2001 Peugeot 406 D9 Engine Vibration

Peter C

Peter C

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Well, back in about March, I replaced the fuel pump and filter. This turned out to be a drawn out, messy job. Then, about 2 weeks ago I had to replace the battery. If you go back to May 2021, I had the timing belt, tensioner and water pump replaced. I did point out at the time that, like the serpentine belt, HD is probably the original one but both the HD and SB were not replaced.

Let us now go forward to early this week. I should add that with a new battery and fuel pump, the car starts up really well. Okay, so early this week I noticed an engine vibration which was apparent when depressing the clutch pedal. Only short runs to the paper shop plus a couple of others totalling about 40 mins all up. It's taken me until today to work out what's going on and I reckon it is the harmonic balancer. It's worth noting that my opinion is not guaranteed as it comes from someone whose main experience is with 504s which, as most will know, don't have a harmonic balancer.

I gather that driving a car with a failed harmonic balancer will cause stress on the engine with the likelihood of damage, significant or otherwise. to said engine. I cannot imagine it has been happy with the vibration.

With an educated guess, what is the likelihood of damage to the engine as of today? Needless to say, I won't be driving it until resolved. Any thoughts or comments would be appreciated.
 
Not really a non cylindrical clunk but a noise a bit like a noisy alternator bearing or dry tappet. I should add that my hearing isn't great so I may not hear subtle noises.
 
Does it have a one-way alternator pulley?
Edit - No it won't, being petrol EW10.
 
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Don't know about a one way alternator. With the amount of vibration, it couldn't be the alternator. It just sounds a bit like a dodgy alternator.
 
Edit: it's petrol EW10, so my comments don't apply to this car, which had presumed diesel ...
I don't know what your 406 would have, but early C5 HDi had a 3-piece damper and a 'normal' fixed alternator pulley. Then it changed to a one-way 'over-running' pulley and a more normal 2-piece damper sometime in late 2001. You get bad vibrations (i.e. not good ones!) at idle / low rpm with the 2-piece damper combined with the early pulley and the same happens if the one-way pulley jams. The three-piece dampers were relatively (very) expensive and failure prone, but you cannot successfully mix and match the two systems.
 
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Okay. The vibrations do seem more apparent at lower revs, although they're very evident when operating the clutch at any speed.
 
Can you post a video so those who know stuff can listen?
 
EW10J4. I plan on talking to the place that did the timing belt in 2021. I'm almost certain it's the harmonic balancer as the symptoms fit. The symptoms and are not like an engine mount, dud spark plug, etc.

I'm concerned the crank/bearings have been damaged. In addition to a new HB, I'm wondering if a new timing belt is a good idea.

Of course, cost is a big factor in the course of action. It would've been good if they had just listened to me in 2021 when I told them that the HB had never been changed.
 
Paint a line across the rubber with liquid paper and you will soon see if it has let go and the inner and outer metal parts can move relative to each other. Or is there an obvious wobble in the outer part?
 
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Sorry, it's an EW10J4 petrol. I meant to say HB earlier on. Harmonic balancer.
 
David S said:
Does it have a 2 or 3-piece damper? The 3-piece damper has two rubber rings, whereas the 2 piece only one. Paint a line across the rubber with liquid paper and you will soon see if it has let go and the inner and outer metal parts can move relative to each other. Or is there an obvious wobble in the outer part?
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As well as painting a line across the harmonic balancer, I would take off the accessory belt and run the engine without it and see if the vibration and noises have gone. The answer will then determine where you look next.

Dave maybe on the money in post #2
 
Sorry, ignore my comments about a one-way pulley. I was thinking HDi and petrol won't have that.. Wrong engine.
However, do mark it and see if the outer moves in use.
 
Okay then. I'll do that check. Might have to wait till tomorrow.
 
So it’s a 2 litre I assumed yours was a v6 being a 4 I would be concerned about the clutch release bearing and the snout it runs on. Disregard the flywheel comment.
 
Thank you. I've just spoken to a retired mechanic friend who also thinks it could be clutch related.
 
Well, the retired mechanic has dropped by and reckons it is the clutch. The giveaway is that the vibration is very apparent when the clutch pedal is depressed. Not really great news. I'd like to keep the car and given that the timing belt and water pump are two years old, the fuel pump and filter are a few months old and the battery is two weeks old, I reckon that a DIY clutch in the driveway could be an option.
 
Peter C said:
Well, the retired mechanic has dropped by and reckons it is the clutch. The giveaway is that the vibration is very apparent when the clutch pedal is depressed. Not really great news. I'd like to keep the car and given that the timing belt and water pump are two years old, the fuel pump and filter are a few months old and the battery is two weeks old, I reckon that a DIY clutch in the driveway could be an option.
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Which you referred to in your first post - makes sense that the clutch would be the primary suspect.

Potentially $2,000 plus for parts & labour, but I vote fix it - better the devil you know than the devil you don't, and if you buy another 2nd hand car you're buying someone else's problems...
 
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