How I did it / How To - CDTi Thermostat Change (Quick driveway method)

DMGRS · 19th May 2016, 01:12

I know there's many methods of doing this - from the 'quick as possible with minimal tools' to the 'remove everything!' approach.

I did my first today, going for a quick approach, on my newly acquired ZT CDTi. This is how I did it...

1. Remove parts around thermostat needed for access (I removed engine cover, airbox cover, rear upper engine mount / tie bar, swung black bracket attached to this out of the way, air conditioning pipe 'P' clip near waterpump (allows pipes to move a little, handy for later). Undo the nut holding the hydramount (acorn mount) to the main engine mounting bracket.

2. Remove the lower engine mount (inspect it while you're there) and jack the engine up - using wood or a large area jacking pad between the sump and jack. The CDTi sump is NOT strong, and needs the load spreading out to as much of the surface area as possible.
You'll want to jack the engine up to the point where you can access all thermostat mounting bolts easily (I used a standard 1/4 drive ratchet and socket set) and also to a point where you can get a pair of decent pliers on the spring clip holding the coolant hose to the thermostat.

3. Remove the coolant hose from the bottom of the thermostat, unbolt the metal coolant rail, and remove the thermostat mounting bolts.
You'll need to remove the coolant rail mounting bolt nearest the thermostat (follow it around the back, and you'll see it) so you'll have some flex to work with - I bent mine back ever so slightly to allow room for the thermostat to be slipped out around it.

4. Throw old thermostat in the bin, and celebrate being half way to victory!

5. Fit new O Ring (STC4540, we have them here - STC4540 @ DMGRS) to the coolant rail, making sure the old one has been removed first - and that the metal of the rail is relatively clean. Use a bit of wet and dry to perfect the surface if needed.

6. Reverse the above procedure - the hardest bit is fiddling around with the coolant rail to get everything lined back up.

To be honest, I was quite happy with how easy this job was in the grand scheme of things. It could have been much worse!
I managed it with a basic tool kit (1/2 and 1/4 inch drive sockets, pliers etc).

Shopping List
Quite a short list - just the thermostat and O Ring. Links below are clickable, through to the items on our Shop:
STC4540 O Ring
CDTi Thermostat - V3

A bit more reading on the CDTi thermostat, and options out there: http://www.the75andztclub.co.uk/foru...d.php?t=164968

A few pictures of the 'adventure' -

Spenrex · 19th May 2016, 20:01

Crikey that sounds brave

more power to your elbow mat

ChestersDad · 20th May 2016, 06:03

Nice one Mat - thanks for posting -t his sort of helpful and well presented post is just enough to tip the balance and to encourage us to have a go!

trebor · 20th May 2016, 06:54

Well done a job not many tackle given the easier options, what temperature is your car now running at out of interest ?

stevie04 · 21st May 2016, 20:17

Just the job I need to do asap. Thermostat and o ring ordered

spyder · 21st May 2016, 20:39

Nice how to Mat. The other useful tool that helped with mine. was a flexible 1/4" 200mm extension.

I also removed the liner and wheel to get into some of the lower bolts. Really not a bad job as you say.

T16 · 21st May 2016, 22:10

This is one of the easiest jobs Iver evr done on a zt.

Give me this over wrestling and destroying door cards to fix knackered rubbish quality door solenoids any day.

Dragrad · 22nd May 2016, 01:39

And now in the How To's

DMGRS · 27th May 2016, 17:05

Thanks for the feedback chaps! I only posted this as I've always been told this is a stinker of a job - in the end it wasn't too bad.

Now sitting at a rather toasty 93 degrees according to the IPK - ranging from 91 to 94 when changing speeds etc.
Never thought I'd see that on a CDTi...

Sprinter · 8th July 2016, 11:00

Hi Matt, thanks for posting the how-to. I've ordered the 'stat and o ring from you and will be replacing the unit while servicing the car in the next week or two. While out and about the other day I used the OBD to show the temp and it was only around 79 - 82. I think it has been like this since I got it but I've never noticed the cold in the winters, so I've left it this long. Looking forward to having it put right.

19th May 2016, 01:12	#1
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,320 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	How I did it / How To - CDTi Thermostat Change (Quick driveway method) I know there's many methods of doing this - from the 'quick as possible with minimal tools' to the 'remove everything!' approach. I did my first today, going for a quick approach, on my newly acquired ZT CDTi. This is how I did it... 1. Remove parts around thermostat needed for access (I removed engine cover, airbox cover, rear upper engine mount / tie bar, swung black bracket attached to this out of the way, air conditioning pipe 'P' clip near waterpump (allows pipes to move a little, handy for later). Undo the nut holding the hydramount (acorn mount) to the main engine mounting bracket. 2. Remove the lower engine mount (inspect it while you're there) and jack the engine up - using wood or a large area jacking pad between the sump and jack. The CDTi sump is NOT strong, and needs the load spreading out to as much of the surface area as possible. You'll want to jack the engine up to the point where you can access all thermostat mounting bolts easily (I used a standard 1/4 drive ratchet and socket set) and also to a point where you can get a pair of decent pliers on the spring clip holding the coolant hose to the thermostat. 3. Remove the coolant hose from the bottom of the thermostat, unbolt the metal coolant rail, and remove the thermostat mounting bolts. You'll need to remove the coolant rail mounting bolt nearest the thermostat (follow it around the back, and you'll see it) so you'll have some flex to work with - I bent mine back ever so slightly to allow room for the thermostat to be slipped out around it. 4. Throw old thermostat in the bin, and celebrate being half way to victory! 5. Fit new O Ring (STC4540, we have them here - STC4540 @ DMGRS) to the coolant rail, making sure the old one has been removed first - and that the metal of the rail is relatively clean. Use a bit of wet and dry to perfect the surface if needed. 6. Reverse the above procedure - the hardest bit is fiddling around with the coolant rail to get everything lined back up. To be honest, I was quite happy with how easy this job was in the grand scheme of things. It could have been much worse! I managed it with a basic tool kit (1/2 and 1/4 inch drive sockets, pliers etc). Shopping List Quite a short list - just the thermostat and O Ring. Links below are clickable, through to the items on our Shop: STC4540 O Ring CDTi Thermostat - V3 A bit more reading on the CDTi thermostat, and options out there: http://www.the75andztclub.co.uk/foru...d.php?t=164968 A few pictures of the 'adventure' - __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off Last edited by DMGRS; 19th May 2016 at 20:18..

19th May 2016, 20:01	#2
Spenrex Avid contributor MG ZT-T Join Date: Sep 2015 Location: Holmfirth Posts: 236 Thanks: 51 Thanked 39 Times in 30 Posts	Crikey that sounds brave more power to your elbow mat __________________ [SIGPIC][/SIGPIC]

20th May 2016, 06:03	#3
ChestersDad Still 75less :-( 1988 Defender 90 Join Date: Jun 2011 Location: Carmarthenshire Posts: 531 Thanks: 15 Thanked 93 Times in 37 Posts	Good post... Nice one Mat - thanks for posting -t his sort of helpful and well presented post is just enough to tip the balance and to encourage us to have a go! __________________ Don't save for the future as someone else will lose it for you!

20th May 2016, 06:54	#4
trebor This is my second home Rover 75 CDTi Connoisseur SE & MG ZT Saloon 190 Join Date: Jun 2007 Location: Coven Posts: 12,523 Thanks: 526 Thanked 1,877 Times in 885 Posts	Well done a job not many tackle given the easier options, what temperature is your car now running at out of interest ? __________________ www.midlandsnanomeets.co.uk Robs Car Gallery Coven near Wolverhampton WV9 2000 Cowley Built Rover 75 2.0 V6 Club SE/ Atlantic Blue/ Sandstone/Walnut (daily driver) 2003 Land Rover Freelander 1 TD4 HSE Helsinki Blue/Black Leather (swmbo daily driver)

21st May 2016, 20:39	#6
spyder This is my second home 75 CDT Auto Tourer , Rover 45 , Astra, Zaffira, Chev Captiva Join Date: Mar 2011 Location: Wilts Posts: 3,342 Thanks: 203 Thanked 436 Times in 360 Posts	Nice how to Mat. The other useful tool that helped with mine. was a flexible 1/4" 200mm extension. I also removed the liner and wheel to get into some of the lower bolts. Really not a bad job as you say. __________________ Chrome skull caps, EGR cleaned (original housing), Mondeo lower mounting, 12V outlets in the armrest and tourer boot, cat fixed, working FBH, Lidl plenum covers, DD with reverse camera.New speakesr/Tweeters with MDF rings. wood dash, Memory leather seats, wooden finished steering and handbrake, Xenon headlights.

21st May 2016, 20:17	#5
stevie04 Newbie Rover 75 Connoisseur SE Saloon and Rover 75 Tourer Contemporary SE Join Date: Mar 2014 Location: Strathaven Posts: 27 Thanks: 0 Thanked 3 Times in 2 Posts	Just the job I need to do asap. Thermostat and o ring ordered

21st May 2016, 22:10	#7
T16 I really should get out more....... ZT CDTi 135, ZT260SE Join Date: Feb 2011 Location: Dundee Posts: 2,877 Thanks: 10 Thanked 331 Times in 213 Posts	This is one of the easiest jobs Iver evr done on a zt. Give me this over wrestling and destroying door cards to fix knackered rubbish quality door solenoids any day.

22nd May 2016, 01:39	#8
Dragrad This is my second home *None DROWNED** Join Date: Aug 2007 Location: Cardigan Posts: 33,339 Thanks: 1,257 Thanked 1,664 Times in 1,081 Posts	And now in the How To's __________________ Andrew Ich Dien Problem solving is... lateral thinking SEARCH FIRST ...ASK LATER...

27th May 2016, 17:05	#9
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,320 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	Thanks for the feedback chaps! I only posted this as I've always been told this is a stinker of a job - in the end it wasn't too bad. Now sitting at a rather toasty 93 degrees according to the IPK - ranging from 91 to 94 when changing speeds etc. Never thought I'd see that on a CDTi... __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off

8th July 2016, 11:00	#10
Sprinter Posted a thing or two Jag S-Type 4.2 V8 Join Date: Apr 2011 Location: Derby Posts: 1,645 Thanks: 271 Thanked 427 Times in 293 Posts	Hi Matt, thanks for posting the how-to. I've ordered the 'stat and o ring from you and will be replacing the unit while servicing the car in the next week or two. While out and about the other day I used the OBD to show the temp and it was only around 79 - 82. I think it has been like this since I got it but I've never noticed the cold in the winters, so I've left it this long. Looking forward to having it put right. __________________ “Time flies like an arrow. Fruit flies like a banana.”