renault laguna temperature

grattsim · Post by **grattsim** » 14 Apr 2004, 00:50

My temperature gauge increases with speed, it rises to around half way and then falls back to normal once I have slowed down. Any ideas on what could be causing this would be most helpful.
[:D]

arry_b · Post by **arry_b** » 14 Apr 2004, 02:35

Thermostat stuck open seems most likely.

grattsim · Post by **grattsim** » 15 Apr 2004, 23:24

thanks for the idea, I've fitted a new thermostat not so long ago. Could it be electrical?

lonbk · Post by **lonbk** » 18 Apr 2004, 06:45

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

thanks for the idea, I've fitted a new thermostat not so long ago. Could it be electrical?
<hr height="1" noshade id="quote"></blockquote id="quote">
My Haynes manual says that is caused by a faulty voltage regulator

grattsim · Post by **grattsim** » 18 Apr 2004, 20:17

I read that, as far as I knew the regulator was all part of the alternator? Is there another one as the alternator seems to be working fine?

lonbk · Post by **lonbk** » 18 Apr 2004, 22:18

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

I read that, as far as I knew the regulator was all part of the alternator? Is there another one as the alternator seems to be working fine?
<hr height="1" noshade id="quote"></blockquote id="quote">
You need to test the output voltage. Conect a voltmeter to the battery
and start the car. the voltage should remain between 12 to 13 regardless of engine speed

grattsim · Post by **grattsim** » 22 Apr 2004, 19:16

I've tested the out put voltage, it seems to stay aroun 14.3 which I thought was pretty good. Is this to high?

Post by **philhoward** » 22 Apr 2004, 23:59

Are we not thinking about the instrument voltage regulator (feeds the instruments); if your fule gauge goes up when the temp gauge does, then it's at fault.
14.3V sounds a little high to me; where did you measure it? At the battery or the alternator output itself? May be about right for actual alternator voltage; i'd expect to see around 13.5 at the battery itself.
Another possibility is a weak water pump, or blocked radiator. The rad may be helped by flushing the cooling system.

grattsim · Post by **grattsim** » 23 Apr 2004, 01:30

It was tested at the battery and now reads 14.57, where would I find the instrument voltage regulator? Above the fuse box?

Post by **philhoward** » 23 Apr 2004, 02:10

That seems a bit high to me; i'd suggest getting the alternator checked out by an auto-electrician before you start blowing bulbs!
The instrument regulator si normally part of the actual dashboard instruments.

arry_b · Post by **arry_b** » 23 Apr 2004, 04:36

I think you're barking up the wrong tree looking for an electrical problem I'd expect to see 14.4V at the battery terminals just after you've started the car and you're not far off that(although as Phil says - keep an eye on the alternator and the battery electrolyte level).
If the thermostat is new (and is in the right way up), then a radiator flush is next on your list.
Does the rad have any cold patches when the engine is warm?

grattsim · Post by **grattsim** » 23 Apr 2004, 15:39

The thermostat is new and I've tested it in hot water, what would you recomend for flushing the rad, I was once told costic soda worked best. Although I though this might be a little strong? Any other good products out on the market that can be recommended?

grattsim · Post by **grattsim** » 27 Apr 2004, 20:52

I've done a radiator flush, but nothing has changed so my opinion is that it still has something to do with the electrics. Where would I find the voltage regulator behind the dash? Or what else could be causing it to get hot with speed.

grattsim · Post by **grattsim** » 04 May 2004, 01:05

could it be possible that if air was entering the system then this could cause it to heat up with the speed increase, and then as I slow down the air escapes. As it can cool down within 100-200 yards once I slow the car down. Such an annoying problem!!! Although my obsessive need to find the problem doesn't help...

mikgram · Post by **mikgram** » 08 May 2004, 16:42

the voltage regulator is probarbly on the back of the speedo rev counter assembly, years ago I had a mark ll granada ,when you turned on the lights the temperature gauge went almost into the red if the
lights were off it stayed right in the middle,the problem was the voltage regulator.