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        General >> Give/Need advice to/from others >> Re: No heat, 2.0i 8v DOHC. (most likely NOT an air
        
(Message started by: Tompion on Jul 26^th, 2013, 9:42am)

Title: Re: No heat, 2.0i 8v DOHC. (most likely NOT an air
Post by Tompion on Jul 26^th, 2013, 9:42am

It can be difficult to shift air from the matrix or the hose from the matrix to the pump but the chances are the matrix is partially blocked. It’s surprisingly difficult to detect a blocked matrix, water from a hosepipe will flow quite happily when flushing it through in either direction.

You won’t have caused damage by having the matrix hoses reversed.
You shouldn’t be able to detect via the gauge when the stat “kicks in”.

Title: Re: No heat, 2.0i 8v DOHC. (most likely NOT an air
Post by rixivee on Jul 26^th, 2013, 12:34pm

on 07/26/13 at 09:42:10, Tompion wrote:

Well, I'm going to swap the thermostat to Motorcraft one. Also ordered new expansion tank cap and

I tested radiator after a run in the city. I could easily keep my hand on it. From below it wasn't even warm.

My friend says that it's possible that incorrect flow has eaten the wings of the pump. Or the pump could be just plain faulty. (More rpm -> better performance from poor pump)

What does THAT sound like to you? I'm going to backflush the core with air and cleaning chemicals. I did that last winter but obviously the flow direction was wrong(just normal flushing) since the pipes were incorrectly. Also going to switch the thermostat and water pump.

Oh and one more thing. Before the thermostat was changed.. Gauge readings were a bit higher if I remember correctly.

This is driving me insane.. I don't want to open the fascia! :(

Title: Re: No heat, 2.0i 8v DOHC. (most likely NOT an air
Post by Tompion on Jul 26^th, 2013, 3:25pm

I think cavitation damage to the pump is highly unlikely, there’s nothing about the pipe run to & from the matrix that would matter either way you connect it.

Flushing the matrix is probably your best bet.

Before I changed my matrix I used to flush it when the heater packed up, but it only lasted a few weeks or months before needing doing again. The hose from the matrix to the pump was always a problem – I fitted a valve so I could release the air. After you flush it blow the water out of the matrix & fill the system slowly that way the rising level may push the air ahead of it which it can’t do if the matrix is full.
After changing the matrix airlocks were no longer a problem.
The stubs of the matrix can get brittle with age & split so best to leave the hoses in place when flushing.

Title: Re: No heat, 2.0i 8v DOHC. (most likely NOT an air
Post by rixivee on Jul 26^th, 2013, 8:31pm

Update:

5 minutes of idling will start rising the gauge reading. Then, immediately after starting to drive and rpm gets higher.. The gauge reading drops.

My friend, who's a car mechanic, says this is sign of bad water pump. He suspects that cavitation has indeed eaten the pump wings or at least helped the process. However, he also confirmed that airlock could cause this too but he tried removing the possible airlock with no result, which makes him believe there isn't air.

Blown head or gasket is highly unlikely, because there's no other symptoms.

Back to my evil car laboratory :-X ...

Title: Re: No heat, 2.0i 8v DOHC. (most likely NOT an air
Post by Tompion on Jul 26^th, 2013, 10:30pm

Just looked back for a reply I gave for a similar problem:
“My 2.3 behaved much the same in cold weather with a faulty thermostat.
It wasn't so bad on slow roads, but would hardly leave the blue on the gauge at speed if the CC was on.
I assumed it was colder air at speed plus the fans, but found it was rev related.
If I left it in 1st & let the revs rise the temp gauge would drop, presumably more coolant getting by the stat.”

A partially blocked matrix will tend to make it worse - you could try bypassing the matrix to rule that out.

Title: Re: No heat, 2.0i 8v DOHC. (most likely NOT an air
Post by rixivee on Jul 31^st, 2013, 12:16am

Removed the first post by an accident but oh well..

I'm currently replacing the heater matrix because my clutch died and got to do other big maintenance too.