Expansion tank level.. Griff 500... any new thoughts on this
Discussion
I know this has come up many times, and I also know how individual’s cars run at different levels etc… My car has run all year at 33mm from the bottom, where as I know others run 2/3rd’s full in the expansion tank….
But why?..
looking at the expansion you get in water from 20 deg to say 90 deg it’s nowhere like the air gap I’m running (close to 1 ltr)… Why does the coolant need all this expansion potential?... My other car runs on the level line if it’s cold or hot… So what’s happening in the V8’s?...
It was suggested on one post that a low level is indicative of a head problem about to start…. A slight weep on the gasket allowing an amount of gas into the system but controlled if you like so it does not just blow it all out?
The reason I’m thinking about this again is that I had my car on the rolling road over the weekend… It spent about 3 hours on there… Having run at 33mm all year I measured it when I got it back and it had cooled off… It had gone down to 19mm??... why
I’ve had the sniffer in the tank a month ago and it showed no trace of exhaust gas or whatever it detects…. And the system has been filled by many people and heater pipes removed etc to get rid of trapped air.
Just can’t get my head around why these things vary so much and then throw a bit more out for good measure??
Anyone had low level develop into a head failure?.. or high level into a head failure….
I’m also running a 1.3 bar cap… if it was 1 bar I’m sure the expansion tank would be empty now??.. Any thought?
But why?..
looking at the expansion you get in water from 20 deg to say 90 deg it’s nowhere like the air gap I’m running (close to 1 ltr)… Why does the coolant need all this expansion potential?... My other car runs on the level line if it’s cold or hot… So what’s happening in the V8’s?...
It was suggested on one post that a low level is indicative of a head problem about to start…. A slight weep on the gasket allowing an amount of gas into the system but controlled if you like so it does not just blow it all out?
The reason I’m thinking about this again is that I had my car on the rolling road over the weekend… It spent about 3 hours on there… Having run at 33mm all year I measured it when I got it back and it had cooled off… It had gone down to 19mm??... why
I’ve had the sniffer in the tank a month ago and it showed no trace of exhaust gas or whatever it detects…. And the system has been filled by many people and heater pipes removed etc to get rid of trapped air.
Just can’t get my head around why these things vary so much and then throw a bit more out for good measure??
Anyone had low level develop into a head failure?.. or high level into a head failure….
I’m also running a 1.3 bar cap… if it was 1 bar I’m sure the expansion tank would be empty now??.. Any thought?
Edited by TVR Beaver on Monday 2nd November 08:22
But would be good to understand what's going on here?.. the coolant volume increase 20-90 deg calculates about half what we see in the tank (with regards to air gap)... so where does the rest come from???.. Is it a positional issue with the tank being below the water levels in the heads / manifolds etc?.. and if so... why?
.
When on the rolling road they have to run at full belt to adjust the high sites.. this coupled with the 90 deg engine temp is something you don't do on the road.. usualy high temp low speed... or high speed low temp... so get them both up there and the guy says it's possable to push a bit more out?? Hope he's right.... strange things these Tiv's arn't they!!
.
When on the rolling road they have to run at full belt to adjust the high sites.. this coupled with the 90 deg engine temp is something you don't do on the road.. usualy high temp low speed... or high speed low temp... so get them both up there and the guy says it's possable to push a bit more out?? Hope he's right.... strange things these Tiv's arn't they!!
its just that it sit's at 33mm unless you give it a real good thrashing as on the rollers... then it pushes a bit more out???... is it because at this RPM / duration the system is leaking a bit and pressurising from the cylinders... or is it due to increased temp and water flow not seen on the road?? Not sure??
Here's my experience of expansion tank levels.
I've had a Griff 500 for some years, bought from a respected dealer in Winter. When I first checked the expansion tank, it was dry, so of course I refilled it (using the correct filling method etc) leaving the expansion tank half full. At the next check it was empty.
To cut a long story short, I did this a number of times then accepted that the car runs OK with an empty expansion tank. It's steady at 90 deg, and did around 20000 miles in this condition, including a Le Mans trip with outside temp around 35 degrees!
Around 18 months ago, following a service, I suddenly found that the water in the expansion tank was about 1" from the bottom, where it has stayed ever since - there appears to be no reason for this, and the car ran just the same.
I think this bears out that some cars can have a different level in the expansion tank and still run OK. (I've recently found the fans are permanently on, but this has just occurred in the last couple of weeks and is another story ...)
I've had a Griff 500 for some years, bought from a respected dealer in Winter. When I first checked the expansion tank, it was dry, so of course I refilled it (using the correct filling method etc) leaving the expansion tank half full. At the next check it was empty.
To cut a long story short, I did this a number of times then accepted that the car runs OK with an empty expansion tank. It's steady at 90 deg, and did around 20000 miles in this condition, including a Le Mans trip with outside temp around 35 degrees!
Around 18 months ago, following a service, I suddenly found that the water in the expansion tank was about 1" from the bottom, where it has stayed ever since - there appears to be no reason for this, and the car ran just the same.
I think this bears out that some cars can have a different level in the expansion tank and still run OK. (I've recently found the fans are permanently on, but this has just occurred in the last couple of weeks and is another story ...)
I have no end of arguments with regards to expansion bottle levels. Here's my two pence worth. My car was dumping coolant out to the point it become within an inch of the bottom of the expansion bottle. Through elimination it was eventually diagnosed with very small leak on the head gaskets. These have now been repaired and I can run mine 2 inch's BELOW the filler neck, thats about 3/4's full and it never dumps or looses coolant. Now at that time it had a standard radiator, I have now replaced this with an radtec alloy rad and it made no difference to the level in the expansion bottle. I still run it 3/4's full, no problems all year round. Also a friend of mine has a griffith 500 as well and he too runs it at this levels with it never loosing coolant. I have never figured out or heard a logical explanation as to why so many Griff's run low in the expansion bottle and others run higher!!! The only answer peple give, is 'its the way they are', but where is the logic in that!!!
Craig... I've tested for Hydro Carbons in the bottle and not a one... and also no bubbles after running.. the swirl pot stay air free... so I'm 100% I don't have a gasket leak or it would show.. especialy in the HC check...
The guy's at V8D said one of their cars would run at 3/4 full for ages.. but if it did fall for what ever reason... it would then keep going till it reached 1" from the bottom??.. that's why I asked the orig question... thinking once air got in there to any great extent, could this then be the cause of pushing water out as it expands greater than water at temp... so if you only have enough to cover the expansion say 1/4 of a tank... will the bottle hold this level?...I've never tried it?.. David says it will just push out??...
Who knows.. just fitted a 82 deg stat tonight and been for a spin... will see if this changes anything from the 74 I had in before??
The guy's at V8D said one of their cars would run at 3/4 full for ages.. but if it did fall for what ever reason... it would then keep going till it reached 1" from the bottom??.. that's why I asked the orig question... thinking once air got in there to any great extent, could this then be the cause of pushing water out as it expands greater than water at temp... so if you only have enough to cover the expansion say 1/4 of a tank... will the bottle hold this level?...I've never tried it?.. David says it will just push out??...
Who knows.. just fitted a 82 deg stat tonight and been for a spin... will see if this changes anything from the 74 I had in before??
Im not saying all cars that push out coolant have head gasket leaks (been accused of that before!), but I still cannot understand the reason why the cars are all different.
If my car would only run with 1" of coolant in the expansion bottle and say I filled it with another 2" of coolant, I presume the cars that pump it out would slowly resort back to only 1" of coolant!
If my car did this I would have to ask myself, where is all the air (the air inside the expansion bottle from coolant level to cap, and that is a lot of air!!) going???? I would presume the coolant is rising in the bottle through thermal expansion, slowly pushing the air through the cap for the coolant to go from the bottom of the bottle to the top. Now this can only occur for two reasons. 1. Simply the cap is leaking and not sealing the cooling system (and not allowing it to pressurise) and allowing the air to escape, and the coolant slowly rising until it reaches the cap. or 2. The system is going over the PSI release of the cap and the cap is venting off excess pressure, until the coolant reaches the cap and this is vented off as well.
I can't really see any other reason why the coolant would escape
Thanks.
If my car would only run with 1" of coolant in the expansion bottle and say I filled it with another 2" of coolant, I presume the cars that pump it out would slowly resort back to only 1" of coolant!
If my car did this I would have to ask myself, where is all the air (the air inside the expansion bottle from coolant level to cap, and that is a lot of air!!) going???? I would presume the coolant is rising in the bottle through thermal expansion, slowly pushing the air through the cap for the coolant to go from the bottom of the bottle to the top. Now this can only occur for two reasons. 1. Simply the cap is leaking and not sealing the cooling system (and not allowing it to pressurise) and allowing the air to escape, and the coolant slowly rising until it reaches the cap. or 2. The system is going over the PSI release of the cap and the cap is venting off excess pressure, until the coolant reaches the cap and this is vented off as well.
I can't really see any other reason why the coolant would escape
Thanks.
Apologies for resurecting this thread from the dead.
I topped the coolant up on my Griff recently as it was about an inch from the bottom of the expansion tank. Since I have topped it up I have noticed a couple of time whilst stuck in traffic steam comming from the front of the bonnet. It seems that this continues until the car has reverted back to the coolant level being an inch from the bottom of the tank, then it is happy again.
The temperature read out from the car always stays between 70 and 80 beofore the fan kicks in and seems to be fine.
Is this anything to worry about?
I topped the coolant up on my Griff recently as it was about an inch from the bottom of the expansion tank. Since I have topped it up I have noticed a couple of time whilst stuck in traffic steam comming from the front of the bonnet. It seems that this continues until the car has reverted back to the coolant level being an inch from the bottom of the tank, then it is happy again.
The temperature read out from the car always stays between 70 and 80 beofore the fan kicks in and seems to be fine.
Is this anything to worry about?
I would check that its definately coming from the expansion tank. If so, keep an eye on it but its probably 'just one of those things'. If you read through the rest of the thread, there would seem to be no rhyme or reason why the water levels vary so much.
If there's no sign of water coming from the expansion tank cap, then further investigation is needed.
I'm still getting my head round the fact that it sits very low in the engine bay and its not constantly full of water - but thats just me
If there's no sign of water coming from the expansion tank cap, then further investigation is needed.
I'm still getting my head round the fact that it sits very low in the engine bay and its not constantly full of water - but thats just me
simples.. no air in.. no water out... like when you pull a glass out of a bowl of water upside down.. .until the air get's in, the water stops in the glass... same here.. as your system has no air in it.. and non can get in due to the level in the bottom of the bottle.. no water will come out... It's a simple syphon type system...
.
my car runs about 30m from the bottom with a 1.3 bar cap on.. .I have no leaks... I don't have Carbons in the coolant (as checked by the garage) and no bubbles when stopped... so no problem...
I'd just keep an eye on it.. .if it stays where it is, that's it's level...
If you do get any of the above, then further investigation is required...
.
my car runs about 30m from the bottom with a 1.3 bar cap on.. .I have no leaks... I don't have Carbons in the coolant (as checked by the garage) and no bubbles when stopped... so no problem...
I'd just keep an eye on it.. .if it stays where it is, that's it's level...
If you do get any of the above, then further investigation is required...
Gassing Station | Griffith | Top of Page | What's New | My Stuff