Testing before problems Occur? - PeachParts Mercedes-Benz Forum

imagesinthewind · #1 01-30-2008, 03:24 PM

My car is running AWESOMELY right now. Starts well (though she does think about it still when the cold is 20* or below), idles very smoothly, goes from 0-60 in about 18 seconds. That was tested from a stop at an on ramp onto I-25 while switching lanes. It takes 5 seconds from a stop to 20MPH.

So, my question is, can I do things like Compression Tests before problems occur so I have a baseline of what she was doing while happy? Just so I know how to do it in the future?
Maybe cleaning the ALDA, too.

I was also thinking of doing a diesel purge just because. Would this be overkill since right now she's doing well. Is there usch a thing as too much preventative maintenance?

Thanks!

rs899 · #2 01-30-2008, 03:41 PM

Doing a compression test while it is running well is a great idea. Just hope you never need to use the data later.

I am a big proponent of PM. When I got my cars a few years ago I went through them and replaced a lot of things that still had some life left in them.
I see nothing wrong with it if you are in these cars for the long haul. I figured they were about half used up, so I went ahead and rebuilt the front ends, rear subframe bushings/diff mount, flex discs, center support bearing, brake hoses, shocks. My rationale is that , once done, these should be good for the lifetime of the car (or mine), and will restore the car close to the way they left the factory, performance-wise. And that also took some of the risk out of breakdowns etc later on. Of course, I still have old engines and transmissions to worry about. I am slowly rebuilding a 300D transmission from 2 parts trannys I have and one probably good one. I know that sooner or later the one in the 300D will fail and I will have a rebuilt one to slap in- or I may just take the opportunity to swap in the fresh one before the tired one fails.

Rick

toomany MBZ · #3 01-30-2008, 05:17 PM

A picture paints a thousand words.
But as rs899 and yourself mentioned, you can get a base line, and perform maintenance, should last a long time.
I do a purge on all cars shortly after purchase, now I know what goes in the tank, I'm not concerned about any more, but may later too, "just because".

Mismost · #4 01-30-2008, 05:56 PM

I'm all for PM. I appreciate your desire to dump cash into your car, you love it....that's a good news, bad news thing! But think about this, it is wearing out every time you use it. You KNOW over time the compression will get low...just wait until it gets there and THEN spend the money to fix it.

Frankly, these old MB are not great collector type cars. Sure, we love them, but most folks could give a rip....to them, it's just an old car. But, I tend to look at things like cars with a "loose money/break even/loose lots of money" kind of mind set. Notice there was no "make money" in the above? Now I really don't care what you do with your car, that's your business. I just what to show you a different line of thinking.

In the words of the singer/songwriter John Prine..."Stop wishing for bad luck and knockin' on wood". Enjoy your ride while she's purring...she'll puke on you soon enough! Don't let "budgeted money" burn a whole in your pocket.

imagesinthewind · #5 01-30-2008, 06:09 PM

Quote:

Originally Posted by toomany MBZ

A picture paints a thousand words.
But as rs899 and yourself mentioned, you can get a base line, and perform maintenance, should last a long time.
I do a purge on all cars shortly after purchase, now I know what goes in the tank, I'm not concerned about any more, but may later too, "just because".

What book is that photo taken from?

kerry · #6 01-30-2008, 06:25 PM

I'd wait until the next time I have the glow plugs or injectors are out to do a compression test. Don't see how it would help to get one at the moment.

barry123400 · #7 01-30-2008, 06:34 PM

You could get the recommended thirty thousand mile service information and slowly do the proceedure yourself. Probably lists many items to check for wear etc.
These services were primarily intended to keep reliability up I believe. Also great way to learn about many areas of the car as you check them.
Possibly will also list a lot of things like lubricating your door and hood hinges, cleaning and lubrication of sunroof mechanisim and feeder cable as well for example, checking out belts, flushing the brake and power steering system, treating your doors weatherstripping, checking your voltage regulator for remaining brush length, checking brake pads, suspension, steering, and things like shocks for leaking or wear. I have never seen the list myself but it does exist.
I believe the valve clearances on your model are to be checked every fifteen thousand as well for example. Especially if you do not have any knowledge of when last checked they might be really overdue. Less chance of damaging a valve in the engine to keep on top of this stuff. After the first time it is a piece of cake so to speak.
This is real preventative maintenance at it's best and you can do it in stages. More time intensive than financially driven as well.

toomany MBZ · #8 01-30-2008, 06:44 PM

Quote:

Originally Posted by imagesinthewind

What book is that photo taken from?

From Star magazine, (Sept/Oct 2004) when you join MBCA, you get a subscription, AFAIK, that's the only way. I have a few lying about. Also the sales brochure turbo diesel, there's a torque curve in this one, from 1985 and a spec brochure.

t walgamuth · #9 01-30-2008, 06:45 PM

If it ain't broke, why fix it?

As far as diesel purge....never did it. I have owned about 30 benzes, mostly diesels. When I get a new (to me) one I change oil and all filters, install bilsteins and michelins and check the brakes. I would before too long purge and renew the brake fluid, too. I would also probably treat the fuel with injection cleaner and biocide, just to be sure.

I would check the belts and wash and wax it and enjoy.

About fifteen years ago, I bought a new (to me) '83 240d. It was a nice clean car with, IIRC, 170K miles or so on it. I pulled it in the garage and changed the oil, filter, fuel filters and air filter. The next day I headed for canada on a full day drive. My wife said..."you sure you wanna take that new car on a long trip like that after just getting it?" I said..."sure, its fine". It was.

I have never ran a baseline compression test on any motor of mine. I have only done it when a problem is suspected or as a prepurchase check.

If you feel the need to do something, I will check....I am sure one of mine needs a thing or two.

Tom W

imagesinthewind · #10 01-30-2008, 07:26 PM

Well part of this whole thing is learning.
I have a compression tester but never used it.
I wasn't planning on taking it somewhere to have these things done,
I was planning on doing them myself. Most of the stuff I listed wouldn't
cost more than time and in the end I would have one under my belt if
the time ever came to need to do them to the DHs car-the non-running
beater that will be my project this summer.

I do agree that if it ain't broke. . .

hangit · #11 01-31-2008, 08:39 AM

Quote:

Originally Posted by imagesinthewind

Well part of this whole thing is learning.
I have a compression tester but never used it.
I wasn't planning on taking it somewhere to have these things done,
I was planning on doing them myself. Most of the stuff I listed wouldn't
cost more than time and in the end I would have one under my belt if
the time ever came to need to do them to the DHs car-the non-running
beater that will be my project this summer.

I do agree that if it ain't broke. . .

You go girl!

John