Bleed screw for coolant on Berlingo 1.9D (DW8B engine)?

[jugo]

Hi folks,

I found this great forum through the 1.9d coolant change thread but it doesn't really have a solution. I've also read this Coolant renewal thread.

I am trying to drain all coolant out of my DW8B engine Berlingo (1.9D) but most I can get out are 4 litres with a cool engine (closed thermostat) and 6 litres with a hot engine (due to open thermostat I guess). According to the specs there should be appr. 10 litres inside.

Here are some photos I took. One shows the bleed valve on the "heater matrix"? I found that one and opened it. I also opened the "expansion tank filler cap". But neither with cold nor with hot engine there is more than 6l of coolant exiting the system. I have only disconnected the bottom hose from the radiator, the one shown on the photo.

Could anyone please help me locate the "bleed screw" that is supposed to be on the cylinder block or on the "engine compartment bulkhead"? I guess without opening that one it is impossible to drain the system fully.

Photo of the engine. I think it is a DW8B.

   

Close-up view.

   

Side view

   

This bleed valve I found

   

This hose I disconnected

   

[jugo]

BTW, I found the following for the DW8B engine.

The bleed screw 2 in this drawing is the one I already found. But which part of the engine is the first drawing (drain screw 1) showing?

   

This drawing is rather abstract and there is no bleed screw at location 3. Unless it is hidden and under the engine, which wouldn't make sense however.

   

[brodfather11]

I just had a look for the drain plug on my DW8B but its either well hidden or is not on my  "WJY" version.  In your side view it should be under the brake vacuum pump at the rear of the engine. Easier accessed from below I think.
Why do you want to get all the coolant out ?. A good flushing twice or thrice with clean water will renew it all.  Considering that the heater matrix is below the bleed screw for the heater there will always be some coolant left in it , unless you take out the heater unit.

[jugo]

I just had a look for the drain plug on my DW8B but its either well hidden or is not on my  "WJY" version.  In your side view it should be under the brake vacuum pump at the rear of the engine. Easier accessed from below I think.
Why do you want to get all the coolant out ?. A good flushing twice or thrice with clean water will renew it all.  Considering that the heater matrix is below the bleed screw for the heater there will always be some coolant left in it , unless you take out the heater unit.

The coolant wasn't replaced for maybe 10 years (if ever) and it is quite brownish (oil, rust?). I was hoping to get it out completely, flush it several times with fresh water and then also clean the system with Liqui Moly 5189.

Since I can't get out more than 4l when the engine is cold, I assume flushing it with a hose will only flush the radiator and hoses where the 4l came out. It will not flush the engine where the remaining 6l are hidden, right?

So how to flush the entire system without opening the mysterious drain screw that apparently nobody ever found? ;-) At least I couldn't find a single photo or description of it during three days of Internet search :-(

As I mentioned earlier, if I drain it when the thermostat is open (risky because very hot coolant, but I protect myself), I get 6l out. Still far from the 9 to 10l it should have. And the thermostat would close immediately once I flush it with cold water anyway, I guess.

I think we have the same engines. Mine is a WJY too. I am really trying to locate the drain screw since three days on the engine, trying to image it from all sides and using mirrors to see badly accessible places. No luck. But I am no expert.

[jugo]

In your side view it should be under the brake vacuum pump at the rear of the engine. Easier accessed from below I think.

I am just back from outside. Used a mirror and strong light (midnight here) to take a close look at the rear side of the engine where the brake servo vacuum pump is on the left side. There is no screw, at least no screw which looks like it is unique and doesn't hold anything. There are screws but they are on each cylinder so probably regular screws.

Haynes writes:

"4 To assist draining, open the cooling system bleed screws. These are located in the heater matrix outlet hose union (to improve access, it may be located in an extension hose), on the engine compartment bulkhead and, on 2.0 litre engines, on the top of the thermostat housing (see illustrations)."

I understand this as following:
- only the 2.0 litre model has a bleed screw on the top of the thermostat housing
- all other have bleed screws on the "heater matrix outlet hose union" as well as on the "engine compartment bulkhead"

Yes, mine hasn't one on the thermostat housing (check). It has one on the "heater matrix outlet hose union" (check). But where is the one on the "engine compartment bulkhead" and what actually is a "engine compartment bulkhead"?


Since I can not imagine that Citroen service will replace only 4l or 6l out of 10l when they do the service, this means that there must be another drain/bleed screw even on the 1.9l model.

[brodfather11]

The engine compartment bulkhead is the bulkhead which surrounds the engine and gearbox, it protects the driver and passenger from exposure to the engine and associated risks from.
    
"- all other have bleed screws on the "heater matrix outlet hose union" as well as on the "engine compartment bulkhead"  " This refers to the one you found , the only one on the heater outlet or engine bulkhead

The bleeder that you found for the heater is mounted on the hoses going through the metal bulkhead. The drain plug you or I cant find,  is according to the diagram beside a sensor which  may be for oil pressure or oil level. I can find that sensor but cant see enough round about it .

You could always take the thermostat out . Stick a hose pipe in the hole with the bottom rad hose off.

[jugo]

Couldn't find that drain screw. Managed to get out 7.5l in another trial, this time with hot engine and keeping the engine running for another 2min or so while the coolant drained. Since I drained and filled it now something like 4 times, almost none of the original coolant should still be inside. Unfortunately this is a dirty method because it also means not all of that radiator cleaner was drained either. I used it on two iterations. Going on a 1200km trip tomorrow. We'll see if all is okay

P.S.: Didn't want to open any thermostat housing because the three screws look rather rusted and like they could shear easily. Also not easy to access. The car is 11 years old now and has 250,000 km. A real pack mule going a lot on unpaved roads.