300 TE Squeal, Hydraulic Leveling and 4matic questions

[hippiecar]

I have had for short time, I have put 1,000 miles on it, a 300 TE with 4matic seems nicely cared for 123 K on working odomoter. Tranny, motor, air conditioning all work fine. My other 300E never has any issues. It is like new. I love straight sixes including my Cummins diesel pickup, and my first car a Toyota Landcruiser 1964. Would appreciate any advice on 300 TE.

First Question: I have a squeal that occurs usually when cold and persists for a few seconds. Doesn't occur every time started. Does have some association with whether the air conditioning compressor is on or not, but it seems to happen when the air conditioning compressor doesn't appear to be engaged. Compressor may just add belt tension and noise from belt may be affected by its drag. I have adjusted slightly the idler wheel on upper passenger side of car which tightened belt somewhat and have sprayed belt dressing on serpentine belt. Belt doesn't have cracks but seems a bit loose compared to my 300 E and what I'd expect, and there is one portion with slight fraying on edge.

I've read a lot of archived info here but I'm trying to decide whether this is my first logical choice, which would be 1. need new serpentine belt, or 2 is it a problem with the idler or belt tensioner, or 3. if it is the air conditioning clutch. Air conditioning, once car is warm does not cause any noise change on squeal which goes away after warm. 4. Finally, I have read here about an air pump that might squeal. I know nothing in re this. Can't localize the sound yet because it is a bit rare. Obviously, so far when its cold and I am ready with the hood up to try to id it, it doesn't occur.

I have been unable to have it squeal while I had my belt dressing ready on startup to be sure on belt. Still could be a manifestation of some pulley dragging I suppose. Air conditioning compressor when looking under hood with engine running sounds just a bit "louder" than I might think but this is very subtle to imaginary on my part perhaps.

Second question: I have the hydraulic leak from the self levelling system that I have read about. Repair I hear is costly. If kept full are there problems just buying hydraulic fluid (somewhat costly though from MB) and driving. What is the downside of just letting it run dry and going without the system? Is there a cheaper similar hydraulic fluid alternative to the $18 per quart at MB dearship?

Final question: I don't know how to tell if the 4matic is working until it snows again. Will it show up with loose sand just by starting up and looking for wheel spin and do I want to try to drive it somewhere with such conditions? No lights going off telling me it's not working. I'm a newbie to the 1st gen 4matics. When I test drove it it seemed on a gravel road to be working when I tried reverse and start quickly, but I'm not certain. What am I in for in the coming years generally with 1st gen 4matic? Is it worth it? This car is in Utah so snow happens. My college freshman daughter will be driving this but we borrow it for the 7 seat capability from time to time.

Thanks for any advice. I've been reading the archives but could now use any opinions/advice.

Doc

[Stickman]

(1) Replace the serpentine belt now that you have put belt dressing on it. Bad juju.
(2) Any good hydraulic fluid works just as well as the MB Stuff. Just siphon it out and change it every year so it doesn't absorb water. - Buy it by the 5 gallon bucket. It's cheaper that way. DON"T let it run dry. Check fittings & trace the lines from the bottle back.
(3) 4-Matic? Never needed it.

[hippiecar]

Thanks Stickman. All good advice. If after replacing belt squeal goes away I'll know.. If not, it'll help narrow things down. I appreciate the advice re hydraulic leveling too.

[augapfel]

You don't say what year the TE is. Not all years had th air pump so it would be nice to know what year you're talking about.
Regarding the squeal, are you absolutely sure that the noise is coming from the engine compartment? I ask this because it is fairly common for the D battery-sized air sampler electric motor located to the right of the glove box to squeal for a short time when it first starts up. The bushings dry out with age. Two of my 88s did this and locating the source of the noise the first time really drove me nuts. This little motor/fan sucks air through a tube that runs up the a-pillar to the small grill located next to the sunroof switch. It helps the HVAC system get an accurate measurement of cabin temp.
As for the SLS, letting the system run dry is not an option. The SLS accumultors *are* the shock absorbers for the rear suspension. The shock absorber-looking things you see at the rear wheels are hydraulic cylinders that support the rear of the car. Let the SLS run dry and the back of the car will drop onto the ground and stay there.
Can't help on 4Matic since I don't own a car with it (and don't care to).

[hippiecar]

Aguapfel
Thanks very much. It is especially helpful to know that the hydraulic system is essential, not just auxiliary. I'll check further re th air pump. Greatly appreciated. By the way the TE is a 1992.

Doc

[hippiecar]

Sorry re name typo Augapfel.