Diesel thermostat definative answer

[rossocorsa]

hmmm rather sounds like I've wasted my money, it hasn't arrived yet but I am guessing I will be consigning it to the rubbish pile in the garage oh dear what a let down

[Mintee]

Originally Posted by t_i_m

Very true Phil, it just seems as though Wuzerk and Mintee have had better results with the other stat so I can't help thinking this one may not be as effective.

So just change the stat.

It appears there is a Vauxhall 'stat that is rated at 92°C If I were in your position I'd stick one of them in (and not drill holes in anything - they'll have a cutaway that will do!)

[trebor]

mine fitted today and early results good, previous max was 75, achieved a consistent 82/84 on a run of about 15/20 miles, then onto the motorway and peaked at 87 for the first time ever, consistently around 82/84.

Cabin was definitely warmer and temp reaching sufficient to switch off FBH although this not yet tested

it does droip down when the load is off the engine but never below 80

Will keep testing tomorrow and report back

[rossocorsa]

Originally Posted by trebor

mine fitted today and early results good, previous max was 75, achieved a consistent 82/84 on a run of about 15/20 miles, then onto the motorway and peaked at 87 for the first time ever, consistently around 82/84.

Cabin was definitely warmer and temp reaching sufficient to switch off FBH although this not yet tested

it does droip down when the load is off the engine but never below 80

Will keep testing tomorrow and report back

that isn't a deal better than my car is already without the new stat I was hoping for nearer to 88 as an aside interestingly on my car the scangauge from the OBD socket gives slightly different readings to the instrumnet diags out by 1 to 2 degrees at times which is odd

[calibrax]

Originally Posted by rossocorsa

that isn't a deal better than my car is already without the new stat I was hoping for nearer to 88 as an aside interestingly on my car the scangauge from the OBD socket gives slightly different readings to the instrumnet diags out by 1 to 2 degrees at times which is odd

I think you'll find Scangauge refreshes more quickly than the IPK, so there will usually be a slight difference. Scangauge is more accurate.

[wullie480]

Evening all.

Some will recognise my user name from the other side so hello to all who remember me and hello to all those who don't.
Anyway I fitted one of thses inline stats to both my ZT's yesterday and have noticed an improvement temp shows running around 80C compared to mid 60's before fitting.
After reading comments about them not being sealed I may remove and fit a 92C stat and refit with Hylomar to see if it makes a difference.
Is it likely that the ambient temp is to cold to allow these up to proper running temp?

[wuzerk]

I repeat that with the meziere housing and a 90.5C 'stat it has only opened three times over the last two months. Todays max reading was 87C on the OBD which just proves that the diesels struggle to produce enough heat in the winter. Going downhill or ticking over will never give a high reading. I have one of these British housings for my son and I could fit a Chevy 'stat in it if you continue to read too low with the supplied one, but that will make no difference if the engine cannot get to your 88C. Where it may make a difference is in the size of the bleed hole or the fit in the housing. I did think it was quite easy to blow through the new type housing. The advantage of this mod will obviously be more noticeable the lower your previous readings were. Somebody said their max reading was 62C, he will be delighted. Someone with a reading in the low 80s not quite so much. My max pre mod was
74C, I am delighted.
EDIT: It would be interesting to know if you could feel warmth in the radiator when the OBD reading is at say 80C i.e. how much coolant is escaping past the closed 'stat.

[BigRuss]

I had certain reservations when I saw the stat fitted to Phil's car yesterday, although I was impressed with the ease of fitting, the look and quality of the stat housing and the neatness of how it fitted, I did wonder about it's suitability in controlling the temperature correctly.

Firstly there will be approx 10-15C difference in the temperature between the engine water jacket temperature (measured by the IPK/Scanguage) and the actual temperature in the top hose. (Add a second digital temp sensor/guage into the top hose and you'll see if you watch the two guages together you'll see exactly what goes on in the cooling system under all load conditions)

Another thing to consider would be the cooling effect of the airflow through the radiator hitting the alloy casing of the thermostat housing but suspect this would only be a small amount and with the car moving.

Looking at the original design the stat is fitted to the return, this will restrict the flow through the radiator then will allow an amount of cooled coolant into the engine before it shuts again. Fitting a stat to the outlet will allow a bigger slug of cooled coolant to be drawn into the engine before it's shut off by the thermostat (basically it will over-cool).

It may be better to locate the themostat into the return, it's something that needs a little more thought and ideally some accurate temperature readings need to be taken, but I'm sure a perfect solution cannot be far away.

Russ

[rossocorsa]

Originally Posted by BigRuss

Looking at the original design the stat is fitted to the return, this will restrict the flow through the radiator then will allow an amount of cooled coolant into the engine before it shuts again. Fitting a stat to the outlet will allow a bigger slug of cooled coolant to be drawn into the engine before it's shut off by the thermostat (basically it will over-cool).

can't really see that being much of an issue I don't think the amount of cooled water will vary that much as once it is cut off by the stat there is no flow in the rad irrespective of whether stat is at in let or outlet

[BigRuss]

Intead of the coolant being cut off by the stat before the engine as it would normally, it lets the cooled water fill the engine block before it's cut off by the stat.

Russ