metal bits in the valves!!! - PeachParts Mercedes-Benz Forum

Sierra240d · #1 09-25-2006, 06:54 PM

hey all,
I posted earlier about a non runner and pulled the valve cover and there is a bit of metal sitting on top of the head around the valve springs. A little metal in the oil but not much...
what do you guys think. Is it terminal? there dosn't seem to be oil in the coolant... could this be 'normal' wear on the cam?

or am I just dreaming
cam does not seem to be scored, everything else looks fine in there.

thanks

Tomguy · #2 09-25-2006, 09:01 PM

Define a "Bit of metal" - shavings? How much? Or an actual PIECE (or more) of metal? If there is ANY metal in your engine it should be the slightest amount in the oil canister when you change your oil filter. My 4.5 has a VERY slight amount of metal shavings with each oil change that I attribute to the new rockers wearing to match the used cams. It'd be half the size of a BB if I were to add them all together. Any noticeable metal shavings in the engine probably means the filter is bypassed. Check the filter (and change it and the oil) and I'd also suggest dropping the pan and making sure nothing is clogging the oil pump.

Do a compression check. You'll have the pan off, inspect the rod bearings visually. See if the rods have a lot of play at the crank. It could be good that you caught it early, or it could already be too late for the engine. HOPEFULLY the bits of metal (most likely from the rod bearings) didn't score the cylinder walls.

Sierra240d · #3 09-25-2006, 10:22 PM

The metal can best be described as fine shavings in on the top of the head around the valve springs. No chunks just fine shavings... Also very fine particles in the oil, barely noticable.. no chunks.

When I try to crank it over it wants to start but quickly dies. There is a noticible tick sounds like a valve but intermittant, quite loud.

When the chain gear mark and the mark on the can hold line up the crank reads 1-0 degrees so the timing seems good.

I'll pull the pan and check the crank.

If a bearing is bad is that a job the DIY'er is capable of?
I can't put any more major money in to this car... so if this is it ...it is it

Thanks

t walgamuth · #4 09-26-2006, 05:53 AM

i seldom disagree with tomguy but i think maybe on one point i would here.

if the shavings are in a spot where there is not a lot of oil flow they may lay on the top of the head and not be swept into the pan. therefore the oil pump may not be by passing. and i dont see how the bearing material would get up onto the top of the head.

it seems to me it must be originating in the top of the head area.

have you checked glow plug funciton?

this is the most common way for a dieseel to not start.

but you should clean it all up and probably drop the front oil pan too and clean that, then change the filter and oil before running it.

when diesels wont start ususlly it is something simple.

good luck

tom w

Mike D · #5 09-26-2006, 07:28 AM

I'm thinking timing chain problems. Perhaps a collapsed tensioner or guide gone bad. This could be one explanation for the metal shavings (aluminum scrapings from the housing) on TOP of the head. It could also explain the start problem. A "tweaked" spot in the chain could be the "tick" sound. Perhaps a replaceable master link has decided to replace itself?

Use a magnet to determine the physical makeup of the shavings.

Palangi · #6 09-26-2006, 09:23 PM

What is the condition of the cam lobes? Maybe tight valves are shaving the cam lobes or rockers?

Sierra240d · #7 09-27-2006, 12:35 AM

Thanks guys...seriously...thanks. I'm not with the car right now but as soon as I get back to it I'll get started answering these questions.

I do agree the origin of the 'bits' is most likely on top of the head, the largest bits are still up top.

As far as the clearence... I'm not sure. I checked 3 intakes and they seemed acceptable, but didn't check the rest (I will when I get back).

I don;t know the type of metal (magnet check to come) but I did notice a bit of odd markings on the back end of the rockers. I will attach a picture. I'm not sure if it is normal.

The timing chain looks newish. tention seems good and timing seems to be dead on. But just to make sure can one of you guys tell me the best way to make sure that the timing is right?

Thanks
Steve

Sierra240d · #8 09-28-2006, 11:04 PM

OK.... So I checked all the valve clearence and they all seemed OK... mabye a bit loose but nothing to worry about. Pic attached of the cams... Dosen't seem to be scoring but the lifters seem to be wearing a bit far back (towards the intake manifold) But these are the first merc lifters I have had a good look at.

Pulled the oil pan. A bunch of metal/sludge in the bottom. Mostly very very fine metal shavings but a lot... possibly 1-3mm deep in places, also found 2 chunks of metal, very flat could be small bits mashed togather some how. pics attached.

the oil pickup was completely clear... like new looking, nothing in the screen not even a bit of sludge. That is odd to me and may suggest a new pickup. Also the timing chain looks pretty new also. I do not have records for this car from recent owners just the first 120k of perfect up keep.

every rod bearing I could get my hands on felt tight. I could not get a thing to wiggle by hand.

What do you all think? Where is this metal comming from? could the oil pump be bad? Since the pickup is so clean mabye the pump was changed and installed worng and destructed and thats where the metal is comming from?

Or am I just dreaming... I hope I can get her running she is in such great shape, it would be a real shame to part her out.
What should I do next?
Thanks
Steve

Mike D · #9 09-29-2006, 08:06 AM

Let's quit shooting in the dark here.

First things first. The shavings (fine metal particles) MUST be originating (or originated) in either the head or timing chain area. The oil pump first supplies the filter with pressure and the oil flow enters the block oil passages and then the cylinder head area. The valves are supplied by small oil passages located in the cam towers and is distributed by the oiler pipe. This pipe has some pretty dang small holes over each cam lobe and I seriously doubt you can get "bits" of metal through the holes.

Oil is also splashed into the chamber by the timing chain.

Those are the only two ways the valve area receives it's oil supply.

What condition is the oil filter and housing? A small amount of grunge in the bottom of the filter housing is normal. I've changed out some filters where the sludge was touching the bottom of the filter and the car was fine.

Had the oil pan been recently changed? A new gasket, bolt heads clean?

How are the timing chain guide pivot pins? The ones you remove with a slide hammer. Are the threads clean? If they are, judging from the condition of the engine, then the chain has been recently replaced. Does the top chain guide have a black fiber slider? Is it worn? Turn the engine through a complete revolution. Has the replaceable master link lost it's lock?

The metal flakes in the picture COULD be parts from old chain guides.

You just might have inherited a sloppy job from a not so experienced P.O.

Pull either the injectors or the glow plugs and do a compression test before you go any further. If you do not have a minimum of 275 P.S.I. then go no further. The engine won't be worth the effort.

If you do have good EVEN compression, clean the pan, wash down the head and timing chain area (I use diesel fuel in a pump-up weed sprayer) re-install the pan, change the filter, fill with oil and then treat the "no-start" condition.

I'm not saying you don't have major problems with the engine but you gotta do things in a sequence when it comes to diesels. Compression is #1.

$30 for oil and filter is a tiny investment.

david s poole · #10 09-29-2006, 11:43 AM

think you better check your cam oiling rail those pcs look like cam bearing material.

Sierra240d · #11 09-29-2006, 05:38 PM

Thanks Mike and David,
this is what I got...

oil filter and housing look normal.

Oil pan looked old... could have been previously removed but they did not change the gasket.

Timing chain looks to be in good shape master pin is intact. But the tentioner guide has no rubber/felt liner left on it... could that be the culpret? Tensioner looks old. I had to remover the A/Ccompressor to get to it and that had not been done in a while... plus the bolts are old on the tensioner.

mabye I'm missing something but I can't turn the engine over using the crank bolt anymore... There is no oil, no pan, no filter... is that causing me to no be able to turn the engine? It seems to be compressing, because after I pull it returns to the same position.

I want to check chain strech again after reading more on this forum.

Cam oilers look OK to me. Every time I have pulled the cover nothing is dry and there looks to be plenty of oil getting around. How do I check the cam bearings? It dosn't wiggle at all.

Do you think the guide for the tensioner could cause the metal build up? also what is a 240d supposed to read on the harmonic balancer?

Thanks
Steve

Tony H · #12 09-29-2006, 06:14 PM

There are firms that will analyze your oil sample and determine the origin of metal particles and other foreign material. Don't know what the cost is-never checked into it.
Tony

Sierra240d · #13 09-29-2006, 08:38 PM

thanks for the advise tony.

trying to check for chain stretch... when the tick on the cam gear lines up the harmonic balancer reads 2-3 degrees is that acceptable?

Mike D · #14 09-29-2006, 08:55 PM

2 to 3 degrees is acceptable. I'm guessing you found the engine not turning problem?

To do the compression test you need to use the starter. Hand cranking just wont do it.

Sierra240d · #15 09-29-2006, 11:12 PM

Engine not turning was because when a certian little lady was playing in the drivers seat she left it ingear

I think At this point I'm going to try to get her started... if that happens I'll change the tensioners and guide and hopefully all will be honky dory... thanks again for all your help, I'll keep you all posted.

Thanks
Steve