How to diagnose waterpump death (now coolant loss)

batwad · Post by **batwad** » 22 Aug 2004, 00:44

sassenfrassenrassen
My car's been intermittently overheating of late and today went past the dreaded 110 mark. I was suprised the STOP light didn't come on though; at what temp does that happen? It's also been losing coolant at a rate of about a pint a week, but with no obvious source of leak. Naturally I've been topping up.
When I hopped out of the car I found the fans going ten to the dozen, but the whole radiator was cold. Top hose was scalding (thermostat replaced about six months ago), as was the immediate area around the rad thermoswitch. Bottom hose was cold.
Could this be a dead water pump or blocked radiator? I intend to flush the entire system tomorrow and was wondering if there's any way of testing the water pump for functionality.
Also, any classic locations from which coolant is lost?

np · Post by np » 22 Aug 2004, 02:37

I think if the water pump had packed up,you`d really know about it.I have seen a few fins on the water pump break off though,through old age.This happend to a couple of fork lift trucks at work.How many miles has it done,petrol or td?If it were me,i would give the whole system a good flush through,replace the thermo stat,& get a new expansion cap.Its not dear.My Xantia used to lose about a litre of water with no trace,until i found it was coming out the cap.They only cost about £5,& that cured it.
Peugeot/Citroen share the same engines along with loads of other stuff.My warning light has only come on once,towing our caravan up a long climb in France,outside temp was 40c.The water temp went above 110c,off the scale,proberly about 113c.Then the orange light came on,but not the red stop light.

Stuart McB · Post by **Stuart McB** » 22 Aug 2004, 22:41

If the top and bottom hoses are cold wouldn't this mean the thermostat wasn't opening? I think that there have been cases of new stats not opening enough. Have a search of the Citroen site for thermostat. As for water pump failer, usually they make a right old noise when there about to let go. They also tend to start leaking. I'd go for the rad cap and stat my self and also give a good back flush.

P 2501 · Post by **P 2501** » 23 Aug 2004, 13:42

I think the stop light comes on at 115 c. From what you say it sounds like a blocked rad not the water pump, give it a good flushing and see what happens. I would be concerned about the loss of coolant though a pint a week is a fair amount to be using.Headgasket?

batwad · Post by **batwad** » 24 Aug 2004, 14:34

Okay, so I flushed the rad on Sunday morning and nothing unsurprising came out so I don't think it's blocked. From the sounds of it, the water pump is okay. What's really troubling me is this coolant loss, which seems to be the cause of the overheating. When I started opening up the system in order to empty it for flushing there was no coolant at the top bleed point, none by the fuel filter screw and none at the radiator. Looks like the loss is worse than I thought. How I haven't cooked the engine I don't know...
I bought a new radiator cap to see if that stops the loss, but if it doesn't I'm at a bit of a loss as to where it's all going. I don't think the head gasket has gone as the coolant was clean and mayo-free and there was no sign of bubbles in the header tank upon refilling. I'll try the stone-cold-30-second-test tomorrow morning to confirm.

P 2501 · Post by **P 2501** » 24 Aug 2004, 15:31

This does sound a bit odd. I think i would check everywhere under the bonnet when the engine is warm to try and find this leak. It could be a pinhole leak on the back of a hose (that metal one on the back of the engine sometimes goes like that) or a small hole in the rad which only leaks under pressure.

Mosser · Post by **Mosser** » 25 Aug 2004, 04:26

sometimes the radiator can leak and slowly drip onto the cross member underneath where it just evaporates away without you ever seeing it,
Try filling the radiator to the brim and then put the expansion cap on then let the car warm up till the fans kick in then look for small tell tale signs of steam everywhere, it could even be inside in the heater matrix!!

batwad · Post by **batwad** » 25 Aug 2004, 13:26

I did the 30-second head gasket test before setting off today and it sounded okay. There was an ever-so-slight 'sigh' when I took the cap off, but nothing that sounded like a pressure build up. I'm not really sure how much of a hiss I was supposed to be looking out for though, is a small wheeze normal/acceptable?
I'll be thoroughly checking the engine bay when I get home tonight for leaks in the places you folks have suggested.
I'm loathe to put Radweld in the system as I've seen it do more harm than good. Has anyone had any good experiences to counter this?

VisaGTi16v · Post by **VisaGTi16v** » 25 Aug 2004, 14:14

I bought a brand new water pump before and fitted it and found the engine to be overheating so naturally I checked everything else, even took the head off to see if the liners had moved and blocked a waterway or something. In the end I took the "new" water pump out to discover the impellor bit had come off the rest of it as it had a nice crack in it, faulty manufacturing! grr

Mosser · Post by **Mosser** » 25 Aug 2004, 14:25

Radweld has worked for me in the past temporarily, i have never got more than 6 months driving before it leaking again though (about 35k miles for me) and it seems to make the engine run at a slightly higher temperature too

chriswales6 · Post by **chriswales6** » 25 Aug 2004, 16:28

I haven’t used Radweld myself, but I’ve put Barrs Leaks radiator sealant in two cars. My first car a 81’ Ford which was leaking a pint a week from the radiator. From memory it held for the best part of a year with minimum top-ups, finally decided to bite the bullet and replaced the radiator. While I was undoing the hose on the bottom of the rad the pipe snapped off the rad so I guess the sealant was doing it’s job.
At the start of the year the low coolant light on my 306 started coming on around once a month. I put some sealant in the water at the start of the summer and the level has been constant, but I know it’s not a permanent fix and I’m keeping my fingers crossed that I win the lottery and can buy a new car before I have to replace the rad.
If you intend keeping the car it’s better to find the source of the leak rather than using sealant. My guess would be that it’s radiator leaking, but it’s an expensive part to replace if it isn’t leaking.

batwad · Post by **batwad** » 26 Aug 2004, 13:59

I popped the bonnet when I got home last night to look for any leaks when the car was hot and I could quite clearly hear some gas escaping from the radiator cap, so it looks like the system is over-pressurising for some reason.
Dare I ask this question ... is this head gasket? [:(!]

solara · Post by **solara** » 26 Aug 2004, 16:59

Could your internal heater matrix be leaking? Check for dampness, but Im sure youd notice a pint a week in the car! Tell tale signs are misty windscreen on warm up.

batwad · Post by **batwad** » 26 Aug 2004, 18:45

There's no misty windows or dampness in the car, so I don't think it's the matrix.

bikeboyz · Post by **bikeboyz** » 27 Aug 2004, 01:38

Another oddity for loosing coolant is the age of the liquid if it is this "Green" premixed jollop! I had an old 106 with the old 1400 diesel engine which started using coolant for no apparent reason, a few panics with the warning light coming on - but no obvious reason. It was in fact the coolant breaking down and loosing its high boiling point properties. So its worth draining, flushing out and filling again. But like all things french its never easy - I expect you'll need to presurise the header bottle etc!