W124 230TE - heater matrix

[Murkymerc]

The metal cover has a rubber seal...or at least mine did. New one came with the new thermostat.

 

[adrianb]

Thanks Tony/Murkymerc. The problem is that the remains of two of the old thermostat bolts look like they are holding the old cover on. I've tried a couple of gentle taps with a hammer, but that hasn't loosened it. There is what looks like black mastic all around the cover seal edge. The old bolt heads broke off leaving nothing proud of the cover to get to grips with.
What I might try is getting underneath with a long screwdriver and tapping from below. The thermostat head looks to have a bit of an overlap all round, so there might be enough to get some purchase.

I've uploaded a couple more pics:

http://www.flickr.com/photos/brightsrus/4445632818/

and:

http://www.flickr.com/photos/brightsrus/4445632076/

In the second you can just see the thermostat through the outlet. It looks like it might be in the closed position, but maybe that's just wishful thinking.

 

[The Crooner]

What's really important is that you have enough purchase on the remains of the screws to be able to get them out.

I think that I would be looking at ways to sacrifice the cover to ensure no further damage to those screws - maybe some judicious saw cuts?

Tony

 

[adrianb]

Sucess removing the thermostat cover. Basically I broke it up with a pair of pliers. On the outlet side it almost fell apart. The other side was a bit more resistant, but not much.
Each bolt fits through a metal collar embedded in the plastic housing. Two of the bolts had expanded with corrosion, making them a very tight fit against the collars.
The outlet stub where the top hose to the radiator connects is also reinforced with a thin metal collar under the plastic stub.
The rest is pretty flimsy, and I can see why the Mercedes replacement is all metal (aluminium I think).
The thermostat sits in a recess that makes up part of the lower, metal housing. The thermostat seal rests on a supporting lip on the lower housing under the outer edge of the thermostat.
Although it's hard to be sure now that I've broken it up, it looked like the plastic thermostat cover/upper housing had no separate seal to the lower, metal part, but just relied on the contact between the upper and lower housing faces. Whoever last worked on the thermostat seemed to have smeared the faces with a black sealant of some kind, that is going to be hard to remove without scratching the sealing face of the lower metal housing.
Pics to follow.
I've ordered a new housing, but it will be the cheap replacement rather than the Mercedes part until I'm sure about the state of the water pump.

 

[adrianb]

Thermostat cover pics:



No joy with those thermostat cover bolts. But I did get a s/h water pump (thanks Rob), complete with thermostat housing. This seemed very handy, as the buyer for my old Espace is coming today, and I needed to shift the Mercedes. I was feeling all chirpy about this, having read Haynes, thinking how I would just swap the the thermostat housings, fill the cooling system and reverse it up out of the way all in an hour or so. Plan to replace the water pump over the next couple of days.
When it was time to remove the old housing, discovered that one of the hydraulic suspension pump metal pipes is attached with a lug to one of the lower thermostat housing bolts. And the bolt is long, and maybe too long to to be undone fully without knackering the pipe (as you'd have to bend the pipe in order to pull the bolt free). The other option I was looking at was to remove the complete suspension pump assembly from the engine block but leaving all the pipes attached. Haynes just describes dismantling the pump and depressurising the suspension hydraulics before suspension pump removal - surely you can't have to do all that in order to remove the thermostat housing/water pump - or maybe you have to do it on the estates.
Has anyone replaced their water pump/thermostat housing on a W124 Estate?

 

[adrianb]

Pics of the thermostat housing, bolts and the rear suspension hydraulic pipe.

 

[adrianb]

Finally managed to remove the two seized thermostat cover bolts. Even after several days of WD40 application they were reluctant. Though very corroded, there were still the remains of a thread on both. Found some nuts to match the thread. Screwed on two, one on top of the other. unscrewed the lower nut until it was tight up against and aligned with the upper one. Used a spanner on the nuts to loosen the bolts, and a socket to remove.
Getting the bolts out let me use my s/h thermostat housing cover, and avoid dealing with the hydraulic suspension pipe for a bit, and so refill with coolant and move the car.
The s/h housing is metal, with what looks like a seal around the lower outside edge. Can you get these separately?
I'm still looking for some guidance on the suspension pipe problem. I don't want to get the hacksaw out on the suspension pipe lug, but can see this happening.

 

[television]

I can let you have the water pump replacement instructions, also the thermostat

 

[adrianb]

Thanks Malcolm that would be very helpful - do I need to leave my email address again?

 

[television]

Thanks Malcolm that would be very helpful - do I need to leave my email address again?

If you can give me a clue as to what it started with I can find it among the 1500 in my book

 

[adrianb]

Thanks Malcolm: w124@d****p

 

[television]

I found it and details sent just ask if you need anything

 

[adrianb]

Thanks very much for those Malcolm. Reading through the guidance notes I've got a few more queries:

Thermostat housing removal
I still can't work out how to remove this without either unbolting the hydraulic suspension pump or depresurising the hydraulic system and detaching the rigid pipe from the pump. Neither the Mercedes notes nor Haynes seem to mention that one of the bolts securing the thermostat housing is a kind of bolt-on-a-bolt. There is an "integral" nut that fits under the rigid suspension pipe lug. It is this integral nut / bolt head that secures one side of the thermostat housing. A thread continues up from this, through the lug, and another nut on this thread itself secures the rigid pipe that is attached at one end to the hydraulic suspension pump, and at the other to a flexible suspension pipe hose. When the integral nut/bolt head is undone, it pushes on the lug. See:

http://www.flickr.com/photos/brightsrus/4473195243/in/set-72157623728312976

Can the hydraulic pump can simply be detached detached from the engine without depressurising the hydraulic system? If it can, that would make removing the thermostat housing a doddle.
I might need to do this, as I'm not sure if my s/h thermostat housing cover is a proper fit for existing base. There is a fairly major amount of leakage around the cover/base join, though I admit I didn't replace the thermostat seal. The original lower housing was very corroded and even now it's been cleaned up and smoothed down, is quite pitted all around the lip. The metal cover seems to have some kind of integral seal around the outside of the bottom edge where it fits into the lower housing. I suspect this was ruined when I pushed it in to place on.

Thermostat housing - engine head seal
Does it need a gasket or some kind of sealant? When the bolts were loosened off, I couldn't see any sign of a gasket or sealant.

Water pump gasket/seal
The notes mention that if the timing chain cover has been sealed with a liquid sealant, then a paper gasket has to be used when refitting the water pump. This might be a stupid question, but how can you tell if a liquid sealant has been used for the timing chain cover - is it pretty obvious once the pump is off? If sealant hasn't been used, is "002 589 00 20 10" the only kind of sealant that should be used for the pump? The gasket is super cheap, so would there be a real problem if used when it shouldn't be?

 

[adrianb]

Job Start

I'm about to make a start replacing the water pump. Answering my own question about the thermostat housing to head seal - yes there is a gasket for this. I also got the gasket for the water pump, and the two together cost about £4.50. As I want to change the thermostat housing and I'm not sure about the whether the suspension pump can be removed without depressurising the system , I'll just have to cut through the lug.

From reading around, these are the main tasks:

Remove radiator

Slacken / remove ancilliaries drive belt

Remove fan

Remove water pump

I was very impressed by the Parrot's rear disk / hub removal guide. I'll try and take pics as I go and see what we end up with.

 

[adrianb]

Have replaced pump and am reassembling - pics will be uploaded later. Two questions:
The replacement pump has an extra, small outlet (about 5 - 7 mm diameter) at the base that isn't on the original - am I OK to seal this up? Do I need to ? Maybe it is just some kind of drain outlet. I figured it must be for something like the screen wash heating option.

Accessories belt tensioner bolt torque: Haynes lists torque settings for the "auxillary drivebelt tensioner mounting bolt" and "auxillary tensioner pulley bolt", but in the descriptions only mentions "tensioner bolt". The torque settings are very different so I want to double check - is the "tensioner mounting bolt" the same as the "tensioner bolt"? Haynes shows in it's diagrams the "tensioner bolt" as the one with the adjustment pointer/scale, so my guess is it is this one that needs the higher torque setting (59lb/ft).

 

[television]

I can let you have the correct details what engine do you have please

 

[adrianb]

Thanks Malcolm.
It's a 230TE, engine: 102982 22 197893

 

[television]

Thanks I can let you have the PDF for this,, please PM your Email address

 

[adrianb]

Beyond the call of duty

Thanks I can let you have the PDF for this,, please PM your Email address

Really many thanks Malcolm for spending time helping this weekend, especially as this is a busy time for many. I'm trying to get the "bus" back in working order to take sprogs and side-kicks to a friends for a few days over the Easter break. Arrangements were made for me to do the transport duties, so am under pressure to get it fixed by Monday.

 

[television]

All details for the tensioner sent to you