Rover V8: Coolant level, how important?

[IPAddis]

I've just checked the coolant level after the engine was rebuilt on Thursday. The expansion tank was completely empty and the swirl tank needed a reasonable amount of water/coolant added to get back to the top of the threads. Is this likely to have caused problems?

I was watching the temperature gauge and it was working normally (for once, thanks to a new sender) with the fans cutting in, temperature gauge dropping, fans cutting out, etc. Also, the heater was blowing out hot air so I presume the heater matrix was being fed with hot coolant. I think there was at least some coolant in the swirl tank and when I opened the radiator bleed screw, water came out with only a small drop in the swirl tank.

I've driven home (4 hours) and then to work yesterday, all in fairly cool weather but I'm a bit worried I've warped the heads or something equally expensive. I presume a pressure test is the only way to confirm?

It was probably an air lock so I have bled the system and will watch the levels and check for leaks.

This has not been a good year for TVR problems

Thanks,

Ian A.
96' Griff 500

[2 sheds]

I would say that as you've kept an eye on the temperature gauge and the weather has been cold you should be OK, Its worth pressure testing though to make sure there are no leaks.
Tim

[plipton]

2 sheds said: I would say that as you've kept an eye on the temperature gauge and the weather has been cold you should be OK

As the temp hasn't gone above normal running temperature you should be OK. (Fingers crossed)

A close shave, though !!!

[seb]

Ian,
I wonder if your set-up is the same as my 400 V8S, it sounds like it. If so you've nothing to worry about. What looks like an expansion tank (as most cars have, including my old 350i) isn't - it's an overflow tank and should be fitted with a standard non-sprung radiator cap (my overflow tank is always empty). With this system the pressure limited radiator cap (15lb) sits on the swirl tank. If you fill the swirl tank to the top and run the car the pressure created will blow some of the excess coolant through the pressurised cap into the overflow tank. Typically the coolant level settles around 2 or 3 inches down the swirl pot. At first I used to keep filling it up to the top until reading other's threads about this issue. The level now is consistently a couple of inches down the swirl tank, which I can just reach with the end of my finger. On a lot of cars the 'expansion' tank is part of the pressurised system, on my V8S it's not it's just there to catch any excess coolant that the engine needs to shed while settling to a level.

Steve

[IPAddis]

seb said: Ian,
I wonder if your set-up is the same as my 400 V8S, it sounds like it. If so you've nothing to worry about. What looks like an expansion tank (as most cars have, including my old 350i) isn't - it's an overflow tank and should be fitted with a standard non-sprung radiator cap (my overflow tank is always empty). With this system the pressure limited radiator cap (15lb) sits on the swirl tank. If you fill the swirl tank to the top and run the car the pressure created will blow some of the excess coolant through the pressurised cap into the overflow tank. Typically the coolant level settles around 2 or 3 inches down the swirl pot. At first I used to keep filling it up to the top until reading other's threads about this issue. The level now is consistently a couple of inches down the swirl tank, which I can just reach with the end of my finger. On a lot of cars the 'expansion' tank is part of the pressurised system, on my V8S it's not it's just there to catch any excess coolant that the engine needs to shed while settling to a level.

Steve

I'm 99% positive that I have a swirl tank and an expansion tank but that the expansion tank should be half full. It always used to be.

Thanks for the suggestion though.

Ian A.

[seb]

You probably do have both. The swirl pot is the large cylindrical tank just behind the radiator, which should have the pressurised cap on it. The expansion tank is usually mounted on the bulkhead with a blanking cap. On most mainstream cars the expansion tank allows for the expansion of coolant up to 100 degrees, the level fluctuates according to coolant temperature and is sucked back into the main system when cooling. In this system the pressurised cap fits on the expansion tank to allow for pressure relief if overheating occurs. On the V8S the pressure difference due to rising operation temperatures is accomodated within the swirl tank. If overheating occurs coolant is released by the pressurised cap into the 'expansion' overflow tank. I'm not sure if this lost coolant can be sucked back into the swirl tank. On mainstream cars the expansion tank has two pipes attached, one at the top near the blanking cap to allow the excess coolant to expand into the tank and one pipe at the bottom of the tank (below the coolant level) to allow coolant to be sucked back into the main system as the temperature drops and the pressure decreases. I'm sure that my overflow tank only has one in pipe and an overflow pipe if the tank fills up.

[boosted ls1]

My Rovers always suck in a load of water after a rebuild. I take them for a drive to warm the system up and then park up to let things cool down. After that I top the water up to the correct level. You should be fine especially as you kept an eye on the guages and heater etc. Mike

[Ballistic Banana]

I had my Rad fixed and also changed all the pipes and the collant now sits right near the bottom of the expansion tank.
It used to sit about halfway up/down dont know the reason why it has changed but i have had no problems with overheating etc
Also i remember seening this in other threads and people seem to find it settles at all different levels .

BB