The Function and Malfunction of the Diesel Thermostat

[kaiser]

[QUOTE=T-Cut;904740]I think we're 95% there on this. I've set out a few images to help the orientation of stuff.

This first image is from Rimmer's site showing the stat/housing as it comes.



And there you have it. The big disk controls the flow into the radiator this you can't see, it is hidden in the plastic . The small disk (which you can see) controls the flow to the orifice that must clearly be below it when fitted.
My bottom dollar that is a return into the engine water ways.

So in a nutshell it works like on the V6. There is no pressure sensing here.

[Mike Noc]

That sounds about right, although the big valve disc controls the flow from the radiator not to it.

So are the valves arranged to bring the radiator in series with the heater matrix circuit as the thermostat opens? Which funnily enough is how I thought it worked when I first looked at it.

Mike

[kaiser]

Originally Posted by Mike Noc

That sounds about right, although the big valve disc controls the flow from the radiator not to it.

So are the valves arranged to bring the radiator in series with the heater matrix circuit as the thermostat opens? Which funnily enough is how I thought it worked when I first looked at it.

Mike

I don't know, of course, but usually the flow will be from the pump, to thermostat to radiator.
I would be surprised if this is different here. Where on the Diesel sits the pump??

[blacknwhite]

Originally Posted by kaiser

I don't know, of course, but usually the flow will be from the pump, to thermostat to radiator.
I would be surprised if this is different here. Where on the Diesel sits the pump??

I agree to disagree.

[T-Cut]

The pump is located as shown in the Rimmer drawing.



The port I mentioned is clearly visible at upper left of the mounting face.

Looking at the way the pump is orientated, suggests to me that the secondary/inner valve stops flow coming into the stat housing from the port. Does this port connect internally with the head? I assume the output from the pump is from the upper right of the casting, especially from the shape of the gasket, but I can't figure out where it goes into the engine.

TC

[blacknwhite]

That is a standard thermostat that happens to be in the wrong position (to replace) because in the Rover the configuration was 90 deg in the wrong direction (it wasn't ment to be so awkward). The stat is a simple open/closed stat. Nothing more, nothing less. Your all looking for something that doesn't exist. Does no one have a bust stat? I'll add to my previous post of two poss faults - 3rd the shank bends under temperature and does not close on the bed (it leaks constantly).

Surely someone has had one of these apart.

[T-Cut]

Just a note about the smaller spring behind the secondary valve. I believe this is simply to ensure closure of the valve without over-loading the spindle moving from the wax capsule (which also needs looking at). The spring takes up any over-throw (as Mike_Noc suggested) due to the manufacturing tolerences. If the valve disc wasn't floating, the pressure on it could buckle the disc.

From what bit I've seen here, it seems that the wax capsule is concentric with the push rod/spindle - a bit like the clutch slave cylinder. ??

TC

[T-Cut]

Originally Posted by blacknwhite

That is a standard thermostat that happens to be in the wrong position - - - The stat is a simple open/closed stat. Nothing more, nothing less.

Sorry blacknwhite, I don't agree, but we'll know soon I think.

Surely someone has had one of these apart.

Go to start.

TC

[blacknwhite]

When I say "wrong position" I don't mean engine wise.I mean the engine was desinged to be installed front to back (not transverse as in 75).

In the front to back configuation, it's easily accessible to change.

I still think your looking for something that is a simple problem (manufacturing).

First rule of engineering when something breaks - don't look for a complicated answer to what you think is a complicated problem. Always look at the simplest thing first. 90% of the time, you'll be right.

[T-Cut]

Originally Posted by blacknwhite

When I say - - - -

I'm sure you're right on all four points, but none actually addresses the subject of the discussion.

TC