whines/shreeks when cold: '82 240D - PeachParts Mercedes-Benz Forum

adamkat22 · #1 12-13-2011, 05:33 PM

i have two cold related things. probably(?) not related but posting them together:

NOISE:its just now gotten below freezing at night here, and the last two mornings my car has made this sound coming from the vicinty of the windshield wipers (honestly can't tell if its from inside or outside the car) and its like wind is whipping through a small crack. gets really wining and high pitched. when i slow down (below 10mph?) it stops, but i can be at a higher speed and put it in neutral and the sound continues until i've dropped to a crawling speed. its happened two days now (the first two consecutive days that my car has been able to start!). both days i've turned around and brought the car back home. later in the day when i start up it doesn't happen (which makes me think its cold related). i have been warming the car up for 10-15 minutes before driving in the morning. the sound makes me nervous like something is about to blow or snap or some witch is going to smash through the hood. any thoughts?

COOLANT LEAK: I also have a coolant leak. When I look down at the radiator I can see coolant gathering on the lip below the upper hose, and falling to the ground from there. On the opposite side of the radiator is almost looks like the radiator is sweating or weeping (which I assume is coolant). Does this mean I have to replace the radiator? As long as I check levels regularly (I drive an hour to work) can I put off the radiator l swap till this weekend you think?

Thanks for your awesome advice as usual! I swear one day my car will stop breaking and I'll just answer other peoples questions!

DIESELVOLVO · #2 12-13-2011, 06:24 PM

It's the speedometer cable.

Radiator shop to pressure test and repair, another few days most likely no prob. but never any sure bets with something like that.

adamkat22 · #3 12-13-2011, 06:32 PM

awesome. thanks! this weekend i'll have more time to deal with radiators. and i assume the speedo cable can wait till then as well...so long as i wear earplugs to work for the rest of the week?

JHZR2 · #4 12-13-2011, 06:57 PM

speedo cable will shreak if bent wrong. Im chasing this on my BMW though. Much below freezing and I get a nasty shreak as wella s a little belt noise. I think it is either the alternator or the water pump, leaning towards the pump.

piccolovic · #5 12-13-2011, 07:31 PM

It could also be loose belts. The drop in temp could be enough to make them squeal, although a bad speedo could drive you crazy too. In the interim . . . turn up the stereo!!! wink

JHZR2 · #6 12-15-2011, 09:03 PM

I got an email response saying that there was a new post - but its not loading. Here is what it claims is posted here, "in terms of the coolant leak: i know dieselvolvo said get it to a radiator shop and have it tested and repaired. partially cause i'm low on cash and partially cause i actually trust folks on here more than i trust mechanics (i'm new to my area and don't have one i know/trust yet) i wanted to check in a little more about the radiator leak. does anyone have strong opinions on this barsleak stuff? i couldn't really find more than a mention of it in past posts, but i don't see the harm in just trying it out unless you all tell me otherwise??"

The main question is how much does it leak? Are you talking very small amount or does it drip when cold and steam when hot? Does it just spittle a little when it is hot and pressure rises?

Ive seen decent temporary repairs on plastic radiators using JB weld, and epoxy. Material compatability, cleanliness and prep are key.

The other thing to do is go to the GM dealer and get coolant sealing tabs. Crush them and introduce them into the radiator. I thin Bar's has a similar product that is crushed walnut or similar.

Go sparingly though. I wouldnt want to be creating more issues, like a worn water pump, because of attempting a temporary fix.

piccolovic · #7 12-15-2011, 09:30 PM

I've seen vehicles go for years with a "Stop-leak" fix. Just don't overdo it. Remember most of these fixes are for small problems . . . not the length of the seam on the top of the radiator!!!! I have also seen people plug up their radiator beyond redemption because they thought "some is good . . . more is better." One guy put it in with every oil change for 5 years!!!!! I ended up owning that car after fixing when he broke down in my neck of the woods with a radiator that couldn't be rodded. Was pricy in the boondocks to R & R the radiator, water pump, and while there, I changed all the hoses and thoroughly flushed the system, including heater core, and thermostat. 6 months later, he finally bought a new car, and I inherited the otherwise meticulously cared for Rambler Hardtop to drive for 10 years. My grandfather also tried that . . . except he had the crack in the crease of the length of the radiator . . . didn't do a damned thing to help the situation. He still ended up buying a replacement radiator.

Ether · #8 12-15-2011, 10:09 PM

I've had the cold weather shriek in two of my old Benz's. Both turned out to be emanating from the speedometer mechanism itself and not the cable. I was able to prove this by removing the speedo on a cold day and spinning it up with a hand drill only to hear it screeching away.

The fix for mine was to carefully spray some fresh lithium grease on to the gears in the speedo. I suspect the old (perhaps original) grease no longer flowed properly when below a certain temperature.

YMMV but this worked for me, twice.

JHZR2 · #9 12-15-2011, 11:53 PM

Quote:

Originally Posted by Ether

I've had the cold weather shriek in two of my old Benz's. Both turned out to be emanating from the speedometer mechanism itself and not the cable. I was able to prove this by removing the speedo on a cold day and spinning it up with a hand drill only to hear it screeching away.

The fix for mine was to carefully spray some fresh lithium grease on to the gears in the speedo. I suspect the old (perhaps original) grease no longer flowed properly when below a certain temperature.

YMMV but this worked for me, twice.

Could be, but again, IMO it is the angle of the drive into the speedometer. The cable can have a slightly angled entry due to curvature, and impart an imbalanced strain. It may well be the bushing that is causing the squeal.

But it doesnt mean that there isnt an underhood squeal. The OP should be able to discern if it is coming from right in front or out under the hood. Important to know...

piccolovic · #10 12-16-2011, 04:30 PM

Is that kinda like the old peppercorn (ground) trick?