Need Technical Info and advice on SL engine work! Urgent
 

I have a 560 SL which is familiar to most of you here on Shop Forum. Today, I took my car into the Shop for the Timing Chain replacement as the car has 120K on the speedo. I wanted to be sure that I didn't have a chain failure.

The car was running like a top. Tach sat dead hard on 500 RPM and the car never missed a beat. I got a call at around 3PM and was asked to stop by the shop.

Seems that when the chain was replaced and the engine started a racket was coming from the engine which has been determined that the Valves were misaligned and had eaten into the head. Just 3 valves on the right hand side. As it looks to me, I have 3 burned and cracked valves on the intake side. May be two exhausts and one intake, not sure, I am busy vomiting while I write this note.

My question is how could I have valve and lifter (Stated that the lifters did not have the valves properly aligned) problems and the car run as well as it did? Could the problem be that a valve was bent when the chain was installed. They removed the head to repair the bent valve and decided that because of other damage that could be seen that it was time for me to pay for a valve job?


It really doesn't matter now as I have no choice but to do the work. however, is there any way to tell what caused the racket and the valve noise after the chain install. Can you see a bent valve and how do I get my hands on the bent valve to prove thats what happened?

Could it be that I had a serious problem waiting to happen or am I getting hosed into engine work I shouldn't have to pay for?

I'm not looking for sympathy just some technical understanding. It could be they bent the valve or valves and the inspection turned up the cracked valves and wear and that would need to be done sometime up the road.

Am I getting hosed or has a mistake turned up a problem that would have needed to addressed in the near term?

Who do you trust in this world and how do you know when you are being taken advantage or not? I guess that is the age old question.


Any and all advice and direction appreciated.

Sounds to me like they let the chain miss a tooth on one side during the new chain installation if it were running good/smooth/no noise when you took it in.

I know for a fact that the valve will not bend when the chain is off by 1 tooth. I believe it was off by more then 1 tooth when they started it up after the chain was replaced.Burnt or bent valves would not show up after a chain replacement. If you didn't have the problem before, you wouldn't have it now. I've been working on MB's for 16 yrs now and never found a burnt valve after I replaced a chain. good luck & dont't let them bend you over.

How do I handle this problem? (See Previous Post)
 

This car has 121K and I use it every day for about 150 miles per day. The car runs/ran terrific. As I said it idles beautifully and performed quickly off the start and had super power at all speeds.

Here is my point of view on what has happened and I would like some comment from the group.

When the shop called me they said that they thought they had screwed up and that when they installed the chain they had done something wrong and bent a valve. They removed the head and put a level across the top of the valves and pointed out that one Valve was higher than the other. They say that this could have been the case for some time? I don't think the car would have run that well if that were the case!
Am I wrong or are their extenuating circumstances that the car would run great with this condition? Comments Please!

I believe that the chain was installed wrong and bent the valve. Now that the valve is bent you remove the head and look at the valve bottoms and you see cracking and some valve wear on 2 other cylinders. Rather than bite the bullet on bending the valve they go to me and say " You have valve issues and they need repair. We should remove the head and have it redone". It costs me money and they are off the hook.

The real issue here is that it is true that I saw valve cracking and some wear or debris on 3 of the valves. Two valves had a baked finish that was a tan ceramic color. I believe it to be the first and last valve in the head.

Based on the observation, I would probably be back to them in some months to have the valves done anyway. This episode just moved the head work up a bit.

The question I have is that even though it may have been good fortune to uncover the problem now, Why wouldn't they just admit the error and accomodate me some little bit. Would anyone in the business do that or am I a dreamer?

What would you do in these circumstances?

Another question: What causes the valves to crack and some to carbon up worse than others?

The one valve was higher because its stem was bent and it will not fully seat into the valve seat.

You are being hosed - they screwed up the timing when the installed the new chain and did not check the basic timing before they attempted to start the engine. This is a HUGE oversight on their part.

They should fix this problem with NO cost to you. The only question in my mind is wether or not they are competent to fix the damage they have done to your car. Based upon their results of a timing chain replacement I would say NO.

Has this shop done work for you before?

I agree!!
 

You are 100% correct I think we need some accomodation.

The guy has done alot of work for me prior to this. I was going to take it down to Donnie in Atlanta to get the chain done but figured after reading a great deal about the install it can't be that difficult. ( I defy you to find a Post on the Board that talks about Valve bending on timing chain installs)

It is my stupidity that cost me major bucks.

Gotta think this is my last stop at this shop!

Consoling thought!
 

As I previously said, I probably would have needed the valve job down the road anyway! I just didn't need it Right Now!

Pure speculation...
 

but my money says that when the chain was rolled in, a guide wasn't used. What happens then is the chain jumps at the right cam. The next time it jumps whicle rolling in will cause the valves to contact the pistons. That is why, on almost every t-chain DIY response you read you see the suggestion to roll the crank over two complete rotations (a complete cycle). If the cam timing is off you won't be able to make 2 rotations by hand AND if you don't do 2 rotations by hand you won't know if the cam timing is off (and if you did everything right and didn't have the chain jump, 2 rotations will be smooth and easy).

Now, have they looked at the left bank? That is the side that usually eats it when a chain goes.

I would argue the labor involved and the bent valve(s) are the shops bill, I would also suggest doing a complete valve job of the rest while the car is apart (your bill).

Many thanks Mike!
 

Yes, I went and looked at the problem and asked about the drivers side. He mentioned that it might not need work. I said, take the head off and lets look and see. I'm going for both sides while we are here at this point!

What we have developed here is a trust issue. I have no faith now in the shop. Better late than never! I'm going by again in the morning to check to see if he pulled the other head. I just might keep my mouth shut until I get the car back on financial adjustments.

The other issue is I need to go to the machine shop and look at that tomorrow as well.

Thanks for the reply. I respect your opinion. Always have!

What is the name of the shop.?

Scott
Baltimore

Hunt Valley Imports, Chris Connelly
 

Not Hunt Valley Motors!

There you go.

Its their problem no matter the cause.

We have done hundreds of valve jobs and thousands of chains. It doesn't matter what happened since they were in control. Believe me a MB v8 with 120k needs neither a valve job or a chain. The only thing it realy needed was upper chain rails.

About 20 years ago I got my first taste of reality on this subject. We did a preventative chain and tensioner (no rails). About a month later the car had a ignition problem (maybe even caused by our work - the green wire from the distributor to controller was intermittantly shorting to the valve cover. During a time of deficient ignition the thing dieseled and ran in reverse direction for a moment. Happens quite frequently with such problems. The rails broke and while trying to start the car the valves on the left side bent.

So whose fault is it? Doesn't matter. We did the one and only free v8 valve job in the 25 years we ahve been in business.

There just isn't anyway to justify doing preventative maintenance that includes doing the work that was to be prevented. I am trying to point out that this is not a technical issue. The technical issue is moot. This is a business issue at this point. Fault has no part in it.

Thanks, Steve!
 

I just left the shop after mulling this over all night.

What really upsets me is the fact that yesterday the mechanic(owner) tells me that the valve was like that before the chain was done. What that says is that I am STUPID. I am just a stupid customer that will believe whatever I am told.

My problem right now is that the Head is off, the other Head is in process of being torn down, and I am facing a big price tag.

The money and the valve job are not the issue. As Steve points out it is not now a technical issue. The shop has lost all technical credability.
I can't be sure that the work he must now do to rectify the problem will be done honestly and reputable and when the job is done and the bill is paid, in what condition will the car be.

Should I tow it out of there? Should a novice like me watch every step of the repair? What would I see? What do I know? The majority of us out here know enough to be dangerous. This is a real problem. How do you know when the bolts are all in and the car sits running in front of the shop that did the work, that when you drive away with an empty wallet you are behind the wheel of a time bomb waiting to go off?

I don't know! What a dilemma!

Many thanks to all on this Board that contributed to my help in the above and thanks to all who try in their own way to help another. That is what these Boards are for and it speak volumes as to the members of this Mercedes Shop fratenity.

Thanks to all as I am off to the bank to get the blood money to pay in a week or so. What sort of accomodation will be made? It remains to be seen. I'll keep you POSTED!

You need a second opinion and you need it before it goes back together.

you may wish to document an understanding (both parities) of all that has taken place and consequent solution(s)

I would ensure this document/ understanding is formally agreed upon as it may serve as your recourse in the event that post repair issues arise

this may provide some measure of comfort for you to proceed with the repairs at this shop while rebuilding some trust

best regards
-fad

Valve Question!
 

Steve: the only way I can get a second opinion is to get the car towed out of there and find someone else in the next day or two that can do the work.

The Gods truth is that I have checked out everyone in my area and sad to say all are not the best.

A guy in Fairfax, Va Don Pool is supposedly OK but who knows! As previously stated I'm a bit screwed!

One other question for the Board regarding valve seals?

Are they different sizes for exhaust and intake valves?

fad! Thanks
 

Still using Zaino?

Document of Understanding is OK and I'll make an effort based on the results. I'll put in writing all that he claims he has done and incorporate the repair order along with an overview of the problem and the supposed solution. Good Point.
Problem is getting him to sign it.

Another thought would be to recap the problem and send him a letter along with a specific outline of what he supposedly did.
This puts the job in writing and gives me a small small ground of space to stand on!

Any thoughts?

Hi Tom- Oh yes- I'm still using Zaino on the E500 and E320 Coupe but not so much anymore since there's now plenty of the product on. I'm using a rather vast supply of other products in the garage cabinet for the other vehicles.

You may be able to convince the shop to provide input to enhance the document (create ownerhip on their end) and then also execute it as a sign of good faith. This may be positioned from their perspective as appropriate in the best effort to provide the reassurance necessary to continue to do business with them (now and in the future).

hope this helps and let us know how things turn out.

Best regards
-fad

If someone did that to my car, and then tried to evade responsibility, and then tried to give me some BS about "needing a valve job soon anyway," I would judge them to be both incompetent and dishonest. I would not trust them to go any further.

IMHO, you should get your car out of there ASAP, and to a competent shop - R & H in Owings Mills comes to mind. There are several other good shops.

Then you need to see a lawyer about damages.

Tom,

I don't mean to sound like an ambulance chaser but it might be time to 'lawyer up' as they say in Texas. A free consultation with a lawyer might tell you which way to jump. Check with the better business bureau and see if the company has had complaints before. Put an ad in the local paper asking for other prople that might have had similar experiences with the company. If the co. sees that you are looking for other customers it might (or should) tell them that you are looking to make a legal case against them. This might help them to see your side. If the company is a relatively small independent one they might realize that it would be better to pay the mechanic's labor on a valve job at $20 an hour or so than to pay a lawyer $300 an hour and stand a chance of getting nothing. To pay a lawyer $100 to write a preliminary to the co. might be enough to show them that you are in it for the long haul.

The advantage that the shop has is that by you signing the work order they have the ability to put a mechanic's lien on your car. Without a lawyer the only bargining point you have is the shop owner's own morals and ethics, of which, apparently, he has very few.

I have worked on cars for about 45 years and this sounds like a classic inexperienced mechanic screw up that the garage is trying to get you to pay for. You are at a distinct disadvantage because they have all the parts (evidence) and can claim that, 'well it was like that when we found it'. You can't prove that your car ran perfectly before it came in anymore than they can prove that it didn't. But, they have the advantage. They can pick up a hand full of bad valves from the scrap bin and swear that these came from your engine.

The only way that valves get bent is from some outside force, i.e., out of timing, or foreign object in the cyl. Valves just don't bend on their own. Valves wear and burn and get carbon on them, but they don't just bend over time. Get your old timing chain if you can. A good mechanic can tell you if the chain is worn enough that it might have caused the timing to jump. I assume that you still have the original camshaft sprockets in the engine. At 120k miles neither should be worn enough to cause the timing to jump.

Good luck, and fight a good fight.

The Saga continues!
 

Well, I'm looking for more amunition.!

This AM I contacted the Shop to determine the status of my Valve, Head job as the Head is at the Machine Shop being worked.

The latest comment was that Valve Seals and Guides were needed and they had to drop them off this AM. It seems that the latest story is that the car was an accident waiting to happen. the chain install triggered the problems and the valves are showing "burnt" due to the car running lean.

I gotta feel this is an effort to justify the job and to get paid for the work. No doubt that will happen. My question is, what makes it run lean? This guy has done all the tuning over the last two years and the car ran great. Can the darn thing run that good and still be set up lean!

Gag!

Words fail me (almost).

If the shop tuned the car, that would have included setting the mixture both with a tri-gas meter, and then checking the lambda operation, both of which would have detected lean operation.

Also, when the plugs were changed, they would have shown signs of lean running.

Performance would have suffered as well, and a common condition known as "lean misfire" would occur at idle.

Did you or Mr. Hunt Valley note any of these conditions?

So now Mr Hunt Valley is in effect saying that he either tuned the car to run lean or tuned the car incompetently.

And the assertion that the new chain triggered or somehow uncovered the problem is complete and unadulterated BS. What caused the problem is that they installed it wrong. There is no other way a well-running engine could suddenly turn into a pile of parts.

I need questions to ask!
 

Chuck!

Thanks for the comments.


What I really need to close this out is s series of things that should be paide close attention to on reassemble.

What kind of things to look out for and what questions to ask: Was this done, how about this etc!

All help appreciated

Tom,

It seems to me that the biggest problem you have here is that they claim that your valves were BENT before you came into their shop. The reapir of these valves is where the big money is going to be. Whether the valves were BURNED was, as I understand it, not part of the original problem. There would have had no reason to have pulled the heads and discovered the burned valves unless they had bent the valves in the first place. The term 'burned valves' should never have even been mentionesd regarding changing a timing chain.

By saying that your valves are burned they are trying to justify removing the heads where they 'accidently' found bent valves. They are on a fishing expedition for reasons to 'discover' bent valves and cover their incompetance.

I think that you are in for a big surprise when you see the repair bill for your car. I think that I would talk to a lawyer before I pick up the car. Once you have taken delivery of the car you have in effect accepted the repair shop's version of the story. Once you accept this version it will be difficult to make a claim and you will have much less recourse under the law.

If this situation becomes legal be sure to ask for proof of the mechanic's conpetance, i.e., diplomas, certifications, etc. Make the repair shop prove that the mechanic is qualified to work on your car. Talk to other mechanics about how the timing chain should be replaced and write it down. Ask the mechanic how, during the proceedure, he would prevent the engine getting out of time. How many of these jobs has he done and can the shop prove this?

Good luck.

I agree with Dude and Kip. But since you asked, the only real issues are getting the chain/cams/crank in the right position and adjusting the pre-load in the hydraulic elements of the ball studs. I assume they know how to torque the heads, clean the gasket surfaces, etc.

But if you pay for anything more than the original repair you are getting royally screwed.

any mechanic that dose a chain job and dose not rotate the engine by hand more than several times checking and rechecking timing marks on both cams and balancer should be working on golf carts. When I did chain job on my 500 SE I turned it and returned it till I was absolutly 100% postive that that masterpeice of a power plant did not make the dreaded sound of valves hitting pistons on start up. If it were my shop you would get the car back with new valves new guides new seals,a wax job and a written apology rather than a bill..........
William Rogers......

Unless one has real good experience, one could never understand how illogical this whole picture is. I have been responsible for hundreds of 116/117 engine valve jobs. All due to chain failure valve/piston collisions.

Never is a long time for me, but if I have ever seen a burned valve in a 116/117 engine it would have to have been a pre 76 adjustable valve engine that had its maintenance massively abused.

The only possible exception to this would be a engine that had prior engine work that was done very poorly. I can't stress enough the reality of this motor. It just don't do what is said to have happened with a virgin motor at that mileage, not even double that mileage.

100% Correct
 

Steve:
You are 100% correct. Anyone will tell you that a burnt valve in this engine comes along NEVER in this engine.

The mechanic claims that when he took it apart, the tiny little caps on the top of the valves were different sizes. Two of these (name) were thinner than the other 6. He claims that someone was in the engine before and something happened? and they put these thinner caps(?) on the top of these two valves to get performance rather than doing a complete valve job.

I have no clue as to what that could be and therefore I am at a complete loss as to what is going on. For all I know its supposed to be that way?

At any rate, the explanation of what is going on here is beyond my comprehension. I'm telling you with all sincerity that this car was driven close to 100 miles per day at hiway speeds, it never missed a beat, Power was awesome, idle was dead on at 500 RPM and never moved. You could barely hear the engine run. Since they replaced the valve seals about two years ago, never any oil consumption. No noise from the chain, just a small amount at start up for less than an instant.

The chain was replaced due to mileage (124K) as preventative maintenance. This is what they are telling me:
They started up the car and a terrible racket ensued. they shut it down and they pulled the Head on the passenger side and noticed that the valves were out of line two were higher than all of the rest. They claim the valves were not bent? They claim that they had seated themselves in the head too deeply and that when they disturbed the chain and reassembled this caused the damage. He still swears that the valves were not bent. I'm going to the machine shop today to verify that. The valves had carbon deposits on 5 out of 8 valves and the very front valve looked perfect with the exception of the beige ceramic finish on it. With the naked eye the tops of the pistons are tan as well and the sleeve looks perfect. It sounds as if his claim is that the car may have been running lean and that the valve work was done sometime ago and that someone screwed around with those caps I mentioned.

My point is : How can the car run so well and then come up with all of these problems on a chain replacement?

Is he BS'ing me to get paid for the work, did he make a mistake, did someone go in there before and make a change to sell the car? Its beyond my comprehension.

All comments welcome!

I am leaving for a 17 hour drive for a funeral in a few minutes in my 560 sel with 180K miles on it. I had the timing chain replaced 2 years ago - on spec - but did not do the upper chain guides or tensioner. I had the parts and was going to do it myself - then the funeral changed the timeline for repair for me. I contacted the Mercedes dealer here and got a firm quote of 3 hours to change the upper guides and tensioner - max price of $350 CDN. using my parts. I took the car in on Tuesday at 8AM. The "new" guy got the job. To make a long story short - I watched most of the time as he stumbled and got help from an experienced tech. He finished the job at 6PM. They honored the firm price of $350 for labor even though the "newbie" took 2 1/2 times longer to do the job. I usually do my own repair work and know how this car should perform. When I got home the idle was rough and lumpy. After inspecting everything I found he forgot to hook up 2 vacuum lines and he broke one in half. 15 min later the car was running great again. I mention this for a reason - if the guys at your indy are giving you the gears to cover up shoddy workmanship - it may be worth your while to pay a Mercedes dealership tech - who knows these motors - to go there and survey the situation and give you a written opinion as to what he thinks really happened. - You might need an expert witness if the dealership you are at now decides not to be nice and you are forced to take legal action. Also the opinions of Steve, as posted above, and other experienced Mercedes Indies should be kept until your shop's "judgement day" - when they give you their "final" price for the work. They could prove helpful in making your point. Just my comment.

More Info!
 

Spoke to the Machine shop1 He claims that no valves were bent. He claims that the two valves that were bad comes from two cylinders running lean.

Either Injector problem, wiring problem or something else causing the cylinder to run lean and develop the problem
He claims that the condition would take 15000 miles to manifest itself.

Again, how can we get such good performance prior to chain replacement, get a valve noise after chain installation and have these type of problems discovered?

The caps I referred to in the above post are called lash caps and as stated two of these were thinner than all of the rest!

I'm still confused!

Can anyone give me a thought here?