P38 temp gauge .

[Rextheute]

Righto ...I require a brains trust transplant !

My p38 1995 model has a weird temp gauge - I have spent 3 days staring into the Internet ,both here and into range rovers net . - I have over loaded ...

In a nutshell , the gauge rises normally , then sits at just before the third stroke ,occasionally rising to the red mark .

So from my reading it appears that the becm has set points in it halfway is approx 80deg the 3rd stroke is approx 85 deg and red is 90deg ?

Now I purchased a laser thermometer which gives me approx 55- 60deg at the top of the manifold - where the sensor is at approx 4 inches . This is when the gauge is at half
If it rises I have not had it go over 85 deg at top of motor and approx 50 at the bottom - returning to motor .exterior of thermostat is approx 50 deg .
The radiator is new and doesn't appear to have any hot spots , thermostat ,sender and coolant change .
Gauge is apparently within spec according to mechanic - checked with computer .
I am ..... Or is that I AM going mental , I spend my time staring into the gauge . So I have purchased another seperate temp gauge as my wife has referred to me as " a bit possessed "

Any ideas ?
Car goes fine , so I don't want to kill it - it has had a new motor at some point , doesn't use coolant or oil and hasn't according to my laser gauge got hot even when towing my camper .
Suggestions ....

[DT-P38]

Hi there,

Check your expansion tank cap and perhaps renew to be sure it is holding and letting off pressure when required. Also check the overflow pipe to be sure it is not blocked.

Check for noise around your water pump at idle and sustained moderate rev's... if it's bearings are on the way out it could be seizing off and on.

Take it to a radiator specialist and get a power flush. Maybe get a new/second hand temp sender and see if it stops the weird stuff?

NOTE: I am not a mechanic, these are based on my experiences and memories of others experiences on here and in the real world. :angel:

[mtb_gary]

Rex

I share the paranoia :eek:. So much so that I bought an aftermarket digital thermometer that measures the temperature of the metal rather than the water ($99 on eBay) I have it set so that an alarm will sound at 105C. If there's no water in the system the standard dash thermometer will not recognize a problem. I have it mounted under the dash so that it is a bit out of the way. I can read the display through the steering wheel. To my surprise on such an old radiator (it is flushed every 2 years) the temperature even in peak hour traffic on a 44c did not climb over 95c. I regularly check the temperature, it sits around 84-86c right where it should be. I have been a bit less paranoid about cooking the motor since fitting the gauge, as for every other squeak, rattle and hum....that's another story ;).

Gary

[Rextheute]

Yes also have new expansion cap !

The pump was also replaced "recently " and doesn't seem to be noisey or loose .

Might blow through the expansion pipe ....not now , will wait till weekend .

My super ears will hear all the other noises now , but will still be watching the bloody temp gauge .



I think it is because all the numpties who have never owned a p38 get involved in the " engine will die " bandwagon . Mine has done now almost 5000km since I bought it ..nothing has gone awry its a lovely car to drive and makes me feel special , everything works , and was previously owned by an enthusiast owner but , I lust after a 4.8 motor with a tow cam , i don't really need it would be nice tho !

Ps it has almost 270,000km on it now

[TheTree]

I too have an engine watchdog which was on the car when I bought it. I think they are excellent insurance!

Also my 96 model has a resistor in the line from the sender which was apparently a fix to make the "Center :censored: Weighted" factory gauge read a bit more accurately

Steve

[Rupert Prior]

make sure the earth to the engine is good and check the charge rate. just to be sure, the gauge sender is the single terminal one not the twin. it may have the gauge from a bosch car in it which will make it do strange things. the becm's some times play up and drive the gauges mad. the thermostat can also be a problem.

[Rextheute]

"Centre weighted " switch , hmmmmm that would make sense - it reads the same over a range of temps ( 65 - 75 deg ) then the next step up .

[daf11e]

Rex I had a similar situation about 18 months ago where my gauge would creep up and back down at random and after many weeks of watching the gauge and replacing parts it was suggested that I may have a new faulty thermostat. Only having put a new one in a week before I didn't think it could be bad but with nothing to lose I bought another thermostat and put it in......I couldn't believe it the new one I took out was stuck half open...havnt had a problem since and the gauge is rock solid halfway.

[p38arover]

I watched my Scan Gauge today and mine sat between 85-87 deg C in traffic and on motorway.

[benji]

Rex where abouts are you in country vic?
there's a few of us with nanocoms and the like that could read the ecu temp sensor reading.
I'm in Bendigo.

Sent from my SM-G900I using AULRO mobile app

[Rextheute]

Do you drink ? :p

I'm in Romsey ....not far from Bendigo !

[Rextheute]

EG01 2 Twin Sensor Engine Transmission Temperature Alarm Quick FIT Display | eBay (http://www.ebay.com.au/itm/161720849411?_trksid=p2055119.m1438.l2661&ssPageName=STRK%3AMEBIDX%3AIT)


is this the temp alarm / gauge ?

[TheTree]

Mate

That's one of them, there is also

ENGINE WATCHDOG TM2, Engine Overheating Alarm, Gauge & Sensor (http://enginewatchdog.com/)

And I remember someone fitted a unit from Sth Africa as well

Steve