I need an answer on this quickly...the lesser half needs the car on Thursday to travel to London!![:)]
Now I've got that out of the way, the facts!
The engine warms to hot a little quicker than normal but doesn't overheat!
The upper pipe gets hot!!
The lower pipe gets warm!
The radiator is colder than a penguins' arse!
In traffic the fan cuts in but takes ages to cool.
The fan can continue for up to 10mins after I've turned off the engine.
I don't think its the thermostat, or water pump. They were replaced within the last year.
I think it's a blocked radiator, chances are that it's caked with limescale or something. Lots of tap water in its' history!!
How can I clean it out? Any good flush stuff about?
I only did the head gasket last Xmas, I don't want to have to do it again.[V]
I know it looks like I've answered my own question but any other thaughts / ideas would be welcome, if it's something else at least I won't have to rip the radiator out![:D][:)][8D]
PS It's the 16v!
Cold radiator, warm engine!! Please Help. Anyone?
Moderator: RichardW
It does sound like the radiator is clogged up, probably with limescale if you have been topping up with tap.
Try firstly draining the coolant and disconnecting the radiator hoses and flushing/reverse flushing with a hosepipe. This might dislodge some of the crud in there.I am afraid though that by this stage they are often beyond help and a new rad is the only way to go. If you are keen to avoid headgasket meltdown, don't mess about-just get a new one.
Try firstly draining the coolant and disconnecting the radiator hoses and flushing/reverse flushing with a hosepipe. This might dislodge some of the crud in there.I am afraid though that by this stage they are often beyond help and a new rad is the only way to go. If you are keen to avoid headgasket meltdown, don't mess about-just get a new one.
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by P 2501</i>
It does sound like the radiator is clogged up, probably with limescale if you have been topping up with tap.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Cheers for that! I've just been out looking for flush additives! Nothing industrial enough. It'll cost me £110 for a new rad.
It wasn't me that used tap water! The previous owner had, it caused a rotten cylinder head, blowing gasket, pipes leaking. He was an engineer, apparently.[:(!]
It does sound like the radiator is clogged up, probably with limescale if you have been topping up with tap.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Cheers for that! I've just been out looking for flush additives! Nothing industrial enough. It'll cost me £110 for a new rad.
It wasn't me that used tap water! The previous owner had, it caused a rotten cylinder head, blowing gasket, pipes leaking. He was an engineer, apparently.[:(!]
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Yes silting up and consequent failure of these valeo rads is so common i think there must be a design flaw in there somewhere. I have known of folk who change the coolant every other year with good quality coolant and distilled water and still have trouble. Seems to always be cold in the bottom two thirds as mentioned above, and/or failure around the base in the centre (like mine did). Not too expensive for a new one though.
Update :
Removed rad from car....[:(!][:0][V] Those little pipes weren't made for big hands!
Flushed it out, forwards, backwards, upside down, filled up, drained out...repeated several times.
Checked the flow in all directions and cleaned the expansion tank of brown gunk.
I then refitted it, a little silicon grease made reassembley pleasant, then refilled and bled system with coolant and mineral water mix.
Took the car for a drive, the temp still came up fairly quickly, got to around 90 on the gauge, then dropped to 80ish. So the thermostat works! It then spent most of the journey doing that, up down up down. So the thermostat and radiator seemed to work fine.
When I arrived home and parked I knew something was definately different, the fan hadn't come on and the temp wasn't climbing. I sat it at idle for nearly five minutes, revving occassionally to get the fan to come on.
It came on and then went off within a short while.
The most important thing was that the radiator itself was hot, all over.
Thanks for advice it could have been so much worse, £110 to be precise!![:D] I've got the 'V' festival to go to this weekend and that's my beer money.
Now, did I have my Tetanus recently???
Removed rad from car....[:(!][:0][V] Those little pipes weren't made for big hands!
Flushed it out, forwards, backwards, upside down, filled up, drained out...repeated several times.
Checked the flow in all directions and cleaned the expansion tank of brown gunk.
I then refitted it, a little silicon grease made reassembley pleasant, then refilled and bled system with coolant and mineral water mix.
Took the car for a drive, the temp still came up fairly quickly, got to around 90 on the gauge, then dropped to 80ish. So the thermostat works! It then spent most of the journey doing that, up down up down. So the thermostat and radiator seemed to work fine.
When I arrived home and parked I knew something was definately different, the fan hadn't come on and the temp wasn't climbing. I sat it at idle for nearly five minutes, revving occassionally to get the fan to come on.
It came on and then went off within a short while.
The most important thing was that the radiator itself was hot, all over.
Thanks for advice it could have been so much worse, £110 to be precise!![:D] I've got the 'V' festival to go to this weekend and that's my beer money.
Now, did I have my Tetanus recently???
Update 2 : ???
Took the car for a slightly longer drive around town. The temperature went a little higher and the fan cut in when stationary.
When I finally arrived home, the fan continued for some time.[V]
The centre portion of the radiator was cold where the fan blows through. And hot nearer the upper hose side. When the fan finally stopped the radiator started to get hot again. It was like a slow moving wave, that took about two minutes, moving from the hot side through to the expansion tank side. Then the entire radiator was very hot to the touch.
What is going on??
Is there air in the radiator? There was a lot of pressure at the release cap when the radiator was cold, trying to open it caused pressurised coolant loss! Once the whole radiator was hot the pressure cap could be released with no coolant spillage at all.
Any ideas anyone? [V][?][?]
Took the car for a slightly longer drive around town. The temperature went a little higher and the fan cut in when stationary.
When I finally arrived home, the fan continued for some time.[V]
The centre portion of the radiator was cold where the fan blows through. And hot nearer the upper hose side. When the fan finally stopped the radiator started to get hot again. It was like a slow moving wave, that took about two minutes, moving from the hot side through to the expansion tank side. Then the entire radiator was very hot to the touch.
What is going on??
Is there air in the radiator? There was a lot of pressure at the release cap when the radiator was cold, trying to open it caused pressurised coolant loss! Once the whole radiator was hot the pressure cap could be released with no coolant spillage at all.
Any ideas anyone? [V][?][?]
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Paulxmski</i>
Possibly getting crud coming through from the block as temp rises might need to flush block through also. I guess you did add water slowly while running engine over with filler cap off til thermost opened to avoid trapped air of course.
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No![:I][?] I just filled with all bleed points opened, using a header bottle. Once bubble free coolant flowed I closed the bleed points in sequence, lowest to highest.
How does running the engine, whilst filling with coolant, help?
Possibly getting crud coming through from the block as temp rises might need to flush block through also. I guess you did add water slowly while running engine over with filler cap off til thermost opened to avoid trapped air of course.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
No![:I][?] I just filled with all bleed points opened, using a header bottle. Once bubble free coolant flowed I closed the bleed points in sequence, lowest to highest.
How does running the engine, whilst filling with coolant, help?
Update 3 : ???????
The radiator has been hot now for 3 journeys!
The temperature has been a little less than predictable. The car warms up, the thermostat opens and the temp drops. It does this for a while, up and down, until the oil temp is up.
Then it starts playing funny buggers....sometimes in traffic the temperature is fine, other times it rises sharply and the fan cuts in. I then get moving again but the temp stays high, it then suddenly drops to around 85 / 90 on the gauge.
Could the thermostat be faulty??
The temperature gauge is an indication of engine core temp isn't it?
So if the temp rises but the radiator isn't blocked and the thermostat stays shut, well, have I answered it for myself?
Or is it the water pump? Can't think of a theory behind that.
The radiator has been hot now for 3 journeys!
The temperature has been a little less than predictable. The car warms up, the thermostat opens and the temp drops. It does this for a while, up and down, until the oil temp is up.
Then it starts playing funny buggers....sometimes in traffic the temperature is fine, other times it rises sharply and the fan cuts in. I then get moving again but the temp stays high, it then suddenly drops to around 85 / 90 on the gauge.
Could the thermostat be faulty??
The temperature gauge is an indication of engine core temp isn't it?
So if the temp rises but the radiator isn't blocked and the thermostat stays shut, well, have I answered it for myself?
Or is it the water pump? Can't think of a theory behind that.
I would possibly have a look at the rad fan thermostat switch. Just had similar problems with a fluctuating coolant temp on a 16v.
Its most probably the cut in and out settings are faulty.
Removed unit and tested. Found cut-in temp was about 96C and the cut-out was around 78C, causing engine thermostat to be constantly opening and closing every time cooling fan came on.
Temp gauge does indicate core temp which about 8-12 degs above rad temps.
If faulty, would recommend fitting another new engine thermostat.
Shouldn't soak-up to much beer money.
Peter
Its most probably the cut in and out settings are faulty.
Removed unit and tested. Found cut-in temp was about 96C and the cut-out was around 78C, causing engine thermostat to be constantly opening and closing every time cooling fan came on.
Temp gauge does indicate core temp which about 8-12 degs above rad temps.
If faulty, would recommend fitting another new engine thermostat.
Shouldn't soak-up to much beer money.
Peter
To some degree ive had a similar problem for some time, fans coming on, slightly higer temp. I took it to a garage in Gloucester who found nothing wrong, he assured me there was not a problem, even changed the thermostat, the rad was changed 6 months earlier. I suppose in miles terms ive done 10,000 with it and nothing serious has happened. One prob that happened at the same time was the engine STOP light and high temp came on together, but it was winter and maybe damp in the bitron unit, stopped after a spray of WD40.
Crossed my mind it might be the water pump losing it fins and ability to pump the water round the engine and rad. If it had not been for the STOP lamp i suppose I would have driven aroundwithout even knowing,which was solved by a spray of WD40.
Crossed my mind it might be the water pump losing it fins and ability to pump the water round the engine and rad. If it had not been for the STOP lamp i suppose I would have driven aroundwithout even knowing,which was solved by a spray of WD40.
Pete
Well worth taking out the rad thermo switch and testing to confirm temp settings.
With my recent running temp problems. Bench tested 2 old units with about 50-75k. One unit the fan cut-in temp was 96C (plus 10 degs -- around warning light stage, 105ish) and on another, the cut-out point was right down to 72C,(82C at thermostat) so consequently the engine stat was nearly closed. This would cause the engine temp to rise above normal when accelerating while the thermostat was reacting to the fully open position, as there's about 10degs temp difference between thermostat and thermo switch positions. A similar pointer, as you mentioned, warning lights would show and then disappear once the fans cut in.
Also with some new ones, temp settings can be slightly wayward to the listed range.
Now always test before fitting new.
R
Peter
Well worth taking out the rad thermo switch and testing to confirm temp settings.
With my recent running temp problems. Bench tested 2 old units with about 50-75k. One unit the fan cut-in temp was 96C (plus 10 degs -- around warning light stage, 105ish) and on another, the cut-out point was right down to 72C,(82C at thermostat) so consequently the engine stat was nearly closed. This would cause the engine temp to rise above normal when accelerating while the thermostat was reacting to the fully open position, as there's about 10degs temp difference between thermostat and thermo switch positions. A similar pointer, as you mentioned, warning lights would show and then disappear once the fans cut in.
Also with some new ones, temp settings can be slightly wayward to the listed range.
Now always test before fitting new.
R
Peter