Running temperature too high???
- Thread starter rockdemon
- Start date
Is this a higher temperature than before? Is it the same sender unit as before? Remember that guage isn't a precision instrument, it's just a guide. Ideally it would sit in the middle of the green, but it may not be sitting higher because it's getting hotter, but just because it needs a different sender.
Hi Harvey,
It's same sender as before, and is sitting higher than on the old engine, but the old engine was running so badly it's possibly irrelevant ( It had more oil going through the carbs than petrol....)
Maybe i'll change the sender. It goes lovely now the tunings getting there. Got a lovely effortless turn of speed like it should have, and it seems wrong that it could be overheating when it seems to be running so nicely...
Rich.
It's same sender as before, and is sitting higher than on the old engine, but the old engine was running so badly it's possibly irrelevant ( It had more oil going through the carbs than petrol....)
Maybe i'll change the sender. It goes lovely now the tunings getting there. Got a lovely effortless turn of speed like it should have, and it seems wrong that it could be overheating when it seems to be running so nicely...
Rich.
I can't remember all of what you did to the engine, but depending on that it may be running warmer than previously, particularly if you're using all the newly found performance, which may put a cooling system that coped OK with a poor engine, under a bit too much stress. The problem with a guage reading like that it makes you think it's running hot even if it's not.
Gut feel says it's not overheating. I'll run it for a few days ( shorts journeys only) and we'll see what happens.
It's a p6 engine, which looks ( and sounds 8) ) to be in good condition internally, with SD1 heads, with my original P6 manifolds and carbs. I've cleaned out the coolant channels with a hose pipe fitted a 74 degree thermostat (without a hole - i know some have a small bypass hole?), and left the slightly rich needles that were in the carbs in there. (They might be a little too rich, but rich doesnt cause overheating from my limited knowledge...)
Maybe advancing the ignition a little would help - might give that a shot just in case...
It's a p6 engine, which looks ( and sounds 8) ) to be in good condition internally, with SD1 heads, with my original P6 manifolds and carbs. I've cleaned out the coolant channels with a hose pipe fitted a 74 degree thermostat (without a hole - i know some have a small bypass hole?), and left the slightly rich needles that were in the carbs in there. (They might be a little too rich, but rich doesnt cause overheating from my limited knowledge...)
Maybe advancing the ignition a little would help - might give that a shot just in case...
Hello Rich,
Rover V8 engines can and do develop air locks with the resulting increase in running temperature, when a thermostat is used that does not have an air bleed hole.
Running a 74 degree thermostat which is really a bit too cool for the U.K, the needle should typically sit at the very edge of the green, just above the white.
Ron.
Rover V8 engines can and do develop air locks with the resulting increase in running temperature, when a thermostat is used that does not have an air bleed hole.
Running a 74 degree thermostat which is really a bit too cool for the U.K, the needle should typically sit at the very edge of the green, just above the white.
Ron.
Hello Rich,
The photo of your temp gauge,...what was the ambient temperature, and for how long had the engine been running at the time the photo was taken? What were the driving conditions?
Ron.
The photo of your temp gauge,...what was the ambient temperature, and for how long had the engine been running at the time the photo was taken? What were the driving conditions?
Ron.
Hi Ron,
So that means I should drill a hole in the thermostat?
I'm going to check the 3 thermostats i've had - as the cause of the initial 'overheating' was really the silly person doing the mechanics getting the wiring the wrong way around between the otter switch and the temp sender... could be the initial one had a hole. Thanks for pointing that out!
The car had run for about 5 minutes and then been for a little 5 minute drive and settles consistently at that temperature when driven. It was about 25 degrees and sunny out today, but it does the same when it's cold and rainy too.
Rich.
So that means I should drill a hole in the thermostat?
I'm going to check the 3 thermostats i've had - as the cause of the initial 'overheating' was really the silly person doing the mechanics getting the wiring the wrong way around between the otter switch and the temp sender... could be the initial one had a hole. Thanks for pointing that out!
The car had run for about 5 minutes and then been for a little 5 minute drive and settles consistently at that temperature when driven. It was about 25 degrees and sunny out today, but it does the same when it's cold and rainy too.
Rich.
Hello Rich,
Waxstat thermostats that were available during the 1980s (quite possibly before then too) used to come with jiggle pins for the very reason of preventing air locks. When omitted, a 3mm hole is drilled with the hole positioned at 12 o'clock. This prevents air being trapped on the manifold side of the stat and subsequent overheating.
Given the time your engine has been running, that temp is far too high, so either the stat itself is the problem, air bleed hole or not, or the sender or gauge is incorrect. As Richard suggested, an infrared thermometer of something of a similar nature that will allow validation of your engine temperature.
Ron.
Waxstat thermostats that were available during the 1980s (quite possibly before then too) used to come with jiggle pins for the very reason of preventing air locks. When omitted, a 3mm hole is drilled with the hole positioned at 12 o'clock. This prevents air being trapped on the manifold side of the stat and subsequent overheating.
Given the time your engine has been running, that temp is far too high, so either the stat itself is the problem, air bleed hole or not, or the sender or gauge is incorrect. As Richard suggested, an infrared thermometer of something of a similar nature that will allow validation of your engine temperature.
Ron.
Well the reading on the guage is definitely much higher than the norm for a P6B. But equally it doesn't sound as if the engine is overheating! As a matter of principle I'd renew both the thermostat for one with a hole/jiggle pin and the temperature sender. It is just possible you have one for a different V8 application in there - SD1 perhaps?
After that I'm afraid it's just a case of driving it and observing how it behaves. You soon get used to the way your particular car is happy and can then spot when something different happens. I think the key observation is that the temperature remains steady no matter what the driving conditions.
Chris
After that I'm afraid it's just a case of driving it and observing how it behaves. You soon get used to the way your particular car is happy and can then spot when something different happens. I think the key observation is that the temperature remains steady no matter what the driving conditions.
Chris
Hi Chris,
I'm going to drill that hole tonight after work... If i make a mess i can always leave the thermostat out till a new one arrives
i guess that would prove the issue anyhow....
I've asked around to see if anyone has an infrared thermometer. And if that shows a high temp i'm going to have assume something is amiss with my job on the heads as there isnt really another explanation...
Rich.
I'm going to drill that hole tonight after work... If i make a mess i can always leave the thermostat out till a new one arrives
i guess that would prove the issue anyhow....I've asked around to see if anyone has an infrared thermometer. And if that shows a high temp i'm going to have assume something is amiss with my job on the heads as there isnt really another explanation...
Rich.