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-   -   560sl leaky valves (http://www.peachparts.com/shopforum/tech-help/42895-560sl-leaky-valves.html)

arran 07-26-2002 08:04 AM

560sl leaky valves
 
I have a '87 560sl with 89,000miles. I've driven it the last 30,000. It has been a well maintained car. Since Feb I am now on my second set of plugs because of leaky valves. My new mechanic says I'll need the whole valve job, including timing chain, around $4000. He also stated my engine mounts and brackets were gone, another $800.
From everything I've read I fear the diagnosis is correct. However, as a girl, I'd like another opinion and any referrals to a great mechanic in the Dallas, TX area.
I love the car and want to keep it and drive it for a long time, I just want to find someone I can trust to work on it.

Thanks guys

dpetryk 07-26-2002 08:14 AM

Leaky valves ?? What exactly does he mean? Valves can leak in two ways. Either valve stem seals are leaking oil, causing high oil consumption and posible oil fouled spark plugs, or they are burned and the engine wont hold compression. Since you mentioned that you had to replace the spark plugs, I assume that oil fouling and the valve stem seals are the culprits. If the engine compression is good replace the valve stem seals and the timing chain, rails etc. That will be alot less expensive than a removing the heads and doing a valve job. These engine usually dont need a valve job at 89k miles, but they do need seals.

The price quoted for the engine mounts sounds really very high to me. You might get a second opinion from a different more trusted shop.

joe p 07-26-2002 09:49 AM

M117 engines will "leak" from the guides. Top end rebuilds are not that unusual at 130K or better. Timing chains are simply cheap insurance. The only thing I wonder about is the "brackets" Unless the car took one hell of a hit in the front I've never seen these (motor support brackets) bad. Mounts shouldn't be $800.00 either.

Watch for camshaft and rocker wear on these as well.


Joe

Jerry Hudson 07-26-2002 02:49 PM

My 88 560SL has 124,000 miles on it, and while it might have a little oil leak-down past the valve guide seals, it doesn't foul the plugs. You might try running a heavier weight of oil (20w50) for a while to see if that helps. Eventualy the valve guide seal will need to be replaced, but this might buy you some time.

Timing chain and rails: definitely change before 100,000 miles. I just had mine done for $500.

$800 for motor mounts alone seems high, but if he is also changing subframe mounts for that amount it doesnt seem to bad. Rubber mounts around the engine compartment don't last more than 10 years so they should all be replaced. I had all this done on my car early this year at an MB Dealer and it was right at $800. Hope this helps..

arran 07-26-2002 03:24 PM

Thanks for all the info.The "leaky valve" statement was my description. I picked up my car today and was armed with more questions after reading your replies. I need motor mounts and subframe mounts, $800.00 It was explained to me about replacing the seals, timing chain etc for around $1600.00 presuming the guides are okay. Wait and do the guides when needed. I last changed my plugs five months ago for the same problem and I am not burning excessive oil.
The charge for labor on motor test engine (due to rough)ride and replacing the plugs was $197??

Linda

joe p 07-27-2002 08:25 AM

Ok, subframe mounts and motor mounts..... $800.00 is about right. 560's have a tendicy to walk the guides, causing a low grade skip, plug fouling and some oil useage. Seals are nothing but a bandage in most cases, however if the money is tight, I'd try it. The guide walk is a tough diagnosis to nail down with the engine intact. Like I said before, chains are cheap insurance.

There is one way to look at it, the seals and t-chain are XX.XX amount of $'s, then in 30,000 miles you spend another XXXX.xx.
If you do the entire repair now (I pull 107 engines to do top ends)it costs XXXX.xx, which should be cheaper overall. My approach to a 107 top end is pull the motor, reseal the entire thing with a new chain, guides, tensioner etc..... bottem end reseal, water pump, t-stat, full intake reseal and so on. Other than higher parts costs, the labor is pretty much the same as doing the heads, chain and guides with motor mounts in the car. Not to mention you get everything dried up at once. This covers the rear seal and plate as well.

This is also prime time to replace the rag joint on the steering box if questionable at all and subframe mounts are a breeze with the motor sitting on a engine stand.


Joe

arran 07-27-2002 10:00 AM

Thanks Joe,

I will be much better informed and feel more confident dealing with my mechanic. It sounds like getting the total job done, if I intend to keep the car, is the way to go.

Thanks again,
Linda

stevebfl 07-27-2002 10:24 AM

Maybe I should make a recording.

If you wish all that stuff done, ship me the car and I'll finish it in a week, you can fly in and spend the grand you would save on a Florida vacation.

But if it were my car I would replace the valve guide seals (and only do the head work if you find a loose guide - extremely unlikely). While the valve covers were off I'd solve my chain liability by replacing the upper rails. I would do all that for you for about $800. My God, its only got 89K on it.

Maybe I should get a transporter.

engatwork 07-27-2002 10:54 AM

Steve - a transporter and a "loaner" passenger van for use in the mid Fla area would probably get you some out of town business. Throw in a couple Disney tickets and there you go :):). Vacation/car maintenance plan :) - sounds good.

stevebfl 07-27-2002 11:38 AM

What a plan.

joe p 07-28-2002 09:38 AM

Well, the best I can offer is a trip to Emerald Isle or Ashville.

Steve, I had a 560sel with 80k on it a few years back and the guides damn near fell out of the heads. I had a 300se a few months back that had over 1/8" of side play in the guides, 85k. Some of them eat parts faster than others my man.

I just not a big fan of bandaids.


Joe

stevebfl 07-28-2002 12:03 PM

I have repaired hundreds of MB heads (or my shop has). We use the factory go-no go gauge for guides to test randomly the guides we are replacing. Heads with 200k regularly pass.

We have put valve guide oil seals on at least a thousand MBs. We have never had a case where our risk taking was proven unjustified. I submit that by taking no risk, requiring complete resuurection, for each case one can never know what will work. I have striven to find these lines and have taken the risk for my customers to judge when they should drop $800 or $2500. In the case of valve guide oils seals I have never lost, point blank.

I aproach driveability diagnostics the same way. I strive for the single cause. I loose quite regularly. There is probably nothing quite as cut and dryed as this VG oil seal issue. I'm sure I could make more money by being 100% sure and doing the $2500 job every time. I could even do better if I charged $4800 for it. I'll have to work on that part. But, I do this cause I like it, and hitting the target without a shot gun is what makes it fun.

If the medical industry did things my way medicine would cost less than 1% what it currently does. Unfortunately we would bury the losses. I've done real good at this for a long time. I wouldn't recommend it if one wishes to make money.

BDBENZ 07-28-2002 12:15 PM

seals
 
Bravo, Bravo......great integrity! I wish that I lived closer to your shop. Keep it up, and thanks for all of the advise. BD :cool:

joe p 07-28-2002 11:11 PM

Tell that to the previous owner of the 92 300te I picked up at auction. He spent 800.00 doing stem seals and a chain at the local dealer. It used more oil after the repair than before.

I pulled the head and was suprised it didn't drop a valve as the guides had a very noticable trench cut to the outboard side of the guide. I've seen small block chevys drop valves with less side slop in the guides.

Each to his own but, I still stand on one princible, either fix it right the first time or let it alone.

I've spent most of the last 10 years fixing "quality" repairs done by "qualified" and "certified" "technicians.

m117's tend to leak oil from the backside of the heads after 140k or so, why not kill 2 birds with one stone? Not to mention the intake o-rings harden and leak, injector seal o-rings leak, rear seals leak, front seals leak, motor mounts collaspe and steering shaft joint deteriotate. Age plays a significant role as well. Some of the worst cars I've seen for BIG repairs were low miles units.

Why not cover all in one repair?

Yeah, big bucks but...... add the costs of all those repairs together and I'd bet the pink slip on my 1 ton that it would be a damn sight more than repairing all those one item at a time.

Ignoring the normal wear and tear items for individual repair on a case by case basis knowing it will happen starts to infringe on my sense of ethics. Especially when you know beyond a shadow of a doubt that it will be yet another expense for the client.

This is the main reason I let my customers decide and dictate exactly how their car will be repaired. Knowledge is power and I firmly beleive in educating my clients as to their options.

Sure, you can argue you've never seen guide wear, never seen the tensioner ramp wear out, never seen a m117 main oil pan leak and so on, but they do and will.

I've seen the results of many a bandaid repair over the years, sometimes they hold well and other times they are a waste of time and cash. At the very least let the owner decide if they want to roll the dice.

It's like the old debate about lock cly's versus cly's and steering locks. I've seen that bite a bunch of people back quickly. They replace the cly and the damn steering lock freezes 2 months later.


Joe

stevebfl 07-29-2002 07:58 AM

If one is doing valves seals and there is a problem, it's what being a technician is all about.

My goal as a technician is to minimize my customers cost to drive their automobile. My ability to make the above judgements is what I'm all about. Anybody can hit the target with a shotgun. When I quit having fun doing this, I'll do something else.

Decisions are what I do and people pay me for this ability.


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