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Robert Gardner
Experienced User
Username: bobg

Post Number: 18
Registered: 12-2012
Posted on Sunday, 10 August, 2014 - 14:04:   Edit PostDelete PostView Post/Check IP

Recently replaced the water pump on LRA13020, and replaced all belts as well. Drove about 15 miles from repair shop at 65 mph, yellow coolant light/buzzer came on briefly, pulled over and upon inspection found that coolant had discharged from the plastic fill cap on the expansion tank.

From what I have read from a couple forums, this could be caused my either a faulty cap, expired cap washer or bad pressure relief valve on the expansion tank.

Does anyone concur with this and is there something else that could also be the culprit ?

72 Shadow

Thanks Bob
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1241
Registered: 6-2006
Posted on Sunday, 10 August, 2014 - 16:12:   Edit PostDelete PostView Post/Check IP

If the buzzer went then it must have been overheating at the rear of A bank. Possibly the whole engine.

If it wasn't overheating before the pump was fitted then the cap or seal is unlikely. But not impossible.

What happened subsequently?

It may have been an air lock. Did the garage run it up a day times?

Was the thermostat replaced?

Was the viscous coupling locked up when hot?

Is the water pump working? I've had one with the impellor freewheeling.
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Robert Gardner
Experienced User
Username: bobg

Post Number: 19
Registered: 12-2012
Posted on Sunday, 10 August, 2014 - 16:45:   Edit PostDelete PostView Post/Check IP

Hi Paul, Coolant light came on previously and thermostat was replaced, that was about a year ago, Car sat idle for most of the year after that, Never had the buzzer sound until the water pump malfunctioned, Water pump was rebuilt and functioning properly as far as I know because this was replaced a matter of days ago.

"Run it up a day times", Not sure what that means.

Thermostat was replaced about 200 miles ago

I have absolutely no idea what the viscous coupling is, Sorry.
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1242
Registered: 6-2006
Posted on Sunday, 10 August, 2014 - 17:27:   Edit PostDelete PostView Post/Check IP

few times, not day times:-(


I had a rebuilt pump that was freewheeling when we took it off again. Only happened once but I assumed it was fine but couldn't work out why the car was overheating.


Run engine until hot and then try spinning the family by hand.


If you rev the engine tin top hose should pressurise slightly.
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Nigel Johnson
Prolific User
Username: nigel_johnson

Post Number: 127
Registered: 12-2008
Posted on Sunday, 10 August, 2014 - 19:45:   Edit PostDelete PostView Post/Check IP

Paul is posting from his phone again!
He means the fan not the family.Do remember to turn the engine off when testing the fan.
Tin top hose,he means the top hose.

Regards, Nigel.
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1243
Registered: 6-2006
Posted on Sunday, 10 August, 2014 - 20:27:   Edit PostDelete PostView Post/Check IP

lol. Thank you for the translation service Nigel :-)

I must read my own posts!!! Before sending.

I should have also said that by the time the buzzer is going off, the engine is already reaching a critical temperature and on the way to head gasket or picked up piston problems, so do be very careful.

The orange light is no longer a low coolant light but becomes a stop immediately because your engine will blow light.:-(
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Jan Forrest
Grand Master
Username: got_one

Post Number: 607
Registered: 1-2008
Posted on Sunday, 10 August, 2014 - 21:11:   Edit PostDelete PostView Post/Check IP

"Predictive texting"! Waste of time. I always disable it.
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Brian Vogel
Grand Master
Username: guyslp

Post Number: 955
Registered: 6-2009
Posted on Monday, 11 August, 2014 - 00:08:   Edit PostDelete PostView Post/Check IP

This incident refreshes my interest regarding the specs on the OEM temperature sender and on whether an alternative can be fitted that would give an earlier warning.

Virtually every time the warning buzzer is mentioned the comment follows, "but if it's gone off your engine is probably already damaged." To me, this negates the buzzer as a warning; what it's telling you is that you've already had damaging overheating.

I have not yet located information on the temperature at which that warning sender kicks in and activates the warning buzzer. It would seem that the opportunity exists to put something in that would warn that you're well above what would be expected for "within normal limits" but is still well below "your engine is fried."

Does anyone know what temperature triggers the original warning buzzer sender and/or whether one can fit an alternative that goes off earlier, but not such that it will go off when things are on the warmest end of "within normal limits"?

Brian, who's never understood why the warning temperature sender wasn't changed to a lower temperature over the course of 15 years
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Chris Browne
Prolific User
Username: chrisb

Post Number: 143
Registered: 2-2010
Posted on Monday, 11 August, 2014 - 03:01:   Edit PostDelete PostView Post/Check IP

Hello Brian,
I took these figures from a workshop manual and kept a note of them for future reference. The overheat buzzer comes on at 150 degrees C. It goes off at 140 degrees C and the normal operating temperature is 115 degrees C.

Kind regards,

Chris
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Brian Vogel
Grand Master
Username: guyslp

Post Number: 957
Registered: 6-2009
Posted on Monday, 11 August, 2014 - 04:30:   Edit PostDelete PostView Post/Check IP

Chris,

Thanks very much for posting this.

Now I will have to set about finding a suitable something that moves that on/off range down at least 15° C/59° F. Of course, this will be after soliciting IR thermometer readings from folks who have just had their cars out for a strenuous run during very warm weather. You don't want the thing coming on when you're running normal hot, not damaging hot.

For those who have IR thermometers and might be so inclined, would you please take temperatures at the thermostat housing and near where the temperature sensor is located under the above conditions and post them?

For those of us who still "think in Fahrenheit":

Normal Operating Temperature: 239° F | 115° C

Buzzer Kick-On Temperature: 302° F | 150° C
Buzzer Turn-Off Temperature: 284° F | 140° C


Brian
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Bob uk
Unregistered guest
Posted From: 94.197.122.93
Posted on Monday, 11 August, 2014 - 03:28:   Edit PostDelete PostView Post/Check IP

I have seen impellers fall off. Rare but it can happen.
At 65 mph the fan will be coasting and going with the flow.
To check water pump remove stat elbow and spin pump by hand and water should pump out. Or flick the starter.
The system is a good system . I like to remove the little pipe to the head tank for burping the air out.
If coolant put in with the stat shut then the shadow can get a lock. So I always get engine up to temp before I go for a run, and check it.
My stat jammed shut which is very worrying because ones mind does start to think the worse. So I fitted a temp gauge.

(Message approved by david_gore)
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Nigel Johnson
Prolific User
Username: nigel_johnson

Post Number: 128
Registered: 12-2008
Posted on Tuesday, 12 August, 2014 - 02:33:   Edit PostDelete PostView Post/Check IP

My pleasure Paul.;-)

Regards, Nigel.