Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: TheBoy on 22 April 2007, 15:13:04

Title: What should I believe?
Post by: TheBoy on 22 April 2007, 15:13:04
The figure that the engine management reckons the coolant temp is, or what the dash gauge reads?
Title: Re: What should I believe?
Post by: Auto Addict on 22 April 2007, 15:16:51
I think you know the answer to that yourself ;)
Title: Re: What should I believe?
Post by: Markjay on 22 April 2007, 15:26:03
The first thing they teach you when you take flying lessons is always trust the instruments and not your instincts.  :y

Not sure what happens when you have two sets of instruments showing different things though...  :o I guess you crash?  ;D

Title: Re: What should I believe?
Post by: Auto Addict on 22 April 2007, 15:28:40
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The first thing they teach you when you take flying lessons is always trust the instruments and not your instincts.  :y

Not sure what happens when you have two sets of instruments showing different things though...  :o I guess you crash?  ;D


Bale out ::)
Title: Re: What should I believe?
Post by: Markjay on 22 April 2007, 16:08:50
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The first thing they teach you when you take flying lessons is always trust the instruments and not your instincts.  :y

Not sure what happens when you have two sets of instruments showing different things though...  :o I guess you crash?  ;D


Bale out ::)


Does TB's TD have a sunroof?  :o
Title: Re: What should I believe?
Post by: Dave-C on 22 April 2007, 16:09:15
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The figure that the engine management reckons the coolant temp is, or what the dash gauge reads?


My sentiments too!  Please read my http://www.omegaowners.com/forum/YaBB.pl?num=1177252579 , Advice all greatly received..
Cheeeeeeeeeers DC
Title: Re: What should I believe?
Post by: TheBoy on 22 April 2007, 16:09:58
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The first thing they teach you when you take flying lessons is always trust the instruments and not your instincts.  :y

Not sure what happens when you have two sets of instruments showing different things though...  :o I guess you crash?  ;D


Bale out ::)


Does TB's TD have a sunroof?  :o
Of course it does ;)
Title: Re: What should I believe?
Post by: Markjay on 22 April 2007, 16:16:25
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The first thing they teach you when you take flying lessons is always trust the instruments and not your instincts.  :y

Not sure what happens when you have two sets of instruments showing different things though...  :o I guess you crash?  ;D


Bale out ::)


Does TB's TD have a sunroof?  :o
Of course it does ;)


This is for AA:

sunroof [san-røøph]
noun
 
rectangular-shaped hole in the roof of some posh cars covered by a glass windows to allow the sun in
 
 
[Mid-19th century. Probably from Latin sanus roofus as found on ancient Centurions' carriages]
 

 ;)
Title: Re: What should I believe?
Post by: Auto Addict on 22 April 2007, 18:52:31
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Quote
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The first thing they teach you when you take flying lessons is always trust the instruments and not your instincts.  :y

Not sure what happens when you have two sets of instruments showing different things though...  :o I guess you crash?  ;D


Bale out ::)


Does TB's TD have a sunroof?  :o
Of course it does ;)


This is for AA:

sunroof [san-røøph]
noun
 
rectangular-shaped hole in the roof of some posh cars covered by a glass windows to allow the sun in
 
 
[Mid-19th century. Probably from Latin sanus roofus as found on ancient Centurions' carriages]
 

 ;)
 

....and still no pictures.....
Title: Re: What should I believe?
Post by: Taxi_Driver on 22 April 2007, 18:59:52
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The figure that the engine management reckons the coolant temp is, or what the dash gauge reads?

Believe the one that suits  :y

Whats the difference between them then?

If the EM reckons the coolant temp is -20C and you can burn yourself on the engine.....then it lies....it also lies if the engine is stone cold and EM reckons its 1000C   ;D
Title: Re: What should I believe?
Post by: TheBoy on 22 April 2007, 20:27:02
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The figure that the engine management reckons the coolant temp is, or what the dash gauge reads?

Believe the one that suits  :y

Whats the difference between them then?

If the EM reckons the coolant temp is -20C and you can burn yourself on the engine.....then it lies....it also lies if the engine is stone cold and EM reckons its 1000C   ;D
The gauge reckons the engine is flippin hot.  The Engine ECU reckons the engine is even hotter...
Title: Re: What should I believe?
Post by: Marks DTM Calib on 22 April 2007, 20:31:05
Engine ECU is the one to go by.....
Title: Re: What should I believe?
Post by: TheBoy on 22 April 2007, 20:33:58
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Engine ECU is the one to go by.....
Its getting flipping hot then ;)
Title: Re: What should I believe?
Post by: Taxi_Driver on 22 April 2007, 20:37:38
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The figure that the engine management reckons the coolant temp is, or what the dash gauge reads?

Believe the one that suits  :y

Whats the difference between them then?

If the EM reckons the coolant temp is -20C and you can burn yourself on the engine.....then it lies....it also lies if the engine is stone cold and EM reckons its 1000C   ;D
The gauge reckons the engine is flippin hot.  The Engine ECU reckons the engine is even hotter...

Ok seen your other thread and personally would believe the EM temp.

Heres a stab in the dark......does the tractor have a aux cabin heater?? normal on some diesels...
Coz i believe how these work is to heat up the coolant thereby heating up the interior faster.
Just wondering if its fubared and continually heating the coolant.....may explain the too hot temp of the coolant  :-/
Title: Re: What should I believe?
Post by: TheBoy on 22 April 2007, 20:38:41
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The figure that the engine management reckons the coolant temp is, or what the dash gauge reads?

Believe the one that suits  :y

Whats the difference between them then?

If the EM reckons the coolant temp is -20C and you can burn yourself on the engine.....then it lies....it also lies if the engine is stone cold and EM reckons its 1000C   ;D
The gauge reckons the engine is flippin hot.  The Engine ECU reckons the engine is even hotter...

Ok seen your other thread and personally would believe the EM temp.

Heres a stab in the dark......does the tractor have a aux cabin heater?? normal on some diesels...
Coz i believe how these work is to heat up the coolant thereby heating up the interior faster.
Just wondering if its fubared and continually heating the coolant.....may explain the too hot temp of the coolant  :-/
No, it doesn't have aux heater....
Title: Re: What should I believe?
Post by: Taxi_Driver on 22 April 2007, 20:42:24
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The figure that the engine management reckons the coolant temp is, or what the dash gauge reads?

Believe the one that suits  :y

Whats the difference between them then?

If the EM reckons the coolant temp is -20C and you can burn yourself on the engine.....then it lies....it also lies if the engine is stone cold and EM reckons its 1000C   ;D
The gauge reckons the engine is flippin hot.  The Engine ECU reckons the engine is even hotter...

Ok seen your other thread and personally would believe the EM temp.

Heres a stab in the dark......does the tractor have a aux cabin heater?? normal on some diesels...
Coz i believe how these work is to heat up the coolant thereby heating up the interior faster.
Just wondering if its fubared and continually heating the coolant.....may explain the too hot temp of the coolant  :-/
No, it doesn't have aux heater....

Told you it was a stab in the dark....oh well it wont be that then ::)
Title: Re: What should I believe?
Post by: Kevin Wood on 22 April 2007, 23:27:04
So if we believe the ECU sensor it's getting too hot?

If there's flow through the expansion tank when hot, it might be worth dipping a thermometer in there if you can do so without it boiling over - just to give you a third figure to really confuse issues  ;D

Well, if it IS too hot, the pump, thermostat and radiator cap are OK if must be the rad. clogged, surely?

Kevin
Title: Re: What should I believe?
Post by: TheBoy on 23 April 2007, 11:20:58
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So if we believe the ECU sensor it's getting too hot?

If there's flow through the expansion tank when hot, it might be worth dipping a thermometer in there if you can do so without it boiling over - just to give you a third figure to really confuse issues  ;D

Well, if it IS too hot, the pump, thermostat and radiator cap are OK if must be the rad. clogged, surely?

Kevin
Radiator replaced a week or so ago....
Title: Re: What should I believe?
Post by: Kevin Wood on 23 April 2007, 11:31:15
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Radiator replaced a week or so ago....

Ahh. I'd missed that.

Hmmm. This is really getting tricky. I think you must have a problem with coolant circulation. If the coolant was circulating through a new rad efficiently, in England, in April, I doubt the engine would be capable of generating enough heat to drag the temperature high enough to pop the expansion tank cap when the car is on the move.

Pump is OK. Thermostat is OK. Rad is OK.

That leaves the engine itself. Blocked coolant holes in head gasket? You mentioned there was evidence of an additive in the system?

Kevin
Title: Re: What should I believe?
Post by: Jimbob on 23 April 2007, 11:38:02
can you not get it hot, then drop a 'real' thermometer' in the tank and see which is closest?
Title: Re: What should I believe?
Post by: Markjay on 23 April 2007, 13:04:00
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can you not get it hot, then drop a 'real' thermometer' in the tank and see which is closest?


Firstly, if you let the engine warm up with the cap open, or open the cap once it is hot, it will de-pressurise and boil and the temp will get out of range very quickly..

But more importantly, the temperature changes along the route of the cooling system, so you will need to take to comparative measurements at exactly the same spot...

In principal both the gauge sender and the ECU sensor may provide correct but different readings if they are placed in different parts of the cooling system..

I think the way forward is to check the gauge display by using an alternative sender, alternative dash, and also potentially running a temp wire straight between the two... may not be very practical as you need to have the spare bits, but if done it should prove conclusive.
Title: Re: What should I believe?
Post by: Jimbob on 23 April 2007, 13:11:44
There you go then!  I certainly have a lot to learn!

Have seen it boil like that when having to top up on the motorway, didnt know thats why it did it though.
Cant even solve my own coolant leak :(
drips out at times, somewhere at the back of the engine above and behind the oil filter, really need to get that fixed.
(HBV replaced, was damp, now dry, suspect that was problem 1 of 2 fixed)
Title: Re: What should I believe?
Post by: TheBoy on 23 April 2007, 14:05:34
tbh, i knew the answer, as i have the kit available for diagnosis.

A quick check shows that the temperature that the instrument panel thinks is correct, and the temp that it displays on its dial are very, very different....


But it stimulated debate ;)
Title: Re: What should I believe?
Post by: Jimbob on 23 April 2007, 14:09:14
So....Can you calibrate the needle?
Title: Re: What should I believe?
Post by: TheBoy on 23 April 2007, 18:31:52
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So....Can you calibrate the needle?
Nope, the gauge is Donald.  It reads a temp between 94 and 96, which covers the range (according to ECU) 88 to 103...
Title: Re: What should I believe?
Post by: Kevin Wood on 23 April 2007, 21:29:48
Even if it's 103 I wouldn't expect it to boil over. IME (not on this engine admittedly) it takes 115 - 120 with a decent amount of antifreeze and a pressurised system, although the pressure at which the cap blows will make a difference.

Kevin
Title: Re: What should I believe?
Post by: TheBoy on 23 April 2007, 21:32:59
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Even if it's 103 I wouldn't expect it to boil over. IME (not on this engine admittedly) it takes 115 - 120 with a decent amount of antifreeze and a pressurised system, although the pressure at which the cap blows will make a difference.

Kevin
I've seen the engien ECU at 105 without trying too hard (read 97 on dash)...
Title: Re: What should I believe?
Post by: Taxi_Driver on 23 April 2007, 23:21:31
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tbh, i knew the answer, as i have the kit available for diagnosis.

A quick check shows that the temperature that the instrument panel thinks is correct, and the temp that it displays on its dial are very, very different....


But it stimulated debate ;)

Only coz you believe what your tech2 and ecu temp is telling you against a 'mechanical' pointer.....i would be the same.....comp systems must be correct! ....tho they do get it wrong sometimes.....but not in your case i reckon.....so is it looking like waterways are a tad blocked then? not much else left imo  :-/
Title: Re: What should I believe?
Post by: TheBoy on 24 April 2007, 21:02:57
Yeah, I've run out of ideas on this one...
Title: Re: What should I believe?
Post by: Auto Addict on 24 April 2007, 22:50:24
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Yeah, I've run out of ideas on this one...

Mr Muscle drain unblocking fluid? ;D
Title: Re: What should I believe?
Post by: Kevin Wood on 24 April 2007, 23:18:58
Got to be worth flushing it with something pretty aggressive. If it has, as you suspect, had some nasty additive in the cooling system it could have blocked some of the coolant holes in the HG. Some of these are pretty small to control coolant flow for even cooling. If they are blocked they will restrict coolant flow to parts of the engine, and reduce overall coolant flow, perhaps to a level that would result in the overheating you are seeing.

As it is misbehaving mainly when given a hammering, when demand on the cooling system is greatest, this would tally with what you are experiencing.

Only other course of action I can think of is to take the head off and see what condition the water jacket is in. A new HG will eliminate any problems with the coolant holes and the possibility of the problem being the HG itself, which I know you don't suspect for valid reasons.

Everything external to the engine itself has been eliminated now.


Kevin
Title: Re: What should I believe?
Post by: JamesV6CDX on 24 April 2007, 23:30:54
If it's HG, Jaime is taking me out for a pint  ;) ;D
Title: Re: What should I believe?
Post by: TheBoy on 25 April 2007, 10:37:09
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If it's HG, Jaime is taking me out for a pint  ;) ;D
LOL, you will need your Weetabix - remember this is a straight 6 head....