Hi all.

I have a little problem with my car.
I left it idling on the drive because I have a problem with not getting any hot air out the vents.
It was idling for about 10-15 mins, the cooling fan kicked in eventually as the temperature rose, it never hit the red.
Then after I turned off the engine, the expansion tank was hissing, steam was coming out of it (I also have a new cap on it) and the water level rose about 15mm above the maximum level.

Car is a mk4 fiesta, 1.25.

Any ideas on what the problem could be?

Cheers, Jason

 

Sounds like a water circulation problem, I'd be looking at the water pump!

 

heator control valve gets my vote

 

I've had this problem a little while, and I replaced the water pump with a brand new one about 2 weeks ago. And its still happening.

 

Would that also cause the overheating problems / steam coming out the expansion tank?

 

You deffo have a circulation issue. You may have a blocked heater matix or control valve. I think water pumps either work or don't - you need to start pulling pipes off at various places to chaeck for flow with the engine running - DO NOT DO THIS ON A HOT ENGINE.

You can reverse the flow on the heater matrix and even put a hose pipe on it for flow.

Are you sure you are not getting pressure in the system from potential head gasket failure? This would cause what appears to be boiling. Is there any air bubbles present in the expansion tank when running?

 

can do will cause all kind of probs

 

There are no bubbles in the expansion tank, no.

Is there an easy way to check to see if the head gasket is going?

Cheers.

 

something simple as blocked rad cake up at the rad exit???

 

you need a sniff test done for the headgasket has failed and allowing combustion gases into the coolant system replace the heater control valve and i reckon all will be good

 

How would I check that?
Remove the radiator?

 

Cheers, I did small tests before thinking I had a head gasket problem.
I checked the exhuast, no white smoke coming out, or any sweet smells, no coolant in teh oil or on the lid, no loss of coolant. So ruled that out, but obviously need specific tools for that.

Last thing I want to do it throw even more money at my car after other work i've done, and for it not to be fixed.

 

....run a hose pipe through it! (hose off each end)

 

I don't think it is head gasket. I tend to agree with Mechanic - heater control valve but could also be the thermostat or blocked heater matrix.

 

Ok, will give that a try.

 

So if the heater matrix is blocked, or the thermostat is gone, will that cause the engine to overheat like im experiencing?

It wont overheat if I'm drving at all, only if I sit still in traffic, or just sat idling for a while it will start to overheat, but it never goes into the red, never has, the fan kicks in way before it even gets close to the red.

Cheers for all your help so far.

 

do you bleed the system correctly when you fitted a new water pump?

 

Well I bled it how I normally would when I replaced the coolant, is that right or wrong?

 

Just read something on the internet...


Can a thermostat increase fuel consumption if it has gone bad?

 

Yes, if your engine is running cold it may require additional fuel as it might be triggering cold start and also the engine is not at its optimum thermal operating efficiency.

 

That makes sense, thank you.
Off to get a new thermostat tomorrow then, and maybe a (coolant) temperature sensor.

Do I need to get a new housing or can I use the old one?

 

old housing is fine

 

Thanks for your help everyone.
Ill get these parts tomorrow and hopefully have time to fit them tomorrow and i'll let you all know how I get on with it.

Cheers Guys

 

I just replaced my thermostat and coolant temperature sensor because I was having some issues of the engine overheating, and also not being able to get hot air into the car.
The car would over heat when i've been driving then am sat still for 5 mins or more, the engine temperature would rise and then the cooling fan would kick in.

So now, I've replaced the 2 parts, and refilled with coolant, now I don't know what this problem is.
I started the car and let it idle for a while, while keeping an eye on the coolant level.
Then all of a sudden steam starts coming out of the fill hole.
Even with the cap on, steam pushes its way out. The engine heats up to almost red, which i've never had before and then the cooling fan kicks in, which is also very late compared to normal. But it doesnt make any difference at all! The temperature just keeps on rising. So I turned the engine off for a moment, then slowly started undoing the cap letting all the steam and build up of pressure out.
If I do it too fast, the coolant just boils over the top.

Will a faulty heater control valve cause it to over heat or anything?
The right hand pipe that goes into the hcv is hot, but all the others are cold.

Also, the pipe that goes into the right hand side of the expansion tank, then to the right side of the engine block, when I turn the engine off, it bubbles alot, what does this mean?

I really don't know what I'm doing wrong.

Please help!

 

yes the heater control valve can cause all the problemms you are saying

 

have you checked the heater matrix to see if its blocked?

 

Have you ever thought about banging your head against a wall Doug, its just as painful mate

Steve

 

Just bypass the heater control valve for now to rule that out and be careful how much coolant you put in as it's surprising how much is held in the engine you don't know about,I've had this happen loads of times.
Fords in general are pretty forgiving when it comes to bleeding etc,google e36 coolant issues to see a total nightmare of a car to bleed!!!
Sometimes it can help to put slightly less coolant in,run it up to temp,knock the engine off,remove the coolant cap when cold enough and leave it off overnight to let any bubbles escape.
Oh another one I've thought of on them is to take the small pipe that leads back to the expansion tank at the tank and bleed it that way.
Heater valves are hugely common failures on these,I've got one to do on the ka when I get back.

 

ive never known a siezed heater valve cause overheating, but in theory it could, it sounds to me like you have an air lock due to not bleeding the cooling system correctley please explain how you have bled it when working on it and ill tell you if you are correct or not

 

lol i can see why he has gone for the stat could of been that

 

i used to hate bleeding them till i got my vacuum bleeder from snap on before that it was a nightmare lol used to just about manage by lifting just the front of the car in the air about 3 foot to make the rad cap the highest point in the system lol

 

i have matey have it cause over heating

 

i got one of them now as the insignia and new astras are a bitch to bleed specially the xer engines

 

brilliant bit of kit aint they

 

yeh mate there are excellent

 

Glad I'm not the only one who hates bleeding my e36!!!!
I have found that putting about 2 litres less than required initially really helps,as it takes fucking 11.5 litres anyway so there always seems to be some left in the system somewhere or other.
I'll look into these pressure bleeders,sound good.
A positive car/van to bleed is a Nissan vanette/serena,big rad with cap,big expansion tank next to it,header tank up high and bleed valves right at the highest point of the system,it pretty much does it alone but if you get stuck there's loads of easy access areas.
I've never seen mine go over 1/4 on the gauge with boiling heaters.

 

Thanks for all your help so far.

I'll check the heater matrix tomorrow and see how that goes.
Also now, I let the engine rest for a few mins, the coolant in the expansion tank dropped so I topped it back up and let it run again.
The engine heats up still, not as quickly as it did, but still heats up then the fan kicks in and cools it back down again. There is pressure building in the system still and stays there when its hot.

And also, now all the pipes to the heater control valve are hot.

So, after emptying the system.
I slowly filled it back up with the coolant, upto the max line and when it stayed there, I started the engine and let it run for a bit, keeping it topped up. Thats pretty much it.

I replaced the lid and left the engine running, the coolant level dropped so I slowly undone the lid and topped up some more.

I also held onto the accelerator cable a bit to increase the revs a bit, and that also helped bleed the system, I saw some air coming up through the system, so topped up again.

Thats pretty much it.
I left it to idle for 10 mins, the fan kicked in once or twice, and then i switched off the engine. The coolant level in the expansion tank I noticed was rising up a bit, maybe 10mm then falling again, continuously.

Thats all I did apart from drive it round the block.

I bet this is all wrong, it would be my luck

Cheers

 

the way i always do fords is this,
fill to max
start up and hold about 2000rpm till fan kicks in, this is with coolant cap off
when fan has shut off top up tank to max if neccesary
job done

unless its a early ka as that would also include letting it spew boiling water out of header tank until fan kicks in then topping up lol

 

I'm getting there with it, so i'm hoping it is just the heater maxtrix.

I'll hopefully have a look at that tomorrow.

Cheers all.

 

Ok, so the level in the expansion tank went down again and I will top it up after I have finished.
I removed the heater control valve and heater matrix, which was full of coolant, probably from when I first changed it.
The inlet and outlet connectors on the heater control valve literally just snapped off, I squeezed the end of the pipe with just my fingers and it all just crumbled and fell out.
I'm going to get a new heater control valve this afternoon and hopeffully that will sort out my heating problem.

The engine temperature still rises, if I drive for a while, the temperature gauge will happily sit right in the middle of the gauge.
If I stop for a few mins, the temperature starts slowly rising and then there is a point when I start to smell the coolant in side the car.

Really getting annoying.