Fish or cut bait - PeachParts Mercedes-Benz Forum

#1 07-26-2002, 01:08 AM

Decision time. What would you do?
Facts, 1983 240D, 140K owned since 133K, nice car but burns 1 qt per 469 miles and buzzes (clutch or driveline problem) Paid 2K for the car 5 months ago and have replaced timing chain, valves adjusted, misc repairs totalling $1500 so $3500 in it now.

1. Replace clutch (900 from indy merc or 600 clutch mart), do nothing about oil burning and have people behind me hate me.

2. Replace clutch, and have valve seals replaced (425) Seals may not solve the smoking or maybe for only 10K miles (stems and guides may be too far gone)

3. Replace clutch (900 or 600) and have a complete valve job done ($2000) total 2600-2900.

4. Sell the car.

I can't do any of the repairs myself so I am at the mercy of the mechanics (I do have much faith in him as do several of my friends who swear by him) What would you do?

190D22 · #2 07-26-2002, 01:15 AM

Selling it you're still going to be out money. If you've got the budget to get all the kinks worked out I would do that. Because once you get everything sorted out with her you will have yourself a reliable car that will last you many years to come! I am fighting mine out, and it seems to be settling off now with things that are failing. I hope my exhaust system will be the last thing for a while. Though I'm due up for new tires in a few months, but that was known before I bought the car.

Either way you're going to be out money. Now I am more for the repair the car route personally, buuut maybe you should let her go before you throw over 10 grand into it like I have with mine...

Maybe some other people on here have some more insight.

#3 07-26-2002, 03:32 PM

For now, I would just replace the clutch. The oil burning may lessen with better care of the car, I assume you have flushed and replaced all the fluids if you are not sure the last time this was done. But the previous owner may not have used a diesel engine oil, if you have switched to such there may be some improvement after a few oil changes. If not, then consider the valve job at that time. But you will have driven the car much more and seen if any other hidden problems exist, or if that $2000 will restore the car to near new condition.

If you sell the car and buy another in the same price range, you will still be looking at most likely performing some repairs similar to the above anyway. With the car you own, you know the cost, buying another might result in higher cost repairs.

#4 07-26-2002, 04:14 PM

You've missed an important step here. Have you done a compression test?

Assuming that the compression test is okay, I would continue pouring oil in this darlin' 'til it won't start in cold weather even with a block heater used. One of the things that separates the operation of a diesel from that of a gas engine is what happens when it begins using oil. With a gas engine, spark plug fouling and other ills that prevent the engine from running, come along with oil usage. With a diesel, as long as it starts and runs, you can drive it until it gets to a point that you can't carry enough oil with you to get where you're going.

Replacing the valve seals will probably not do much on this engine. If you could do it yourself it would be a worthwhile experiment because the parts cost only around $15 or so. Since you have to pay for the labor, this becomes an expensive experiment.

If the compression test comes out bad, you then need to go one step further and determine if the leakage is from the top or the bottom. If it's only the top, you can do a valve job, if it's from the bottom, you need to carefully consider the alternatives which will be more expensive than any of the choices you have in the survey.

Best of luck,

dabenz · #5 07-26-2002, 07:02 PM

If you can arrange it, adjust the valves again and then do a leakdown test with the compression check. And be there for the test.

Like TxBill and LarryBible say, leaking from the bottom (past the piston rings) isn't cheap but a diesel engine can handle it for a long time. You'll need an entire engine sooner or later. Decide to fix or roll the dice again with another car.

If you're not leaking from the bottom then you're in luck. Quality valve jobs cost half of a new engine. Decide to fix or roll the dice again with another car.

That "smoke" may just be partially burned fuel. 140k is not a lot of miles for this engine. One of the tricks is to only fill engine oil to halfway between the marks on the dipstick, because of the goofy rear crankshaft seal. Oil above halfway tends to run out there. A cheap and easy check as it makes a mess. If that's the case then it's on to fuel and driving habit issues.

The buzzing clutch may not be the clutch. You're going to have to find a real good, experienced mechanic to find the real cause.

Finally: is a 19yr old car really worth the frustration if you can't work on it? Things wear out and need fixing. I became my elderly aunt's favorite nephew again after I fixed her Caddy a few years back. Had a buzz and vibration. Two dealers couldn't find it. Took 30min to diagnose and replace a u-joint. Not being able to work on a car is not a strike against the owner. Or against a shop (how many rear wheel drive independent suspension MB diesel cars do you see on the road today?). Only lucky collectors get their money back out of a car, and not with these cars. The rest of us use them for jobs, transportation to other stuff, or for the pleasure of the car itself. Only you can decide where the buck stops.

engatwork · #6 07-26-2002, 07:33 PM

dabenz - well said

#7 07-26-2002, 07:35 PM

Excellent advice! I should have mentioned the compression, 400, 400, 400, 380 tested a couple of months ago.

Still wavering between the three options this a.m. it was sell the car, lunch it was valve job, after lunch down to fix the seals, now after reading the above comments its do nothing on the engine and still the monday decision time gets closer (there should be spooky music in the background here!)

I've talked myself into thinking the buzz is the flex plate. If it is a bearing of some kind wouldn't that call for a clutch job since your there anyway?

engatwork · #8 07-26-2002, 07:49 PM

Tim - 1/2 the enjoyment of owning a car like this is turning the wrenches on them. Learn how to work on the car and then try to wear the hood hinges out.

JimSmith · #9 07-26-2002, 10:06 PM

Tim,

The figures you cite for compression test results look pretty good to me. I would try to find out where the oil is going. There are a couple of possibilities that will be cheap to have fixed, like a vacuum pump diaphragm. When these fail lots of oil, especially at idle, gets into the intake manifold and you can get quite a bit of smoke.

Throttle linkage connections on the intake manifold side of the engine are supposed to open a flapper kind of air intake valve as you transition from idle to operating the engine to make the car move. If this is not working correctly, it can result in an intake manifold vacuum which is not an intended condition. This could draw more oil past the intake valve seals than would normally pass there, adversely affect the vacuum pump diaphragm, and draw engine oil mist from the connection to the top of the valve cover.

Other sources can be more difficult and expensive to fix, like valve seals. But with good compression I doubt there is a lot of oil being consumed from oil getting past the rings.

I recently switched oil from a regular Mobil 1 15-W50 to Mobil Delvac 1 on my ancient 240D with over 280,000 miles. It has made a significant improvement to all aspects of running and starting the car, including oil consumption. I have also learned (and taught my daughter who uses the car) not to fill it all the way up with oil - it will just leak out the rear seal on that car and seem like it is using way more oil than it really uses (leaking is not really using oil). Simple solution, park down hill and don't fill it more than half way.

Wait until you have a really good handle on the scope of your problems before you feel the need to decide its fate. Like others have said, once you get the problems solved they are long lasting, reliable machines. Yours sounds like it is basically a good one. Jim

#10 07-27-2002, 12:50 AM

Would a diaphram vacuum problem cause oil burn only at idle or all through the range idle to 75 mph? I think I am just going to print all the advice and show to my mechanic to see what he says. I like solving small inexpensive problems first so maybe these suggestions will be a punch list.

JimSmith · #11 07-27-2002, 01:43 AM

Tim,

The case is worst at idle with a fully ruptured diaphragm as that is the only time when that little butterfly plate in the intake closes and makes any intake manifold vacuum. During normal operation you still burn oil through that path, but it is not as nasty. If the diaphragm is completely ruptured the event at idle is alarming. If the butterfly plate is stuck partially closed when you run though, it will generate a manifold vacuum, which as noted, is not a natural condition for the design of the engine.

Sounds like a good approach to systematically evaluate a number of possibilities. A quart in 700 miles or less is a lot oil consumption, especially if you are not leaking any or much.

Good luck, Jim

View Poll Results: What would you do?
replace clutch only	2	22.22%
replace clutch and valve seals	1	11.11%
replace clutch and get valve job	4	44.44%
sell car	2	22.22%
Voters: 9. You may not vote on this poll