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funny noise

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69tr

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The brides 67 MB 230sl has a noise when revving the engine. I sounds like the fan hitting the shroud. I have checked the clearance around the fan and everything looks good.

Someone please tell me this is a simple problem. Even a bad water pump would not be all that bad..

I have found that I would rather work on my TR than the MB.

As always, all help appreciated, Pete
 
Is the fan plastic?

If you have a long screwdriver, you can use the handle as a crude stethoscope and check to find the location of the noise if it's internal. Just BE CAREFUL where you stuff it while all the whirly-bits are turning!
 
The fan is plastic. I considered buying one of those automotive stethascopes, but the way noise telegraphs in close areas, I didn't know if it would work. Small investment. Better to get the end of it stuck in the whirly-bits than me.

Thanks, Pete
 
The pointy-end goes to the machine, remember /bcforum/images/%%GRAEMLIN_URL%%/jester.gif

The 'scope can reveal a remarkably accurate amount of data. A noisy waterpump, for example, will be HIGHLY obvious with a few probes around the areas of the engine.

A plastic fan can distort amazingly when spun up. There should be some obvious "rub marks" on it and the shroud if that's what's causing the noise.

Keep us up on what you're doing/finding!


And remember:

"Schtuppin der digits in der verks mit der motorschpinnin ist VERBOTEN!"

/bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif
 
My first thought was motor mount. Just a thought. /bcforum/images/%%GRAEMLIN_URL%%/grin.gif
 
Doc, thanks. I was wondering how to get the 2 rubber ends around the motor. And that sharp end looked to be a bit uncomfortable to the ear.


I looked at the fan and the shroud and could not find any rub marks. I have had the bug for the last few days and have not done anything on the car. If I feel better today, I am going to take it to a local shop. There is a guy there that worked on these cars in Germany. I told him about the noise and he did not sound optimistic. Said he could tell more when he could listen himself.

The motor mounts seem solid and the engine does not move too much.

Thanks again, Pete
 
Those mounts are STOUT. What you describe is a sound from something reciprocating. If it isn't the fan sucking itself forward to contact the shroud, my next guess is the timing chain. But as the internet is a poor excuse for a stethoscope, best thing is a trained ear nearby. Good luck and report back on what you find out.
 
I was on the Pagoda forum and a couple guys suggested that I remove the valve cover and check the timing chain tension. They also mentioned that the valve cover might be too tight and hitting the valves. I will try to check this out next week.

Still recovering from the bug thats going around.

Pete
 
I have the valve cover off and can see the timing chain. Does someone know how to tell if the timing chain has too much slack?

Thanks, Pete
 
If you can deflect it on the unloaded side (starboard, IIRC) it's too slack. I'll try to find the REAL spec's. But I think the manuals for that thing are about 50 miles away from me. /bcforum/images/%%GRAEMLIN_URL%%/frown.gif
 
Doc, Thanks again. I can detect a little slack but let me tell you the rest of the story

While I was at the front of the engine I noticed that the alternators belt was loose. I had two thoughts. The first was "man, I hope this ain't the problem" The other was "man, I hope this is the problem"

Sure enough, I tensioned the belt, put everything back together and the noise was gone.

All of my time in maintenance (not automotive) has taught me to look for the most obvious and most likely things first and work from there. I have preached this to my people. I guess I need to step back & take my own advice.

The positive side of this is that I got some really good advice and some hands on experience.

Any way, thanks for all the help, Pete

PS: This is not the most or last stupid thing I will do
 
Someplace here onna forum was a similar instance. "It's ALWAYS th' STUPID stuff that'll bite ya inna butt." We tend to OverTech problems. BTDT.

Glad ya got it sorted, Pete!
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]PS This is not the most or last stupid thing I will do [/QUOTE]

I regularly find that to be so....

/bcforum/images/%%GRAEMLIN_URL%%/jester.gif


"funny" noises seldom are funny....
 
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