M119 is still running hot...What temp does yours run at? - PeachParts Mercedes-Benz Forum

Dcraig · #1 11-13-2006, 11:51 PM

Sprung for the $500 fan clutch today and the car is STILL running hot. New radiator last month because I thought that was the problem. So $1000 in the last 2 months and I still have the problem.

As I understand, the cooling is controlled by the radiator, the fan clutch and the aux. fans. It seems that as the temp. rises, the fan clutch should kick on. If the temp keeps rising, the aux. fans kick on. Since my fans aren't working, I don't know how much cooling the fan clutch is capable of.

Where does everyone elses M119 run at? I'm so confused.

Dcraig

ProV1 · #2 11-13-2006, 11:53 PM

mine is around 80, usually slightly below.

deanyel · #3 11-14-2006, 12:07 AM

Try a new radiator cap if you haven't already. Mine runs about 90 but will run at 100 with the belly pan.

Dcraig · #4 11-14-2006, 12:10 AM

I think I might need a new radiator cap. Can that really cause the temp to keep climbing?

What else is left?

Dcraig

Dcraig · #5 11-14-2006, 12:46 AM

The temp will go up to normal and then will slowly climb to about 105.

I thought the water pump is either an all or nothing?? The rad hose at the bottom has a metal coil in it to keep it from kinking. When I first started up the car after the new fan clutch, there was a lot of air moving, so much tha the aux fan started turning slowly be itself.

The thermostat was the first thing I changed because it was cheap. I figured I'd start with the cheapest fix first.

Other than the expansion tank and the cap, I don't know what's left. I'm pretty sure the cap is holding pressure. I'm not getting any leaking around it.

Dcraig

Dcraig · #6 11-14-2006, 01:44 AM

Just took the car for a spin. Got the temp up to 100 and came home for a look. Seems like the fan clutch isn't coming on. I could spin it by hand pretty easily before I left (under 80) and just as easy at 100.

I don't know if it's a gradual thing or it is either on or off. I would think at 100 it should be on.

Thanks,

Dcraig

suginami · #7 11-15-2006, 01:36 PM

Quote:

Originally Posted by Dcraig

Since my fans aren't working, I don't know how much cooling the fan clutch is capable of.

I was reading over your first post, and the above statement confuses me.

When you say "since my fans aren't working", do you mean the clutch fan, or the low and high-speed auxiliary fans aren't working?

There should be two fans (in tandem), and they should both be running at the same time, whether at low speed or high speed.

When your a/c is running, these two fans should be on low speed all the time.

When you get to a set temperature, probably around 110 degrees, these fans should be running at high speed. You will easily be able to hear the fans running when you are in the car, even with the windows up. It sounds like a 747.

What JimF.'s cool harness does is change the resistance, tricking the fans into coming on at high speed at a lower temp.

It sounds to me like your auxiliary fans aren't working, either at low speed, or high speed, or both.

Why didn't you take it into Enrique at Mr. MB Motors anyway?

Further, I don't know why you are thinking your water pump is bad. If it is not leaking, and if the bearing isn't shot, it means it's turning, and therefore working.

If the bearing was shot, the car wouldn't be driveable anyway, as the pump would sound like a screaming chicken, and then eventually freeze up, frying the belt.

Dcraig · #8 11-15-2006, 02:06 PM

The story is: The car started running hotter than I remember, climbing to 110 frequently. The aux. fans would kick in and bring it back down to just under 100. Thinking it was the thermostat, I changed it, but the car still ran the same. Next I ordered a new Behr radiator, and changed that. Still no change in the temp. Then the 'check engine' light came on so I went to see Enrique and he pulled the code: bad tranny vacuum modulator. He said I was ok to drive. At that time I asked him about the cooling issue and he said possibly the fan clutch. A couple weeks later, I was on the freeway and saw the temp near 120. I limped home and saw the aux. fans didn't/wouldn't come on. So now I've been changing the fan clutch, but the car still gets up to 100 degrees.

After reading Jim's site, It seems the fan clutch doesn't kick on until after 100 degrees, so I wouldn't know if it's working or not. On my Jeep Grand Wagoneer, when the fan clutch was engaged, the fan was hard to turn when the engine was warm, easy to turn when the engine was cool. The new fan clutch is pretty easy to turn all the time.

I never did think it was the waterpump, someone suggested it. The expansion tank does hold pressure, but I could use a new one.

I was having the car towed to Enrique this morning but AAA didn't send a flatbed and they are really busy today. I'll shoot for tomorrow.

Thx,
Dcraig

suginami · #9 11-15-2006, 02:17 PM

Quote:

Originally Posted by Dcraig

I limped home and saw the aux. fans didn't/wouldn't come on. So now I've been changing the fan clutch, but the car still gets up to 100 degrees.

There you go again. "I limped home and saw the aux. fans didn't / wouldn't come on...."

There's your problem. If the aux fans didn't / wouldn't come one, why did you then suspect the fan clutch? The aux fans weren't on, and they should have been on.

Are we using different word for the same item? The fan clutch is for the viscous coupled fan connected to the front of the motor.

The aux fans are the electric-driven fans at the front of the radiator.

Dcraig · #10 11-15-2006, 02:30 PM

It doesn't seem normal that in 65 degree weather, driving around town, that the temp should reach 110 degrees and the aux fans come on. Am I wrong?

It is going to Enrique because the fans won't come on, but, it doesn't seem that the car should get hot enough to kick on those fans unless something is not working properly.

In the summer the car would stay between 100 and 110, day and night. The only thing that saved the engine from meltdown were the aux. fans.

We are talking about the same things.

Dcraig

suginami · #11 11-15-2006, 03:07 PM

Just guessing here, but the aux. fans should be on at low speed nearly all the time, even at idle, and is what normally keeps your car in normal operating range.

If they are not on, then your car quickly goes up to higher temps, and then the high speed engages, which saves your engine from overheating.

I'm not saying your viscous fan is bad. Could be.

When I owned my 1993 W124 300E (3.2) "E320", I had the same overheating problem, took it to Enrique, and he showed me that the fans weren't engaging at low speed.

I thought it was my viscous fan, but he showed me that it was working, and explained that they rarely go bad.

DRICHFL · #12 11-16-2006, 02:03 AM

Quote:

Originally Posted by Dcraig

It doesn't seem normal that in 65 degree weather, driving around town, that the temp should reach 110 degrees and the aux fans come on. Am I wrong?
Dcraig

It is normal for E420 as long as the temp is not in the RED. It may get close but the fans will not allow it to exceed into the RED.

deanyel · #13 11-15-2006, 04:36 PM

I don't think you have a fan problem. It's either a bad thermostat or a bad radiator/expansion tank cap.

suginami · #14 11-15-2006, 05:55 PM

Quote:

Originally Posted by deanyel

I don't think you have a fan problem. It's either a bad thermostat or a bad radiator/expansion tank cap.

but how do you explain the fact that his low speed aux fan is not on? They are on at low speed whenever the a/c is used, which is basically all the time. The HVAC system always has the a/c engaged, except when using the EC button.

Dcraig · #15 11-15-2006, 06:59 PM

I have the EC on all the time, but rarely have the AC on. It needs to be re-charged, so I just keep it off. One of the things I need to get around to.

Now the AC fan has stopped working. There isn't a relay that works the AC fan and the aux. fans is there? The AC fan has been dying a slow death I think so I don't think they're related.

Dcraig