ZX TD water temp problem?

IanD · Post by **IanD** » 26 Jan 2005, 15:20

Usually it takes only around 4-5 miles for the temp gauge to get up to 85-ish degC but this morning I was driving around for about 35mins & it was still only just showing 70.
I checked the radiator & it's absolutely stone cold all over. The top hose going into it is pretty warm but the hose coming from the bottom is pretty much stone cold, there appears to be some heat further up in the pipe nearer the engine but that could be just down to heat soak from the engine maybe? When I squeeze the top hose the water level does go up & down in the header tank
I'm thinking it's most likely to be the thermostat? Whereabouts is that located?
Thanks,
Ian

ralph · Post by **ralph** » 26 Jan 2005, 15:31

Follow top hose - the thermostat housing is at the other end from the radiator.
Drain system, take off top hose, then undo the thermostat housing.
You could test the thermostat, but since you've gone to the trouble of dropping the coolant, I'd just replace it. Make sure you replace the o-ring so you get a water-tight seal when putting the housing back on.
It sounds like the thermostat is stuck open.

jeremy · Post by **jeremy** » 26 Jan 2005, 15:54

unless you drive hard these engines don't necessarily produce much heat and if you've got the heater running hard it may well do all the cooling.
When I fitted a temperature gauge to my BX TD I found I could get to work with the gauge barely moving (in April). I repplaced the thermostat and really the only difference is a slightly better heater and a gauge which responds a bit quicker. On a cold morning while waiting in a queue in our ZX 1.9D I noticed that the temperature gauge had dropped back to its cold position. Out of water? - no heater's working nicely - came back to normal when I got onto the motorway but still took several miles.
jeremy

IanD · Post by **IanD** » 26 Jan 2005, 16:04

Interesting you say that Jeremy, I actually had the heater running full blast all the way to work this morning with the windows open because I was trying to get the smell of takeaway out of the car/my clothes LOL The heater never seemed to get up to it's normal full temperature either?
Thanks very much for your advice aswell Ralph, found the thermostat housing[:)]. Do you have any views on the above scenario?
Cheers,
Ian

IanD · Post by **IanD** » 26 Jan 2005, 16:11

To clarify the above, I wonder if by having the heater on full from around a mile from home I have managed to dissapate so much heat from the engine that the water has never got hot enough for the thermostat to open & let water into the radiator? Hence why it's absolutely stone cold? But then on the other hand how would the top hose be warm? Apart from maybe heat soak but it seemed too warm for that?

Oscar Too · Post by **Oscar Too** » 26 Jan 2005, 19:41

When I've been stuck in traffic I've been able to lower the temp on the ZX by turning the heater on full and leaving windows open.
But it's worth checking the thermostat, for sure.

bxbodger · Post by **bxbodger** » 26 Jan 2005, 20:59

its the cold weather- mine has been hovering around 70 for the last few days, until I hit the motorway when it quickly gets up to normal!!!

jeremy · Post by **jeremy** » 26 Jan 2005, 21:15

proper test - from cold, start engine and feel temp around thermostat and top hose and top of rad. With car stationary you should be able to feel when thermostat opens and heat flows into top hose. It should be quite distinct.
It'll take for ever and you'll probably go to sleep waiting!
Leave it a bit longer and eventually the fans should start.
Spec of thermostat on diesels changed to about 83 degrees now from original 92 degrees.
how long do they last - our ZX 1.9D seemed to have failed at 53,000 miles, 8 years. BX was 14 and had done 187,000 miles but may have been done before or dud for years - made little difference on either except for better heaters.
Jeremy

oilyspanner · Post by **oilyspanner** » 26 Jan 2005, 21:29

Mines been overcooling with the colder ambient air, sits around 74 until I get on the open road, I think its down to the thermal efficiency of the diesel engines, unless theyre working pretty hard the heater can take out all the spare heat without the thermostat opening, I once felt the radiator on my 1.9 Na BX diesel after 5 hours on the motorway at 75-80 MPH, It was cold, the stat hadnt even opened, the TD motors generate lots more heat when theyre making boost but with the tall gearing and traffic thats rare in winter.
Stewart

IanD · Post by **IanD** » 26 Jan 2005, 21:31

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by bxbodger

its the cold weather- mine has been hovering around 70 for the last few days, until I hit the motorway when it quickly gets up to normal!!!
<hr height="1" noshade id="quote"></blockquote id="quote">
But today wasn't as cold as recent days & the temp has always got up to 85-ish within 4-5 miles in the past. I'll see what happens tonight on the way home (with normal useage of heater rather than running flat out with windows open). I'll give Jeremy's idea a go if the temp still doesn't get up to normal [8D]
Cheers lads[:)]
Ian

bxbodger · Post by **bxbodger** » 26 Jan 2005, 21:41

<blockquote id="quote">quote:<hr height="1" noshade id="quote">But today wasn't as cold as recent days <hr height="1" noshade id="quote"></blockquote id="quote">
It was in Essex!!!

IanD · Post by **IanD** » 27 Jan 2005, 15:16

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by bxbodger

<blockquote id="quote">quote:<hr height="1" noshade id="quote">But today wasn't as cold as recent days <hr height="1" noshade id="quote"></blockquote id="quote">
It was in Essex!!!
<hr height="1" noshade id="quote"></blockquote id="quote">
Maybe so, but I live in deepest darkest Cumbria [;)]
Well I just used the heater as normal last night rather than full blast with windows down & it got up to temperature as normal. When I stopped I checked the rad & it was warm.......problem solved [:)] However, when I get the cambelt done I'll be getting the thermostat changed just as a precautionary measure as I plan on keeping it a while yet [:)]