406oc.co.uk

Hey everybody, yesterday my beloved 406 started making some very worrying clank-clank sounds just as I was arriving home.. (like 200m from home I could suddenly hear some clanking sounds from engine bay.. the more I rev up the engine the faster the clank was)

So I pulled to my driveway and checked the engine:

https://www.youtube.com/watch?v=uxsutrjHdfM

but could not see anything obvious what it could be.
The auxiliary belt is ok, the cambelt I can't see as it is under the cover..
I have the engine cover from underside installed as well so could not see anything without jacking up the car.

Any idea from just the video what it could be?

I will be looking under the car, checking the crackshaft pulley and cambelt as well this weekend (if weather allows).

Also a little background how this happened..
So a few weeks ago/maybe months my 406 lost all it's OOOMPH.. or acceleration suddenly.
It accelerates normally from stationary, but as you get faster around 30mph and higher the car just don't accelerate when I press the pedal.
It will eventually get there but it's feel like snail.. also if I push it too much a lots of black smoke will come from the back.
From all the possible things I can think of (faulty turbo, dirty EGR valve, faulty MAF sensor..) I think it could be the MAF sensor as I was driving
without the wheel arch covers after some servicing and I ran through some significant pools of water which got so much water splashed on the intake that the engine actually stalled and I had to stop. So I think the MAF just corroded afterwards and the issue started some time after this incident.

Not sure if the clanking has anything to do with the acceleration problem tho..

Eek! That sounds pretty horrific And why is there so much vapour (water?) coming out of the engine? That can't be right.

Umm, it's not sounding like engine death to me (admittedly it's hard to say on a vid), could be crank pulley (remove belt), waterpump, probably not timing belt shredding... Maybe you could use a long screwdriver as a stethoscope and try and localise it.

I fear Steve's right, that does sound ominous, especially since you beleive it may have drawn water into the engine.
Definitely worth running it with the auxilliary drive belt removed to see if that stops the noise. Hope it does

Sounds like a bit of broken piston ring sitting on top of a piston.

Peter

So I had some time today and yesterday and did some checks..

First, no issues with auxiliary belt, cam belt or crankshaft pulley.
Next, I decided to change the oil + filter and here I found the problem.
When I drained the oil there was less than 1 litre of oil in it there..

Put a new filter + topped up with 5l of new oil and started up the car.
The clanking was still there at first but in about 5 seconds it stopped and the normal sound returned :-)
So, it was definitely something that was caused with low oil, not sure if any permanent damage was done or it will be fine..
I went for a short ride around the block and the car was smoking white smoke really bad every time the gas pedal was pressed.

So today I went to check the MAF sensor and when I opened the air filter I found another major problem.. the airfilter was shreded and blocked the air intake. This is probably due to that water intake I had a couple of weeks/months ago. Anyway I changed the filter, cleaned the MAF from blockage and put it all together, tried to run without MAF plugged in but the car still smoked really bad anytime I gas pedal was pressed :/

I was trying to figure out if MAF is faulty with multimeter and was taking some measurements whit engine running but then out of nowhere I've noticed the car leaked the oil from the exhaust
Switched the engine off, checked the oil level.. no marks on dip stick. Looks like it's bellow minimum again.

So, not sure what to do next.. it looks like the engine has definitely some serious issues.
Any idea what could be wrong with the engine? And if is fixable?

Here is some footage + pictures from today: https://www.youtube.com/watch?v=uValYVSiD3c&t

Looking at your video, I think Peter may well be right. No fixing here with a new MAF sensor.

Seems that oil is leaking into the combusion chambers, then leaving unburnt via the exhaust, together with unburnt diesel fuel. Given that the engine is running relatively "smoothly", I think only one piston is broken (piston ring or maybe even a piston rod).

It could also be a blown head gasket. If that is the case, it must have a huge hole in it, considering the amount of oil that is leaking out.

If I were in your situation I would do a compression test first. In any case, I think you will have to lift off the head. You will then be able to see the damage, whether it is the head gasket or the piston (ring or rod).

Or you might as well save yourself the hassle and consider a replacement engine.