From one extreme to the next

Well I purchased a new 88 degree thermostat yesterday and set about swapping it over today and it transpired I did have an 82 thermostat fitted but after testing it and finding it worked ok I was a bit stumpped as to why the lack of temperature was so dramatic until I looked at the gasket.


DSC07496 by mikeyp78, on Flickr


DSC07497 by mikeyp78, on Flickr

it is clear to see the indentation on the gasket and the position of the thermostat when sitiing on the gasket that when I fitted this it must have moved slightly when I fitted the front housing :oops: Quite apparent is the gap around part of the stat that would have allowed water to by-pass it, I don't think that this would have done any favours. Anyway all was not lost as I fitted the new 88 degree stat, which incidently sat in the housing much better than the other one. Oh and I did remember to drill the small hole at 12 O'clock :wink:
 
Hi Mike,

Some thermostats have a calibrated bleed notch to prevent air pockets forming, and this is placed at the 12 o'clock position. The genuine Land Rover items that I have seen have this feature. The bleed notch is better than a jiggle pin and there is no need to drill a hole. Some stats on the other hand not designed with the intention of possible fitment into a Rover V8 may not have this latest feature, so drilling a hole in a stat such as this is essential.

Ron.
 
Ok, time for an update - when I fitted the 88 degree thermostat last Tuesday I took the car off to a club meet that night which was a round trip of 60 miles, I found the gauge right up at the top of the green almost on red and would not fluctuate at all :roll: upon advice from some of the guys that night I re-fitted the old 82 degree thermostat the following day, correctly this time I might add, and took the car out for a test drive. This time the temperature was at a more sensible level moving between the '5' and 'P' on the gauge. It's still a little high and maybe I'm being picky but when I was initially having overheating issues people were saying to check the sender, Chris York in particular suggested that if an SD1 sender was fitted they don't work properly with a P6 gauge. It occurred to me yesterday that seeing as I have an SD1 engine it's more than likely an SD1 sender. Has anyone else encountered this problem?
 
I am following this closely, My car barely got into the green, but did appear to run hot, although never boiling her stack. I bought a replacement temp sender and stat, and also renewed the carb stack to radiator pipe as it had imploded and fitted an MGB header tank. I am now only just off the red, but put the old sender in, and its back to just into the green. I think I'm going to have to invest in a decent remote temp gauge to find out what temp I'm running at.


John.
 
John said:
I am following this closely, My car barely got into the green, but did appear to run hot, although never boiling her stack. I bought a replacement temp sender and stat, and also renewed the carb stack to radiator pipe as it had imploded and fitted an MGB header tank. I am now only just off the red, but put the old sender in, and its back to just into the green. I think I'm going to have to invest in a decent remote temp gauge to find out what temp I'm running at.


John.
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Its sound like we have similar problems John. I know that no two cars are the same but it would be nice to have a reasonably accurate gauge just to make sure that nothing bad is happening.
 
MikeP wrote,...
upon advice from some of the guys that night I re-fitted the old 82 degree thermostat the following day, correctly this time I might add, and took the car out for a test drive. This time the temperature was at a more sensible level moving between the '5' and 'P' on the gauge.
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Hi Mike,

What was the ambient temperature and the traffic conditions like?

Ron.
 
SydneyRoverP6B said:
MikeP wrote,...
upon advice from some of the guys that night I re-fitted the old 82 degree thermostat the following day, correctly this time I might add, and took the car out for a test drive. This time the temperature was at a more sensible level moving between the '5' and 'P' on the gauge.
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Hi Mike,

What was the ambient temperature and the traffic conditions like?

Ron.
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Hi Ron,

If you mean when it was stuck at the top of the green and didn't budge it was about 14 degrees centigrade and I was mostly doing motorway driving at 70 mph.

rockdemon said:
http://www.maplin.co.uk/pocket-infrared-thermometer-220790

That's how i know what temp sleipnir is at. It does stay at 88 degrees. Gauge reads just below the red.

Rich
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Thanks for that link Rich, any thermometers I had seen were really expensive and I couldn't justify the cost. I'm not overly concerned because the gauge is fluctuating depending on airflow, its just I want to confirm that all it is is an over reading gauge.
 
MikeP wrote,...
Hi Ron,

If you mean when it was stuck at the top of the green and didn't budge it was about 14 degrees centigrade and I was mostly doing motorway driving at 70 mph.
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Was that with the 82 degree stat Mike? If so and assuming that the cooling system is functioning correctly, then the sender does seem the likely suspect.

Ron.
 
SydneyRoverP6B said:
MikeP wrote,...
Hi Ron,

If you mean when it was stuck at the top of the green and didn't budge it was about 14 degrees centigrade and I was mostly doing motorway driving at 70 mph.
Click to expand...

Was that with the 82 degree stat Mike? If so and assuming that the cooling system is functioning correctly, then the sender does seem the likely suspect.

Ron.
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That was with the 88 degree stat Ron, I think that was allowing the at to run too hot.
 
On the drive down to Whitewebbs this morning my temperature gauge was doing its usual trick of moving all over the place from normal to high and I was convinced the gauge crept up when the lights were on and dropped back to normal when they were switched off; however when I pulled over to use my phone the gauge was in the red and the lights were off, very strange, maybe the lights aren't a problem but I did notice some 'smoke'coming from under the bonnet but when I opened it I couldnt really see anything so put it down to the sub zero temperature being able to see this 'smoke'.
On the drive home it was very much the same so I planned to check the engine temperature with my IR thermometer, so with the engine idling and the gauge in the red i checked in various positions with parts of the inlet tower and around the temperature sender at between 110 and 120 degrees C :shock: . I reversed the car back into the garage and when i was about to shut the door I saw 'smoke' coming from the grill, I opened the bonnet and parts of the engine was smoking :shock: Of course this is probably residual oil and gunk on the engine burning off but surely the engine cant be overheating after all the work I have done on it? I appreciate some parts of the engine would be hotter than others but I would expect the temperature by the sender to reflect the temperature registering on the gauge so if this is over 100 degrees C and the gauge reflects this then I don't have a bad earth causing overreading but still an overheating issue.

Am I measuring the temperature in the rigfht place and what if it is overheating what is causing this as its had a new Rad, coolant and thermostat including an expansion tank?
 
That is overheating. In the position you describe mine shows 88 degrees.

If the engine has been flushed out it must be the rad i guess?

Rich
 
rockdemon said:
what about the heater matrix?
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I flushed the matrix when I did the engine and all seemed good, as far as I could tell. I drove the car last week and all seemed fine so today is the first time that it has done this. When I changed the sender a few weeks ago and check with the IR thermometer it was reading about 85 degrees so when the gauge was sitting high I took it as over reading.
 
i guess that leaves you looking at headgaskets and the like but you'd expect other symptoms surely?
 
rockdemon said:
i guess that leaves you looking at headgaskets and the like but you'd expect other symptoms surely?
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That's what I thought, the usual 'mayonnaise' under the oil cap, or maybe that's not always the case :?
 
I guess a pressure test or something. Dont listen too much to me though - wait till someone who knows what they're talking about makes a more educated guess ;)
 
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