203 Low Temp Rad Stat

whitenemesis

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Has any one changed the 'stat on the low temp rad? Does this rad 'stat have any impact on the warm-up period?
 
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I guess that's a NO then??
 

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I think this has cropped up before IIRC. There was a thread about identifying the part but it could be last year
 
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Yup, it was reading that thread that triggered my curiosity. The stat is clearly visible in front of the rad and behind the horns.
 

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Has any one changed the 'stat on the low temp rad? Does this rad 'stat have any impact on the warm-up period?

I was involved in the last thread on this subject. My final comment, which wasn't answered by anyone, was -this is a "low temp rad" by definition which means the stat will open earlier than the normal one but how much earlier? -
My observations seem to indicate a reasonably quick warmup to about 65°, then a longish period from there to full operating temp. My thoughts were that the low temp rad stat might have opened at 65°, thus slowing down the warmup process. In cold weather with a diesel, I think the low temp rad can almost keep the temp under control in "easy" conditions. Mine takes a good 15km to get to full op temp.
Someone suggested that the low temp rad is often prevented from working in Finland. This would suggest that they find the warmup quicker without it. I haven't gone that far in my climate. Might be risky.
 

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There is no thermostat shown on this rad 22

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Its on one of the hoses leading to it, inline.
 

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IIRC wasn't the conclusion from the other thread that the thermostat couldn't be purchased separately and only came as part of a larger assembly which made the cost prohibitive?

I wonder if a generic in-line stat which opens at the same temp and had the same flow rate could be fitted. I have seen a few for sale on eBay.
 

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IIRC wasn't the conclusion from the other thread that the thermostat couldn't be purchased separately and only came as part of a larger assembly which made the cost prohibitive?

I wonder if a generic in-line stat which opens at the same temp and had the same flow rate could be fitted. I have seen a few for sale on eBay.

I believe that Alex found what he called a "good part number" for it. Check out the last few posts in this thread http://forums.mercedesclub.org.uk/showthread.php?t=93101
 
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whitenemesis

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A0052033975 - £24
 

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Ahh I must have stopped reading that thread before it came to a conclusion.

Who is going to fit one of these and post back warm up times?

I have my full grill blocked at present, with a cut out for the air intake and bonnet catch mechanism and it still takes a god 10 miles to get up to 90 degrees in this weather.
 

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It was my car that the main dealer wanted to sell me a load of hoses and bits to get the stat. Going to try to order one on that part number and see what happens.
 

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I probably will not get a chance to do it for a couple of weeks as work is busy, but will post up results. My car warms up to 65-70c within about 10 miles but struggles up to 80+. that takes 20 miles at least, even in warmer weather than we have now and the main stat has been done so this must be the answer, hopefully!
 

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I probably will not get a chance to do it for a couple of weeks as work is busy, but will post up results. My car warms up to 65-70c within about 10 miles but struggles up to 80+. that takes 20 miles at least, even in warmer weather than we have now and the main stat has been done so this must be the answer, hopefully!

I agree, but pose the question - is the low temp stat supposed to open earlier? Given the name "low temp rad", it is almost a given.
 

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Maybe not, If the unit is located post rad in the flow direction it would open later thereby retaining the heat in the low-temp rad and speeding up the warming up process. :confused:
 
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whitenemesis

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Mmm, I think we have this wrong...

The low temp rad appears to be for the fuel cooler. Could this affect engine warm-up? Don't think so. :confused:

(I think 'fuel' in the first sentence under Function should read 'coolant' ..)
 
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oigle

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Maybe not, If the unit is located post rad in the flow direction it would open later thereby retaining the heat in the low-temp rad and speeding up the warming up process. :confused:

My understanding of the way it works is that the feed to and from the low temp rad is via the heat exchanger situated on the side of the block. This feed is generated prior to the position of the standard stat and operates separately ie. the flow through the low temp rad can and does occur before the standard stat opens. I think this is the reason for the fairly quick temp rise to about 65° and then a long slow process from there to the point where the main stat opens.
I am no expert so please tell me if I am wrong....
 

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Mmm, I think we have this wrong...

The low temp rad appears to be for the fuel cooler. Could this affect engine warm-up? Don't think so. :confused:

(I think 'fuel' in the first sentence under Function should read 'coolant' ..)

The small rad in front of main rad is definitely got coolant in it.
 

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I am quite surprised that fuel needs to be cooled..
Does it really get that hot ?? (In the UK climate)???
Other Diesels I have owned didnt seem to have a cooling device...
It would be very easy indeed to do a temporary "fuel cooler" bypass.. Just remove the hoses from the small rad and join them together..
Its something I have given thought to..
 

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