had carb - cooling was great - now got EFI engine too hot ??

[little tub]

Hi
Please can I have some help

I have a 4.6 westfield that was running on a webber carb, it had no issues whatsoever with cooling. It used to run at a tad over 90 and come down when driving with the ram air flow.

I sent the car away to be upgraded to EFI, now the car ticks over at just over 100 and goes up to 110. with no temp reduction due to ram air flow.

I am using the same temp gauge but the sender may have changed because the inlet manifold has changed to suit the EFI. So I don't know if the temp is accurate. I have checked that the thermostat is working, it is an 88 degree type, I drilled a small hole on its top.

I have borrowed an Infra red thermometer and found that the bottom hose that returns to the water pump reads about 20 odd degrees lower near the rad than near the water pump. This difference does not alter, even when revving the car to try and get the cool water back to the pump. I would of thought the cool water from the rad (electric fan) would move up the hose to the pump but the temps see stay at a steady gradient from very hot near the pump to cool at the rad. (is this normal)

I think the cooled water is not getting back into the engine, could it be an air lock in the bottom hose or the water pump knackered (very low mileage engine). I guess I am not getting any ram air cooling due to this problem but how do I resolve it ??

I don't have a heater ( I have a bleed tee in a hose loop where the heater would of been), I also don't have a rad filler cap in a westfield.

Please could someone explain how I can get rid of the air block or test the water pump or any other help would be much appreciated.

thanks LB

[little tub]

I read on another thread that by removing the heater can cause a problem with water flow into the rad.

I did a quick test, I put a clamp on the loop that has replaced the heater and ran the car. It had the same problem the cooled water from the rad is not getting back to the pump via the bottom hose. In fact the bottom hose near the pump is slightly hotter that the top hose next to the stat.

There is a a bit of a dodgy up, down and up on the bottom hose going from the rad to the pump. I will try and upload a photo.

cheers

[DEVONMAN]

Sometimes the heater loop will allow hot coolant to return to the engine block via the pump inlet without going through the rad.
Can you explain more fully the layout of the heater loop and if possible provide a photo of the hose /header tank layout.

[little tub]

bottom hose near rad it is at least 20+ degrees cooler than at other end near pump.

if the water is flowing from the bottom of the rad to the pump, surely this hose should have an equal temp ??

the hose goes up, then over, down and back up. Could an air lock be stopping this flow and how would I get rid of it.

Consider that this hose is in the same position as when the engine ran a cool temp with the carb ???[/url]

[DEVONMAN]

I read on another thread that by removing the heater can cause a problem with water flow into the rad.

I did a quick test, I put a clamp on the loop that has replaced the heater and ran the car. It had the same problem the cooled water from the rad is not getting back to the pump via the bottom hose. In fact the bottom hose near the pump is slightly hotter that the top hose next to the stat.

There is a a bit of a dodgy up, down and up on the bottom hose going from the rad to the pump. I will try and upload a photo.

cheers

Did the conversion include installation of a later type front cover and water pump which is designed to run anti clockwise?

[little tub]

Sometimes the heater loop will allow hot coolant to return to the engine block via the pump inlet without going through the rad.
Can you explain more fully the layout of the heater loop and if possible provide a photo of the hose /header tank layout.

Thanks for the reply, my index finger is pointing to the hose that comes under the inlet manifold then into a Y connector, one hose goes to the bottom of the header tank and the other loops back to my other finger. This loop was where the heater was connected previously.

[little tub]

I read on another thread that by removing the heater can cause a problem with water flow into the rad.

I did a quick test, I put a clamp on the loop that has replaced the heater and ran the car. It had the same problem the cooled water from the rad is not getting back to the pump via the bottom hose. In fact the bottom hose near the pump is slightly hotter that the top hose next to the stat.

There is a a bit of a dodgy up, down and up on the bottom hose going from the rad to the pump. I will try and upload a photo.

cheers

Did the conversion include installation of a later type front cover and water pump which is designed to run anti clockwise?

It has the same front cover as before with the carb which I think was a later front cover as it looks new ?

please explain ?

cheers

[little tub]

I don't think it can be running anti clockwise because with the infra red thermoter I could tell the rad was hotter at the top (inlet) than the bottom (outlet). The bottom hose at the rad was at least 20 degrees cooler that the top hose, but the botto hose as it nears the pump was as hot as the top hose.

???

[ChrisJC]

Firstly you need to double check the accuracy of the temperature gauge. Can you get hold of a thermocouple type thermometer (i.e. one that contacts the object you are measuring)?
It could be a storm in a teacup.

The other point is that since the front cover hasn't changed, there could be a problem with the heater / thermostat bypass circuits. I guess it's a car type front cover rather than a Range Rover one ? Have you got some photos taken from a bit further back so we can see the overall arrangement of everything?

Chris.

[DEVONMAN]

Firstly you need to double check the accuracy of the temperature gauge. Can you get hold of a thermocouple type thermometer (i.e. one that contacts the object you are measuring)?
It could be a storm in a teacup.

The other point is that since the front cover hasn't changed, there could be a problem with the heater / thermostat bypass circuits. I guess it's a car type front cover rather than a Range Rover one ? Have you got some photos taken from a bit further back so we can see the overall arrangement of everything?

Chris.

And could you clarify if there is any tee connection into the bottom hose. Also besides the bottom hose, is there a hose connected to the water pump return neck?

[little tub]

Thanks for the replies !!

I think I have sussed it out, I borrowed another Infra red thermometer from a local garage and compared readings from my car to another.
It seems the temp sender is knackered, the gauge is reading about 15 to 20 degrees high.
Also it had an airlock which was rectified by jacking the car up at the front etc. I will get another sender in tomorrow and see what happens.

cheers

[DaveEFI]

I'd say there are probably several sensors out there which look the same but aren't. The SD1 uses at least two - even with a gauge which looks similar (but has different markings)