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Timing/oil pump chain


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It is a mechanical spring tensioner/guide. I suspect there may be some top end noise until oil pressure comes up and warm oil is fully flowing. Possibly also expansion of seals or other bits closes clearance as they heat up...Have Glenn listen to it - might be normal noise for age of the engine. Compare to another running cdi. Cokld weather amplifies the sound of every little diesel rattle.Bil :sun:

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..... I suspect there may be some top end noise until oil pressure comes up and warm oil is fully flowing.....Bil :sun:

+1 on that observation.Mine has always done that (less so when you use an oil pan heater) and it's another reason to accelerate slowly and keep the RPM's below 2500 or so until you get that first "blob" in the coolant temperature indicator.It stands to reason that even 0W40 won't flow well until it's warmed up.Note, keeping the RPM's low and accelerating slowly minimizes spooling of the turbo which is likely also getting less than it's share of warm lubricant when you first start a cold engine!Brrr! -16C this AM :cold: MZ
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  • 2 months later...

I got Inno's smart to London and took it to the dealer and had the techs listen to it when it was cold, 3 different opinions:1. timing chain.2. starter.3. engine.Took it to the machine shop that has rebuilt 2 cdi's, their opinion:1. chains.Up on my hoist and listened to everything with a stethoscope. Three of us concur that the noise is coming from the oil pump area.Could be the oil pump, the gear, the chain/tensioner, or all of them. We removed the oil and there are a lot of metal shavings present. That indicates that it is probably the oil pump gear teeth that are being worn off.My friend took pictures with his cell phone and I got them today.When you look close you will see all the metal filings on the magnet.I got 2 other opinions today and both said that by just replacing the sprocket and chains would be a waste of time and money.In their opinion the steel filings will have affected the bearings,the lifters, and the rocker arms.They suggest that the engine be torn down and rebuilt.Any other opinions????

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Right after the oil pump is the oil filter....if the filter was not blocked completely by the filings and bypassed, it could be that the bearings etc are OK. However, bearing shells are cheap and perhaps lifters are too.....I doubt rocker arms would be too bad....Glenn, thanks for helping with this, it is great information.Inno, good luck with this, and sorry you had to be a guinea pig, but your experience is teaching us a lot.

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Not as sorry as I am! ;-)My concern is that rebuilding the motor would cost roughly what the car is worth on the resale market. It would be an easier decision if it were a $20,000 Benz...Mike, are you suggesting that only a partial "rebuild" would likely be necessary, if the filter has done its job?

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Yeah that's what I am saying, I would tend to inspect a couple of crank bearing journals when the engine is out, if they are scored, then you definitely need a rebuild, but if not you can probably just reassemble it with only new chains and tensioners (and a thorough oil gallery flush to clear all the bits of oil pump gear out) and it should be OK. New bearing shells are cheap insurance if the crank looks OK (I assume the bearing shells are cheap, they should be no more than a couple hundred $).Is Glenn going to do the work with you, in his shop?The oil filter, being located just downstream of the oil pump, means that before the oil can get into the engine proper, it has to be filtered first. So that filter should have trapped the particles that could damage anything that comes later in the oiling circuit. The oil sump on the other hand would be full of shavings and that's OK.

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Hi Mike,What you say makes sense and was in line with my thinking, i.e. look for a fix that is not necessarily a full rebuild.Glenn is offering to work on it, but any serious rebuilding would need to be done at a machine shop.

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  • 1 month later...

The pictures will show the source of the noise....that's the oil pump gear with the teeth worn off. Then the oil pump cover rem'd- shows scoring where the oil pump gears were seizing. The oil pump cover with a new one on the right.Bottom one shows where the chain was wearing away a mounting.Now off to the shop :D

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Do you think the soft metal bottom cog somehow protects other components by sacrificially destroying itself? We see these things over and over, and I ask myself why not replace it with a tougher cog - unless that would just lead to greater destruction?And... "plus one": what is the initial cause? Most days I'm fine, but some days I am scared spitless of what will happen to my wee smartie! More medicine, please, nurse.Bil :sun:

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I don't think the idea is to make the gear chew itself to bits, it's not a good plan! There is a potential market for stronger oil pump gears, I think, but the internal damage to that oil pump is mind-boggling. Unless the engine was run dry, it should never get like that!

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Good question, like the chicken and the egg, which came first?? Maybe poor quality gear, lack of lubrication, lack of filtration, lack of oil, who knows????Only thing we can do is more frequent oil changes.One experienced tech recommended a german made synthetic oil- Liquid Moly. I tried that in Lilbitz and 2 people noticed that the engine was quieter.Today we had the engine rebuilder come to the shop to help us examine the parts. Cam gear and chain shows excessive wear, 1 rocker showing increased wear. Hydraulic lifters will be replaced.Parts alone are now approaching the $1000 mark

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I think what has happened is the gear getting chewed to bits is what caused the oil pump wear: the filter is post-oil pump of course so all those particles would be in the oil pump causing the wear pattern and then get filtered out in the oil filter right downstream. I am pretty sure the engine was never run dry.But Glenn, was the oil pump chain tensioner intact or broken?Therefore the best diagnostic to catch this is to cut oil filters open and inspect for particulates inside. If you see any, a prophylactic rebuild of the oil pump drive is in order.

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I do not like the look of that sprocket. The new one!

That does not look like the tooth form I am so familiar with that transmits the force from the chain to the sprocket in line with the centerline of the chain. That sprocket looks as though the chain will be forced out from the sprocket, with the tension on the chain the only thing keeping it seated in the sprocket. The slightest diminishment of the tension, or an increase in torque (minus 20 degrees start with 7500 km on the oil) and the chain will ride up on the sprocket. It just looks wrong to me! Compare to this and you'll see what I mean. The root is very shallow.

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Well 7 1/2 days in the shop, and 40 hrs of labour and the job is done! Not going to attempt that any time soon!My friend from the machine shop suggested we inspect the cam shaft and have a close look at the liters and rocker arms. That was a good call. The lifter for the #2 exhaust valve was broken and the rocker arm was showing wear. Replaced all the lifters and the bad rocker arm.To remove the camshaft we had to take off the hi pressure pump. But to get at the pump we had to take off the egr. While the EGR was out it was cleaned and blown out.So it was a basic engine rebuild without doing the pistons, valves and rings.We had a bit of heart failure when we first tried the engine- just a clunk. Tried again same thing- thought the engine was seized. Turns out it needed a new battery. Original battery no longer able to turn the smart engine over.Also discovered a bad front bearing, altenator and an i/c fan.Happy to say it purrs like a kitten and has good power!!!

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  • 5 months later...
  • 2 years later...
  • 4 months later...
On 2012-01-06 at 8:42 PM, inno said:

I am having a similar noise problem. It appears to be coming from the right side of the engine, somewhat forward. I am attaching a short sound clip with the ticking noise. Any comments would be much appreciated. The oil light is not going on by the way. Are there any shops in Toronto that do this work cheaper than MB? I don't want to risk driving any significant distance. Smart Noise

Is this also applicable to petrol 450?

 

Edited by TorqueJunkie
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