Overheating

[Guest piddy]

Hello All.

I have a question regarding the connection of a Sierra heater unit.

I fitted the Sierra heater into my car in about October and it has been running lovely.

But after removing the engine and replacing it recently I have found today on the first run that the temperature gauge is showing in the red all the time, even with the electric fan running.

I have loosened the highest hose on the system to release any trapped air.

I may of connected the heater up the opposite way round than before.

1.Does the water flow both ways through the heater?

2.Or is it one-way traffic only?

3. Should the heater have to be run to purge the air from the system?

Any comments welcome.

Piddy.

[Guest Mr Pid]

Hi,

 

As far as i am aware, most matrix's dont realy mind if you run them either way, if it did have say a one way valve in it or something then it would build up loads of pressure and end up bursting the pipes.

 

The system itself should bleed itself up with no probs. The only other thing to check maybe would be the thermostat.

 

Are you sure you havent got a faulty guage/temp sender unit. If the engine actually overheats/overflows then it does sound like a plumbing problem otherwise it could be an eletrical fault.

 

Good luck

 

Stu

[Longboarder]

The heater hose on the exhaust manifold side of the engine is the return hose and must come from the upper connection of the two on the heater matrix or the heater will not be self bleeding. It is worth running the engine with the rad cap off after filling . You will see bubbles or the water level drop as the heater bleeds air. Keep topping up. Also make sure that you haven't done anything to make the engine run hot like retarding the ignition.

 

Nigel

[Guest piddy]

Hello.

I done some more tests today.

I dont think the dial can be telling the truth.

I ran the car with rad off to release any air,also I changed the pipes over on the heater just in case.

After doing two 15 mile trips yesterday and three five mile trips today,the rad has not kicked out any water which I believe it would have done if it was truly overheating.

Also I've notest that when I stop and sit in traffic the temperture dial goe's down and not up.

I therefore belive it must be the sender or dial in the instrument cluster.

doe's anyone know if these can be tested?

Piddy.

[Les Welsher]

Piddy.

I had something simular to that on my car. When the engine was hot the temp. gauge barely got above the cold mark and with the engine ticking over in traffic the needle used to move down to the bottom of the cold mark. I changed the temp. sender ( £7 odd from Mr. Ford, luckily I had my old one with me as there is a black dot one and a green dot one, for different gauges I presume ) now my needle sits smack in the middle of normal.

 

Les

 

Ps. I noticed that there is a Mr. Pid on this site, no relation I suppose

[Guest daveg]

Piddy

 

To test I would remove the sender from the radiator/block (I don't know where it is yet) and leave it connected to the loom. It will need an earth (I use croc clips) and immerse the sender in a scaupan (or tin) you should have a cold reading on the gauge.

 

Now heat the tin with a blow lamp (be careful!) and the guage should start to rise. Boiling point = 100 deg which should be in the red as max temp of water in the engine with the cap on is 110 deg.

 

Hope that helps...

 

Dave

[Guest piddy]

Hello.

Les.

Yes I've been down the sender road before there are more like twenty different temperture senders I tried to get a new sender when I put the engine in with no joy but managed to get one from the scappy that worked great. No Mr Pid is no relation not that I know of anyway.

 

Dave. cheers for that I'll do a bit of cooking one day this week to test it out.

Piddy

[Guest piddy]

Hello All.

Thanks for the help so far.

I've checked five senders and fitted the one that looked the closest IE it showed just below the red with water in pan starting to boil.and tested the gauge by earthing it and it made the needle go to maximum.

But on the next trip same again needle in red in about five minutes and stayed there. I cant see what else to check.everthing seems to work until the engine is running or hot.

Any ideas?

Piddy.

[Longboarder]

Hi piddy, did you actualy put in a different engine or is it the same one. If different do you know how it went before it got to you. Does your fuel guage do wierd things when the temp guage is acting up?- Possible panel earthing or voltage regulator problem.

You need to decide if this is an overheating problem or a wrong temp gauge reading problem. Try running the car on the drive for 20 minutes or so with the fan on and see if it boils. Plus see if there is variation in the readings with engine revs first at 1000 then at 2000.

Nigel

Edited May 3, 2003 by Longboarder

[Les Welsher]

Piddy,

the cooling system is pressurised which makes water boil at a higher temperature, I would fit a sender that showed about normal with the water in the pan starting to boil as long as the system is not actually boiling over when your driving.

 

Les

[Big Jim]

Right, stop buggering about with pans of water! You need to get the correct sender to match the GAUGES, not the engine, or car that it came from. RH was suppling clocks from the Escort mark 5, but anyway it's easy to find out on a 2B, the part number is on a bloody great sticker on the back of the clocks. Once you know what the part number is, go and ask uncle Henry's men to do a "where - used" on their computer, (If they are too thick to, then you'll just have to get them to surf through the models, Escort first) this will show which car that particular set of clocks were originally designed for, now get the sender that matches them.

 

If you are still having problems with the readings after that, it's your cooling system and not the clocks / sender that's at fault.

[Guest daveg]

Piddy

 

As Jim says, you could check the gauges-senders compatibility...Its correct that the pressure increase will increase the boiling point (that the whole reason for the pressure). I use a thermometer in the can while heating it, this is also the way to test the thermostat.

 

Normal running temperature is about 90 degrees, this should give a reading in the centre of the guage. You could stick a thermometer into the rad by removing the cap.

 

Dave

[Guest piddy]

Nigel.

No it's the same engine.

Fuel gauge is ok.

I'm sure it's not overheating I'bve done several 20-30 minute runs without loosing water.

Les.

I've tried fitting the sender that shows normal when the waters started to boil it shows just below normal when driving but drops when stationary.

Jim.

The clocks are from a Capri I know the sender has to match the dials. I brought a sender from ford last year when I fitted the engine but it didn't work cant remeber which way it showed now.

 

The way I feel there is some thing wrong that probaly isn't the sender because the needle drops when I stop in traffic ( it would normally go up)

 

Piddy.

[Longboarder]

If you're confident its electrical and not the sender you need to check voltage supply to the instrument voltage regulator, no less than 12.6 at tickover and 14 ish above this rpm. Output from volt regulator stable (at 10v I think) at 0-3000rpm and the same at the guage. Check and perhaps fit temporary good wires, batt to volt reg, sensor to gauge and guage to earth. Then see if its OK. The only reason I can think of for normal readings when driving but drop at idle is faulty volt reg or bad connection probably between volt reg and the gauge itself causing low stabilised volts reaching the gauge at low rpm. (But this is probably all b*ll**ks)

 

Nigel

[Big Jim]

You've got the wires arse-about-face on the gauge (technical term that!) the sender should be wired to the

- 'ive side of the gauge, it's easy to check, just take the wire off the sender, touch it to earth, and the gauge should go full scale up.

 

Thinking about it, the + ive feed to the various gauges should be "common" as all the senders are on the -ive side of any gauge. Is none of your other gauges misbehaving?