Hi,


is it worth attempting a replacement heater matrix work yourself or leave it to the garage?

It's a bugeye

Cheers

 

My heater matrix went on my 03 STI. Cost a bloody fortune to fix. The garage said imagine they start with the heater matiorx and build the car around it. I think like anything it is a DIY job if you have the time and the competence, but you have to do a lot of work to get at it.

 

+1 - sadly the same in most cars.
It is just as likely to be the pipes running to it ir indeed the clip/joint onto the matrix.

 

good luck mate started my classic at 9am finished at 11pm , its a dash out job and loads of aggro , i bought the complete heater and matrix from grade a .

 

It's do-able, but expect the car to be off the road at least for a day.

This might help, https://www.scoobynet.com/scoobynet-...er-matrix.html

 

Looks a bit of a job and I've not got the time to see the job thru if it takes longer with a little baby and job!

Trouble is my car has boosting issues, keeps overheating and the heating on full whack is very poor - the Scooby garage reckons there is some kind of blockage in the matrix that is preventing the water working its way around - hence the overheating? I'm prone to agreeing as my heater is rubbish on full pelt.

Would this affect the turbo and keep it from boosting at seemingly random points?

thanks

 

Having a blocked heater matrix will have **** all effect on the over heating issues. If the matrix is in the off position then no water runs through it, it has a bypass so the water flows around it without going through the matrix. Thinking logically; otherwise in the summer with the heater turned to cold it would overheat all the time.

I strongly suggest you take it to someone who actually knows a little about cooling systems. It may be you have a blockage/silted up rad/stuck thermostat/knackered water pump or a failing head gasket but definitely not a water flowing through the heater matrix making it overheat. It may be the heater matrix is silted up but it would only cause it to run cold - that all it would do.

Take it to an automotive cooling expert, let them sniff/pressure test it to rule out HG failure and diagnose the real problem. It might well be you havve an air leak.

PM me if you want to talk it though

 

I'll have a word but so far radiator has been flushed once and then ended up being replaced.

The reason the mechanic thinks it's the matrix is because the pipes that enter/exit the matrix are cold when the gauge goes into the red? The hose by the rad is hot.

I see the logic in what you're saying so will see what happens today.

I don't know if it's related to the turbo boost issue?

When the gauge shows red it is typically after I've had a good spirited drive - could this point to anything?

Thanks guys for your help!!

 

I would say thermostat stuck closed or blocked and or fans not kicking in, do the fans work???

The heater matrix sounds like it is blocked but as i said that will only stop it from getting warn it is not required to cool the car at all + the water/coolant has to be able to bypass the matrix as i explained earlier. When you had the rad changed was the cooling system flushed and also bled properly as well/ also it could be an airlock just adding to the confusion.

 

i done mine in about 4 and half hrs once you get stuck in its not so bad and make sure you remember how it all goes back.i took loads of photos as i done it but i must admit im not sure i would do it again lol

 

The fans work fine - I've told the mechanic what you've said and he has eliminated all the stuff you said. He has flushed the system and ensured there's no air locks.

I have asked him to check if the turbo boost issue is linked as I did do some heavy driving on the days it has overheated - trying to almost force the turbo to kick in ..... could be related or just a coincidence?

 

Hmmm, I really cannot see how the matrix could cause your overheating. To test connect a hosepipe to it (one of the pipes leading to it) and disconnect the other pipe and turn the hosepipe on and slowly increase the flow, not full! if water flows out of the disconnected end then it is OK, also move the heater control from hot to cold and see if that affects the flow.

If the thermostat has be checked then if it was me i would just replace it for the sake of a fiver or so. it may be opening late if at all

TBH it sounds like it might be HG and ask if he has sniff tested it. Are you loosing any coolant???

 

just been on the blower and we know it's not the head gasket as the engine is ticking over nicely, been checked etc.

The engine is pressurising too much to the point it might go pop - so that's what he is going to look at. The turbo thing might just be a coincidence

Will ask him to do the above tests and come back to me

 

HG failure will not always affect tickover, if you are getting gasses leaking into the coolant then tickover remain unaffected but it will over pressurise the system to the point it will vent through the overflow pipe. You rad cap/expansion bottle cap will have a spring that is set to a certian pressure and will lift to allow the excess pressure out.

Has he sniff tested the rad??? a sniff test is a chemical test using what look like a pipette (in a lot of cases and any gas in the coolant will change the colour of the dye.

I would look to the thermostat, change it as a matter of elimination, simple, quick job.

The heater matrix feels like a bit of a red herring but get them to check it or do it yourself as i described, again simple, quick job.

Bare in mind i havent seen or touched the car and going from what you have described and said then TBH unless you have absolute faith in the garage then i would be dubious of their diagnosis and the route they are taking as they should have done what i suggested already to fault find.

 

I am popping down later so will go thru everything with them based on your suggestions

I have mentioned the sniff test and I think he will do it.

I've been going to the same garage for a while so I do have faith in them and he has been very good with past jobs so I can't fault him.

Will report back later once I have some responses to the above.

thanks for all your help everybody - especially Paul

 

You are welcome however, a sniff test should have been done sooner rather than later and if they haven't already done it then apply foot to ***!

 

lol - will do!

 

To add, to thoroughly rule out the heater matrix then they can bypass it by joining the two pipes together - the inlet and outlet pipes before the matrix. that will tell you 100% it is/not the heater matrix that is causing the problem.

again simple quick job.

and ask them if there is a heater matrix bypass valve and if they have checked that. Some cars have a valve separate to the matrix.

 

cheers matey

I am hoping they'll be able to recreate the issue as I've driven it for two days withouth problems (have kept off boost as I thought this was reason)

fingers crossed!

 

the only way i found my hg were going was my forge header tank split,when i had it welded and put back on under boost it split again.other then that i had no idea there was anything wrong. 1st scoob i had did have the same prob (hg) but the matrix split hence me doing a d i y on it.always best 2 get it checked as its ££££ when it goes wrong

 

Update?

 

Well the latest is:

As the car had been sitting for several months during the harsh winter we had last year, when the engine was rebuilt the ancilliary pipes etc were left as they were. Having water in them, whilst it was stood still caused corrosion etc.

Thanks for the recommendations you made Paul - especially about flushing out the matrix. This was done and the matrix is fine so it's saved me a wad of cash!! It has flushed out some crap from the matrix so hopefully it's made my heaters perform better

The pipes that carry the water around the engine are currently being replaced. To make matters worse, the bolt/nut (??) that forms the guides for the belts snapped so the upshot is the block is being changed!!

The constant coldness and then hotness of the engine (fault must've been there for a while despite not showing on the temp guage) has caused the bolts to bed in and make them weak

The Scooby mechanic I took it too has been as good as gold and has promised I won't be paying any more and it will end up costing him more than it will cost me

Hopefully tomorrow I'll be able to pickup a fully functional car that runs sweet and boosts when it's supposed to!!

Thanks Paul and the others for your help!! I'll keep you posted with progress!