300TE Running hot, sound like radiator? - Page 5 - PeachParts Mercedes-Benz Forum

disley · #61 09-04-2011, 12:37 AM

Quote:

Originally Posted by cypress

Not sure what model you own. But before you get a new one, you should either short the VFC temp switch's connector or apply 12V directly to the VFC to see if the clutch fan comes on or not 1st.

I am right in the middle of modding my cooling system. Replaced my 87c thermostat to 79c one. Replacing my dual 100/110c temp clutch/aux fan switch to a lower dual 91/99c temp switch to see if sufficient. If not, I will add engine rpm "idle" into the mix.

I'm waiting to hear the results of these changes.
I don't know what temp my thermostat operates at, it was renewed in January when I did the radiator.
I added a 'cool harness' to the aux fan switch, they come on hard after the temp passes the 100C mark on the temp gauge. The MB mechanic tells me that's 90C, and I've read here both 90 and 100C, so until I check it manually, I'll operate on the assumption it's the higher of the two.
I'm getting the viscous clutch changed on Monday, I'll let you know how much difference it makes, if any.

ps2cho · #62 09-04-2011, 01:05 AM

Unless Australia is different to the US, here it is 100C.

Ivanerrol · #63 09-04-2011, 02:23 AM

Quote:

Originally Posted by disley

I'm getting the viscous clutch changed on Monday, I'll let you know how much difference it makes, if any.

disley. Changing the VFC is a pretty straight forward job if you can swing a spanner. I assume you got a price for one of MB spares in Canberra. Sachs is OEM however Behr is also used for these engines.

Keep in mind that the VFC only comes into play after the engine heats up to around the 95 - 100c mark and then only cools the engine down efficiently when the engine revs up when you are moving forward.
If the case is where you are in traffic sitting still the engine will heat up to around 105 - 110 degrees and then the front mounted electric aux fans come into play. The front fans should operate at low speed with the AC on whe the engine gets a little hotter.

The VFC has no effect at freeway speeds. If the engine is getting hot at freeway speeds then there are other factors causing your problem.

If your car has not been running the proper MB coolant over a few years then chances are you will have other problems that will be needed to be looked at.

To get some more ideas for Australian conditions and get advice from Sydney based members go to the MB Spares MB Blog : http://ozbenz.net/

benzme · #64 09-04-2011, 05:31 AM

The German guys that look after my car when I can't, have 40 years experience as Mercedes techs. They told me the hash mark above 80 is 90c.

I posted this and Arthur Dalton kindly corrected this misunderstanding. I now have no reason to believe MB would go to the trouble of recalibrating the entire temperature sensing regime for the (small) Ozzie market.

When the gauge in my TE indicates half way between 80 and the next hash mark, the thermostat is fully open and the temp is about 87. That is where about it stays in all conditions.

I believe Mr Dalton. I hope he does not mind me quoting his PM.

Quote:

Temp indicator hash markings on ECT gauge are in 20 Degree C increments.

60/80/100/120 -Centrigrade
The 100C mark is Factory Test Indicator mark used in testing preocedure of both gauge and sensor for specification accuracy.
The sensor/gauge test procedure is to sub. a 38 ohm resistance in place of the sensor. The gauge will then align with the 100C indicator marking.

A Dalton
BenzTechs
__________________
A Dalton

cypress · #65 09-04-2011, 12:56 PM

Quote:

Originally Posted by benzme

I think you might be talking about an electro magnetic clutch and not a viscous clutch. Not much choice with the VFC.

I would be reluctant to drop from 87 to 79c. Most Mercedes I am familiar with are designed to run best at around 87 plus. Unless you reside around South Hades

.

Yes, silly me...I was talking about a electro magnetic clutch, not VFC.

I changed the thermo to 79c last year, no noticeable changes/improvements.

cypress · #66 09-04-2011, 12:58 PM

Quote:

Originally Posted by benzme

The German guys that look after my car when I can't, have 40 years experience as Mercedes techs. They told me the hash mark above 80 is 90c.

I posted this and Arthur Dalton kindly corrected this misunderstanding. I now have no reason to believe MB would go to the trouble of recalibrating the entire temperature sensing regime for the (small) Ozzie market.

When the gauge in my TE indicates half way between 80 and the next hash mark, the thermostat is fully open and the temp is about 87. That is where about it stays in all conditions.

I believe Mr Dalton. I hope he does not mind me quoting his PM.

That's interesting, I shall test how accurate my temp gauge is.

cypress · #67 09-04-2011, 01:22 PM

Quote:

Originally Posted by disley

I'm waiting to hear the results of these changes.
I don't know what temp my thermostat operates at, it was renewed in January when I did the radiator.
I added a 'cool harness' to the aux fan switch, they come on hard after the temp passes the 100C mark on the temp gauge. The MB mechanic tells me that's 90C, and I've read here both 90 and 100C, so until I check it manually, I'll operate on the assumption it's the higher of the two.
I'm getting the viscous clutch changed on Monday, I'll let you know how much difference it makes, if any.

My car is a W201, I noticed it has an additional spot next to the current dual 100/110c temp/fan switch for an additional switch. So that's what I did, I added a lower dual 91/99c temp/fan switch & connected them in parallel (so it's like a raid setup on a PC). If one fails, I have the other to fall back onto. I just wired them up yesterday, so not much testing on it yet.

My concern is not so much when the car is moving, but when the car is idling or in stop & go traffic with A/C on in hot summer days. If turning on the electro magnetic fan "sooner" still does not cool the coolant/engine enough under these extremes. Than engine rpm/idle will come into play (got this idea from BW member), electric aux fan will come on as well.

sptt · #68 09-04-2011, 09:07 PM

Alrighty...I think I have a poorly designed fan clutch or something. It does not roar and the electric fans are the only thing that ever gets very loud in the engine area. I heard an older MB the other day and you could hear that fan clutch. Since I got the car, I have never heard mine sound that loud. I don't think it is defective but not designed to work in this car or I would hear that thing kick in over the electrics when hot an idling, no?

lsmalley · #69 09-04-2011, 09:32 PM

Is there a way to modify the fan clutch so that it spins with the pulley?

benzme · #70 09-05-2011, 02:22 AM

Quote:

Originally Posted by lsmalley

Is there a way to modify the fan clutch so that it spins with the pulley?

You mean spinning at engine speed? You don't wanna go there. Even when operating correctly the fan spins slower than pulley (engine) speed.

As someone here pointed out the plastic fan and coupling are not designed for sustained high speed. Surprising how much damage a disintegrating plastic fan can do

.

lsmalley · #71 09-05-2011, 03:03 AM

damage? what do you mean? I was asking because my fan clutch went out too and I'm in 115° weather in the desert. and would like to do it temporarily until I change my clutch

Ivanerrol · #72 09-05-2011, 06:51 AM

The VFC disengages at high revs. It's there for high traffic situations.

You are better off putting a temporary over ride switch in which will operate the auxiliary fans when things get hot.

disley · #73 09-05-2011, 07:28 AM

Quote:

Originally Posted by Ivanerrol

disley. Changing the VFC is a pretty straight forward job if you can swing a spanner. I assume you got a price for one of MB spares in Canberra. Sachs is OEM however Behr is also used for these engines.

Keep in mind that the VFC only comes into play after the engine heats up to around the 95 - 100c mark and then only cools the engine down efficiently when the engine revs up when you are moving forward.
If the case is where you are in traffic sitting still the engine will heat up to around 105 - 110 degrees and then the front mounted electric aux fans come into play. The front fans should operate at low speed with the AC on whe the engine gets a little hotter.

The VFC has no effect at freeway speeds. If the engine is getting hot at freeway speeds then there are other factors causing your problem.

If your car has not been running the proper MB coolant over a few years then chances are you will have other problems that will be needed to be looked at.

To get some more ideas for Australian conditions and get advice from Sydney based members go to the MB Spares MB Blog : http://ozbenz.net/

Thanks Ivanerrol I used to do all my own maintenance, it's time I started doing it myself again.
If I change my thermostat I'm going to replace the coolant, what is the recommended coolant I should use?
I also like to have a couple of liters in case I need to top the coolant up.
While I'm at it, is there a specific oil that's recommended, for the 2.6 engine, that's done 200,000km?

benzme · #74 09-05-2011, 08:45 AM

Quote:

Originally Posted by lsmalley

damage? what do you mean? I was asking because my fan clutch went out too and I'm in 115° weather in the desert. and would like to do it temporarily until I change my clutch

I meant potential for damage. As Ivanerrol says the viscous fan is for low speed cooling and you would be better off installing a earlier cut-in switch for the electric fans. We have very hot summers here and when my vfc was inoperative the thermo fans managed the cooling well with the factory switching point of 107 deg.

lsmalley · #75 09-05-2011, 01:11 PM

I think my aux fans cut in at 105°, but is there a way to install a mechanical fan that spins with the engine instead of a viscous fan? My brother in law has a '72 blazer with a mechanical fan. Is there any adverse reactions with using one?