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Discussion Starter · #1 ·
Has anyone got any ideas on whether lifter / tappet noise at idle is normal on the 32 motor? With just over 11000 miles my 32 has developed a noisy right rear lifter. There is a noticeable rattle / ticking at idle and the specific lifter has been identified with a mechanics stethoscope. It only rattles / ticks once the motor is fully warm, nothing is noticeable when driving normally and the revs are up and power seems normal. Is this something I should be badgering the dealer about or something that should be accepted as normal for this engine? Any input / comments much appreciated.
 

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I wouldn't consider it normal, but I also wouldn't expect the dealer to tear down the engine to fix it. Make sure it is in the dealer's records as a complaint, so you will be covered later.

Some German cars are very sensitive to oil weight. Any chance that you have an oddball oil weight in the car?
 

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Discussion Starter · #3 ·
OrangeMarlin - 4/4/2006 8:54 AM

I wouldn't consider it normal, but I also wouldn't expect the dealer to tear down the engine to fix it. Make sure it is in the dealer's records as a complaint, so you will be covered later.

Some German cars are very sensitive to oil weight. Any chance that you have an oddball oil weight in the car?
Thanks OrangeMarlin.

On the oil weight, it is dealer serviced and spec is Mobil 1 (which I assume is a given weight - or are there different specs of Mobil 1?). I have no reason to suspect an incorrect oil weight as the dealer is generally reputable.
 

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Mmmm, your car is a left hand-drive, right?

Well, my car is a C320 Right-hand drive, but uses a similiar engine, 3.2 V6. I also had an intermittent tappet sound (ever so faintly) on my left bank, away from the drivers side but at the rear of the engine, low down. The sound was only imminent once the engine is up to operating temperature and especially pronounced if I come to a rest.

I had it checked out and even though it sounds as if it is coming from the left bank, the dealership told me that it was an MOT valve situated furthest from the drivers side. Naturally, I argued that it could not be and they also told me that it was not present on the newer models due to the fact that they had a valve in between to equalize vacuum inside the engine and the other items requiring vacuum on idle.

To cut a long story short it makes a noise on the rear of the left bank, the bank furthest from the drivers side when warm as the valve opens and closes, its actually an echo in the cam box. All they did was fit a non-return vacuum valve and wallah!

Quiet as a Merc should be [:D]

Worth checking out before you let them touch the engine. Apparently, only the V6 engines have these vacuum control units which sits against the firewall called MOT valves.
 

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Discussion Starter · #5 ·
Hi Nizaam & thanks for the reply.
As it turns out mine is a right hand drive (SLK32 AMG). Thanks for the info. It could potentially be the cause as it is definitely from the rear of the engine and although it sounds to me like it is coming from the right hand side (i.e. the engine side closest to my drivers seat) rear cylinder bank (and with the stethoscope the right rear valve gear sounds noisier than the rest) I can't rule out the possibility you have raised. Interesting in particular is that mine is also only noisy when warm.

PS: I see from your email address we're in the same part of the world.
[:D]
 

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Thanks OrangeMarlin.

On the oil weight, it is dealer serviced and spec is Mobil 1 (which I assume is a given weight - or are there different specs of Mobil 1?). I have no reason to suspect an incorrect oil weight as the dealer is generally reputable.
There are MANY versions of Mobil 1, and only a few are of the primo Euro specification. On top of that, I've heard some horror stories about the type, quality and quantity of oil that dealers put into cars. It's one of the reasons that I actually change my own oil.

If you had an oil change in the last 300 miles, and the tapping started after the change, then I would definitely suspect some off-weight oil.
 

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Agree with Orange.

My dealership used Castrol in my car since new, I checked the service books. I couldnt understand why they swore my Mobil 1 but never used the stuff in your car????

If you have followed some of my posts I mentioned that my car was using oil, 1 liter of oil for every 1'000kms. That was prior to me switching to Mobil 1. I insisted on them swtitching over to Mobil 1 and now, 2'000kms later, no more oil usage. Weird huh?
 
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