Thermostat change

[bikermike87]

Hey Folks,

I'm planning on checking my Thermostat over the next couple of days, I've looked on the wiki and it may just me being blind, but is there a deffinitive way to check if it is stuck open?

My engine temperature never gets above the white bar, red light remains on. Heaters blow warm air into cab but not onto the winderscreen. When I hit 55mph+ the blowers seem to blow cool air.

So 3 questions?
1.How do I check if it is stuck open? (I've checked wiki and I must be blind)?
2. Could this be partially to blame for my calculated 18.3mpg?
3. Is the following link the right part for the 2.1DJ engine?
http://www.brickwerks.co.uk/shop?page=s ... ory_id=118


BTW 10days into syncro ownership and I couldn't resist driving into a muddy field and checking the diffs and the 4wd. All good. Rear diff is a bit sticky though, takes a bit to go in and get back out.

Thanks all

[axeman]

once you have removed the t stat begin to boil some water in a pot (on the cooker) before it boils you will see it open, and close once the water cools down. the mpg is in the right ball park, i managed between 18 and 23 mpg, on my van.


neil

[silverbullet]

Warm but not hot? Could be airlocked heater but maybe the cable for the demist flap is broken too. Does the engine exhaust smell rich (petrolly) even when warmed up? Hard to tell, but if the return hose from the radiator has some heat then it's open - check when starting from cold afer a fw minutes driving i.e. still cold, all heat should go round the bypass/heater pipes.
Watch that thermostat housing as they are £95 (?) and the top cover is about £20...the corners go *ping* with old age - just a reminder!

[bikermike87]

once you have removed the t stat begin to boil some water in a pot (on the cooker) before it boils you will see it open, and close once the water cools down. the mpg is in the right ball park, i managed between 18 and 23 mpg, on my van.


neil

Thanks Neil.

I shall remove it and give it a go. Would it affect MPG? I mean, will it think the engine is cold and use more fuel?

Any pointers for removing the thermostat?

[silverbullet]

Never run any engine without a stat. There will be no backpressure in the system for the pump to work against and it will cavitate i.e. just thrash but not circulate any water. You will blow the heads off.
Can't be too forceful about this, I've seen very expensive engines wrecked by owners who took the stats out, convinced that it would go faster because it tricked the ecu into thinking it was always on the warm-up cycle...

[bikermike87]

Warm but not hot? Could be airlocked heater but maybe the cable for the demist flap is broken too. Does the engine exhaust smell rich (petrolly) even when warmed up? Hard to tell, but if the return hose from the radiator has some heat then it's open - check when starting from cold afer a fw minutes driving i.e. still cold, all heat should go round the bypass/heater pipes.
Watch that thermostat housing as they are £95 (?) and the top cover is about £20...the corners go *ping* with old age - just a reminder!

Yeah it always smells pretty rich, the one thing I noticed when I was sat in a traffic jam the other day after 2 hours of driving.

Is the link the right one for my engine?

[bikermike87]

Never run any engine without a stat. There will be no backpressure in the system for the pump to work against and it will cavitate i.e. just thrash but not circulate any water. You will blow the heads off.
Can't be too forceful about this, I've seen very expensive engines wrecked by owners who took the stats out, convinced that it would go faster because it tricked the ecu into thinking it was always on the warm-up cycle...

Sorry mate, I meant remove it and put it in the pan of water and heat it up to check it opens.

I will use your method first though and check the radiator return pipes (with the thermostat in)

[axeman]

it is the right stat for your engine but i would advise that you buy the top of the stat housing as ian sad they do tend to break when disturbing them, from memory i think that your van if it is lord norths old van it had a 2wd t stat housing (plastic not alloy) but is was 8 or 9 months ago that i last saw the van and i know that he spent a lot putting it right.

neil

[silverbullet]

Sorry mate, I meant remove it and put it in the pan of water and heat it up to check it opens.

I will use your method first though and check the radiator return pipes (with the thermostat in)

No worries - wouldn't want anyone to make the mistake like one or two of my past customers...£5k rebuild (ontop of the previous one) and they still can't understand what they did wrong

[bikermike87]

it is the right stat for your engine but i would advise that you buy the top of the stat housing as ian sad they do tend to break when disturbing them, from memory i think that your van if it is lord norths old van it had a 2wd t stat housing (plastic not alloy) but is was 8 or 9 months ago that i last saw the van and i know that he spent a lot putting it right.

neil

Yeah Lord North did mention something about that. I might send him an email just to check again!

Thanks guys, it's great everyone knowing my own van more than me

[LordNorth]

I pinged you an email last night, hopefully it may help a little.

The cooling system was put back to how it should be and I understand a new thermostat was popped in.

If you let it tick over for an age you will see the guage rise to about half way and hear the fan kick in. Your right though - in winter the heater is cool and in summer you don't need it!

The red light I think is poor wiring from the water level sender in the coolant bottle thing.

It was with everything else, next on the list of work to be done!

Good luck

[Simon Baxter]

18mpg is fairly average for a WBX, don't expect much more and you won't be any more dissapointed.

[bikermike87]

18mpg is fairly average for a WBX, don't expect much more and you won't be any more dissapointed.

Yeah I guessed it wasn't far off, but any improvements I can make would make a big difference with the mileage I'm doing. I think 20mpg is reasonable, considering most people quote 18-22 and mines a panel which is running 16" wheels at a 9% plus increase on overall rim diameter (I've read staying under 5% is ideal).

I tested the spare thermostat and it works (boiling the pan). As most of you know my basic knoweldge is poor but willingly improveing. I thought it was such a simple but clever piece of kit. Temperature controlled mechanical device...

Looking into them abit more, they use them in industrial greenhouses to open windows when the temperature rises....