Scraping sound and then ...omg - PeachParts Mercedes-Benz Forum

DaimlerChrysler · #1 05-13-2005, 08:40 AM

Most likely it was the bearings in the water pump went bad. I had a mint 1968 BMW 2002 that without any warning the bearings in the water pump seized up knocking the fan blade out of alignment causing the fan to dig chucks out of the radiator.

Usually a water pump will leak first, but mine didn't. Just fix it and try not to cry too much!

mykg4orce · #2 05-13-2005, 10:29 AM

So you are saying there is a connection between the water pump and the fan? If the pump is bad then how did my car run at 85 degrees the whole time, even in slow traffic?

schumi · #3 05-13-2005, 10:42 AM

if water pump was bad car would have overheated. sounds like the fan clutch went out.

mykg4orce · #4 05-13-2005, 11:14 AM

I agree...otherwise how would you explain the smell? As I said the car ran fine, at first I thought the car died...but engine was still running, very quietly.

mykg4orce · #5 05-13-2005, 11:14 AM

does anyone have any tips on replacing the fan clutch?

A264172 · #6 05-13-2005, 11:34 AM

Are you sure it's the clutch?

The scraping sound... sounds like the bearing bracket (bolts onto the block and holds the pulley that the fan clutch is attached to in place). In my case I found it because the pulley was rubbing against the crank pulley, squeling, and sending a tiny fountain of metal shavings upward from the area of the water pump.

Try to wiggle the fan (when its not running) back and forth... if it has a lot of play the bearing is shot. Even with a bad bearing the poly-V belt will hold it in place to a degree.

Good luck.

nglitz · #7 05-13-2005, 04:00 PM

It's not the water pump. The only connection b/t the pump & the fan on the M103 is that they're driven by the same belt. I just finished replacing the "bearing bracket" as it's called in the parts listings. It's a casting that bolts to the front of the engine & holds the bearing that the fan & clutch bolt to. That bearing is a fairly good sized double row ball bearing. Mine wobbled around & made growling noises for an amazingly long time before I discovered the problem.

Look down between the fan & engine, with a flashlight if needed. Grab the tip of a fan blade or two & try to move it front & back. If it rocks on the clutch, bad clutch. If the clutch rocks with it, bad bearing, need the bracket assy. They typically go for $85 on eBay. That's where I got one. It is a Lemforder brand, an OEM for MB. In my case, the growling noise was the bottom, back edge of the fan pulley (no grooves, flat side of the belt) rubbing on the block. It didn't wear the pulley out and just shined up the block, so no real damage & it got reused.

I'm not going to go through the whole procedure, as it's detailed pretty well in a number of threads. I will say that it's much easier if you pull the radiator first. Mucho more knuckle clearance. while you're in there, might as well take a look at the other idler bearings and the tensioner, too. And, of course, the belt.

HTH,

Boudreaux · #8 05-20-2005, 10:22 AM

Quote:

Originally Posted by mykg4orce

So you are saying there is a connection between the water pump and the fan? If the pump is bad then how did my car run at 85 degrees the whole time, even in slow traffic?

Your car was not running cool because MB displays the temperatures in CELSIUS. When converted, 85 Celsius is actually 185 Farenheit, which is a not super-hot but if left unchecked with a broken cooling part could possibly do further damage.

Good luck.

mykg4orce · #9 05-20-2005, 11:46 AM

All I know is that the normal operating temperature is 85 Degrees, my car was running at about 80-83 range.

Also the fan clutch now seems to work but continues to make noises. The fan spins but I cant be sure it is working properly.

Again I need some insight from people who have replaced their clutch without using this special tool as circled in the attached image two posts up.

gmercoleza · #10 05-20-2005, 12:17 PM

In celsius, 100 degrees is the boiling point of water (much less confusing than Fahrenheit, don't you think?). But you don't just put water in the cooling system; you put a mixture of antifreeze and water which has a slightly higher boiling point, perhaps around 105 to 108. In addition, everything is under high pressure which further raises the boiling point of the mixture to around maybe 115. I don't know about on your car, but on my 300E the "red zone" on the temp gauge is at 120 degrees.

Once the water starts to boil or bubble, you have a gas/liquid mixture rather than just liquid flowing through the cooling jackets. The gas will not absorb heat as quickly as the liquid, and the temperature of the metals shoots through the ceiling quickly, resulting in warpage or other damage. Rapid cooling (like turning the engine off or - worse yet - adding cool water to the cooling system) can cause cracks in the metal, much in the way an ice cube cracks when you drop it in a glass of water. In all cases, the key to avoiding damage is to prevent boiling from occurring in the first place.

As long as your coolant/water mixture is not boiling, you are fine. And 85 celsius is not even near the boiling point.

mykg4orce · #11 05-20-2005, 12:23 PM

exactly.

mykg4orce · #12 05-21-2005, 12:28 AM

An update.

After discovering metal shavings around the clutch pully, saw that the pully was rubbing against the crankshaft pully, slowly sanding off the metal exposing the aluminum below. Anyway when I was moving the fan back and fourth I saw no movement, well I attempted to lift the clutch pully with my hand, as to move it up, it actually moved quiet a bit. When I took the belt off, it was apparent that the bearings have been worn out.

I am going to need a new pully as well, because the edges on the pully (aft side) have been worn down. I already have a new clutch on the way. I am wondering tho, is it possible to repair the bearings in the bracketery. I mean there must be a way instead of replacing the whole unit.....????

Any thoughts....