CDTI thermostat housing

GP1005 · 14th August 2021, 10:32

I have a water leak from the CDTI thermo housing. Haynes says I need to remove water pump and engine/hydro mount.

Can anyone tell me if these items both need to be removed please

Thanks
Gary

RogerHeinz57 · 14th August 2021, 10:50

The usual cause of leaks from this area seem to be the pipe seal that comes from the top of the housing. I have done a number of theromstats on these. They are not impossible, however there seems to be plenty of fiddly bits to attend to not least the attachment of this pipe around the back of the engine there are loads !
I would ignore the Haynes idea of removing the water pump because the thermostat bolts on to it and can be accessed after removing the upper engine mount etc. The seal is the item that really matters and would make sure you have a good one available prior to attempting the repair along with some fresh coolant to replenish the system with. I never got the metal pipe off the car, but managed to manipulate it away far enough to detatch from the housing. You will need a torx set of small sockets and using 1/4" drive kit will allow easier working conditions for this repair. The usual support to the underside of the engine and well worth removing one end of the lower engine mount too, this allows the engine to be lifted much higher and so much better access to where you will be working !

Richard1973 · 14th August 2021, 18:15

As you were typing your question I was doing this exact job.
I agree with the reply above.
Free the lower stabiliser at one end and then its a case of remove the engine cover and air filter cover.
Unclip the pipe from the MAF and remove it from the MAF and turbo.
It's then a case of releasing the air con pipes at a couple of places to allow them to move and then undo the engine mount.
Only real issue I had was then engine did not want to release from the hydro mount and then did so quite suddenly putting pressure on a radiator fitting and PAS pipe.
Once the engine is high enough its then two bolts on the coolant rail to give it a bit of movement, the coolant hose clip, the retaining bolt for the rail into thermostat and the 4 thermostat bolts
The thermostat can then be wiggled out.
I followed the advice and put a trace of rubber on the o ring to assist refitting and then eased the new thermostat into place bolting it up slowly around the 4 bolts equally.
Refitting is then reverse of removal for everything else.

GP1005 · 14th August 2021, 18:56

Thanks Guys - really useful info. Have ordered the seal from DMGRS so will start the job when it arrives. Fingers crossed.

14th August 2021, 10:32	#1
GP1005 Regular poster MG ZT-T CDTI Join Date: Feb 2011 Location: Ashford Posts: 61 Thanks: 5 Thanked 1 Time in 1 Post	CDTI thermostat housing I have a water leak from the CDTI thermo housing. Haynes says I need to remove water pump and engine/hydro mount. Can anyone tell me if these items both need to be removed please Thanks Gary Last edited by GP1005; 14th August 2021 at 10:37..

14th August 2021, 18:56	#4
GP1005 Regular poster MG ZT-T CDTI Join Date: Feb 2011 Location: Ashford Posts: 61 Thanks: 5 Thanked 1 Time in 1 Post	Thanks Guys - really useful info. Have ordered the seal from DMGRS so will start the job when it arrives. Fingers crossed. Last edited by GP1005; 14th August 2021 at 19:12..

14th August 2021, 10:50	#2
RogerHeinz57 I really should get out more....... A Reasonably Priced Car Join Date: Jan 2014 Location: Burton Latimer Posts: 2,530 Thanks: 408 Thanked 1,064 Times in 712 Posts	The usual cause of leaks from this area seem to be the pipe seal that comes from the top of the housing. I have done a number of theromstats on these. They are not impossible, however there seems to be plenty of fiddly bits to attend to not least the attachment of this pipe around the back of the engine there are loads ! I would ignore the Haynes idea of removing the water pump because the thermostat bolts on to it and can be accessed after removing the upper engine mount etc. The seal is the item that really matters and would make sure you have a good one available prior to attempting the repair along with some fresh coolant to replenish the system with. I never got the metal pipe off the car, but managed to manipulate it away far enough to detatch from the housing. You will need a torx set of small sockets and using 1/4" drive kit will allow easier working conditions for this repair. The usual support to the underside of the engine and well worth removing one end of the lower engine mount too, this allows the engine to be lifted much higher and so much better access to where you will be working !

14th August 2021, 18:15	#3
Richard1973 Loves to post Rover 75 Saloon CDTi Join Date: Aug 2012 Location: Mansfield Posts: 287 Thanks: 18 Thanked 69 Times in 52 Posts	As you were typing your question I was doing this exact job. I agree with the reply above. Free the lower stabiliser at one end and then its a case of remove the engine cover and air filter cover. Unclip the pipe from the MAF and remove it from the MAF and turbo. It's then a case of releasing the air con pipes at a couple of places to allow them to move and then undo the engine mount. Only real issue I had was then engine did not want to release from the hydro mount and then did so quite suddenly putting pressure on a radiator fitting and PAS pipe. Once the engine is high enough its then two bolts on the coolant rail to give it a bit of movement, the coolant hose clip, the retaining bolt for the rail into thermostat and the 4 thermostat bolts The thermostat can then be wiggled out. I followed the advice and put a trace of rubber on the o ring to assist refitting and then eased the new thermostat into place bolting it up slowly around the 4 bolts equally. Refitting is then reverse of removal for everything else.