Well take off the valve cover and have a look. To check the lifter turn the crank so that the camshaft lobe is not pushing against the lifter and the valve and push down on the lifter with say a hammer handle. Compare this movement (if any) with the other lifters.

 

Took the car to my regular indi, but they were closed for the summer till Sept 3rd.

Then took it to another indi, 1st thing he said the noise was from under the valve cover, have to take the valve cover off to see.

Turn the crankshaft like you said to test. 1st thing he said was could be camshaft. As I asked him about lifters & tensioner....he said could be those too. But have to remove the valve cover to see.....

xps,

Make sure the noise isn't coming from the belt tensioner shock that mounts to the alternator bracket. When the bushing wears out it makes a similar noise to a stuck lifter.
Mine drove me crazy until I pushed on the shock with a piece of wood and the noise stopped. Replaced the shock and problem resolved.

Good luck

Belt tensioner, shock & serpentine belt, all were replaced one year ago.
I have a stethoscope, no noise from those areas.

 

Thanks, I will do that.

The noise is coming from the front of the engine, by the oil filler cap. The noise gets louder when I accelerate & the noise does not go away (cold/hot engine). Could this also mean a failing chain tensioner?

Is it safe to drive the car in this state or I risk getting serious engine damage?

 

You'll always get more sound coming from the oil filler cap - partly because they are removable and might not fit well any more and partly because the chains are noisy.

If you are worried enough to ask if you should stop driving the car then I think you are better off having a look.

You can write descriptive bits of text and make videos of the sound and we might be able to make some educated guesses but that's a poor third place to be instead of being in front of the car in reality listening to the sound and judging it for yourself.

If the timing chain does fail it will be a bit of a disaster...

 

xps,

Make sure the noise isn't coming from the belt tensioner shock that mounts to the alternator bracket. When the bushing wears out it makes a similar noise to a stuck lifter.
Mine drove me crazy until I pushed on the shock with a piece of wood and the noise stopped. Replaced the shock and problem resolved.

Good luck

 

Took the valve cover off & snapped some pics.

I have no idea what to look for/or looking at. Anything strange/worn you guys can see......is the camshaft ok?

Meantime, I changed the oil filter & oil to 20w50 to see if it'll help.

EDIT: It looks clean & also like there is no oil (there were plenty)...it's because I wiped it down.

 

It does indeed look nice and clean.

How thick was the oil? Did it come off easily? When was the oil last changed? Do you know the weight of the oil used?

I can't see anything particularly wrong in the pictures - but bear in mind I've only owned an M102 for two months (it is of course in pieces on my garage floor at the moment!).

The one thing that I can say is that simplex chains are not considered to be especially reliable (that's the single row ones like you have).

 

I used 10w40, less than 3K km on it. Oil not thick at all, no sludge.

Forgot to add, had valve job/head gasket done 6-1/2yrs ago. Head gasket, valve guides, timing chain, timing chain guide, chain tensioner, valve lifters, etc., etc., ALL replaced.

Yeah, I read your thread on it at peachparts.

Oh whilst you have the cover off push down on the lifters

Too late now, all put back together.

I did pushed down on the lifters using my hand, no play at all.

I tried to move the rocker arms side ways with my hand, a few did move just a bit, while others wouldn't at all.

The timing chain was very tight, no play at all.

 

Oh whilst you have the cover off push down on the lifters

 

Or maybe they are just stuck, will some engine cleaning/flushing help?

Most likely. Throw in some high detergent into the oil just before you change and run hot engine a while or so. Might unstick the lifter involved. If not, you'll have to pull the cover again, find the lifter involved and depress it to help flush it out. If that doesn't work, it has to be replaced.

 

Too late for that now, I just changed the oil from 10W40 to 20W50...will run it a little while & see if this will help 1st. At least till my 1st indi reopens on Sept 3rd & see what he saids.

 

Will a cracked exhaust manifold cause this tapping noise too?

I read a thread at peachparts on that.

 

Can't imagine that it would.

Put a short length of heater hose to the motor and identify the right location of the knock. Either that or a long screwdriver that will transmit the click. Pretty hard to describe a sound so you might be hearing exhaust escaping. But there isn't a reason for exhaust to be described as a clicking sound.

 

The stethoscope couldn't pickup the tapping from the valve cover, BUT the paper tube from a roll paper towel did! LOL
The tapping noise was from the 3rd cylinder area.

Zooming into some of the pics I took, looks like the indi might have diagnose correctly (with the valve cover still on, just by listening to the noise ), CAMSHAFT! Does it look worn???

The indi that will reopen on Sept 3rd allows me to supply my own parts.

1) Should I go with this camshaft from autohausaz?
Your Parts Search Returned 1 Part(s)

2) Or get the real OE camshaft from the MB dealer?

 

I wouldn't be buying anything until you've checked the lifters.

These hydraulic lifters are designed to always be in contact with the cam lobes whether they are on the pointy bit or not! If they are not working properly than I can imagine that they might tap.

 

I second this. Additionally, a camshaft that has actually worn past the hardened outer layer (doesn't happen often) wears down very quickly from that point forward, and the car would begin to loose power on whatever cylinder was affected.

+1 on that.

I would have put in 10W-30, not 20W-50, as a step to free up a possible sticking lifter. I would drain it out at home, leave the filter alone, and refill with 10W-30.

Good luck. I've had to replace sticking lifters in an 84 190D, so yes, they do "wear out" and need replacement sometimes.

FWIW, we've put 10W-30 in our M103 equipped 300SEL, and it actually causes the car to tap when the motor gets up to temp. 10W-40 taps if we run the piss out of the car. I think it's getting enough pressure to the bottom end and most of the top end, but it seems like it tapers out when the oil gets too hot and thin and tries to get up to the No. 1 lifter(s).

There is a procedure in the FSM for testing lifters. It involves the wooden handle of a hammer on the back of the lifter.

 

+1 on that.

I would have put in 10W-30, not 20W-50, as a step to free up a possible sticking lifter. I would drain it out at home, leave the filter alone, and refill with 10W-30.

Good luck. I've had to replace sticking lifters in an 84 190D, so yes, they do "wear out" and need replacement sometimes.

 

The oil passages are small and the tolerances tight in the lifters. Debris can clog the passages and gum can reduce the tolerances and stick them. That will cause them to rattle. That's why I'd suggest a detergent additive to try to solve that. Lighter oil darned sure helps, along with the additive.

Sometimes if you compress the lifter when it's on the flat side of the cam, that relieves either condition temporarily.

In years gone by I've had success with this method but never on a Benz. I've never had the problem in one.

 

Thanks guys! I'll hold off on the purchase of parts.

If you guys all think my camshaft is fine & all think it's the lifters...then I am happy....because that'll be a much cheaper/easier fix.

Because to replace the camshaft, they recommend the 8 rocker arms to be replaced as well....now that adds up.

Meanwhile, I'll dump some oil out & add some cleaning detergent to see if it'll free up the lifters. Adding ATF as the cleaning detergent ok? That's all I have at home now, if not...then I'll have to run out to the store to get some.

I zoomed in some more on one pic, are you guys sure that the camshaft is not worn out?

 

I don't think adding anything to the engine oil is a smart idea. If you want to change the oil ideally you need to do it with a warm engine - but I wouldn't bother changing it until you've checked those lifters!!!!!

(I am persistent)

As for the "wear" marks - a cam won't wear so much there at the start of the rise - I guess it is more likely to wear nearer to the highest point. I'd guess that mark is more likely due to poor manufacturing if it doesn't turn out to be a weird oil optical illusion...

 

My cam lobes look like that, for the most part. You can run your fingernail across the robe to determine if it's been scored or damaged. Also, camshafts tend to round off when they wear.

Yes, to turn the crankshaft you use a 27mm (I believe) socket to turn it clockwise facing from the front of the engine to the back. It won't throw anything off unless you turn it counter-clockwise. If it does go counter-clockwise, you should reset your chain tensioner. Easier not to let it go backwards.

Also, never turn the engine over by the camshaft -- bad idear.

 

Thanks, that's really good to hear...that my camshaft is still good!

Thanks for confirming the procedure!
Good idea, I'll run my fingers across the cam lobe to check.

 

Fingernails! They are good at picking up minute scratches. Also, compare the cam lobe that you think is damaged to the others. The areas leading up to the point are typically very flat, if it's rounded (especially compared to the others) then it may be damaged.

 

Should the A/T shifter be in "P" or "N" when doing this or does not matter?

 

Doesn't matter. The torque converter is a fluid coupling, there's nothing locking the trans input shaft to the engine crankshaft. It could be in drive if you felt like it, but I wouldn't advise it.

 

Just came back from my indi, two mechanics listened to it using stethoscope, both think it's the "camshaft" too. They said if lifters, the tapping sound would be much louder.....that's why they think it is the camshaft. So both indis I went to thinks it's the camshaft. BUT they would still like to remove the valve cover to confirm that it is the camshaft & not the lifters 1st. Booked for tomorrow for this......

They will allow me to supply my own parts & will just charge me labor to install. :thumbsup:

He confirmed that the (Ruville/Febi) camshaft from autohausaz is good.
They also suggested if camshaft, I should replace all the lifters too at the same time...cause they are cheap.

 

On a 2.3L this is an easy job. do it!

 

Whew! Confirmed that it's the lifters & NOT the camshaft.

Found 4 bolts on the 2 rocker arms at the back rather loose, re-torque back to 20NM.

But found one of the bolts in the front really really loose, the thread on the cylinder head is "stripped". Could NOT re-torque the bolt at all, it just turns & turns.
What is the best way in fixing this?

 

Well you seemed to be so keen to go and buy a new cam shaft I thought it was best to shut up and not say any more 'cos I'd just put a downer on your purchase!

But seeing as you've got a different approach I'd say you need to consider a heli-coil. You do need to check if it will be good for the torque you want to apply to the bolt in an alumium head though. I have a gut feeling that it will be within limits on a M8 thread - but you need to check this. There are different - more exotic - thread insert solutions out there too that might be worth considering.

 

But seeing as you've got a different approach I'd say you need to consider a heli-coil. You do need to check if it will be good for the torque you want to apply to the bolt in an alumium head though. I have a gut feeling that it will be within limits on a M8 thread - but you need to check this. There are different - more exotic - thread insert solutions out there too that might be worth considering.

So it is a "M8" bolt?

Stupid me, I should have taken measurements of the "bolt" while I had it out!

Looked through the heli-coil catalogue, for a M8x1.25 (coarse thread)...the max. locking torque is only 6NM. So the heli-coil solution will not work.

The bolt needs to be torqued at 20NM, so I need at least that.

What other options do you suggest?

 

I was keen because the pics lied, if only I ran my finger nails across the cam lobes like Nfsjunkie91 suggest a LOT sooner.

But the "shine" around the cam lobe's edges have worn away just as shown in the pics, but I guess that's ok.

Looks like the heli-coil should do the trick, torgue of 20NM isn't much.

I looked thru the service manual in replacing the lifters, BUT it's so vague.
Anybody done it, is there a DIY?

Do you need special tools to remove/insert the lifters into the rocker arms?
How do you fill the reservoir with engine oil 1st like they suggest?

 

It's easy. You just remove the bolts holding down the lifter mechanism. Pop the lifters and slide new ones in.
Tighten the bolts to correct torque. I managed to break one when I overtightened luckily it didn't damage the threads and I was able to pull it out with an easy out.

 

Thanks!
You don't need to rotate the cam so that the lifters are NOT under pressure 1st?

You didn't fill the lifter's reservoir with engine oil 1st like the service manual suggested?

So it's just that simple, remove the bolts on the rocker arms...lifters slides out, insert new lifters back into the rocker arms, bolt rocker arms back on & re-torque the bolts to 20NM.

 

oiling will not hurt...

 

Read the cam should be rotated too, so the cam lobe is pointing down 1st....