Ford KA mk1 - fettling and diagnosis - First diy car service

[dishman]

Drench the O ring in silicone spray.....it also helps if things are slightly warm.
John

Yeh, I did spray some on my finger and wipe it round the seal. and a bit in the housing, but to no avail.

Maybe I need more, but I did not want to contaminate the coolent somehow.

More liberal then....and maybe if I dip the sensor in hot water before inserting perhaps?

 

[SFK]

Put the old washer on the new sensor and see if it fits without leakage?

 

[Burnerman]

Maybe try with some Fairy Liquid or similar?
Don't worry about the coolant, it will handle that.
John

 

[carmanmemoranda]

Do you remember the old style haynes manuals? Their advice would help...... Simply refit the new 1 and follow the instructions in reverse.

In reality, lots of silicone, or washing up liquid, big physical push, and a liberal dose of swearing.

 

[dishman]

Do you remember the old style haynes manuals? Their advice would help...... Simply refit the new 1 and follow the instructions in reverse.

In reality, lots of silicone, or washing up liquid, big physical push, and a liberal dose of swearing.

Similar to that video I posted.

I initially thought, I'll see how the guy in the video managed....and of course.....there is a cut between him taking the old one out and the new one being fitted. Very helpful....

I did consider taking the old washer off and putting it on the new one, but.....it looks very worn and it was already weeping. Also, I need to put the old sensor back on if I really can't get the new one to fit.

Washing up liquid sounds like a solid idea! I will just warm the washer/sensor end a bit too.

My only concern with all of this is that when I disconnected the sensor I did not get a -40c (or Fahrenheit equivalent) reading on the obd reader. That video suggests this should be the default when a sensor is not connected. Mine went to 60f or around there.

I did connect the new sensor, even if the thing isn't seated in, and it gave me an 83f reading which is certainly lower than the original 120f reading. I had also tried to start the car and run it for a bit (before I did any of this) so I imagine the coolant had a tiny bit of temp to it.

However, the caveat to that is that my OBD reader is as cheap as you can get, so maybe that is something.

 

[dishman]

Well, I tried warming it and using some washing up liquid, but it was a no go.

Although I had to abandon trying as it was dark and started spitting.

But, it didn't feel like it wanted to fit any more than it did before....

 

[dishman]

Update:

Turns out I am not going mad.

I decided to exclude the fact the part was...somehow wrong. I rang a few other parts suppliers and they confirmed the part number I had on my box matched the ford code for the part.

But, to triple check I rang another local company and got them to order the part in, and went with the old part, my new part so I could compare it with their part.

And what do you know, ....they are different.

New part on the left, the "wrong" part in the middle, and the old part on the right.

Visible differences are the washer is much smaller for a start, and it also has the same bevel end that the original part does. The one that does not fit has a flatter end.



Just tried to fit it now....and it went in perfect.

However, my only concern is that the cable has an issue as while the sensor reading is now lower. It's still not matching air temp.

When I removed the sensor it was not showing "open circuit" default of -40c.

I assume this suggests there could be a further wiring fault?

Could it be the end connector block giving some sort of shorted reading?

If it is the connector block....then....in theory....if I remove it and just have the two bare wires....and I get a open circuit reading, that would diagnose it as being the connector wouldn't it.

 

[Burnerman]

How is the car performing with the new sensor in place?
John

 

[dishman]

After replacing the sensor, it seemed to start better when I turned it over straight after fitting, on a single turn.

The issue is, once it turns over, it seems to behave for a good long while after for more test starts ( I assume because there is some temp there).

But, after being left overnight, and the drop in temperature, it required 3 attempts to turn over again. Although it seemed to perform better at doing it.

So I still think it is getting a bad reading from that wiring.

So, looking at this video.

Should I test each terminal of the two prong connector block with my multimeter. Negative lead on the negative terminal and probe with the positive.

He has the same issue but like the previous video his defaults to -40 as an open circuit. Mine does not.

 

[dishman]

This is another enormously helpful video.

Based on all the things he goes through, it seems like I have some kind of short, based on the fact I am getting a positive temp reading when the sensor is disconnected.

This seems to suggest I am getting a voltage of at least around 2.7V.

I need to confirm that with a multimeter, but it seems the most likely scenario.

Hopefully there is some sort of issue with the connector block as that would be the most easy repair.

 

[dishman]

Update:

So, managed to test with a multimeter today, it seems the reference voltage being supplied with the sensor disconnected is around 4.1 v.

This seems to suggest, and please correct me if I am wrong. That there is some kind of resistance on the circuit to the connector block.

This is what might be throwing he ECU baseline measurement off. Firstly it never registers as an open circuit (-40) when disconnected, and therefore the resistance in the circuit means it always assumes there is a bit of temp in the car when it is actually connected.

Could it be something as simple as a slightly dirty/corroded connection? Even though visually it looks fine.

 

[dishman]

Update:

Well, I thought the connection might need a clean, so bought some contact spray.

But, just before I used it, I checked the OBD IAT and ETC readings again, and they both seemed more more in-line with what I would expect on a cold engine.

So I disconnected the sensor connection....and what do you know.... -40!

So all fixed. Perhaps the ECU needed time to reset after getting new values from the new sensor.

Only issue is that another (unrelated) issue has presented itself in the mean time.

The climate control only blows warm air

I have put this down to the Heater Control Valve or the control panel, although more likely to be the former, which should be a relatively simple replacement.

What is the opinion on after-market parts?

The ford heater control valve seems to come in near £100.

Then there are a host of ebay versions starting at £10 upwards (which i assume are mostly crap)

Then there are the ones sold by things like Euro Car Parts et al. Ranging from £20 - £40 with brands I vaguely recognise like Ridex or ERA. Are there certain after-market part suppliers that have a better reputation?

 

[Mottie]

Probably all come from the same factory in China.

 

[Burnerman]

Absolutely notorious for failure, these things.......you should feel a significant temperature difference across the valve if it is shot.
Even some of the cheaper replacements have a 5 year warranty -yeah, right - so why not give it a try?
I seem to remember fitting Valeo valves on the early Fiestas but I don't know if they are still doing them.
John