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Old 04-13-2001, 10:32 AM
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Location: Toronto, CANADA
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I finally found the cause of a rough idle that had been driving me crazy. Dealer says I need a $5000 valve job minimum, as three of the sparkplugs are fouling. They didn't bother to do a compression or leak down test as they said putting the money into the car to do them wouldn't be worth it in the long run. Anyone have any thoughts on this? Althought I can think of better things to spend the money on, even if I spent the $5000 on a valve job, a couple grand fixing up the suspension and 2 grand repairing the sun roof I'm still only out less than 10 grand. Ad on to that 5 grand for other things that might go wrong in the next two to four years and I'm out 15 grand. What kind of car can I get for 15 grand that I can count on? I'll have to think on this for a while before making a final decision. Any input would be appreciated.


Jason Priest
1999 E430
1995 E420 - retired
1986 420SEL - retired
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Old 04-13-2001, 10:49 AM
CJ CJ is offline
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I would shop around and get a second opinion on the price, if in fact that ios what it needs.
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Old 04-13-2001, 10:53 AM
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I echo that. $5000 seems a bit steep...
Bill Streep
San Antonio
'57 190SL (toy)
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Old 04-13-2001, 11:40 AM
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Buy a cheap car and rebuild engine

Buy the equipment that you need, order the parts, make it a two month project
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1988 190e 2.3 - 225K miles, owned for 7 years. I cannot say enough good things about this car. Very well built, even at 225 it ran like new.
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Old 04-13-2001, 12:01 PM
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What other car can you buy for $15k that will as reliable as an old M-B.....? Why another late model M-B of course!

If the other estimates also sound like the repairs will make it cost prohibitive, take to your local classifieds or to find a "new" M-B to replace your ailing ride.

85 euro-spec 300E twin-turbo 5spd. AMG aero kit
89 300CE AMG aero kit
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Old 04-13-2001, 01:30 PM
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Location: Austin, TX
Posts: 576

Yikes! I would agree that you should get a second opinion. It seems to me that you could get that done for around $2000.

As mentioned, you could look for a wrecked one and swap engines.

It's ironic, when I mentioned recently about me looking at a 420, you messaged me that your car was going strong. I hope that didn't jinx you.

There are alot of good cars out there for under $15K. My theory is, the less you spend,the less you loose. The trick seems to be, trading out before something big fails. There are a ton of good S Class Mercedes out there betwwen $5-10K.

Your situation is why I'm being so cautious. After reading your post, I think I might know why the 380SE I looked at idled rough.

We just need to be careful.Good luck.


91 300E 120K
90 300SE 275K (sold)
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Old 04-13-2001, 03:34 PM
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Location: Santa Clara, CA
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Do an ebay search for a 420 SEL. There is one in Ontario selling tomorrow, with 143K on it.
Putting 15K$ into this car over the next couple of years is way too much to invest in a car that age.

I'd also do a compression check yourself to find out what you are up against. A gauge is only a few dollars and easy to use. Lots of ways to foul plugs other than bad compression. How does the car run? Does it have decent power? (with clean plugs)
By all means find an independent shop that will give you a good price. If you find a wrecking yard with a good engine, they will probably also install it for you or can recommend someone who will do it cheaply. If you can't find a local one, do an internet search for used engines.
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Old 04-13-2001, 03:37 PM
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Put a big block Chevy

or Ford drivetrain in it if you want an awesome ride. I recently saw a '79 300CD with a small block Ford drive train that looked and ran good.
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Old 04-13-2001, 04:46 PM
Herr Busch
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Sounds like the "chrysler" influence

If they did not do a compression or leak down test, then they cannot say that it needs a valve job! Am I the only one that has noticed that the dealer just doesn't care anymore- odd, you can get the exact same treatment at the nearest dodge service department. Drives me insane!!
Does your car smoke at the exhaust? I had a problem with fouled plugs. Three of them as a matter of fact. The problem was the oiler tubes under the valve covers. I had taken off the left hand side to do something and apparently cracked one of the plastic holders for the oil tube. When I would hit the brakes (only sometimes) excess oil would go into the breather tube and into the air intake. It is designed for a little bit of oil, not what was going through it then. Three of the cylinders were affected more than the others. I believe it is due to gravity and the path of least resistance. If this is your problem, your cost to fix it is less than a hundred dollars. Check the breather tube. It should remain mostly dry, well not a dripping mess anyway. If it shows signs of excess oil, that is most likely your problem.
BAD VALVES CANNOT BE DETERMINED JUST BY LOOKING AT THE SPARK PLUGS!!!! I am surprised they didn't just shine a flashlight up the tailpipe and tell you the exact same thing.
The "acquisition" of Chrysler was like acquiring cancer (of the brain apparently)!!
Good luck!
Herr Busch

[Edited by Herr Busch on 04-14-2001 at 10:06 AM]
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Old 04-13-2001, 05:45 PM
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Location: Toronto, CANADA
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Thanks for the responses everyone. I too thought the price they mentioned was pretty steep and I was a little concerned they do didn't do any testing. It really freaked me out to hear that diagnosis, as the car drives fine. There is no smoke from the tail pipe or anything. I had suspected it might be something like mootor mounts or a small problem developing with the fuel distributor. I don't know if the service guy is trying to work his way into the sales department or not, but he really went out of his way to tell me not to "waste another dime on the car". I was pretty depressed over that and I'm still not thinking objectively about it. One thing is for sure, I'm not ready to give up on it yet. I am going to get a second opinion. I'll let everyone know what turns up.
Jason Priest
1999 E430
1995 E420 - retired
1986 420SEL - retired
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Old 04-13-2001, 08:15 PM
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Yes, go for a second opinion.

For $5,000-00, I could get a reconditioned engine from Germany, and still have some change left-over.
... Kerry

126 tailed by a 203, 129 leading the pack.
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Old 04-13-2001, 09:09 PM
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I think sometimes some dealers just don't want to work on an old car with a real time consuming problem. They probably would rather work on 5 cars, charging labor and parts, making a profit on both, than work on 1 car. Dealers, like most retail businesses, make their money on volume. I doubt the dealer would actually do the valve job themselves. They would probably send it out, so they don't make as much on labor and really only profit from the valve train parts. My father had an A/C problem and dealer he took it to just kept replacing parts with no fix. They eventually just gave up. He took it to an independant shop and they found out, using the MB chassis manual on CD, that there was a fried resistor in the climate control panel. Dealers rather "turn them and burn them" than fiddle with an "old" car.
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Old 04-14-2001, 03:08 AM
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Our independant service centres will not work on old engines anymore - they reckon its better to replace the entirety with a reconditioned, which I was told is cheaper than to work bit by bit.

Is this not a popular option in the States in terms of saving labour cost?
... Kerry

126 tailed by a 203, 129 leading the pack.
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Old 04-14-2001, 09:51 AM
Join Date: Mar 2000
Location: Gainesville FL
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I started to answer this post yesterday but though better of it. My point would have been the price. The hundreds of valve jobs we have done to single cam MB V8s have almost all been for less than $2k. We are an independent though and in a rural area so our prices are naturally less.

The reason I am writing today has to do with the reasoning behind the job. A compression test will be of NO use. Unless the valves are bent there are almost never compression problems. The problem is oil leakin down the valve guides and this occurs for two reasons. The worse is when the guides become loose in the head and oil leaks between the guide and the head. If your plugs were soaked in oil this could be the case. This problem must be addressed immediately as the bore in the head is being ruined and the valve guide will eventually fall in holding the valve open causing it to hit the piston.

The more common problem is valve guide oil seals which can be simply replaced from the top (5.5 hours labor). For anyone experienced with MB (including most dealers) an original engine with 200K needing valve guide oil seals probably won't have them last due to the wear on the guides. So, a proper recommendation is to fix the oiling problem the proper way by replacing the valve guides. This necessitates reseating the valves as the angles get slightly changed when the new guide is pressed in. This diagnosis is probably the easiest ever made on an MB. Its cut and dried. We sometimes start by making an attempt at the valve guide oil seal replacement. We do the cylinders where the sparkplugs were fouled and through experience we judge the guides with the prearanged concept that if there is a question we will take it apart.

This concept here has so much to do with mileage. I have seen valve guides drop on engines with less than 100k, these have to come apart. But, the course of repair on a valve guide reseal for a motor over 200k has to do with experience, and experience says don't waste the time with just seals.

If the car is in good shape, someone should fix it and use it. Find an independent shop with MB experience that does engine work. Anyone with experience can do good work here as the pieces are built so well.
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
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Old 04-14-2001, 11:02 AM
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Thanks for the repy Steve, I have a much better understanding of the situation after reading your posting.
Jason Priest
1999 E430
1995 E420 - retired
1986 420SEL - retired
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