Diesel In Line Thermostat Housing " How to "

[TeeCee]

Got one of these and installed it. (Tip: If you have a FBH installed, stick a jug under its water pump and disconnect that hose to easily drain the coolant).

While things have improved it is still, unfortunately, carp. Still appallingly slow to warm up when the FBH isn't triggered (I.e. outside temp > 5). Only gets past "eight o' clock" on the gauge when FBH assisted and drops back as soon as the FBH cuts out.

Any ideas? 92 degree 'stat time?

[DMGRS]

It shouldn't do that at all - with any kind of inline stat (even an 83 degree item, as I installed as a test some time ago) you should get to 9 o'clock.

9 o'clock is 75 degrees - 115 degrees, so it should have no trouble getting there!

[Ross R75]

Originally Posted by TeeCee

Got one of these and installed it. (Tip: If you have a FBH installed, stick a jug under its water pump and disconnect that hose to easily drain the coolant).

While things have improved it is still, unfortunately, carp. Still appallingly slow to warm up when the FBH isn't triggered (I.e. outside temp > 5). Only gets past "eight o' clock" on the gauge when FBH assisted and drops back as soon as the FBH cuts out.

Any ideas? 92 degree 'stat time?

The stat you fitted in it is dead. Replace it and all will be well.

[TeeCee]

I put in a QTH107K as detailed earlier in the thread and it's perfect now. Warms straight up to halfway, regardless of the weather and the needle stays rivetted to that spot, even when giving it the beans uphill.
Incidently, it says 91 not 92 on the bottom of a 107k....

I have also come to the conclusion that the 88 degree stat supplied with the housing was duff.

Edit: Gosh, I've just had a thought. Imagine the induced level of swearing, were one to replace the vanilla item only to find that the new one was kaput!

[TeeCee]

So much for that theory. A pan of water and a meat thermometer says that the supplied 88 degree object is spot on.
I'm stumped.

[Trevor1975]

Originally Posted by TeeCee

So much for that theory. A pan of water and a meat thermometer says that the supplied 88 degree object is spot on.
I'm stumped.

I've just fitted one. Inline holder with 88 marked on the stat.

there is a 3 mm hole in the thermostat to pass a small amount of coolant through.

The M47R doesn't produce enough waste heat energy to overcome this at constant speeds up to 75 mph. mine reads 75/76 degrees on the motorway... only up a big hill (10% for 2 miles at 70 mph) does it go up to 88 degrees.

I'm a bit disappointed to be fair, apart from warming up slightly quicker it maintains the same 75 degrees that the knackered original stat runs at.

I might swap it for a 107 unit as listed above, or weld up the bleed hole to properly control the temperature.

The other problem I had was the small end, which was about 6 mm diameter too small for my top hose. I think the earlier hoses, or just my hose, reduced in diameter at the radiator end. I had to resort to cutting up a bicycle inner tube to build up the diameter of the housing to get a watertight seal ... :-/

** edit - just bought a QTH107K on ebay. will fit and report back... **

[T-Cut]

A bleed hole of any size will prevent the diesel reaching the temperature stamped on the thermostat. The original thread on this discusses tests using holes of one size or another. The only stats that will perform as expected are the non-vented type. The vent hole should be soft soldered over rather than welded (far too hot) or bunged up mechanically. I wonder if pop rivet could be inserted - maybe too tight to get the gun in.

A 107C stat would prove quite enlightening I think.

TC

[Trevor1975]

Originally Posted by T-Cut

A bleed hole of any size will prevent the diesel reaching the temperature stamped on the thermostat. The original thread on this discusses tests using holes of one size or another. The only stats that will perform as expected are the non-vented type. The vent hole should be soft soldered over rather than welded (far too hot) or bunged up mechanically. I wonder if pop rivet could be inserted - maybe too tight to get the gun in.

A 107C stat would prove quite enlightening I think.

TC

I think the qth107k stat is rated at 91 degrees. If it also has venting I will plug it before fitting. I have 'chemical metal' which might just do the trick :-)

[Trevor1975]

Originally Posted by Trevor1975

just bought a QTH107K on ebay. will fit and report back...

Fitted the QTH107K today - no bleed holes and 92 degrees stamped on the flange. Fitted in the housing perfectly. Put it back together, topped up the coolant and went for a 20 mile test drive.

It got to 70 degrees slightly quicker again, however cruising along at 70 on the motorway it hovered around 80 degrees.

5 miles later it got to 88 degrees. after that it stayed between 88 and 93 regardless of conditions...

Result!

Just wish it came with the correct thermostat in the first place.

[scorpio]

I want to do this modification to mine but i have a question, Do i need to remove the old thermostat for this to work?

Thanks in adavnce