Rover 75 CDTi THERMOSTAT ISSUE

[Edward Huggins]

In the recent cold snap, I noticed that the engine coolant took a long time to get to temperature. I assumed it was just the weather. But today, at 13C, it took 6 miles to get to the usual 9 o'clock position on the temperature gauge. This suggest a sluggish/sticky thermostat opening. Having just spent £750-00 on a new clutch, I'm reluctant to put my hand in my pocket quite so soon. What are the downsides of continuing to use the car like this - just higher fuel consumption?

[macafee2]

You can get a thermostat to go into the top hose, easy and cheap to fit.
Extra wear and tear on the engine if it take longer to warm up?

macafee2

[75driver]

I’d say 6 miles to get to 9 O clock on the gauge is very reasonable….good in fact for a diesel.
Using the trip computer, does it get to 88 deg C?


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[Odd Job]

Originally Posted by 75driver

I’d say 6 miles to get to 9 O clock on the gauge is very reasonable….good in fact for a diesel.
Using the trip computer, does it get to 88 deg C?


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I'd agree, I've fitted the Renault 'stat modification ( bodge ) when I first bought my car as the original had failed at an unknown time in the past, and the previous owner hadn't a clue there was a problem as it only went to the shops and back!

Mine takes about that length of time to get up to the 9 o'clock position, and my replacement 'stat is rated at 86 degrees as I couldn't find an 88 one at the time of ftting.

[Arctic]

Only if you have done one or more before, first time it will take you most likely take you an hour.

As opposed to 20 minutes at the Nano meets

https://www.the75andztclub.co.uk/for...postcount=1042

I only use gates stat. 89c
https://www.ebay.co.uk/itm/334540173742

https://the75andztclub.co.uk/forum/s...01&postcount=8

Originally Posted by grivas

Hi Arctic, well done for persevering, but how DID you managed in the end, what exactly did you do to avoid the coolant being spilled, I would be grateful for some more detail, thanks, as I am considering doing this mode.

On Thursday i travelled to Wales to pick up my grandson 257mile round trip on this trip i took readings off the OBD see below
After 5mls 74degs
at 23mils traveling at 60mph 74degs
40mils at 70mph 73degs
60mils 65mph 75degs
80mils 70mph 75degs
92mils 70mph 77degs
104mils 70mph 72degs
123mils 70mph and arrived at destination engine idling 84degs
On the way back 152mils covered 70-90mph 75degs
205mils 70-80mph 75degs
End of journey back home idling for about 5mins 82degs i decided to take these readings before i fitted the Gates Thermostat TH01489.

Sunday the 21st August 2011
After stopping at his uncles for a few days i took the grandson back same trip most the temp ever reached on the journey was 78degrees at 30miles into the trip, at 70mph and again at 35mles at 70mph hit some traffic at 173 miles going between 10 -50mph 80degrees so sometime this week i will fit the in-line stat.

Well yesterday i managed to find time to fit the in-line top hose stat got what i needed round me to do the job, spanners dremel tools funnel and a container to catch the coolant which will drain out once the hose is removed.
First take of the engine cover 3 bolts this will give you access to the top hose which the stat fits into this hose is held on by a stainless steel band which will have to be cut, unless your hose as been removed before and you may have a jubilee clip.
As you can see from Fig1 mine as the stainless steel band which i have started to cut.
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I used the black disc which comes with the Dremel tool Fig2
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After first using this disc, i decided it was a bit to large to actually see how the cut was going as you need to be careful you do not cut into the hose so i changed it for a little pointed metal grinding tip, which i did very slowly and kept checking the hose was ok it eventually ground enough for the band to be opened up with some small bull nosed pliers Fig3/4
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I was then able to remove the clip and place my funnel with a bit of garden hose attached to it the other end went into my container to catch any coolant Figs 5/6
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Now with the coolant collected which was very minimal the hose can be removed i tried to fit the stat with out removing the top hose altogether but found it very hard to push in the stat which is a very tight fit indeed, some have managed to do this but i could not Fig7/8
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As you can see after i have silicon greased the stat and inside of the hose i inserted the stat only to find it was very hard to push it home so it was 10mm below the top of the hose so this is the reason i removed the top hose Fig9
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With some great effort and a lot of hard pushing i managed to get the stat pushed in the hose 12-14mm the measurement is from the top of the copper bulb on the stat which points toward the engine.Fig10
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In this photo i show the stat inserted and the measurement from the body of the stat which is 50mm Fig11
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Now the in-line top hose stat is fitted making sure it is central i can replace the hose fit the new stainless jubilee clips and refill with coolant which came out if you do not collect the coolant as i did refill with neat OAT Fig12
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After running the engine with the expansion tank cap off for about 5mins i turned engine off and re-checked the coolant level and topped up to mark, i then put cap back on re-fitted the engine cover tidy up wash hands etc and took the car for a spin after about 3 miles it was up to 75 at only 30-40 mph looking good carried on driving onto the M54 to get some top end speed up at revs of 2000-3000 at 70mph after about 8miles the temp was reaching 86-87 so nice got stuck in a bit of traffic for about 8mins temp reached 91 once driving it dropped back to 86-88 i have yet to do more testing today while taking the wife to hospital so a bit of stop starting driving once she as been sorted i will take the car for another run and check the temps on the OBD and will report back also for the rest of the week and up until the end of the month. Arctic


These photos are an added extra since this post.

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I use an alloy tube but an outside water pipe from a sink will also do the job.
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Nowa days i use a triangle file to file through the original metal band.
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Do quite a few of these at the Nano meets, i already have them made up so just a case of swapping them out.
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[Edward Huggins]

Many thanks for these replies. Perhaps I should have said in the first instance that I have had this fault before about 3 years ago and so I got the MGRS in-line stat and my garage fitted it for me. Is my best option then to get this replaced like-for like? However, I note some of you say that the current temperature rise is what might be reasonably expected for a Diesel. (BTW I do not understand how the "trip computer" oan check the engine temperature. Maybe this is covered in the Rover manual?l)

[Arctic]

Hi Edward.
At least the photo will help others, link below showing how to use the TPK for your engine temp readings.

[Edward Huggins]

Wow! Many thanks. I never knew about this.

[SomersetJeff]

I recently used the DMGRS kit on my Freelander 1 TD4 (essentially the same engine as the 2.0 CDTi) and it works a treat. Engine up to temperature, runs better and the wife is happy that the heater works better

[vilas66]

i'd say that if Your gauge reads 9 o' clock Your thermostat works as it should. Miles and speed (and external temps) are factors that can impact reaching the right temperature.
I would only suggest, as other suggested before, to check the real coolant temp in diagnostic mode. Should be above 82-84°C while driving.

Higher fuel consumption? I drove a car from Belgium back to Italy with a totally shot thermostat. I've (obviuosly) replaced the thermostat and the car runs beautifully since but no (average) fuel consumption difference observed. Hope this helps