knocking

[bigb1970]

Is there anything common which can cause knocking over bumps at low speed ie bushes/shocks/top balljoints/ wishbones

[stuart]

Hi

The front suspension on 98- Passats has 4 wishobones, and an anti roll bar link on each side. These are a very common area for failure.

From what you say, I would imagine one of these wishbones/links are worn.


Stuart

[bigb1970]

cheers what i thought

[billybob]

Recently done my 4 lowers as they were creaking. Now got knocking on O/S. Guess it might be the upper suspension arms now :( The list of jobs is endless!

[bigb1970]

complicated front susp set up on a passat prone to wear

[billybob]

Aye

Nice car but I'd kinda like my weekends back :)

[glynnd]

Welcome to the world of passat ownership!

:biglaugh:

[billybob]

so far this year

new rear discs and pads
new viscous fan unit
4 new lower suspension arms
new oil pump
new clutch
lots of smaller jobs

These jobs suck when you're on your drive in winter. It's cold and gets dark by 4pm!



Still got a bunch more including
a bad boost leak that I can't find
The above mentioned knocking
a petrol smell after turning the car off
A slack gearbox
others

what fun :)

[glynnd]

Have you replaced all the seals to try and cure the boost leak?
The passat boost pipes are the worst I have seen on a turbo car, particularly one that blows up to 30 psi!
I have the same problem cant find mine either!

:biglaugh:

[billybob]

So far I've had the lock carrier off twice to check all obvious hoses (had all larger hoses off individually but I'm struggling to find anywhere other than VW who stock the clips for the small vacuum lines so haven't actually pulled all those off apart from the two coming from the intake manifold which I have replaced as they were a bit ropey. I have also invested in a new diverter valve. I could replace the whole system but that would be crazy and can't afford to buy another item that doesn't actually need replacing.

Someone has mentioned it could be the actuator on the turbo sticking. Not sure how that would give me the sound of a leak but I guess air has to go somewhere.

What exactly do you mean by 'seals'?

cheers

[glynnd]

All the larger boost pipes have seals on them where they connect into the intercooler and the steel pipe running under the rad. There are also a couple on the pipe from the intercooler to the plastic charge carrier running up past the oil filter housing. Also one located in the pipe which connects to the egr valve. They are around £2.60 plus vat each.
By the way which part are you calling the diverter valve and where is it located?

:biglaugh:

[billybob]

I would always call it a dump valve but passat folk call it a diverter valve. Maybe it is slightly different?

These seals, do you mean the big hose clips?
I know the big pipe that runs under the front of the car from one side to the other is quite rusty. I guess it could be a contender. I think I'll buy some duct tape and try patching bits up temporarily.
I've had all the big hoses off to check for leaks and have reused the hose clips as they all seemed fine. Have had the intercooler out and even gave it a wash! Looked fine but I guess these things can be hard to spot.

I'm also gonna whip the turbo off at the weekend and check that over for cracks. Been recommended to test that pressure at which the actuator rod is opening but don't have the tool for that. Will give it a clean though

Also gonna replace a few more of the smaller pipes

[glynnd]

It certainly is called a dump valve.Where exactly is it?
The seals can be found at the ends of each boost pipe, not the clips that hold them in place. Remove the boost pipes and the seals are at the ends where the boost pipes join together. I dont think the steel pipe will be at fault unless its been hit by something.

[billybob]

To get to the dump valve follow the small (probably braided) vacuum hose from the front of your inlet maifold to the wee plastic contraption sitting a foot or so beneath your turbo. vacuum hose will enter on one side and there are 2 1inch(ish) hoses coming off it also.

My hoses to intercooler and large steel pipe only have hose clips. Not seen a seal on any of them!.
What is an EGR valve? Is that also known as the N75 valve? Learning all the time :)

[glynnd]

You need to loosen the clips and pull the rubber boost pipe clear, the seal will then be seen at the end of the rubber pipe.