B6 S4 heavy steering

[Ceramicolive]

Hi to all,

I'm new here and this is my first post I just bought a B6 S4 cab tonight and the steering is very heavy, there is obviously something wrong with it, it drives fine at speed but you still notice that it's heavier than normal. At low speed is where it is most noticeable.

Anybody on here a B6 guru or had this problem? Are pump/rack issues a thing on these I can't find a definitive answer doing a search lots of people reporting it but nobody posting the fix.

Thanks

 

[Mike B]

Have you checked the easy things ?tyre pressures fluid level?Then check for noises and leaks.Maybe the front suspension and tracking need a look by a specialist

 

[Ceramicolive]

Not yet, like I said I literally just bought it and drove it home tonight, I'll have a good look around it tomorrow but just wondered if there was a common fault with these. Thanks

 

[Mike B]

Not surprising for systems to suffer as they age but no I don't know if S4s are prone to it more than others.Has it got a big mileage?I have only topped up my 04 2.5tdi once in 5 years but my 03 TT has just started to leak on 130k and failed its MOT.I didn't notice any heaviness in the steering cos it still had enough fluid left.Topping up is something which is overlooked in servicing

 

[Ceramicolive]

72000 FSH I'll check the basics tomorrow but I'd be surprised if the fluid was low the guy I bought it off had automotive ocd!

 

[Mike B]

It also depends on what you think is normal.The 2.5 is heavy at slow speeds cos its a big Quattro on wide tyres whereas the TT is much lighter

 

[Ceramicolive]

That is a good point. I haven't driven one before tonight but it was a bit of an effort turning into a junction from a main road i.e 90 degrees.

 

[SteveMcB]

If it's OK on the move but heavy at low speed it could also be the servotronic module, mine stuck giving these symptoms.

On the B7 it's above the driver side fuse box, looks like a relay, black with white numbers on it, 640 on mine but there are a few different ones. I'd suggest unplugging and see if you notice a difference or give it a tap to see if it frees up.

Edit - just remembered it was temperature related, as a test try taking it out and warming it up with a hairdryer.

 

[boffin486]

Another possibility is simply the steering coupling - they can sieze up. A good going over with WD40 and some 'wiggling' works wonders......

 

[Ceramicolive]

If it's OK on the move but heavy at low speed it could also be the servotronic module, mine stuck giving these symptoms.

On the B7 it's above the driver side fuse box, looks like a relay, black with white numbers on it, 640 on mine but there are a few different ones. I'd suggest unplugging and see if you notice a difference or give it a tap to see if it frees up.

Edit - just remembered it was temperature related, as a test try taking it out and warming it up with a hairdryer.

Its them same weight at all times I just think it's just more pronounced at low speed. I'll test the relay tomorrow, thanks.

 

[SteveMcB]

Try turning the wheel with the car rolling forward with the engine off, that'll give you an idea of what no power steering feels like. If it's anything like mine Popeye wouldn't have a chance! If you've got power steering but no low speed over assist I'd bet (at least a tenner) on it being servotronic related and another fiver on the module.

Hope I'm right because it'll be an easy (plug in) DIY fix for you. Think the modules are about £140 from TPS but they come up on ebay.

 

[s4mark]

My S4 steering is very light at low speeds and tightens up at speed as it should. My car has done 137k miles so something definateley wrong with yours. As stated, I would check fluid first and if low check for leaks

 

[Ceramicolive]

Fluid level is full, so it looks like either the 640 unit or the module I think unless there is anything else I should check?

 

[rjm180]

Hope its a simple fix for you

 

[Ceramicolive]

It was an easy fix in the end I changed the 640 servotronic relay, it took me 5 minutes and it's back to normal. superb, I even got the relay for £25 so a massive result all round!

 

[SteveMcB]

Nice one - did you take my bet?

 

[Ceramicolive]

hahaha, cheques in the post

 

[CJeff]

Hey - I had the same problem start last week. Heavy steering at low speeds, all of a sudden. Took it to the local shop - diagnosed low pressure at pump, suggested pump replacement and then hoses if that doesn't fix it. Around $2k...
Then I find this. I get on eBay and buy the 638 module for $50. Put it in just now and all fixed.
Just wanted to say thanks so much to all contributors who bother to get online and post these fixes. You don't have to - but it sure is so valuable to all users. Really appreciate it.
I posted one a few years ago on a different forum about a faulty brake switch causing throttle lag, stuttering and other on manual S4 B6. Surprising how many found it and it helped.
Let's keep doing what we do.