few questions:

1)does this banjo pipe have any significance here
2)is there any way to modify the t-stat housing to include a bleed valve for this purpose?
3)whats the proper burp procedure for this application? wheels up, engine revving? I've tried this unsuccessfully

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Max,

the condenser fins are mostly bent in the corners, but I can still see through the center segment.

oddly, the aux fan recently started working after I cut the belt to the ac compressor because it seized up.

last night while on the freeway, the temps stayed close to 100, and then after approx. 30 minutes dropped down to 85ish and stayed constant.

this morning after warm-up, temps rose up to almost 100 again

Looks like you filled the system as best you can, front wheels on ramp and filled upper rad hose. If your system holds pressure and the expansion cap is funtioning correctly, normally what happens when you take it for a high speed drive with engine hot, whatever air in the system will be bled out the cap on the expansion tank and you top off the coolant. I am wondering if you have a blockage somewhere. Do the hose/ rad temp test and report back.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

In these 100f+ degree days, my car runs about 90c to 95c with the A/C on and running 70-75 on the highway. My car has never seen 80c, except to pass by it, even in the winter. It has been like that for the past 10 years that I have owned it. New Nissens radiator 3 years ago due to original one splitting. I also have the plastic fan instead of the aluminum one. Water pump was replaced 8 years ago.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

running the original metal fan with original clutch

AC is non-op at this point.

I would hate to see what happens to my temps if the AC was running...

In addition to this, after filling in and then attaching the upper hose and filling up the overflow reservoir, I start the engine and while it is idling I squeeze the top hose repeatedly until no more bubble can be felt in the hose or seen exiting the reservoir, and the reservoir level stops dropping.

This is on my OM60x engines.

Is there a temperature sensor in the head that is close to the top of the system? Try bleeding out any air at that point, or any other temperature sensor location.

Under hard acceleration, if you can hear bubbling in the heater core under the dash, you've got air in the system. Sometimes that hard acceleration will drive the air out to the reservoir.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

funny you mention air bubbling

I have been hearing sounds from the dash, but just assumed it was loose components jiggling around. perhaps this is what you're talking about?

there is only one temp sensor, located just above glow plugs, center of the block

Air in the heater core (and probably through the system if it is in there) will bubble and swoosh and splatter and sound like liquid is spilling and running all over under the dash. Shut off the HVAC fan and the radio and make the dog stop barking or whatever it takes, and listen for it. If you hear it under acceleration (may take hard acceleration) then that could be part of your problem.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

so steep hill, defrost on, engine revving?

I'm surprised there's no better way to get the air out on these babies.

When filling the top radiator hose, I had the defrost button activated and the aux pump was running.

Is this correct?

It seems there are a lot of variations on bleeding air.

FYI, in my case I had to replace everything due to a front-end collision. It used to overheat when I first got it (especially on mountain passes), but there were dead leaves clogging about half the radiator. After that, 80c was the normal temp right up until the crash. I have no AC condenser or any other AC components now, so it's as free flowing as it gets.

I wondered about the auxiliary fan, but whenever someone asks if it works with coolant temp or only when the AC is on with these cars nobody ever replies. Additionally, I never had it come on before until I hooked up a jumper switch to use in case it ever got hot on the mountain passes again. So I figured I wouldn't worry about it for now. If it needs that for cooling purposes then I plan to get a larger aftermarket fan.

-Rog

rog,

I can definitely say that the aux fan works independently of functioning AC. in my case, a bad clutch on the compressor.

However, I do believe the switch for the aux fan relies on the pressure in the AC system.

I have seen some wiring around the receiver/dryer and I believe that to be the pressure switch for the aux fan.

Oddly, mine came on a few times while the temps were below 100.

I have read that these fans are triggered when coolant temps rise above 100. so another mystery.

I guess if the aux fan kicks in, the car "thinks" that temps are running high because the AC is blowing.

all these things taken into account, I would gather that engine temps without AC blowing should rarely, if ever, reach 100.

right?

Is this new coolant the GM dexcool type?

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

He said he's using Mercedes blue coolant. I'm using G05, which I've used since I got the car and had flushed the old stuff out.

-Rog

Check out this diagram

and look at wiring for items
25 aux fan
21 aux fan relay
20 temp switch 100 deg C for aux fan
22 temp switch 52 deg C for aux fan

It shows the aux fan is controlled by the 2 temp switches via the relay.

I am confused by both being temp switches. I thought one of them is a pressure switch. Maybe what we thought is a pressure switch on the dryer is actually a 52 deg C temp switch?
edit: Looked at the dryer and the switch that controls the aux fan does have a blue wire per the diagram. So where is the location of the 100 deg C switch (the one with the ws = white wire)?

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

If there's air in the heater core, the easiest way to get rid of it is remove the hose at the firewall to the monovalve and fill it with coolant.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked