N/A heater matrix plumbing - Blocking off

[JS2004]

Hi chaps,

 

I realise there are some posts about this - some with the manual diagrams etc however I have taken some pictures under the bonnet and was hoping some people could have a look and circle the right pipes.

 

I am about 95% certain I have figured out which ones it is, but want to check before I do anything as theres a weird little metal "linking" pipe that I am not too sure about.

 

One pic shows the pipes that I think are the heater ones, going into the bulkhead. Another shows the small metal pipe linking two pipes.. not sure what that is. The other pic is just a general zoomed out one.

[shaz2010]

Yeah mate there the wright one's in the middle pic ,ive just done my heater matrix 2 weeks ago . Them clips are a nightmare to get off had to get some very good long nose pliers in there.

[JS2004]

Excellent - I did suspect it was those. I have the bungs for the pipes so now its a case of unclipping and getting in there with the bungs. Those clips are re-usable I hope!!

[shaz2010]

lol no i tired usin them again but there really old so i just got some new ones. the pin just pulls out and all it is ,is a little thin bit on tin and it wraps round thepipe.

[Scooter]

lol no i tired usin them again but there really old so i just got some new ones. the pin just pulls out and all it is ,is a little thin bit on tin and it wraps round thepipe.

 

If you unclip the clamps right up tight to where they enter the bulkhead (I think the quote above is talking about the joint one back from that?) then those should eb reusable ok as long as the bungs are a tight fit.

[JS2004]

Right, once I get rid of this hangover ill have a go at this.

 

As I am just blocking off the heater matrix completely do I need to worry about bleeding the system? The pipes look as if theyre in a high-point of the coolant system so unclipping them shouldnt dump coolant everywhere right?

 

Ive bought some new toyota 4life red concentrated coolant as I am not sure what is in there at the moment, so aim to replace that at some point too.

[Terminator]

Please tell me you are not going to bung up the flow and return water pipes.

[JS2004]

To block it off so that no coolant is routed to the heater matrix.. yes.. why?

[Terminator]

You should not block them off, but link them to maintain coolant flow.There are two good reasons not to bung therm up.

 

1 . You totally destroy the designed flow round the back of the head resulting in uneven cooling of the cylinders. Number six is the hot one anyway, so why risk making it hotter.

 

2, The dead legs are a magnet for air bubbles, as they are the highest points in the system, these become trapped and become little expanding zones in the water system, thus enabling the system to dump excess coolant into the over flow bottle when hot. Any coolant lost will be replace from the expansion tank until what is already lost equals the total volume of the tank. This will induce more air and rapidly make the water system incapable of cooling the engine evenly and can lead to engine write off.

 

I think it was Digsy that wrote a thread on this some years back.

 

Edit found it,,http://www.mkivsupra.net/vbb/showthread.php?111270-Heater-Matrix-bypass&highlight=water not only should you link it but you need some form of restrict or to main the normal designed flow, failure to do this can and has caused head gaskets to blow and possibly warped heads.

 

Edit again, having reread the whole thread, it looks like blocking off is indeed the best option,for flow, however I would want to have bleed valves in the dead legs to be sure there is no air in the system.

Edited December 11, 2010 by Terminator (see edit history)

[JS2004]

Ah,

 

Yes I see the issues now youve pointed them out.

 

This now leaves me confused as I had read a long thread about the benefits / problems with bypassing the matrix with a pipe compared to blocking it off completely.

 

I think the conclusion of the thread was that bypassing the matrix would remove the resistance that the matrix offered to the circuit, potentially leading to blown HGs - wheras blocking it off kept the resistance in the circuit

 

I may have misunderstood the thread that gave me this idea in the first place.

 

The plan was to block off the matrix pipes completely, until I have changed it out - which wont be for a while yet.

 

Going back to the drawing board - Mods please could this thread be merged with my other post, as it shouldnt be treat as a guide anymore. (http://www.mkivsupra.net/vbb/showthread.php?233323-smoke-from-vents&highlight=heater+matrix)

 

Edit - yes thats the post I was looking for - you beat me to it whilst I was replying

[Terminator]

I think it was Chris Wilson's post that rightly said that the matrix is blocked off when the heater control are set to cold. So blocking is better than bye pass. Whether this is short or long term it is important to ensure no air is trapped in the blocked off legs. Sorry if I caused confusion.

[JS2004]

I welcome the discussion mate, its all stuff I want to learn and always better to have someone elses point of view.

 

I am re-reading the post, it was focusing on the whole bypassed matrix issue, which is worse than blocking the pipes with bungs.

 

My original plan was to block the pipes going into and out of the matrix so that no coolant reaches the matrix at all, and is forced through the radiator (no bypassing). It would increase flow rate, which could be a bad thing.

 

The air bubbles were something I was aware of but didnt think about them pooling at the bunged location - I do not know how to get rid of those yet - hopefully it will be in there somewhere

[Terminator]

Just release the clips on the bungs slightly while the system is warmish and still under some pressure, it should push out any air.

[JS2004]

In the first picture, I have only just noticed whilst looking at the engine now.

 

Next to the little purple plug, there is a pipe that comes off the top of the manifold, and doesnt connect to anything. There is also a little black plastic nib type of thing that looks as if that pipe should connect to it, but the pipe isnt long enough. Does anyone know what that bit is? Ill try to take a few more pics.

[JS2004]

Right - thats one set of matrix pipes blocked off.

 

The bungs that I got were difficult to fit over the pipes, so for anyone else doing this I used a mug of hot water and dropped them in there so that they would heat up a little. I also used a bit of washing up liquid on the outside of the pipes to help.

 

On my N/A there was a plug sticking out that is held on by a bracket connected to the bulkhead. I unscrewed this to give more room to work.

 

On each pipe that go into the bulkhead are little metal fastners that use a pin to tighten them. If you turn the pin (anti clockwise I think) it will release more metal strip and allow them to come off. One of mine had corroded so was tricky to release.

 

With pipes disconnected the bungs were fitted and metal fasters reused. I topped up the expansion tank with some additional coolant.

 

Then turned on and let engine get up to temp, before using a rag to unscrew the rad cap. Some air was escaping, and I squeezed the large pipe a little which gave some more air bubbles. Let it idle for a while before revving it a bit. Replaced rad cap, its now cooling off and ill re-check later.

 

Could not detect any leaks of any sort, so hopefully ive fixed it. Turning the heater on doesnt result in smoke (and obviously no heat) so thats a bonus.

 

Terminator - thanks for the additional help in PM`s - appreciate it buddy.

 

Pics : The first one is of the weird unplugged pipe thing.. not sure what that is!! The rest show the result. Hope its of help!