What's that noise

[sdt463]

The vehicle is a chipped td5 130 D/C and when driven easy no noise. Well, nothing out of the normal any way, But when I put the power on a little harder than normal I get a noise that I can't put my finger on. It can be heard best with the window open, and best be described as being like wind howling on a roof bar and can be made to come and go by varying the throttle pedal without actually changing speed.
Hoping one of you has had a similar noise in the past and can give me the heads up.
Thanks in advance Dave

[DieselDan]

Hi Dave,

I'm only guessing, cos I don't have a td5, but what you're describing sounds like turbo "whoosh" noise to me.
As yours is chipped, I'm assuming its fuelling up more and boosting harder than a non chipped td5, so when you accelerate the turbo spins up earlier (at a lower road speed) so there's less background noise to mask it.
Might be worth checking turbo hoses and connections just to make sure nothing obvious is loose, but hopefully someone else with a chipped td5 will let you know if its normal or not!

cheers,

Dan

[MR LR]

This may sounds slightly stupid, but it's not soundproofing that has come away from the turbo (firewall) allwoing you to hear the sucking a lot louder???

EDIT: What Diesel Dan Said!!!

[sdt463]

Thanks Dan and LR. I havn't got any sound proofing so I do hear every little noise. I did wonder if it might be turbo certainly hope thats all it is.
Thanks guy's Dave

[gazk]

If it is a "squealing" sound it is possibly a leaking exhaust manifold. Usually caused by a failed stud or two and warping of the manifold. Number 5 cylinder exhaust studs seem to fail first. Look for black exhaust stains around the head/manifold.

[spudboy]

If is sounds a bit like a squealling fanbelt type of noise, then I'd say you have a leaking exhaust manifold. Under slow and gentle accelleration you don't get it, but if you accellerate smartly - the noise occurs.

That's my vote

[r88inch]

Oh, that'll be a warped exhaust manifold for sure.

The TD5 exhaust manifold warps, especially if chipped, or used under load (my Disco towed a camper trailer and that was enough, my defender had the same problem, but neither was chipped )

The manifold waprs and then snaps the studs, usually on the ends of the manifold (both of mine were on the back end) If you use a torch and look under the turbo heat shield, you may be able to see the missing stud.

The manifold is usually machined and then bolted back in using new (must be new) head\exhaust studs. i cant remember what it cost me.

[sdt463]

No not a squeal guys, more of a howl or a rub. Just had the head gasket and manifold gasket replaced (preventative only), webbing has been cut from manifold and the holes have been opened up.
I have wondered if the hand brake shoe's could rub on the drum when you put extra load on the prop shaft. But just a thought, I dont know enough about the land rover set up to know if it's a real possibility.
Dave

[Fraz]

Ive broken 2 studs on my chipped DC130. You'll know about it, a very distinct hiss under boost.
Try driving along beside a median strip/ concrete road divider etc. the noise will be clearer and you might even be able to separate engine sounds from drivetrain.
Im hearing a faint ting/ringing under load at the moment, I'm sure its the drivetrain but I just havent had the chance to look yet
post back if you find out anything

[sdt463]

I will post an answer when I work it out . I am touring at the moment with a large van on the back but it do's not seem to be geting any worse so I will just wait and see. I am fairly sure its not manifold but starting to wonder if its coming from the front tyers as the torque increases.
Time will tell. Dave