Td4 Thermostat Replacement - The Way To Do It!

[Creeeg]

Like several others here and on the MG forums (those that have Td4s in their vehicles), I've been suffering a lazy thermostat recently. This was really brought to light this week when the temperature dropped and I had virtually no hot air, and the temperature gauge hardly got up to 1/4.

Daunted by the tales of taking the belts off, crankshaft pulley off, water pump off, bending the metal coolant rail that bolts into the thermostat housing, etc, but, knowing I had to do this job, this is what I found when I did the swap this afternoon: it can be done without removing ANY of the belts, pulleys, water pump, etc!

Firstly, get your thermostat/housing from Island 4x4. £35 delivered, which was about the best price I could find. Tis a genuine replacement too.

In addition to your normal tool kit, arm yourself with a set of Torx ratchet spanners (you actually only need an E8). A 1/4" drive E8 Torx socket is very handy too.

Jack the front up and remove the following: engine undertray, acoustic top cover, air filter cover, turbo hose that clips onto the MAF sensor housing, driver's side wheel and side splash shield.

Drain the coolant by removing the rubber hose from the solid metal pipe under/in front of the engine. Next, remove this metal pipe completely - 3 x 8mm bolts and a hose clip where it connects to the rubber elbow hose that goes into the thermostat housing.

Place a trolley jack under the engine and then undo the 15mm bolt and the 18mm nut on the O/S engine mount (the two you can easily get to by the ABS block). You can now raise the engine up and lower it down as you need to.

Working above and through the steering rack hole you should now be able to tweak the four Torx bolts out using a combination of the E8 ratchet spanner and the E8 socket. It takes a while, but the ratchet spanner is well worth the investment here. Also remove the 10mm bolt holding the metal coolant rail into the thermostat housing.

Once it's all undone, you should be able to pull the thermostat forwards a bit. It probably will get stuck on the engine mount and coolant rail, but if you raise the engine up as much as you can on the jack you will just get enough clearance to a) move the coolant rail back a bit, and b) pull the thermostat clear of the water pump. It'll ultimately only go one way: down. It can then be pulled out through the steering rack hole though.

I'd left the rubber hose on it at this point. So I swapped that over and reversed the procedure to get the new unit back in position. Once I'd juggled the engine height about a few times I got all four Torx bolts back in plus the coolant rail bolt. Then I did the engine mounting bolts, then the plumbing and the turbo pipe.

Sadly that's where I ran out of daylight. So I have about an hour's worth of work in the morning to fill the coolant up, and put the other bits back on, but, barring any leaks it'll hopefully be OK. I'll update this post tomorrow.

I just wanted to share my experiences with this job so far (about 3hrs of work currently). I'm not playing this one down at all - it IS a pig of a job, but it CAN be done without removing too much other awkward stuff. Probably important to know if you're planning to do this at the weekend...

 

[Creeeg]

All done - coolant back in, other bits back on and no leaks!

Water temperature gauge now gets up to the half way point in about 3 miles from cold and there's more hot air coming out the vents than I've ever had in 5 years of ownership!

Total job time was 4hrs. Well pleased that's sorted out!

 

[Vissie]

I think you beat book time

Grats.

 

[Creeeg]

Perhaps - I'm not going to start doing that job for a living though!!

 

[Chaser]

well done, all useful information.

 

[garrytd4]

great stuff, i will follow this procedure as i am doing mine sunday, and was actually going to write up a how to with photos but seeing as you beat me to it with a better way than what i was gonna do then i guess i dont have to.
nice one creeeg

 

[Creeeg]

Let us know how you get on.

I reckon some photos would still be of use as well if you do get a chance to take them. Good luck!

 

[roversreturn]

I am part way through changing the stat. and water pump. Mine has hex head bolts not Torx. Not for the faint hearted. Mostly done by braille. Haynes advice is eerrm different.
I'm going to remove the side 'cheek' off the mounting this will give me an extra 1/2".
I dont know if the Auto is any different to the manual but I have little to none up-down movement. I removed the bottom rear mounting to gain extra movement

 

[garrytd4]

yeh when i removed part the the mount (nearest one to stat) i have very little movement too, i gave up in the end but i would like to give it another shot maybe in the spring when it warms up.
it can be done, and every mm of engine movement helps

 

[garrytd4]

oh yeh, the other problem i had was the metal coolant pipe that runs round the back of the engine, in the guide written in this post, it says to remove the bolt that attaches it to that stat, when i removed it, the pipe still didnt budge and looks as though it may need more bolts removing from where it bolts around the back, anyone had this same thing?

 

[Creeeg]

Garry,

The coolant pipe will only move a little bit, and it does take some effort. Not quite sure if you were expecting it to yield several inches or so, but it won't! Millimetres at best, but it all helps with that job, as you have alluded to.

I believe there are other bolts holding the pipe onto that back of the engine, but getting to them is probably tricky.

 

[garrytd4]

Yeh it was only mm and when i tried moving it with a bit of force I slightly indented the pipe, anymore and i could of broke. I couldn't even move it that much to get it clear of the stat, so when I try again I might just try to undo more bolts.

 

[DefUnct]

Hi, i have a TD4 auto and the thermostat is very much stuck open - i have the temp gauge at 1/4 usually, unless the engine is working a little harder.

Given it's -12 over here, i'm in the mood to get it done. What sort of price should i be looking to pay at an independent?

I would try myself, but don't have anywhere dry and warm to do it - otherwise i would love to save some cash.

p.s does the mentioned method work with autos then?

 

[TRXnMe]

Has anyone tried the Renault 'stat trick used on the Rover 75s?

They simply remove the top hose, shove a Renault 4/5 'stat into the hose (it's a very tight fit) and reconnect the hose to the engine, top up and 'presto' warm engine nice and quickly.

There are a range of 'stats that have been tried, the best one runs at 89 degrees C

I'll have a poke about round the wife's tomorrow and see if the top hose looks like the same diameter as the one on the R75

 

[garrytd4]

even if you do that would you still not have to remove the the land rovers stat? cos if you did then you may aswell replace it anyway.

 

[TRXnMe]

even if you do that would you still not have to remove the the land rovers stat? cos if you did then you may aswell replace it anyway.

If the original 'stat has 'failed safe' (wide open) then there is no need to replace it, sticking wide open is the most common 'stat failure on the R75, as a result the owners have worked out the Renault 4/5 'stat dodge

Wife has decided to go out, so I've not got access to hers today, can't get a look at the top hose

 

[garrytd4]

if you mean the top hose that goes from the coolant header i think its about 12-14mm internal diameter (could be wrong) if you mean the thermostat bottom hose its 35mm ID.
Thats on the TD4 anyway

 

[TRXnMe]

if you mean the top hose that goes from the coolant header i think its about 12-14mm internal diameter (could be wrong) if you mean the thermostat bottom hose its 35mm ID.
Thats on the TD4 anyway

I'm on about the hose to the top connection on the radiator, item 4 on the image, it should be the same ID ass the bottom hose, if it is then the Renault 4/5 'stat will be a nice tight, very tight, fit in the hose.

Just got to make sure the bulb is pointing at the engine so the not water gets to it

 

[DefUnct]

ok, finally got my thermostat replaces by an independent over here for a great price. i have a couple of Qs:

1) They said the old one looked fine, totally ok - if it was borked, what should it look like?

2) The new one heats up pretty quick, my temp guage gets to half way (marginally below) - but on a long downhill, where i have my foot of the accelerator, the temp will drop to just below the bottom wavy line - it is -10 here, is that normal?

3) At what point does the engine swich from cold running setting to normal?

Thanks

 

[Creeeg]

1) Mine was the same - looked OK, but the new one climbs quickly to the halfway point where as the old one didn't.

2) Sounds about right to me. Mine has been doing the same in these temps. Once I slow down it soon climbs back up again.

3) Not sure what temperature the stat starts to open (someone else will know). There's a number stamped on the stat that I think is the "fully open" temperature. 88 deg C springs to mind (I could be wrong).