets. I have new bridge bolts and anti seize paste.

SteveG

Many use paper gasket AND sealer. The OEM rubber gasket is very thin and not up to the task. It is also not circular, which may contribute to the failure rate.

The Deputy

Maybe a torx bit headed bolt would work better in that difficult to reach spot.

(This is just an example...not the actual bolt size needed)

http://www.albanycountyfasteners.com...m?1=1&CartID=0

Good luck, with your repair.

Brian.

Paddcomp

Revisiting the rear knock sensor revield it's every bit as bad as the front one. So the intake came off, I've checked the flappy actuator and TPS. Oil breather hoses replaced and the small vacuum lines replaced and check against the diagram in WSM.
No as bad as I expected, once I had the new seals it was back together in a day.
Also used the paper seals along with the O rings on the bridge and filler neck, replaced the bridge bolts with SS allen types.

As I've learnt at lot from this and now understand how to do it, I've ordered flappy bearings and will find a local powder coating company for the refresh. I'll also look in to the dynamic kickdown mod.

dr bob

It is possible to replace the rear knock sensor without removing the intake manifold. I have small hands, so "possible" is possible for me. Can't reach the front sensor from the rear with the intake in place though.

SteveG

Is this thread about water bridge R&R or knock sensors?