Knocking now driving me crazy

[Marshall1975]

Over the past 1500 miles I have changed the following front suspension components but an annoying knock still exists:

Both strut top mounts
Both Shocks
Both Springs
Both Drop Links
Both Ball Joints
All 4 Wishbone Bushes
Both Track Rod Ends
Both Anti Roll Bar Bushes.

And yet the knocking is still there. I have just ordered all 5 engine/gearbox mounts as a last resort.

Any other things I could be missing I would love to know lol.

[DMitch16]

Over the past 1500 miles I have changed the following front suspension components but an annoying knock still exists:

Both strut top mounts
Both Shocks
Both Springs
Both Drop Links
Both Ball Joints
All 4 Wishbone Bushes
Both Track Rod Ends
Both Anti Roll Bar Bushes.

And yet the knocking is still there. I have just ordered all 5 engine/gearbox mounts as a last resort.

Any other things I could be missing I would love to know lol.

Steering gear or inner tie rod ends?

[Roverfan]

Loose subframe bolts have been known to cause knocking as well

[DMitch16]

Also movement of the exhaust due to worn or missing rubbers, bent mounting pegs etc.

[Marshall1975]

Just ordered replacement subframe bolts with the shims as thats an easy win. All the engine mounts have arrived so will do them also this weekend. The bottom pair look fun I must admit lol. Then like suggested the only things not replaced are the inner tie rods. Checked the exhaust from front to back and its very secure. I struggle to get it to knock anything even with me pulling or pushing on it.

[VAG-Abound]

It may sound extreme, but I tracked down where a noise was coming from in the engine by strapping three "Playstation karaoke" type microphones (they were USB and recognised by PC) in the engine bay and using a bit of multi-track recording software to get a "sound space" that I could use to work out the location. Very effective...

[DMitch16]

Yours manual or DSG?

[Marshall1975]

Its a DSG

[DMitch16]

Its a DSG

Check the inner CV tripod joint for play. When worn, can knock a bit before the vibration stage sets in. All good if only an insignificant amount of movement inside the housing in any outward direction (it moves back and forth inside the housing so that is the only major movement the joint should have. Also noise from inner tie rod ends usually only noticeable with full weight of car bearing on them - I found no play when the wheels were off and the car jacked up but a noticeable amount once I'd put the wheels back on and jacked up from under the ball joints thus simulating the load (still on axle stands at the time - I do have two 3 ton jacks though so could do this) . I could then feel the knocks when moving the wheels side to side with the steering lock off. I just replaced the whole rack with a sub £200 refurbed genuine unit as it came with new inners anyway. Plenty of good rack refurbishers in the Midlands / North. Wigan seems to have quite a few.

[Marshall1975]

Thanks for the input Mitch. I'm gonna change the engine mounts which have now arrived and also the inner tie rods in the hope that its not the steering rack lol. If the knock is still there then that's everything except drive shafts and steering rack changed lol.

[Crasher]

I have had a lot of these ZF EPAS steering gears knock and found it to be the inner mounting of the track rod, the “drum stick” in parts counter speak a tiny almost imperceptible amount of wear makes a terrible noise. When they are worn they have quite a characteristic rattle, no so much a regular knock knock but a rapid rattle reacting to the road surface. A few weeks ago we had a chap with a Golf 5 (PQ35 is virtually identical to PQ46) who was being driven mad with a rattle and he had replaced everything and it was a terrible noise but I could not find it, with someone in the car on the lift, rocking the steering showed the right lower drop link was nut was loose as someone had reused the old nut. Quite often I have seen people unwittingly cure a noise and at the same time introduce one.

[Marshall1975]

Thanks for the info Crasher. Have 2 new inner tie rods now so going to replace them. That is always a possibility as I have now had the whole lot apart a few times replacing everything lol. When I do the inner tie rods I will go through everything again checking for correct fitment.

[Marshall1975]

Right both inner tie rods replaced. Fitted new subframe bolts with the spacers. All engine mounts done. Shock horror car still knocking. I can only think maybe one of the new parts was not up to standard when I fitted it. Have been round everything and with load on and off can not find a single thing loose. Beyond belief really lol. Nothing left to change now on the front of the car.

[MrPresident]

Right both inner tie rods replaced. Fitted new subframe bolts with the spacers. All engine mounts done. Shock horror car still knocking. I can only think maybe one of the new parts was not up to standard when I fitted it. Have been round everything and with load on and off can not find a single thing loose. Beyond belief really lol. Nothing left to change now on the front of the car.I feel your pain. Right now I'm chasing a frustrating knocking noise and am replacing parts with no luck. Inspecting the car on jack's, everything feels solid until it's rolling on the road.

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[Marshall1975]

Lol I am genuinely without ideas now. When I say everything on the front has been replaced I'm not joking. Well I tell a lie I have not done the drive shafts but I'm confident the knocking i'm hearing is not a drive shaft.

[DMitch16]

Lol I am genuinely without ideas now. When I say everything on the front has been replaced I'm not joking. Well I tell a lie I have not done the drive shafts but I'm confident the knocking i'm hearing is not a drive shaft.

Did you do the dog bone gearbox to subframe mount as well?

Test the steering with the steering lock and engine off as any steering wear is amplified without power assistance - turn moderately side to side and if you get audible knocking...:D

[Marshall1975]

Funny you should ask Mitch. I certainly did as came off easy but my god trying to get the holes lined up when putting back on is epic lol. I will try the steering in the morning and see what I can find. Thanks mate.

[Crasher]

Top of my suspect lift for new parts or their fitting causing a pattering rattle would be the ARB drop links.

[DMitch16]

Funny you should ask Mitch. I certainly did as came off easy but my god trying to get the holes lined up when putting back on is epic lol. I will try the steering in the morning and see what I can find. Thanks mate.

What is the knocking like?

Definite knock or more of a rattle?
Do you hear it generally, on certain surfaces or other times?
When travelling straight, turning or both?
Pinch bolts tight on struts?
Bearings checked?
Inner OS CV joint boot protector cover on correctly / tightly?
Disc back guards not contacting anything?
Springs are not moving when turning?
Steering COLUMN tight including flexible union?

Its going to be something silly like a loose bolt, something not fully in or something at the back of the engine hasn't got enough clearance - my new DPF took several adjustments to stop it contacting the EGR cooler pipe connection. Horrible rattle as it vibrated against the flange.

[MrPresident]

Did you do the dog bone gearbox to subframe mount as well?

Test the steering with the steering lock and engine off as any steering wear is amplified without power assistance - turn moderately side to side and if you get audible knocking...:DNot trying to hijack this thread, is this the test you meant? Power steering is off, unsure if this noise is normal. http://cloud.tapatalk.com/s/5f4ae9c47c1f0/VID_20200829_192410_1.mp4

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[Marshall1975]

It's a definate knock. Sounds just like a knackered ball joint or drop link. I have replaced the droplink twice in 2000 miles but looking back did not use the best quality ones. Starline I think from ECP. Picking up a TRW one today as you never know. Same with the lower ball joint so have ordered a Lemforder one. The knock is pretty much random but not on fairly smooth road surfaces just over manhole covers and bumps. Everything else you list I have changed or checked. Will give the steering test a try later today. Cheers mate.

[DMitch16]

It's a definate knock. Sounds just like a knackered ball joint or drop link. I have replaced the droplink twice in 2000 miles but looking back did not use the best quality ones. Starline I think from ECP. Picking up a TRW one today as you never know. Same with the lower ball joint so have ordered a Lemforder one. The knock is pretty much random but not on fairly smooth road surfaces just over manhole covers and bumps. Everything else you list I have changed or checked. Will give the steering test a try later today. Cheers mate.

Starline, one of their current budget brands alongside Q Drive and others. It used to be OCAP, and their parts were thinner, weaker and did not last more than 14 months. Buy cheap buy twice they say. I always use TRW droplinks as they are noticeably more chunky and last many years. TRW, Lemförder, Febi, Meyle, Delphi, Moog, Swag, FAG, FAI and other major brands are ALL noticeably stronger looking than Euro Car Parts offerings. I use Auto Doc and Mister Auto (PSA Groupe) via their respective apps but as there is a delivery charge usually order all I need together so when ordering suspension parts for instance I'll order all my service parts at the same time, doubling up items if they are on a particularly good discount rate. Have plenty of family cars to fix and service so never a problem hitting free delivery levels. Delivery takes 3 to 5 working days though but that does not bother me as the savings are good.

[Crasher]

A friend of mine who is a VAG specialist in Nottingham insists on only buying genuine parts from TPS for almost everything but I am a bit more pragmatic and use the company’s that make the parts for VAG such as TRW although getting their parts can be a trial. The steering rack on my Octavia decided to spit out all its bodily fluids, an exchange rack from TPS is £731.95 plus VAT (I am VAT registered) and I won’t entertain these cheap and nasty recon racks so I ordered a Bosch (they bought out the OE manufacturer ZF Lenk) exchange rack special order from Germany which without the surcharge and VAT is just under £400 and when it arrived it was a brand new old stock genuine ZF part made in 2012 with an additional Bosch sticker. Tracking down parts like this gives you OE quality for less money, cheap pattern parts are a buy it twice choice.

[Marshall1975]

Crasher I think genuine/oem is certainly the way forward. I put the new TRW droplink on and seems slightly better but still a knocking. Its clear as day a knocking like heavy metal on heavy metal, not just a tinny knock. I have checked every bolt on the subframe including using the shims. Think I'm going to have to bite the bullet and change the other newish droplink and 2 lower ball joints to more quality parts and then go from there. Did look at the ARB bushes that were done about 2000 miles ago and they seem rock solid so would struggle to see how they would be causing any banging.

[Crasher]

Shims? ARB bushes changed... they can’t. Fill me in.

[Marshall1975]

Many issues across Passats, Golf's, and other VW cars with the subframe knocking. VW issued a fix which was 2 new subframe bolts that came with 2 shims to eliminate the knocking. Seems pretty common after doing a quick google search. Fitted new Antiroll bar bushes about 2000 miles ago so was saying cant see it being them as they are still rock solid.

[Marshall1975]

UPDATE.

I have now replaced the drop links again with TRW ones and the ball joints with lemforder. I have replaced the 4 rear subframe mounting bushes, all 4 rear control arms, both rear trailing arm bushes, both rear droplinks. So everything on the suspension is now new.

I jacked the car up to check everything and no surprise everything is tight and solid with no play. I then while on axle stands used 2 jacks to load the suspension. Checked everything again and as before all tight and solid with no play anywhere. Moved the steering back and forth and smooth as a babies bum with zero noises and nothing at all felt through the steering wheel.

And yes you guessed the knocking is still there. I am now at the point of having a completely new front and rear suspension but with a lovely knocking noise to boot.

[VAG-Abound]

I mentioned above my three microphone kit to strap under there and help track down what it is. Happy to pass on to you if you like. Needs a USB port per mic and a bit of confidence with audio software to get it working.

[DMitch16]

Probably find it's something silly like an object in the glove box, front / rear door bunkers or other cubby hole. Check that your spare is anchored tightly and nothing else rattling around in there. Sound has a knack of travelling.

[Marshall1975]

I was hoping that would be the case Mitch. I stripped the car out a couple of days ago so all that was left inside was the drivers seat and then bare metal but no joy. I'm gonna pop to a local garage next week just to get a new set of ears having a listen as I think i'm losing my marbles now lol.

[MrPresident]

I was hoping that would be the case Mitch. I stripped the car out a couple of days ago so all that was left inside was the drivers seat and then bare metal but no joy. I'm gonna pop to a local garage next week just to get a new set of ears having a listen as I think i'm losing my marbles now lol.Apologies if this has already been done, have you looked into the top mount bushes?

Saw a YouTube video of someone eliminating knocking on his car by doing that. Ive still got knocking on my car but since it's 215k miles I'm worried about investing into new suspension incase it doesn't fix the issue.

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[DMitch16]

I was hoping that would be the case Mitch. I stripped the car out a couple of days ago so all that was left inside was the drivers seat and then bare metal but no joy. I'm gonna pop to a local garage next week just to get a new set of ears having a listen as I think i'm losing my marbles now lol.

I really want to hear what you do, I'm that curious and intrigued but it's been 2 years since I've been up to Lincoln, my daughter went to the University there. I personally used to live the East side of Louth in Manby as a child so know the area reasonably well.

[Marshall1975]

Lol trust me Mitch if I had the time I would be coming to you. Yet again had the car up on axle stands today. Methodically started at the front and checked every nut and bolt. Every bush looking for play. Shock horror everything is rock solid and tight which you would expect from a brand new suspension set up. There is not a single component on the suspension that has done more than 400 miles. I normally enjoy this type of thing being an engineer but this is becoming zero fun at all. It just simply does not make sense. A clear and loud metallic knocking noise but nothing to be found. Even checked the security of the steering rack and it is solid and tight.

[MrPresident]

Lol trust me Mitch if I had the time I would be coming to you. Yet again had the car up on axle stands today. Methodically started at the front and checked every nut and bolt. Every bush looking for play. Shock horror everything is rock solid and tight which you would expect from a brand new suspension set up. There is not a single component on the suspension that has done more than 400 miles. I normally enjoy this type of thing being an engineer but this is becoming zero fun at all. It just simply does not make sense. A clear and loud metallic knocking noise but nothing to be found. Even checked the security of the steering rack and it is solid and tight.Did you replace the upper arm bushings only?

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[Marshall1975]

Are you ready for the list. I replaced

Strut Top and bearing
Springs
Shocks
Drop links
Ball joints
Wish bones and bushes
Inner and outer tie rods
New subframe bushes
All engine mounts

So as you can see every component has been replaced.

[DMitch16]

I usually check suspension and connected parts under full load using these little beauties

37392

Not as easy to find issues when the suspension is extended and letting gravity pull it down.

[MrPresident]

Are you ready for the list. I replaced

Strut Top and bearing
Springs
Shocks
Drop links
Ball joints
Wish bones and bushes
Inner and outer tie rods
New subframe bushes
All engine mounts

So as you can see every component has been replaced.Wow fair enough. This is my worry. Not being able to actually find it. I'm sure you will though. How much has chasing this noise cost so far? I'm super intrigued to find out the culprit.

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[MrPresident]

I usually check suspension and connected parts under full load using these little beauties

37392

Not as easy to find issues when the suspension is extended and letting gravity pull it down.I've thought about this, something similar. Are the wheels static or is there rotating pads

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[Marshall1975]

I did also check all the components with the suspension loaded by having the car on 4 axle stands and using 2 Jack's to lift up the wheels. Everything spot on lol.
I would say total would be around £300 to £350 as I did all the work myself. Not overly bad as I plan to run the car as a work house for at least another 100000 miles so at least the suspension is all new.

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[DMitch16]

I've thought about this, something similar. Are the wheels static or is there rotating pads

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Both, I have items I use between crib blocks and tyres to allow the wheels to turn freely if needed.

[MrPresident]

Are you ready for the list. I replaced

Strut Top and bearing
Springs
Shocks
Drop links
Ball joints
Wish bones and bushes
Inner and outer tie rods
New subframe bushes
All engine mounts

So as you can see every component has been replaced.I have no idea how you managed to do all that for £300-350.[emoji54] I'm looking at £400-500 for a front control arm kit alone unless I settle for a cheapo eBay £100 kit which will probably fall apart.

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[Marshall1975]

You don't need to buy the whole arm. The forward bushes cost me £18 and they were febi bilstein and the larger aluminium housed rear ones were if I recall £40 for the pair and they were lemforder.

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[MrPresident]

You don't need to buy the whole arm. The forward bushes cost me £18 and they were febi bilstein and the larger aluminium housed rear ones were if I recall £40 for the pair and they were lemforder.

Sent from my SM-G965F using TapatalkAh I forgot this is a passat, my Audi A4 you have to just replace the whole arm and there's four on each corner [emoji19] massive PITA

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[Crasher]

Do you have a friendly MOT station with a shaker plate?

[DMitch16]

Do you have a friendly MOT station with a shaker plate?

First time I saw a shaker plate platform in action I thought "Brutal" :scared:

[Marshall1975]

Funny you should mention that. I know the manager very well at my local Kwik Fit so he said pop down tomorrow. But the crazy thing is I think I have solved it. I decided for one more tear down but went the whole hog and pulled the shocks and springs out. The top side of the strut mount which you cannot see looked out of place. On further inspection it looks like it has lost it shape quite a bit. So popped a new one on and have been for a drive with no evidence of the knocking. Going back out shortly for a much further distance so fingers crossed.

[Marshall1975]

37397 Looking at it now the silver disc at the top is sitting square. When I removed the shock and spring one side was not visible and buried in the rubber and the other side was raised quite high.

[Crasher]

First time I saw a shaker plate platform in action I thought "Brutal" :scared:

Have you ever spent time on a rolling road with an engine you have just spent thousands building? For anyone who suffers from mechanical sympathy it is a sphincter clenching experience :bigeyes:

[MrPresident]

37397 Looking at it now the silver disc at the top is sitting square. When I removed the shock and spring one side was not visible and buried in the rubber and the other side was raised quite high.Do you have any audio clips or videos of what the sound was like, just curious if it's similar to mine?. Glad you finally sorted it [emoji846]

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[nick.king]

I've had a noise for the last couple of years, always thought it was the drop links. Was it just a knocking going over an uneven surface?

[Simonson1982]

Sorry not an answer but a question!. I've got knocking aswell and have put it down to the roll bar bushes. I cant get.them from eurocarparts and vw dont sell them separately saying there a part of the whole bar! How did you find replacements? Many thanks

[Marshall1975]

I got them from ebay. Item no 283385093576 is the fronts if yours are 23mm. The rears I also got on ebay. Important you know what size you are after as there is quite a variation in Dia across the passats.

[Simonson1982]

Thanks marshal. I took my subframe off to replace the control arm bushes and have only just now seen that I should have used a locating kit to put it back on so it's still aligned. Apparently this can cause knocks and groans. Could this be your problem after changing one of your other bushes?

[Marshall1975]

No probs. No I changed all the bushes and arms without removing the subframe. I did replace all the bolts with new ones as well as fitting spacers between the chassis and subframe which was an official VW TSB.

[Simonson1982]

Changed my bushes and I've still got the knick aswell! I've got a feeling the big circular bush that holds the dog bone bush allows too much movement and the end of the dog bone is tapping the subframe. They make an insert for that bush. Might be worth a try.

[Marshall1975]

Funny you should mention the insert. I fitted the red powerflex one yesterday and all I can say is horrendous. The vibration on idle is beyond belief lol. I'm about to remove it now lol.

[Simonson1982]

Did it stop the knock though? If not make sure you post what the problem was if you ever find it. Ive had two different mechanics look to no avail with mine.

[Marshall1975]

No it did not stop the knocking lol. Have ordered some new caliper guide pins and sleeves as the caliper on the front left has quite excessive movement compared to the right. Will keep you informed.

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[Marshall1975]

Finally found the issue. After replacing the anti roll bar bushes I obviously did not have the roll bar 100% central. This in turn allowed the lower nut on the drop link to contact with the plastic guard right next to it. Quick adjustment of the roll bar and all good now.

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[DMitch16]

Finally found the issue. After replacing the anti roll bar bushes I obviously did not have the roll bar 100% central. This in turn allowed the lower nut on the drop link to contact with the plastic guard right next to it. Quick adjustment of the roll bar and all good now.

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You can sleep well now then, it's been a mission but must feel good now the noise is no longer there!