Nissan Patrol 4x4 (Africa)

Wilkie wrote:Fanus wat gebeur as jy die koppelaar intrap...

dink hy raas dan bietjie minder, sal later weer toets.
Dit wil ook vir my voorkom of dit net so maak wanneer voertuig warm is.

Ek het al 'n V8 met nat spark plugs gehad wat amper presies dieselfde geklink het

Maar met die diesel het ek nie 'n clue nie

SJC wrote:

Wilkie wrote:Fanus wat gebeur as jy die koppelaar intrap...

dink hy raas dan bietjie minder, sal later weer toets.
Dit wil ook vir my voorkom of dit net so maak wanneer voertuig warm is.

Nee, maak selfde geluid al is die koppellaar in ge trap. En "raas" meer gereeld op idle as onder "load".

Peter Connan wrote:Ek kan net nei dink die is iets in die engine nie. Ek is amper bereid om 'n weddenskap aan te gaan dat die exhaust iewers stamp...

Ek sou 'n kort stukkie tuinslang soos 'n stetoskoop gebruik om te probeer bepaal waar die geluid vandaan kom.

Het nou tuinslang gevat: kry geen geluid op exhaust nie, maar hoot die tik-tik-tik geluid by glow plugs. (kan dit net met tuinslang hoor, nie met die oor nie).
Het ook by manifold en turbo geluister, maar kon niks hoor nie.

The noise at the glow plugs might just be the opening and closing of the valves you're hearing.
Check at each cylinder if the noise is at each or if 1 cylinder is louder than the rest.

Kan ook wees dat n valve seat besig is om los te kom

ricster wrote: The little disc shaped flap that controls the revs of the turbine wheel on the exhaust side has a circlip that holds it onto the arm from the ( can't think of the name of it ) valve diaphragm thingy that pushes and pulls the exaust flap open and closed.

Off the topic, but I can''t stand by while Cedric battles to find the correct words!

The turbo's wastegate actuator is the cylindrical thingy that senses boost levels on the compressor side. It has a spring inside that's preset to a specific boost level and is overcome by the boost acting on the diaphragm above that boost level. When this happens, the diaphragm moves the actuator arm to open the wastegate flap (or valve) on the exhaust (turbine) side of the turbo. This means that some some of the exhaust air bypasses the turbine and is dumped straight into the exhaust, causing the whole turbo to slow down and boost to decrease.

The turbo actuator arm should be adjusted so that you have to pull it about 1-2 mm so hook it over the clevis pin on the flap. If it is set too loose, it will dump boost too early and will also wear down quickly. If adjusted too tightly, the wastegate system will not work properly and the turbo may overboost, causing damage to turbo and/or engine.

If you want to up the boost on the turbo, there are two correct methods:
1. Buy a turbo actuator with a stiffer spring, and set it up as per above.
2. Buy a boost controller. They completely interrupt the boost going to the wastegate actuator until the value you set it to. At that point they will open the airflow to the actuator and the wastegate system will do its work as per design.

Sorry, I know this adds no value to the noisy exhaust issue

Diesel knock?

Further to Cedric and Christo, any malfunction in this area, should show up on your boost gauge (if you have one fitted ). According to Cedric's explanation you will be over boosting, and I am pretty sure you will feel an increase in power.

This is where your gauges are critical. Boost and EGT should show any malfunction of injectors, combustion issues and turbo problems, along with what the exhaust is telling you in the form of smoke signals.

To me, personally, that sounds like something "flapping in the wind", and starting to act as a valve in the pipe. In the absence of any boxes and possibility of internals flapping about, my guess would be the internal layer of the flex joint coming loose, and flapping around. Is quiet at start up, and only starts gets noisy after revving? I would venture to say it has started separating from the side closest to the engine, a good rev bends it over toward the back of the pipe, after which the flow in the pipe prevents it from returning to its original position, and ends up flapping. Bet that if you switch off the engine, and then restart, the noise is gone till you rev it the first time...

Well thats my wild guess at your problem, hope you get it sorted out with minimal damage to your wallet, not that those 3" flex pipes are cheap. Mine cost me R900, seven years ago when I did the Sani.

davidvdm wrote:Further to Cedric and Christo, any malfunction in this area, should show up on your boost gauge (if you have one fitted ). According to Cedric's explanation you will be over boosting, and I am pretty sure you will feel an increase in power.

This is where your gauges are critical. Boost and EGT should show any malfunction of injectors, combustion issues and turbo problems, along with what the exhaust is telling you in the form of smoke signals.
.

Yes got madman and boost gauge installed. Boost seems normal.

Think I will remove the exhaust and see if the sound persist..

That said, the exhaust was installed less than 2 year(20k km's) ago...