Hi There,

I am experiencing a noise through my air cleaner that has left me confused.

The symptoms -
If you stick your ear near the air intake there is a deep booming/echo/thumping/drumming type of sound as the car idles.
If you open the bonnet and feel around the air filter cleaner you can feel puffs of air blowing out of the air filter box.

I hope the above explanation makes some sense.

When this started I took it into the workshop and was told that the breather was faulty and this needed to be changed, the breather was replaced but this did not help at all, the noise persisted.
Next the turbo, that was failing, was blamed and at the end of September I replaced the turbo with a brand new turbo. But the noise persisted and we found that the intercooler was leaking, loosing boost.
The intercooler was replaced at the end of October and the noise is now worse that ever, especially when hot.
I even blocked off the EGR valve thinking I had a stuck open EGR valve, but the reverberating got even worse. So I removed the EGR blank.
If I remove the breather pipe from the inlet system the noise persists therefore it cannot be from the breather.

My next suspicion is that I may have a sticky hydraulic valve lifter that is allowing compression to escape and is being forced back through to the air filter. But what confuses me there is no missfire. I have not been able to get a compression test done every time I bring it up the guys just sort of dodge the topic. I have been asked to use an Wynn's engine cleaner additive on the morning I drop the car off to have the oil changed for the new turbo, apparently we must change the oil after 2000Km's.

The car pulls like a train when it is warming up, especially in the torque curve (2200 - 3500 RPM) but after an hour stuck in traffic she does pull as she should the revs will increase at a constant rate all the way to 3500 RPM, no nice kick in the back.

I need to travel over 5000 km's in december and am worried I might burn a valve!!

Has anyone experienced anything similar?

Regards Thanks

SMG

Mine also makes a noise idling. But there are no puff of air. Sounds like you are being given the run around and they don't really know what's wrong. I would insist on a compression test ASAP to find out whether a valve is leaking. It's a fairly complex procedure as you need to remove intake manifold to remove the glow plugs to do the test

Hi Mike.
I know it is complex, hence why everyone is avoiding the job.

Regards Thanks

SMG

Someone suggested this morning it could be the CAT that is blocked.
With the old turbo leaking the way it was this is a possibility.

I will have a look on Saturday.

Regards Thanks

SMG

Unlikely, if it was blocked your new turbo would be stuffed already.

Oh no please dont say that, i will start crying. Thanks

SMG

If you are driving the car still the turbo isn't stuffed