Does this sound like cam chain rattle? (2.0 HDi 16V)

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19jacobob93

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Tadpole
Tadpole
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Hey guys. I have 2008 308 with the DW10BTED4 engine and 6sp manual.

It has 177k on it. Had full service history until 100k then it goes dark, so who knows what happened in that time! I've replaced all fluids, filters, belts, tensioners, pulleys and the water pump and thermostat since buying.

I have driven it around for a couple months now and covered around 5k KM. It runs mint and I'm originally from the UK, so I'm familiar with these engines as they're in loads of stuff.

My one concern is this noise at start up. Sounds like the cam chain rattles for a second on cold start, or when warm after being sat for a while. It's otherwise relatively quiet with no strange noises or behaviours. Just looking for other experiences with this very short noise on start up.

File is too large so here's a YT link:

Cheers!
 
Cant hear anything untoward there.

FYI, the DW10BTED4 has a cam belt, not a chain. If there is no indication it has been done already, you might want to change it - easy enough job. There are several threads here and videos on youtube showing how.
 
UNM said:
Cant hear anything untoward there.

FYI, the DW10BTED4 has a cam belt, not a chain. If there is no indication it has been done already, you might want to change it - easy enough job. There are several threads here and videos on youtube showing how.
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Hey!

Yes I actually replaced the belt last week including water pump, harmonic balancer, and all pulleys and tensioners etc. attached to the engine. This is a 16V so it also has two camshafts connected by a chain and tensioner.

For the 1-2 seconds following start up after being sat, you can hear a rattle sound. This is coming from that chain area and I'm just wondering whether it's a cause for concern.

I read many owners in Europe don't touch this chain in 500k KM. Mine only has 177k but also a sketchy history after 100k, so I'm not sure if this has caused early wear.

Cheers
 
Perhaps, time for the stethoscope? Lazy tensioner or broken/worn guide pad?

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Have you checked the alternator pulley one-way clutch is not binding. It will make a nasty vibration at idle.
 
David S said:
Perhaps, time for the stethoscope? Lazy tensioner or broken/worn guide pad?

View attachment 240527

Have you checked the alternator pulley one-way clutch is not binding. It will make a nasty vibration at idle.
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That's the part in question! I would guess exactly that, that the guides are worn or the tensioner is being lazy.

I'm going to give the oil a good flush (Liqui Moly engine detox) and replace the oil with 5w40 synthetic (currently 15w40 mineral for a short cleaning cycle) and see if this makes a difference. If it does, then it will confirm that the noise is internal. If there's no change then it could be external such as the alternator pulley as you mentioned.

Given that it's only brief and after sitting leads me to believe it's something related to oil pressure, so I'm starting with a good flush to clean the most likely very dirty oil passages, and a synthetic oil with a lower cold start viscosity.

The engine is quiet and smooth after that initial ome second start up rattle, with no other sounds or vibrations, or any running issues at all.
 
This engine is usually happy on 5W30, maybe 5W40 full synthetic.
 
David S said:
This engine is usually happy on 5W30, maybe 5W40 full synthetic.
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Never been a fan of 30s in diesels! I have some full synthetic Dexos diesel oil to go in after this flush run, which is the viscosity of choice in mainland Europe.
 
David S said:
Perhaps, time for the stethoscope? Lazy tensioner or broken/worn guide pad?

View attachment 240527

Have you checked the alternator pulley one-way clutch is not binding. It will make a nasty vibration at idle.
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Just an update, I think the noise may be the tensioner itself (#6 on this diagram) so I have a new one here that I will fit soon. It's definitely oil pressure related and my theory is that the spring has broken and is unable to provide the required tension until the oil pressure has built up.
 
Having that 15w oil in there even for a short time scares me!
I think the upper side of 40 should be reserved for older/well worn in vehicles or hot summer conditions. I've blown seals being careless with that. Personally, I'm unlikely to use 40 anymore unless conditions are pushing for it.

The engine sounds ok to me also?

Could just be a combination of thick oil, worn cam lobes, slightly stretched chain, guide and cog teeth all just providing a bit of slop which the tensioner is bouncing a bit with?

My pug sounds ugly compared to that. I think I'm hearing water pump bearing tings... wife's driving it, so all good until it isn't.
 
You are aware that this engine should be using low or mid-SAPS (low ash) oil with a C1, C2 or C3 rating?
 
407HDI2.7 said:
Having that 15w oil in there even for a short time scares me!
I think the upper side of 40 should be reserved for older/well worn in vehicles or hot summer conditions. I've blown seals being careless with that. Personally, I'm unlikely to use 40 anymore unless conditions are pushing for it.

The engine sounds ok to me also?

Could just be a combination of thick oil, worn cam lobes, slightly stretched chain, guide and cog teeth all just providing a bit of slop which the tensioner is bouncing a bit with?

My pug sounds ugly compared to that. I think I'm hearing water pump bearing tings... wife's driving it, so all good until it isn't.
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I'm in Queensland, 15W is fine! We ran 10W40 in these in the UK and they were fine starting at -20c... I should add it now has a relevant 5W40 added, but I would have no issue running a 15W40 here.

The engine, overall, is excellent! It's just a second or two of rattling on cold start or after being sat. A recent oil change confirmed it is definitely oil pressure related, as it rattled 3x longer than usual until the oil filter housing was primed. I am almost certain it's the cam chain tensioner, or specifically the spring, which is supposed to take up the slack until the plunger builds oil pressure.
 
All engines make noises until they build oil pressure as crank, camshaft are sitting on their bearings.
I would not worry at all as engine is well worn with 200k
 
driven said:
All engines make noises until they build oil pressure as crank, camshaft are sitting on their bearings.
I would not worry at all as engine is well worn with 200k
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That's definitely true, but I know the sound on start up isn't exactly normal. I think it might cause other issues if left to get worse. I have a new tensioner here to drop in... It's not a big job on these as it just bolts on top of the chain, rather than the new ones where you have to take the cams and chain out to replace it! I'll see if it fixes the issue anyway, but yes, I don't think it's urgent...
 
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