Thread: Exhaust manifold whistle

Originally Posted by land864

So Size is M8
What thread?

Pretty sure it is 1.25.

Thanks team
I went through my stock of spare nuts and bolts and found an M8 with the right thread
Put it in
Tightened it up
Hey presto
Whistle gone
😊😊

Originally Posted by land864

I went through my stock of spare nuts and bolts and found an M8 with the right thread
Put it in
Tightened it up
Hey presto
Whistle gone

Your likely going to be up for a snapped stud shortly then. If it threw a nut off then it's likely that the manifold has warped (super common TD5 motor problem). If you've put a new nut on and tightened it then your trying to flex it back to straight and causing stress. It's great that it's stopped whistling for now, but how long it'll last, and how much harder the repair job has become for next time could be the cost.

But maybe I'm cynical about it having moved onto my 4th manifold in the 253,000km life of my vehicle...

Originally Posted by twr7cx

Your likely going to be up for a snapped stud shortly then. If it threw a nut off then it's likely that the manifold has warped (super common TD5 motor problem). If you've put a new nut on and tightened it then your trying to flex it back to straight and causing stress. It's great that it's stopped whistling for now, but how long it'll last, and how much harder the repair job has become for next time could be the cost.

But maybe I'm cynical about it having moved onto my 4th manifold in the 253,000km life of my vehicle...

X2. The manifold needs to come off, be faced, and preferably ceramic coated. It helps to do a few more things as well, all well documented on various threads here. Removing a broken stud is MUCH harder than replacing it before it breaks, which it WILL do.

Out of curiosity, when does it whistle. Mine has started whistling in 1st and 2nd gears only sometimes. Usually if its been sitting still for a little bit say at lights or just starting off in the morning. I assumed i had split a turbo hose, but could I have the same issue.

Whistles when cold
Good points by all though
Ill get the machining and studs done when a few $ come in

Just logged on to do a search on exhuast nuts and here is this thread. Missing the rear stud nut, might try and get the stud out and replace it. Go a 5.5hr trip on Thursday to Geelong then leaving it with a friend to drive while away so don't want any hassles.

Originally Posted by knuts2au

Just logged on to do a search on exhuast nuts and here is this thread. Missing the rear stud nut, might try and get the stud out and replace it. Go a 5.5hr trip on Thursday to Geelong then leaving it with a friend to drive while away so don't want any hassles.

Pull the manifold. It's much easier that way, the manifold is warped if the back nut is off, the rear stud at least needs replacing before it breaks. Don't, whatever you do, replace the nut before you have dealt with the issue, which is that your exhaust manifold has warped. A VERY common issue, and there is really only one way to fix it. Trust me, getting a broken stud out of the head is MUCH harder than dealing with it now.

Better to drive it the way it is for now. It isn't an expensive job to pull the manifold, face it straight again, and replace the studs, which is the minimum needed. It can get VERY expensive if you need to take the head off because you can't get the broken stud out in situ.