Thermo confused. - Page 2

kaiser · 29th October 2016, 19:00

It is normal to see lower temperatures than the opening temperature of the stat. That will typically happen in cold weather with a heater blowing on full heat and a light load on the engine. In that case the cooling of the engine by the internal heating system and cold air around the engine is enough to keep the cooling system under the opening temperature of the stat, thus rendering the thermostat inoperable (constantly closed). There is thus in this case no physical way the thermostat can influence the coolant temperature, unless the heater is closed.

this is not unique to the 1.8, but happens to any car in certain situations, you see it frequently on the Diesel versions.

SD1too · 29th October 2016, 19:37

Quote:

Originally Posted by g.mc.g

It's well within normal expected parameters.

Quote:

Originally Posted by COLVERT

There is nothing wrong with the readings you have had in the conditions you have described.

Chris,

These two members own diesels which are notorious for low running temperatures and faulty thermostats. They might therefore regard your experience as normal, but it isn't for petrol engines. Please have due regard for the advice given by T-Cut who has the same 1.8T as you do and has taken a keen technical interest in the operation of the PRT.

I also have to warn you that kaiser's posts are baffling since they are contrary to the accepted basic principles of automotive cooling systems.

Simon

Sheraton · 29th October 2016, 19:41

i'm not sure - however the running temps seem a little low to me

and assuming all is well (in this area) with my car - it would indicate a problem somewhere

I've had my 1.8t for a year (just over) and i always have coolant temp displayed, the car suffered HGF after 10,000 miles and roughly 6 months ownership - i blame bad maintenance by previous owner

- since having the repairs done, i haven't had to top-up any coolant (checked every other day at-least) and oil level has been fine.

one thing i've noticed about running temp on my 1.8t k-series (and was considering posting r.e the subject tonight - however it seems relevant to this thread) it seems to me the water pump set-up on the 1.8t is efficient around 3000rpm - at 2000rpm even cruising at 60-70mph on the motorway the temp can rise slightly - not overheating but rising - if i cruise at 90mph (i'm well aware of the speed limit

) 3000rpm the temp will sit happily at 90 degrees
my general/average running temp is probably mid 90's - if i'm in town traffic and i notice temp rise to high 90's i'll knock the heater on, rather than wait for the fan (my fan does work and i've fitted a Gold resistor

)

i don't think my running temps are high

car runs great etc..

i've no experience of the other engines - the 1.8t in my experience seems set-up to be pushed hard through the rev range - the clutch with no springs makes smooth "Rover-like" gear changes difficult - when pushing hard through the rev range however it's a lot smoother (as i'd expect from this type of clutch anyway) and with this observation that, for my car at-least, the coolant system/water pump seems set-up/geared(?) to be efficient at higher RPM

maybe even makes sense for a 1.8 turbo'd k-series

or maybe my car has issues

?

r.e your car - i'd listen to the advice of SD1too and t-cut

Paul.

kaiser · 29th October 2016, 19:51

Quote:

Originally Posted by SD1too

Chris,

These two members own diesels which are notorious for low running temperatures and faulty thermostats. They might therefore regard your experience as normal, but it isn't for petrol engines. Please have due regard for the advice given by T-Cut who has the same 1.8T as you do and has taken a keen technical interest in the operation of the PRT.

I also have to warn you that kaiser's posts are baffling since they are contrary to the accepted basic principles of automotive cooling systems.

Simon

Ha ha Simon. They might do, but I don't!
And what accepted basic principles are you referring to?

Chris G · 29th October 2016, 21:06

Thank you everyone for your thoughts & input on this.
I have booked the car in for its annual service in a couple of weeks with the same mechanic who serviced the car & health checked before I drove it the best part of 3800 miles to the Algarve & back last Christmas..
So in all fairness do trust the guy and he seems to know his stuff.

New PRT has been requested along with new coolant, inlet manifold gasket & water pump.. I'm very attached to my 75 & have no problems throwing a few quid at it..

To be honest I'm not too concerned & am slowly coming round to the idea that the K series has been the victim of a motoring press witch hunt over the years, so people become very critical based on what they've been reading & owners become waaay too paranoid, myself included...

A friend of mine suffered a catastrophic HGF on a 3 year old BMW....
But we never seem to read of such stories.. mmmmm?

29th October 2016, 19:00	#11
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	It is normal to see lower temperatures than the opening temperature of the stat. That will typically happen in cold weather with a heater blowing on full heat and a light load on the engine. In that case the cooling of the engine by the internal heating system and cold air around the engine is enough to keep the cooling system under the opening temperature of the stat, thus rendering the thermostat inoperable (constantly closed). There is thus in this case no physical way the thermostat can influence the coolant temperature, unless the heater is closed. this is not unique to the 1.8, but happens to any car in certain situations, you see it frequently on the Diesel versions. __________________ Worth his V8 in gold

29th October 2016, 19:41	#13
Sheraton Posted a thing or two Rover 75 1.8t Join Date: Oct 2015 Location: Edinburgh Posts: 1,377 Thanks: 384 Thanked 409 Times in 267 Posts	i'm not sure - however the running temps seem a little low to me and assuming all is well (in this area) with my car - it would indicate a problem somewhere I've had my 1.8t for a year (just over) and i always have coolant temp displayed, the car suffered HGF after 10,000 miles and roughly 6 months ownership - i blame bad maintenance by previous owner - since having the repairs done, i haven't had to top-up any coolant (checked every other day at-least) and oil level has been fine. one thing i've noticed about running temp on my 1.8t k-series (and was considering posting r.e the subject tonight - however it seems relevant to this thread) it seems to me the water pump set-up on the 1.8t is efficient around 3000rpm - at 2000rpm even cruising at 60-70mph on the motorway the temp can rise slightly - not overheating but rising - if i cruise at 90mph (i'm well aware of the speed limit ) 3000rpm the temp will sit happily at 90 degrees my general/average running temp is probably mid 90's - if i'm in town traffic and i notice temp rise to high 90's i'll knock the heater on, rather than wait for the fan (my fan does work and i've fitted a Gold resistor ) i don't think my running temps are high car runs great etc.. i've no experience of the other engines - the 1.8t in my experience seems set-up to be pushed hard through the rev range - the clutch with no springs makes smooth "Rover-like" gear changes difficult - when pushing hard through the rev range however it's a lot smoother (as i'd expect from this type of clutch anyway) and with this observation that, for my car at-least, the coolant system/water pump seems set-up/geared(?) to be efficient at higher RPM maybe even makes sense for a 1.8 turbo'd k-series or maybe my car has issues ? r.e your car - i'd listen to the advice of SD1too and t-cut Paul.

29th October 2016, 21:06	#15
Chris G Newbie Rover 75 Saloon Join Date: Oct 2016 Location: Worcester Posts: 28 Thanks: 2 Thanked 1 Time in 1 Post	Thank you everyone for your thoughts & input on this. I have booked the car in for its annual service in a couple of weeks with the same mechanic who serviced the car & health checked before I drove it the best part of 3800 miles to the Algarve & back last Christmas.. So in all fairness do trust the guy and he seems to know his stuff. New PRT has been requested along with new coolant, inlet manifold gasket & water pump.. I'm very attached to my 75 & have no problems throwing a few quid at it.. To be honest I'm not too concerned & am slowly coming round to the idea that the K series has been the victim of a motoring press witch hunt over the years, so people become very critical based on what they've been reading & owners become waaay too paranoid, myself included... A friend of mine suffered a catastrophic HGF on a 3 year old BMW.... But we never seem to read of such stories.. mmmmm?