Blocked Thermostat housing..

[G-Bear]

Took my throttle body off to get it machined by Byron and noticed the hose going to the thermostat was blocked with limescale, it was in the duct on the throttle body itself too.

So I went to remove the hose and it came away from the thermostat housing taking part of the metal from it still in the hose.

I removed the housing, that hole appears to be rusted/clogged? up.

I'm going to replace the whole housing, does this indicate anything else that needs addressing, or is that a common place for them to fail?

[maggspower]

For some reason BMW have made the stat housings out of some really inferior metal, my only thought on this is it is a type of scrificial anode that corrodes before the rest of the engine does, that is just a theory though.

Couple that with the fact you live in an area with "hard" water I believe. Hence the lime scale build up. Yes it is common for these to see this kind of damage.

Just make sure your coolant/water ratio is correct and avoid tap water. Try ready mixed coolant, or clean rain water, or I'll send you a couple bottles of "council pop" from round here

PM on its way.

[G-Bear]

Cheers Byron, council pop sounds like a good business plan... you could bottle the stuff!

I changed the coolant not long ago and used coolant mixed 50:50 with de-inionized water.. but thats not to say whats been in it for the other 22 years!!

Thanks again..

[daimlerman]

If I'm reading the OP correctly,the reference is to the water hoses that are connected to the T/B?
These can be dis-connected,as it is better to keep the T/B cool to improve running.
I ran a single small bore hose from the 'stat housing to the stub at the rear of the block,but I can see no reason not to just cut the original hoses and block them with a suitable plug held in with a jubilee clip.

[G-Bear]

If I'm reading the OP correctly,the reference is to the water hoses that are connected to the T/B?
These can be dis-connected,as it is better to keep the T/B cool to improve running.
I ran a single small bore hose from the 'stat housing to the stub at the rear of the block,but I can see no reason not to just cut the original hoses and block them with a suitable plug held in with a jubilee clip.

That's correct it runs from the TB to the thermostat housing. The engine clearly has been running like this (blocked) for a while. Would it not get hotter from the heat off block without the coolant getting to it? What I mean is, is the temp off the block more than the temp of coolant that goes to the TB?

[daimlerman]

In general,the cold air coming into the T/B via the air filter should keep it cool,hence the reason for deleting the heating pipes.
They are there to warm the T/B in countries where the ambient temperature is very low,the idea is to warm the T/B,not cool it.

I have run my M20 without these heating pipes for years,I reckon it aids fuel economy...my 2.7 is currently returning 32mpg!

[G-Bear]

Okay. Thanks for the food for thought, may well go for the delete option.. well I guess it had naturally already deleted itself..

[maggspower]

Ageed with above, you can delete the TB heating. It is there to combat icing of the throttle in colder climbs.

By the way Greg, just got your TB

[G-Bear]

Ageed with above, you can delete the TB heating. It is there to combat icing of the throttle in colder climbs.

By the way Greg, just got your TB

[gromgsxr]

see here, http://garagistic.com/index.php?page=m2 ... ter-delete

[daimlerman]

see here, http://garagistic.com/index.php?page=m2 ... ter-delete

Over complicated and un-nesessary!

Either a single pipe of,I think,8mm ID from the 'stat to the rear of the block,or trim both pipes near to their source and plug with a bolt and clip.

[gromgsxr]

i had to do it that way as the stub off my thermostat housing came off, m10 tap and a bolt sorted it

[G-Bear]

Cheers for that link gromgsxr. My thermostat housing had broken in the same place, sealed itself off with rust. However the whole housing is manky, so am getting another cleaner housing and am just going to run a hose from the block to the thermostat.

daimlerman, thanks for the advice, as always very helpful.

[gromgsxr]

both those ways work well i had the pipe from the back of the block to the housing for about a year with no issues, until the stub decided to disconnect its self from the housing like yours did so i tapped it and put a bolt in and blanked off the block been good for a few weeks also.

[G-Bear]

Good to have a plan B, if the same happens to me again.

Just popped out to check if the current hose from the block shall reach; I think it'll just make it..

[polsta]

had a nightmare with mine, had no issues when car was on the road, it was ll in place, thought remove it for a clean up- thats when the problem started, it was all sealered on wiht thick gasket stuff, and the bottom stud was all water corroded in, took about 4 attempts, with penetrating fluid,leaving, trying again next day etc, eventualy got it off, and had to get a blow torch and mole grips and that took a while, to remove the stud from the head, lucky enough it all ended up ok, got a replacement housing and new studs in the head, on the flip side it was lucky i took it off and didnt leave it to corrode more and end up with big troubles lateron

so is this delete thing the way to go ?

[gromgsxr]

why would you want warm coolant near your throttle body heating it up colder air is more dense, i didnt have any issues over the winter without it even on the days we saw -20