SD1 EFI
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SD1 EFI
Got a funny which is defeating me.
Drive the car around town etc or at modest speeds and it seems never to need topping up, coolant wise.
Drive it fast, and it appears to push some coolant out of the header tank, past the filler cap. A bottle on the overflow confirms this. And the low coolant light comes on. There are sensors in the rad and header tank. Driving along at speed the light will go on and off at will. But when cooled down, a visual check shows the coolant below the sensor level in the header tank, but never in the rad. Almost like it's finding its own level.
A pressure check hot or cold shows no leaks. I've replaced the filler cap a couple of times, and the seat looks just fine. What I haven't yet done is do a pressure check which includes the filler cap.
Heads were planed to take composite gaskets. Outer row of bolts omitted.
Drive the car around town etc or at modest speeds and it seems never to need topping up, coolant wise.
Drive it fast, and it appears to push some coolant out of the header tank, past the filler cap. A bottle on the overflow confirms this. And the low coolant light comes on. There are sensors in the rad and header tank. Driving along at speed the light will go on and off at will. But when cooled down, a visual check shows the coolant below the sensor level in the header tank, but never in the rad. Almost like it's finding its own level.
A pressure check hot or cold shows no leaks. I've replaced the filler cap a couple of times, and the seat looks just fine. What I haven't yet done is do a pressure check which includes the filler cap.
Heads were planed to take composite gaskets. Outer row of bolts omitted.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
Are you using the Viscous fan? MuscleManta (who is also on the SD1 forumn as someone or other) had no end of trouble with coolant issues, the engine temp of his 4.6 would be all over the place, in the end we removed the fan and went electric....problem solved. I think something had gone wrong with the standard fan, it never really free-wheeled, it was always spinning at a reate of knots!
- Ian Anderson
- Forum Contributor
- Posts: 2396
- Joined: Sun Nov 19, 2006 9:46 pm
- Location: Edinburgh
Do you have a single or double seal radiator / pressure cap?
Single pumps coolant out as it heats and there it stays
Double pumps it out as it heats and then draws it back when it cools
Ian
Single pumps coolant out as it heats and there it stays
Double pumps it out as it heats and then draws it back when it cools
Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
The SDI has a separate header tank. The pressure cap is the correct one - as far as I know. Bought from Rimmer. Another from Ebay. And the old one. All seem to do the same.Ian Anderson wrote:Do you have a single or double seal radiator / pressure cap?
Single pumps coolant out as it heats and there it stays
Double pumps it out as it heats and then draws it back when it cools
Ian
If I rig up a bottle to the overflow pipe from the header tank, it fills with water. Pretty well what is lost from the header tank. But only when pressing on - it stays empty when driving more gently.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
Mine is a (near) standard engine, still 3.5. Has the standard temperature controlled viscous as fitted to the injection models.sidecar wrote:Are you using the Viscous fan? MuscleManta (who is also on the SD1 forumn as someone or other) had no end of trouble with coolant issues, the engine temp of his 4.6 would be all over the place, in the end we removed the fan and went electric....problem solved. I think something had gone wrong with the standard fan, it never really free-wheeled, it was always spinning at a reate of knots!
But the problems seem to happen when driving quite fast - so the fan really won't come into the equation.
The temperature on the gauge does go up and down a bit seemingly at random, even at a steady 70 or so MPH. Between about 90-100 on the gauge.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
Later SD1 have 88C thermostat. That's what I've got fitted.
Can't see it being a head problem. Changed the heads fairly recently for Stage 1 units planed down for composite. Both heads and block were fine on my straight edge and looked perfect. Plugs show no sign of water getting to them, nor does the oil.
I'm leaning towards it simply blowing out past the filler cap, since if I attach a container to the overflow, it fills up when the problem occurs.
Is it possible to get a higher pressure one that would fit? Existing says 15 psi.
What I haven't done is to pressurize the system via the rad filler, to check the cap does hold at approx 15 psi. Will have to make a filler cap to do that, as my kit doesn't include one that fits.
Can't see it being a head problem. Changed the heads fairly recently for Stage 1 units planed down for composite. Both heads and block were fine on my straight edge and looked perfect. Plugs show no sign of water getting to them, nor does the oil.
I'm leaning towards it simply blowing out past the filler cap, since if I attach a container to the overflow, it fills up when the problem occurs.
Is it possible to get a higher pressure one that would fit? Existing says 15 psi.
What I haven't done is to pressurize the system via the rad filler, to check the cap does hold at approx 15 psi. Will have to make a filler cap to do that, as my kit doesn't include one that fits.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
Mine has air-con, so the header tank is brass, rather than plastic with a steel seat for the cap as on others. And it looks OK. I suppose it could be worn in some way at 30 years old.
But I'll make up a way of pressurizing things with the cap in place.
But I'll make up a way of pressurizing things with the cap in place.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y