why is my car heater not working??

[Admiral208]

not sure if anyone will know the answer but my car heater has stopped working, and in this weather, its a bit annoying. Does anyone have an idea why its not working?

 

Symptoms:

- it used to work until about 2 months ago.

- if im driving along normally, the engine temperature gauge doesn't move and stays at 0 (cold)

- If I leave the car running, but stationery, the engine temperature gauge will move to normal operating temp and the heater works.

- If I then drive away, the gauge slowly moves back to cold and so does the heater.

 

I have a good idea what I think it is but don't want to say I case i influence anyone in a Derren Brown sort of subliminal messaging type way.

 

What is the problem. Anyone?

 

James

[Chris_in_notts]

thermostat is knackered

[kili]

Yeah i agree with Chris, sounds like your thermostat is Edited December 15, 2010 by vikpaw
LANGUAGE

[Admiral208]

interesting. That was what i thought. now my problem is that to replace my thermostat, which cost me about £10 to buy, I have to remove air filter, cam belt, timing belt, lots of different covers. PITA!!

[Chris_in_notts]

what car is it?

[Admiral208]

Mk3 Astra

[Chris_in_notts]

seems strange having to remove the timing belt to replace the stat normally a case of removing the housing normally located near one of the large radiator hoses changing the stats over and topping up the water, if you have to drop the timing belt off you may aswell replace that at the same time.

[Admiral208]

yeah. Thats what I thought. When it stopped working, I went and bought a replacement, then got the haynes manual out. Wrong way round! its an absolute ball ache. the stat is located just behind the timing belt cover. Im not particularly confident with car repairs. Do you know if this is an easy (ish) job? Any tips?

[Chris_in_notts]

just done abit of research yes you will need to remove all covers and remove belts and the power steering pump! jesus lol if you can swing spanners it shouldn't be to hard except making sure the timing marks are in line when putting the belt back people would suggest locking them but id just mark them with tippex before you start and make sure they are in line before you start it up.

[Admiral208]

thanks mate. where did you look to find that out?

[Chris_in_notts]

just did a quick google search didnt find any how2's just someone asking the same question

 

Astra 8V Thermostat

[Admiral208]

Ok. Do you think this would be expensive if i took it to the garage?

[Sirbendy]

Relax!

 

As a MK3 and MK4 owner, both with this bloody silly design, you've got an answer.

 

Requires:

 

RENAULT 4, 5, 9, 11, 18, 19, 21, 25 - THERMOSTAT on eBay (end time 19-Dec-10 13:43:14 GMT)

 

1 of. And 2 hose clips, pennies from a motor factors.

 

Simply let the engine cool down, unfasten the clip that hold your top radiator hose to the water pump outlet. Disconnect the hose. It's a git if it's not been moved in a while. Pull, swear, it'll come off.

 

Once it's off, pop the thermostat above in the hose, keeping it as straight as possible. You want the sticking out bit to point towards the engine/pump, as this is the wax pellet that senses the temperature.

 

Push both clips over the hose, push it firmly back onto the pump outlet. Fasten up one clip to hold that hose in the pump. Clip #2 - feel the pipe to locate the flat surface of the 'stat, and put the clip round there to hold the stat tightly in the hose.

 

Kick it in the guts, let it warm up and top up your coolant, job done.

 

The person who designed the X/C/Z series 8 valvers needs a gun to the head for the design...

 

Mine runs at 85-92 all day long now.

[Sirbendy]

Ok. Do you think this would be expensive if i took it to the garage?

 

Gods, don't bother...they'll look at you funny for a start. To get the "normal" stat replaced involves covers off, timing belt off etc. It would cost a bit, yes.

 

Trust me. The solution I've posted (and done twice) takes no longer than 30 minutes and is as easy as wiring a plug...

[michael2k6]

That's not a bad idea. Obviously yout stat is stuck open so a solution is to put another stat in elswhere, between the engine and the inlet to the radiator (by the sounds you've been advised here to put it in the top hose which is fine).

Of course if it were stuck shut you'd be rather screwed with that design! That's rubbish. I'm used to working on mini's. 3 bolts on the cylinder head (or nuts on studs) and it whips right out!

[Sirbendy]

aye, Vx 16 valvers are like that. It's only the 8 valvers (C14/16SE, Z16SE, X16SZ/SZR) that seem to have it in the daft place.

[Admiral208]

Sirbendy. I have had a bit of a shocker today...

 

after reading your post, i decided that i was going to buy the thermostat from a local car parts place rather than wait a couple of days for eBay. I went in and explained what i was doing (which got a few funny looks), told them the part i wanted and they got it for me. Except the thermostat that they sold me (which was for the same model cars as on eBay) was different to the one you suggested on eBay and it didn't fit, it was too wide (by about 2-3mm). So I went to buy the one you suggested on ebay and now the auction has ended and do you think I can find another one the same... NO!

 

Where can I get one from? I thought I was going to have some heat for the journey into work this week but it looks like ill have to wait now.

[Sirbendy]

do you still have the 'stat?

 

You were trying to put the stat in the hose end nearest the engine, yes? It should fit, maybe a bit snug, but it should be fine.

 

Get a jug of boiling water, or a hairdryer or similar heat source and stick the end of the hose in it/use it to heat the hose itself up nice and toasty..cold hoses won't flex, hot hoses tend to expand a bit...and try getting it in there then. Maybe a bit of fairy liquid lubrication on the 'stat might help it slip in. Ooer.

 

What size is your engine? (although IIRC they all use the same hoses!).

 

Option 2 is to put cardboard sheets in front of your radiator and block off the airflow..not as good, but workable.

 

Told you they'd look at you funny.. I've had the EGR valve fail twice on mine at £80 a pop. Now my EGR valve is bolted to the OUTSIDE of the engine, clicking in the air. In it's place is a nice CNC cut blanking plate. Problem solved forever, with better emissions on the MOT! That always gets a grin from the testers.."we see what you did there"..

[Admiral208]

nice. Ive managed to find one. After a bit of research, i found that I needed to buy a Firstline stat, not a Quinten Hazell stat. There is a difference of 3.5mm in diameter between the 2 which should just do the trick.

 

Told you they'd look at you funny.. I've had the EGR valve fail twice on mine at £80 a pop. Now my EGR valve is bolted to the OUTSIDE of the engine, clicking in the air. In it's place is a nice CNC cut blanking plate. Problem solved forever, with better emissions on the MOT! That always gets a grin from the testers.."we see what you did there"..

 

Good work! just like Dick Strawbridge. you should be on scapheap challege!

[Admiral208]

ok people,

 

I put in the new stat over the xmas break, took me about 10 minutes. I get a lovely hot car now but the temperature gauge goes up to 100 degrees and then goes back to normal (90 degrees) then goes back up to 100 and then it goes back to about 95-97 degrees where it stays. Why doesn't it go back to normal operating temperature? any ideas anyone?? the new stat is rated at 89 degrees.

[Sirbendy]

aye, normal. I remember taking the Z16SE for the inaugural thraping down the new A5 at speed, and looking at the gauge followed by "oh***t! TOO hot. WHOA baby..".

 

First one was an airlock..heh. Forgot that.

 

Mine now goes to 100 then drops, same as yours. Only does it once per run, mind you. Sits lower than yours too..about 85-90. I have an automatic though, so I get a bigger radiator with an oil cooler, not sure if that has any impact.

 

"normal" temp..not really sure. It ramps up because the thermostat has moved into a hose, and there's a delay imposed now before the wax stat opens up, so the gauge sender will see higher temps ramping up, then the wax stat opens, readings drop..however, I strongly suspect that the influx of cooler water then shuts the stat down a bit, so it may "bounce" once or twice as the entire coolant amount warms up to the same level.

 

When was the system last flushed? Mine is apparently due a service in 80 days according to my laptop/the ECU (got to love ecoflex servicing). After this weather, that'll be a wheelramps jobbie. Engine oil, coolant, oil and air filter, plug check, and autobox drain and refill will be carried out. I'll do a full flush of the cooling system as part of that - I know I've got a ruddy air bubble in the heater matrix ATM..I can hear it.

[Admiral208]

First one was an airlock..heh. Forgot that.

 

Sits lower than yours too..about 85-90.

 

I had a service only a few months ago. Ive read that there might be an air lock in the system somewhere. how can I bleed the radiator? I would be happy if mine sat at 90, its just a bit too high for my liking at the mo.

[3s-gtech]

^^And one always snaps on Minis... Edited January 5, 2011 by 3s-gtech

[michael2k6]

You're dam right it does then you have to weld a nut to it to wind it out. Or even worse, what i managed last week, bottomed a stud out and cracked the head. Had to do some interesting welding and retapping. But it's allll ok now. But i sat the ruddy cylinder head on its face and snapped the spade off the effin temp sender. So now i need a new one. Grrr.

Glad you're getting somewhere Admiral. Try getting the same size stat which opens earlier, at a lower temperature, if it stays the same. Do these also have an electric fan? It should be cutting in about 92 if it does. Also, unleaded engines run most economically at about 85 - 90 so thats not such a bad temp. But be careful while it's running so hot, dont do the gasket. No worse than it constantly running cold though as the oil wont be getting up to temp in those circumstances.

[Sirbendy]

Vx fans don't cut in until approx 95 deg. Certainly the MK4 doesn't. Mind you, my laptop couldn't communicate with the cooling system control module 2 days ago..hah.

 

Problem with the lower temp stat is that they're hard to find. It's a Renault one in a Vx engine, and the old Renault lumps pretty much used the same stat throughout.

 

The Systems are usually self-bleeding, TBH. I fill mine, close the lid, run it till the fans cut in with the heater set to max heat, then turn off. Wait for it to cool a bit, open the tank and top up if needed. Possibly squeezing the top hose may assist.

 

I recall doing a Mitsu Shogun V6..that had a MASSIVE airlock after a refill..when it let that go it was like Vesuvius going off.

 

Just dropped my Astra into a local garage who kindly booked her in for an emergency MOT at 9.30, after I realised mine had expired on the 4th..*cough*. Reasonably confident - all bulbs work, all ancillaries work, all ECUs check out fine, no DTCs logged, nothing outside of normal operating range in any readout, including pre and post CAT sensors..lets see, shall we..