It won't burp ... searched but need more advice - PeachParts Mercedes-Benz Forum

BodhiBenz1987 · #1 04-02-2010, 05:28 PM

.... so after several snafus I got the coolant flush done on the 240D and refilled it ... it doesn't not want to burp. I did do a search and followed the advice I found there. It's on ramps, I tried filling the upper radiator hose, but it just pours coolant out the radiator where the hose had been attached. There is 2 gallons of 50/50 in there so I'm 3.8 quarts short if my Haynes manual and my math is correct. I've tried running it for a while with the cap off ... it goes up to about 175 (FARENHEIT) and just stays there, but there is some steam coming off the coolant/water at the fill neck of the radiator so it has to be pretty hot. I'm not entirely confidant in my temp sensor, although I don't have specific reason to think it's broken (just based on the overall condition of the car ... heh).
So, what am I missing? What should my next step be? Put the cap on, drive it around a little then put it back on ramps and see if it'll burp?
Also ... I noticed there's a screw on top of the t-stat housing ... is that for bleeding air? Nothing seems to come out of it when I open it, air or fluid.
I know this has been discussed a lot ... I'm just a little paranoid about overheating this. With 8 quarts in is it safe to take it for a drive to heat it up?

leathermang · #2 04-02-2010, 05:44 PM

That should be the bleed bolt..
but I do not know why nothing comes out... does air come out ?

BodhiBenz1987 · #3 04-02-2010, 05:47 PM

Quote:

Originally Posted by leathermang

Some of them have an air bleed bolt on the top... does yours ?

I believe that's what it is ... I can't imagine what else it would be. Although nothing comes out when I crack it (or even take it out) and idle the engine. Does it need to be at a higher temp perhaps?
I also did turn the heat on (not the fan), but the right-hand dial won't quite go to the top ... not sure if that makes a difference. This car has separate dials for left and right.

leathermang · #4 04-02-2010, 05:49 PM

The FSM shows that to be the bleed bolt...
but further than that probably need to check the archives or wait for someone who has had this problem..
if searching use ' JimSmith' as the name...he has talked about burping alot....

leathermang · #5 04-02-2010, 05:50 PM

Why don't you use a pitcher and put water into that hole ?

BodhiBenz1987 · #6 04-02-2010, 05:54 PM

Quote:

Originally Posted by leathermang

Why don't you use a pitcher and put water into that hole ?

Didn't think of that! I'll try ... thanks.
The more I search it seems like a find a lot of people who end up driving it for a while and then saying "oh it finally burped!" So maybe that'll work.
Although I can't find much regarding the bleed screw. I'll keep looking ... got the night off so I can fool around.

kerry · #7 04-02-2010, 06:26 PM

Not sure why you think it isn't full? If it isn't running hot, and you have heat coming out of the vents, it's full. I suspect you didn't get all the coolant out.

leathermang · #8 04-02-2010, 06:37 PM

I am suggesting that is the bleed screw because I saw it in the FSM....

hanno · #9 04-02-2010, 08:42 PM

I'd open the bleed screw, fill coolant tank until it comes out the bleed, then close it. I'm assuming that you drained more than 2 gallons (using radiator and engine block drain fitting).

BodhiBenz1987 · #10 04-02-2010, 10:19 PM

OK ... so I've tried again pouring 50/50 in the URH, and it just pours back out. I tried squeezing the hoses, and all it seems to do is squirt liquid out the rad cap. I tried putting the car back on the ground (so the t-stat housing would be the highest point) and cracking the bleed screw. The temp just keeps climbing at idle, up above 200 Farenheit. Here's an observation that strikes me as odd: The upper radiator hose gets quite warm, but the LRH is dead cold, even when the engine temp is 200 degrees. Am I just daft or should that lower hose warm up as hot coolant goes through the radiator and comes out that hose?

I replaced the t-stat when I did this flush and I'm beginning to think I did that wrong and it's not opening. I put it in the same way as the last one.

konstan · #11 04-02-2010, 11:19 PM

Fill it up as much as you can, start it up, warm it up to the operating temp, squeeze the radiator hoses (careful around the fan!), drive it around, keep adding coolant until it's 'burped'.

BodhiBenz1987 · #12 04-03-2010, 12:00 AM

Quote:

Originally Posted by konstan

Fill it up as much as you can, start it up, warm it up to the operating temp, squeeze the radiator hoses (careful around the fan!), drive it around, keep adding coolant until it's 'burped'.

I'll give it another try tomorrow.

Although tonight, even at 50 degrees out, it was getting hotter than its previous normal operating temps just at idle. Then again, it's occurred to me the old thermostat may have been stuck open, and what I'm seeing now might be "the real normal." We'll see.

I did a search about the lower radiator hose feeling cold and it looks like that's not necessarily out of the ordinary, if the radiator is working. It just strikes me as odd.

Cr from Texas · #13 04-03-2010, 01:58 AM

Are you sure the thermostat is right side up?

BodhiBenz1987 · #14 04-03-2010, 02:38 AM

Quote:

Originally Posted by Cr from Texas

Are you sure the thermostat is right side up?

I think so ... I put it in the way it was in the Haynes diagram, and also the same as the old one that was in there. Pic attached.

kerry · #15 04-03-2010, 03:17 AM

Quote:

Originally Posted by BodhiBenz1987

The temp just keeps climbing at idle, up above 200 Farenheit. Here's an observation that strikes me as odd: The upper radiator hose gets quite warm, but the LRH is dead cold, even when the engine temp is 200 degrees.

Now those symptoms sound to me like an airlock. Do you have heat coming out the vents inside? I'm guessing not. The airlock is at the back of the engine. I would keep it on the ramps, make sure the heater valve is on, and run it for a while with the radiator cap off.
If all else fails, lift the engine over your left shoulder and pat it on the bottom of the oilpan.