Dethleffs Tourer
New member
- Joined
- Jul 12, 2021
- Messages
- 2
- Points
- 2
Fiat motorhome 2.8jtd makes a tappety noise when on light throttle, but only when engine is hot, could this be the EGR valve rattling? If it is, how to resolve this.
Technical EGR valve noise?
- Thread starter Dethleffs Tourer
- Start date
Currently reading:
Technical EGR valve noise?
Communicator
Prominent member
- Joined
- Aug 3, 2019
- Messages
- 2,019
- Points
- 544
There are versions of the 2.8 JTD with, and without EGR, but eLearn states that versions with EGR, are also fitted with a catalytic converter.
My 2006 2.8 JTD has neither.
Have you confirmed that yours has EGR fitted?
Many years ago I rented a Ford Transit PVC in NZ. The engine developed an alarming rattle, which I eventually linked to coasting (minimum throttle) situations, when the engine was at normal operating temperature. We lost confidence in the vehicle, and had it replaced. I was later told that the case of the problem was a stuck EGR valve.
Another possibility is diesel "knock", which can sound very mechanical, and IIRC is caused by too advanced injection.,
My 2006 2.8 JTD has neither.
Have you confirmed that yours has EGR fitted?
Many years ago I rented a Ford Transit PVC in NZ. The engine developed an alarming rattle, which I eventually linked to coasting (minimum throttle) situations, when the engine was at normal operating temperature. We lost confidence in the vehicle, and had it replaced. I was later told that the case of the problem was a stuck EGR valve.
Another possibility is diesel "knock", which can sound very mechanical, and IIRC is caused by too advanced injection.,
- Joined
- Nov 3, 2014
- Messages
- 824
- Points
- 283
Hi
By EGR valve I'm assuming you mean the valve over the back of the engine that is interposed between the exhaust manifold and inlet manifold. I think that EGR valves of this era had a vacuum operated diaphragm. A variable vacuum is fed to the unit via a thin rubber hose. This then pulls the diaphragm against a return spring, and a rod attached to the diaphragm operates the valve. A bit like a giant vacuum advance/retard unit on a distributor, if you remember those.
Because of the diaphragm, I would have thought it would have a considerable damping effect on any vibration, so I'd suggest that the cause of your noise lies elsewhere. If you want to eliminate the EGR as a noise source, you could temporarily remove the rubber hose from it and plug the open end. The EGR will now stay shut.
By EGR valve I'm assuming you mean the valve over the back of the engine that is interposed between the exhaust manifold and inlet manifold. I think that EGR valves of this era had a vacuum operated diaphragm. A variable vacuum is fed to the unit via a thin rubber hose. This then pulls the diaphragm against a return spring, and a rod attached to the diaphragm operates the valve. A bit like a giant vacuum advance/retard unit on a distributor, if you remember those.
Because of the diaphragm, I would have thought it would have a considerable damping effect on any vibration, so I'd suggest that the cause of your noise lies elsewhere. If you want to eliminate the EGR as a noise source, you could temporarily remove the rubber hose from it and plug the open end. The EGR will now stay shut.