Tapping type sound from drive train???

[Nath43]

Hi all,

I have recently purchased a 2001 manual V8 D2, it has been really good apart from the odd leak which I seem to have under control. I have a mysterious problem that I thought I'd ask about as I haven't been able to find a similar post. I have a strange noise which sounds alot like a tappet (or a diesel) but only when I am driving and only until the engine etc. warms up. This obviously makes it very difficult to find. I have changed the engine oil and filter when it was due. I also had leaks from the transfer case and transmission covers and have re-sealed those and replaced the oil. This unfortunately hasn't fixed the problem but at least the leaks have subsided. I'm now thinking the noise could be coming from one of the diffs. Up to now I've just gone with a process of elimination and that seems like the next logical. There is no noise if I just rev the engine with no movement and seems to be no noise while I'm in reverse. Any thought swould be greatly appreciated.

Cheers Nath

[AussieAub]

Check the bolts on the exhaust flange plates that connect the downpipes from the heads to the rest of the exhaust, just before it bends.
(like my technical descriptions...?!?!? :p)
Need to access from under the vehicle.

These bolts have a habit of coming loose (by only a little bit) and give off a ticking type of noise. From what I've been told its the exhaust gases being forced through where the gasket is.

Have had this issue with mine on and off until my mech recently replaced with better nuts and bolts.

Hope that proves an inexpensive fix for you...!! ;)

[mattyg]

Check the universal joint on the front propshaft. These make noises when there on their way out.

[Urban Panzer]

Front prop was my first shout to............but also being a V8, check the manifold to exhaust down pipe gaskets, if they are leaking you get the "tapping" sound.

[Discobaker]

Had this issue with my worst too, you can actually see where the ex gasses are leaking between the flanges. Can anyone recommend a particular type of fastener for this? I assume a nylock nut won't stand up to the heat but I've tried new studs twice now with no joy.
Cheers
Mat

[biggin]

Had this issue with my worst too, you can actually see where the ex gasses are leaking between the flanges. Can anyone recommend a particular type of fastener for this? I assume a nylock nut won't stand up to the heat but I've tried new studs twice now with no joy.
Cheers
Mat


I used stainless steel studs, nuts and spring washers. So far, so good:).
I reckon spring washers are the key.

[AussieAub]

I reckon spring washers are the key.

Second that - they are on mine now too. :cool:

[Discobaker]

Awesome, cheers guys, much appreciated

[nealo]

I have the same....a rattly kinda tapping sounding noise only while the car is cold...and is dependent on acceleration...put the pedal down a bit too far and it starts

I have looked underneath and noticed a crack in the flange on the exhaust on the LHS bank....so here's hoping that will fix it

[Nath43]

Thanks guys, I'm gooing to check that tonight. I did the CV Joints and all were fine. Have been away on holidays in the mean time and not been driving my car all that much. The exhaust problem would be an awesome find and fix!!!! I'll let you know how I go.