Thermostate replacement questions - PeachParts Mercedes-Benz Forum

EricSP · #1 10-18-2008, 08:50 AM

Well yesterday I was driving and noticed my car was running very hot. It wasn't in the Red but was very hot. The Coolant started to over flow from my fill container and the car started to smoke in traffic. I pulled over. After 20 mintues the temp jumped back down so but after 10 minutes the temp started to climb.

I assume it is a faulty thermostate (hopefully) ? other possibilities?

I plan on replacing the thermostate today if a local auto store carrys it or during the week if I need to order it.

When replacing the thermostate how much antifreeze will I lose? I'm concerned since it will be in my home driveway.

I flushed and replaced my coolant last month.

t walgamuth · #2 10-18-2008, 09:01 AM

Put a clean catch pan under the car and catch your coolant. YOu should be able to get most of it and reuse it.

Be careful to get all the coolant in it (you did check to be sure it is full now didn't you?)

After draining and refilling it it can be a bit tricky to get all the air out.

EricSP · #3 10-18-2008, 09:14 AM

Will a large amount come out meaning everything? or a small amount (few cups worth) and I will only have to topoff lost coolant?

t walgamuth · #4 10-18-2008, 10:03 AM

If you are careful and lucky you should be able to catch and reuse most of it. YOu might have to add a cup or two.

If you simply allow it to drain out when you remove the stat you still probably will only lose about a gallon or less of coolant.

85 DSEL · #5 10-18-2008, 10:17 AM

Quote:

Originally Posted by t walgamuth

After draining and refilling it it can be a bit tricky to get all the air out.

VERY TRUE

Pay attention to this detail!

I just flushed mine last weekend for the first time (for me) and had to end up taking the upper hose loose from the radiator and pour coolant into it so that it wouold displace the air pocket in the cooling system.

It helped to have the front of car raised up on ramps or other method....

Good luck

vstech · #6 10-18-2008, 10:27 AM

it's a possibility, but never a certainty. be sure and test your old tstat in a pot of water.
it could also be a corroded water pump, or a bad set of alternator belts., not to mention it could be a very dirty radiator, or condenser. also a possibility is a cracked head or blown head gasket.
have fun!

Brian Carlton · #7 10-18-2008, 10:38 AM

Quote:

Originally Posted by EricSP

Will a large amount come out meaning everything? or a small amount (few cups worth) and I will only have to topoff lost coolant?

1) Drain the radiator to a level that is below the thermostat. Since you cannot tell where this level is.........just drain the entire radiator.

2) When you pull the thermostat, all the coolant that is in the head........above the level of the thermostat.........will come pouring out of the head and disappear all over the alternator and down beneath the vehicle. Yes, you can try to catch it..........but, unless you've got a showroom clean vehicle..........the coolant won't be very clean after it's little travel to the pavement. You'll lose about 1 1/2 quarts.

The total capacity is 11 quarts............5.5 of which should be coolant.

t walgamuth · #8 10-18-2008, 10:45 AM

I have a funnel with a strainer for this sort of thing.

vstech · #9 10-18-2008, 10:46 AM

Quote:

Originally Posted by t walgamuth

I have a funnel with a strainer for this sort of thing.

motor oil doesn't strain out very well...

Brian Carlton · #10 10-18-2008, 10:47 AM

Quote:

Originally Posted by t walgamuth

I have a funnel with a strainer for this sort of thing.

Where are you going to put it..........the alternator is in the way???

t walgamuth · #11 10-18-2008, 11:19 AM

PUt the funnel in the radiator fill hole and pour the coolant that you drained out back into the cooling system without the dirt and so forth that you accumulated from draining it out.

I don't get the motor oil comment? Is your motor covered with oil?

Brian Carlton · #12 10-19-2008, 12:31 AM

Quote:

Originally Posted by t walgamuth

PUt the funnel in the radiator fill hole and pour the coolant that you drained out back into the cooling system without the dirt and so forth that you accumulated from draining it out.

I don't get the motor oil comment? Is your motor covered with oil?

You've been underneath them...........I shouldn't have to explain it to you..........

sixto · #13 10-19-2008, 01:46 AM

Could be a bad fan clutch if it gets hot while idling but cools while cruising.

Sixto
87 300D

Shorebilly · #14 10-19-2008, 06:30 AM

Quote:

Originally Posted by EricSP

car was running very hot. The Coolant started to over flow from my fill container and the car started to smoke in traffic.

This is definitely a symptom of Exhaust getting into the coolant.....head gasket, cracked head, cracked liner......

How much coolant was overflowing.....a little bit, due to expansion.....or a lot due to steam and or exhaust in the coolant.....?

Most Radiator Shops, and "Good" Professional Mechanics have a testing device to ascertain if Exhaust Gas is present in Coolant.....attaches where the Radiator Cap goes.....

SB