1stmbenz

hello everyone

i'm loosing a lot of coolant. between saturday and today, i've used a whole a bottle of coolant. I'm not able to see any visible leaks. My coolant warning did come on and everytime I've add to add coolant. Any suggestions.

Jer

Depending on the mileage on your vehicle, the water pump seals might be going. When the pump leaks the coolant usually appears under the oil pan. Be careful! Don't let your engine melt down!

Arnie

Check your expansion tank cap. If the rubber ring is bad it could be simply evaporating, although a gallon in a few days is a bit excessive. Also pull the dipstick out and check the engine oil. If its foamy and looks almost like coffee with a lots of creamer, you're screwed big time, because it's a head gasket.

cap'n jasper

Check the top pipe on the radiador as this is a favourite. If you can't see a leak anywhere, take it to a garage for a pressure test on the cooling system. They'll break the news to you then if it's the headgasket or not.

1stmbenz

i've checked the oil - oil is clean from recent oil change. i've looked under the car, no sign of coolant. I've also noticed the following things.

When I'm on the highway instead of engine temperature dropping, it starts to increase. Also, oil pressure slowly starts to decrease until its under 1. It takes a little longer for the oil pressure to drop. i'm wondering if its my thermostat. If I look under the hood, I can see the coolant bubbling in the overflow tank. i don't know what to make of this. My fans are kicking in around 100.

1stmbenz

the headgasket is new.

Jer

If the oil pressure is dropping, don't drive!!!!!!!!!!!. The engine might seize, and you'll be screwed!!!! There seems to be a problem with your lubrication system.

If the coolant is bubbling (boiling) the mixture might be too lean on antifreeze. Use a 50/50 water/AF mix for year-round regular use. If the temp is climbing check the thermostat first. It begins to open at 87 deg C. To test it put it in a pot of boiling water at a temp close to 87C. It should open at or near that temp. Also, the radiator might be clogged and will lose its ability to transfer heat to the air. Replace it (if that is the problem).

In the meantime, don't drive the car until you've figured out the oil problem!!!!!!!!!!!!!!!!!!!!!!!!!!!

Kestas

You have the classic symptoms of a blown headgasket (temp rise on freeway, bubbling in overflow). If you need verification, the best way is to take it to a good radiator shop and have them check for combustion gases in the coolant. Plus it looks like coolant is mixing in the oil, dramatically lowering the oil pressure (this is most harmful to the engine). Oil will have a milkshake (or coffee with creamer) color to it. Check it again.

It appears something went wrong or didn't take during head gasket replacement. Perhaps some shortcuts were taken during the job. Was the head checked for flatness?... any corrosion? Was all the old gasket residue removed from the mating surfaces? Was the job done cleanly leaving no burrs or foreign debris on the mating surfaces? Was torqueing done properly?

There's also a possibility of a crack in the head or cylinder bore.

It looks like the job will need to be redone. Make sure all the above questions are addressed the next time it's done.

1stmbenz

this morning I added a half gallon of coolant. I was able to drop the car off with my mechanic. So far he found the thermostat is not opening correctly. Still can't explain the loss in coolant. He will put the car on the lift. I checked the oil yesterday, it was a gold color. Oil was recently changed.

1stmbenz

I've found a gallon of antifreeze in my driveway. Still wondering if I have a water pump problem.

dlafever

From all the data you have given, it looks like the stuck thermostat is the culprit. Consider this, the thermostat did not open, the coolant heated up and boiled out through the overflow tube on the expansion tank. Some cars (the 1993 400E does) have a secondary catch tank under the right fender ahead of the wheel, so unless you fill that one up too, you will never see the coolant, until you replace enough boiled out coolant to fill up the second tank too. Whew.

Ok, so you have boiled your coolant (via the bad t-stat) into your secondary expansion tank. You have replaced your thermostat, hopefully rectifying the primary culprit. If you are now seeing coolant on your driveway, you might have damaged the new head gasket or the water pump or some hose, due to the pressure generated by the previously bad t-stat. As for the oil pressure dropping, it will do so when the engine is getting VERY hot and it reaches its service limit.

The absense of foam in the oil and the fact that you originially did not see any coolant under the car are the basis for excluding the head gasket as your original problem. Unless you are in the Southern hemisphere, or darn close, your temp should never go above 100C this time of year. If your temp is now within range and your oil pressure ( I would change it again, by the way) is at least 1bar at idle, then you just have a coolant leak. Otherwise, you may have a more serious problem. A cooling system pressure test will confirm/debunk the leak theory.

-D

Sonny

It sounds like a warped head or head gasket have a block check done on the cooling system Ive been in the radiator business for 25 years it sounds like something with the head or the headgasket.

230TErry

Hopefully you have the problem sorted by now but in case you have not check under your carpets in the front footwells.

I started loosing coolant last week and found it all in the footwells, some did run out through the drain holes but most stayed in the car. The problem is with the heating system , thats assuming you dont have a/c. The heater matrix can split and it means removing the dashboard to replace.

1stmbenz

my mechanic changed the expansive tank cap that was leaking and also my thermostat. I've noticed the temperature stays between 80 and 100. It sometimes goes above a 100, very quickly after the fans kick in and the temperature comes back down. I may also get a coolant check done on my car too. Just to make sure.

rostov

I think I got the same problem. So where is it leaking from?? Whatdid you have to replace?? What do you mean by "The heater matrix can split"?

Thanks,

rostov

230TErry

Rostov, excuse my ignorance of US spec. cars, in the UK cars mostly have a simple cold to hot heating system. This involves a simple radiator set up behind the dashboard in line with the centre console, hot coolant comes in from one side and returns to the engine via the other ( to the right of the fuse box and left of battery respectively check these first if your car is similar). If water has been used without the correct amount of coolant the core of the heater matrix can rust and leak but sometimes the soldered joints split causing leaks ( this happened to a friends 380se). I have not tackled the job yet but I will need to remove the centre console and most of the dashboard to get the heater matrix out. Parts from a merc dealer are about £400, but Euro-Parts supply exactly the same components for about £80 so do shop around if you need parts.

I dont know about you but its cold here and a damp car does not help.

Let me know how you get on.

rostov

Thank you, 230TErry!
My car has a climate control, but I do not think it's much different in general! It should be the same core and the same “in and out” (for the coolant).
Yes, it is cold here too (-4C with snow), but I need to do it anyway.
I will check it and let you know what I have found.

Thank you!

rostov

dlafever

The difference in the ACC (climate control) systems is that in the 124 chassis they do not have independent left and right side heat controls, necessitating a heater matrix. The non-ACC cars do.

-D

Arnie

Hey, Rostov: is it Rostov Na Donu?

rostov

Oh yes, it is!