Temperature shot to 110

rashmore · Unread post by **rashmore** » 15 Feb 2005, 23:42

Completing fluid level check at lunch, released rad cap and met with hiss (last used 4 hrs prior) Figured not a problem. Coolant level OK.
Driving home, 10 mins into journey, blowers blowing cold air, look at temp gauge - it at 110, pull over into layby, temperature dropping straight away - engine running, no fans whirring. turn off engine and carefully release rad cap. fluid level a little less than before.
As driving home notice that temp gauge goes down when turn right and up when turn left ? blowers now blowing hot air.
Arrive at parents, let cool, open rad cap, level right at base of rad. top up fluid, start up with cap off, fluid drops about an inch and settles. can't see any oil. check oil cap, black as normal, no brown emulsion. no visible water leaks either.
Just got home, so will allow to cool and check level again (once feet warm up...) and interior to see if floor damp - heater matrix
Any thoughts what this may be, other items to check ? car done 46k miles FYI
Cheers

oscarloco · Unread post by **oscarloco** » 16 Feb 2005, 00:37

Faulty thermostat?

PJLarge · Unread post by **PJLarge** » 16 Feb 2005, 01:15

Sounds like onset of HGF to me. My old Volcane was pressurising the rad for a few weeks before it gave up completely. Some days the coolant would stay the same level, other days it would disappear without trace. No mayo in the oil or coolant, my temp stayed constant but the heaters were blowing random hot / cold combinations depending on the orientation of the car. Probably not what you wanted to hear [}:)] Damn French cars [:D]
Phil.

rashmore · Unread post by **rashmore** » 16 Feb 2005, 01:31

Hmmm, not quite what i wanted to hear... curses.
What other symptoms may indicate this is about to happen ? more importantly how do i know if it has happened ?
Presumably HG replacement will not be a straight forward job ?

oscarloco · Unread post by **oscarloco** » 16 Feb 2005, 02:04

If you rev your engine with the rad cap off and see many bubbles forming then you got a Head Gasket gone to heaven.

rashmore · Unread post by **rashmore** » 16 Feb 2005, 02:23

Tried revving engine with cap off, level went down a bit,didn't see any bubbles but then coolant started to gush out of a pipe within expansion chamber agitating surface of coolant( i think - i myself was frozen by this stage so called it a night) will try again when daylight...mechanic up the road reckons either dodgy thermostat, or radiator may be on its way out - he reckons not usually get many HG failures on this engine ? but not sure why temp gauge in car fluctuating when go around corners. will price up new thermosat and rad. looking in haynes book of half truths to see what involved in HG replacement

jeremy · Unread post by **jeremy** » 16 Feb 2005, 03:58

Rad will either leak or block. Blockage takes place from the bottom up so get the car hot - ie fan operating and feel the temperature - should be warm all over - cold bottom - may be able to flush it - best to take it out to do it. Having said that its by no means routine and when I replaced the rad on my TD BX at 190,000 (it leaked slightly) it was spotless inside.)
The fan switch is usually in the 'cold'end of the rad which is the end furthest from the hose from the top of the engine (ie usually off side of car) and a distance from the temperature gauge pickup.
Are the hoses sound - there have been cases of bottom hoses collapsing and blocking under certain circumstances.
jeremy

P 2501 · Unread post by **P 2501** » 16 Feb 2005, 12:55

Air lock? Could explain the intermittant hot/cold air from the blowers,and also possibly the temp gauge moving when going round corners, but that sounds a bit far off maybe.
Have you tried bleeding the system of air?
HG test - take the rad cap off in the morning when engine cold - listen for hiss.if not,replace cap and run the engine for 30 secs (with rad cap on) then switch off and remove cap,again listening for a hiss. If pressure has built up in 30 secs from stone cold you can be pretty certain its the HG.
These engines rarely blow the gasket oil-water almost always cylinder - water.

rashmore · Unread post by **rashmore** » 16 Feb 2005, 14:02

Checked fluid level this morning, slight hiss and a gurgle. fluid level dropped considerably. Topped up with fresh mixture. Now at work, (25 mile journey) let cool for 5, open cap, slight hiss, but coolant level at top as per last top up. checked hoses before undo cap, they seem ok, top hose into rad not hard. temp gauge still change position with direction
Thinking maybe radiator is leaking. There has been odd occasion when see the odd puff of steam from the front, but upon inspection unable to see where coming from, so figured just burning off damp air , as coolant level not changed.
I've not bled system on this car, (and bro has haynes) is there a good/bad way. I gather i need to make a header tank, seal this to rad opening, open all bleed nipples (turn heating to full, top up, start up, keep topping up as fluid comes out of each nipple, close nipples in turn - highest first etc.) seal system run and check.
How many nipples are there ? and what height does header have to be ?
Now to find prices for radiator - any recs on brand ?
Cheers

Danbloke · Unread post by **Danbloke** » 16 Feb 2005, 14:41

On my volcane (petrol) there are three bleed nipples.
1 on the end of a small tube next to the brake fluid reservoir
2 on top of the thermostat housing
3 on the top of the radiator (opposite end to the filler cap)
I think the header just has to be higher than the bleed nipple at 1, and I don't think turning up the heating helps. There isn't a heater valve just a flap that stops air going through the heater.
Hope that helps.

jack.dempsey · Unread post by **jack.dempsey** » 16 Feb 2005, 14:54

After running and then cooling for a while, is your 'slight hiss' an ingoing or outgoing one ?

rashmore · Unread post by **rashmore** » 16 Feb 2005, 15:07

Good question.
When i first checked fluid level at lunch it was defo outgoing as sprayed small amount of coolant everywhere. not sure other times, maybe in as got a gurgle as fluid moved down expansion pipe, but could have been out, as pressure release fluid moved down to fill the void ?.
Got to go out at lunch so will dry area and listen /feel when release cap. also but rad vent pipe into a pop bottle to catch any excess fluid if being pushed out that way.
What would each indicate ?

rashmore · Unread post by **rashmore** » 16 Feb 2005, 18:24

Topped up level. went out for a run, got it nice and hot, fans kicked in. blows warm air thro vents but temp gauge fluctuates with changes in direction. let cool for 10 checked level, gone down a bit. nothing in expansion catchment pop bottle. did hiss upon release but couldn't decide if ingoing or outgoing - didn't feel a draft, nor any fluid spray out.
will look at draining, flushing and changing thermostat at weekend.
what controls the temp gauge in the dash ?

P 2501 · Unread post by **P 2501** » 16 Feb 2005, 20:42

Unless you have a faulty rad cap then you won't get an inrush of air (indicating the presence of a vacuum). This is because rad caps have a one way valve in them that allows the system to suck in air as the engine cools down.If there was no valve (or it was somehow stuck) then a slight vacuum would be created and this could suck in and collapse hoses - not good. If you are concerned about your cap, they are a cheap part around a fiver from motor factors.

rashmore · Unread post by **rashmore** » 28 Feb 2005, 16:16

Update - Created a header tank and bled the system last weekend, came out of radiator straight away, then by thermostat and then after some air out of the top nipple.
Left header tank in situ and waited for fans to kick in. Some rather large bubbles came through, coolant expanded considerably, so siphoned off. Every now and then tiny bubbles come through (like fizzy pop). Eventually fans came on (was freezing), so drain header and replace cap. Leave and check level. All ok
Check throughout week, level dropped slightly but not alarmingly, always a hiss when open – always left to cool. Nothing in expansion catchment pop bottle. Top up yesterday to mark on tank (easier to monitor)
Whilst having spirited drive in this am, puff of steam at front end by bonnet grill when pause at a junction, jump out but unable to see again. Thinking radiator is going as done this occasionally before.
Plus when draining header tank found a piece of red rubbery type stuff that looked like plastic gasket, so maybe it has been leaking before on previous owner and this is the result of a temporary repair – what does ‘rad weld’ go like ? or could it have been plastic gasket ?.
If coolant level remain reasonably constant will leave as is till warmer then contemplate rad change – so hopefully not HG

Sound like a plan ? (assuming passes mot ok tonight lol)