Sounds like lifters...

 

Lifters? Nah man.

 

The center exhaust section is hitting the bracket....

 

Thanks V. I'll jack the car up in the morning and have a good look underneath!

 

Could be a heat sheild that wasn't fastened when everything was buttoned back up...i did this to myself friday.

 

The knocking gets quieter as the car warms up. Heat shield wouldnt care if the car was cold/hot. Would knock regardless.


OP, how long did the car sit during this install?

Mine sat for a week at a shop one time and also had a ticking knocking noise. It turned out to be the lifters. Just let the car warm up fully and it should go away.

 

Thank you. I'll definitely look at that part as well.

Did your "knocking" sound seem to kind of disappear as the car drove and got warmer after about 5-10 minutes?

 

Thank you. I'll definitely look at that part as well.

Did your "knocking" sound seem to kind of disappear as the car drove and got warmer after about 5-10 minutes?

Well, mine was kind of a clicking noise and actually seemed to come alive when the car got warm. It would kind of come and go. Also, if your guy cut the exhaust (in order to avoid dropping the mufflers), I would make sure the clamps are tight too. Whatever the case, you should be able to put your hand (along with a rag so you won't burn your hand) on that center section while the car is running and see if the noise changes. That's how I was able to determine my problem. As far as the other guys reporting the lifters; mine did that too since the car sat on jack stands for about 3 months. But, it went away quickly and that's pretty easy to figure out because the noise is coming from the engine, not underneath the car.

John

 

I had the knocking sound being the exhaust. It did go away when the car warmed due to what I think the mounts loosening with heat... You can cheat this by putting the frame reinforcements above the exhaust brace....Not the right way, just in case you are desperate.
Adam

 

This is a good suggestion instead of the bandaid you have now. See the thread below for more detail. Easy fix.

http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/195987-need-help-exhaust-install.html

 

Okay so i've jacked the car up and gone underneath. Please see my video underneath :1zhelp:

Does this sound normal? Or should it not be "knocking"?

Should i place some material between the exhaust and the brace? I was thinking of shoving an old rag in between there for now?

 

Okay so i've jacked the car up and gone underneath. Please see video underneath :1zhelp:

Does this sound normal? Or should it not be "knocking"?

Should i place some material between the exhaust and the brace? I was thinking of shoving an old rag in between there for now?

That's it! I would just make sure everything is tightened up. Might just be loose?

 

Sounds like the bushings might be loose on the brace.

 

Problem solved! I used some heat resistant wrap, bunched it into a neat pile and placed it between the exhaust piping and the flat "connecting support" part No. 5. Tightened it up good and it hasn't made the knocking sound since :grinyes:

Big thanks to Raikku and everyone for helping out. I wouldn't have known where to start without your guidance! :thumbsup:

 

Ya 68's solution was a cure, not a band-aid. Still have to wonder what step is dropping the exhaust, has to be something with the tranny mounts? Both of you have the updated mounts.

 

It's weird though. After i "sandwiched" the heat resistant wrap between the exhaust and the flat bracket i notice the car is louder now from inside. More of a grumble. Which i don't mind... but hmmm

 

You now are transferring noise and vibration directly it the cross member and into the cabin with sandwich wrap!

Rehang the exhaust correctly with the proper mounts and you should not have problems.

 

Ah, that's what i thought.
It's funny how something so small has caused such a massive difference in exhaust volume from inside.
I'll jack it up and reverse it so that it's Washers > Braces > Bracket like 68's setup (below). The sandwich fix has made it bit too loud for me now :confused3

 

Sorry to hear Dimi but good you've discovered what the cause is.
The mounts have probably perished somewhat and I'd say it's knocking now because everything was taken apart and put back together and tightened properly and has pushed the exhaust closer to the cross brace and caused the knocking.

you'll get it sorted - some repairs tend to lead to others!

cheers
Stu

 

The long braces are wrong too. Where they meet the cross member holding the mounts they should be below the cross member holding it in place. Hope this makes sense. Sorta hard to put into words.

 

I know but read the thread attached to my post 17 for the explanation.

 

No problems at all.

 

So how does the new clutch feel, Dimi?

 

Hey Nick. The new clutch is great. I've been driving the car a lot to help with the break in. Gave it a bit yesterday and no slip so far. Chirped the wheels for the first time in 2nd lol :goldcup:

Thanks for asking mate!

Can't wait to get my CPS's and hoses done (I used your list you sent me to do a big order from ECS, thank you for sending me that!)

I did the reverse set up with the bracket like 68's. Perfect. No more banging noise and no more exhaust drone!