Coolant coming from my filler cap
Discussion
Hi Guy's... could you let me have your thoughts on the following.... I could have air locks in the system but have done a few hundred miles now (how long can they hang around for?) or may be something more serious?.. I had the rad out over winter so coolent all out... and I did notice Sunday that the heater appeared to go up a degree or two on the home run... but why would air coming out of the system also take coolant with it??
So, I have a 5Ltr TVR Griff engine?... Last weekend we travelled 150 miles and got stuck in every traffic jam going.. The fan’s come on at 90 and dragged the temp back down to 80 etc and all appeared to work very well.. and when I got home I checked the coolant level and it was half way up the expansion tank (I think normal position)just where I'd filled it.
.
This weekend we did another 150 miles to Chatsworth (a great day!!) most of it on the motorway, and the temp never got above 80 deg.. but most of the motorway it was running as cold as 65 deg… However on the way back it sat more at 70 deg...Having got home, I again checked the level and it was a good inch under the half way point?? But the temp had not got close to where it was a week before? So why loose coolant from a cooler running system??
.
The coolant is coming out of the cap (you can see the stains on the polished bottle)and it's a new cap.
.
I’ve also noticed that on a cold engine (taking the car out of the garage onto the drive say)… the level will be half way in the garage and then a bit above half way on the drive… like it’s increased in volume?? (this may be missleading as it's pushing against a closed stat)
.
Could it be that I have a gasket leaking… but only at low temp before the engine get’s warm and expands to seal it??
Some suggest a liner may have slipped or there may be porosity in the block?... But I would have thought this would have caused bigger problems?.. and at temp?
.
My car is on a T plate, 99 make.. has 10 bolt heads and is fitted with fibre head gaskets?
.
Although this is no great loss over 150 miles… any thoughts on why it’s happening.. especially at cooler temps??..
Your comments would be appreciated... Cheers
So, I have a 5Ltr TVR Griff engine?... Last weekend we travelled 150 miles and got stuck in every traffic jam going.. The fan’s come on at 90 and dragged the temp back down to 80 etc and all appeared to work very well.. and when I got home I checked the coolant level and it was half way up the expansion tank (I think normal position)just where I'd filled it.
.
This weekend we did another 150 miles to Chatsworth (a great day!!) most of it on the motorway, and the temp never got above 80 deg.. but most of the motorway it was running as cold as 65 deg… However on the way back it sat more at 70 deg...Having got home, I again checked the level and it was a good inch under the half way point?? But the temp had not got close to where it was a week before? So why loose coolant from a cooler running system??
.
The coolant is coming out of the cap (you can see the stains on the polished bottle)and it's a new cap.
.
I’ve also noticed that on a cold engine (taking the car out of the garage onto the drive say)… the level will be half way in the garage and then a bit above half way on the drive… like it’s increased in volume?? (this may be missleading as it's pushing against a closed stat)
.
Could it be that I have a gasket leaking… but only at low temp before the engine get’s warm and expands to seal it??
Some suggest a liner may have slipped or there may be porosity in the block?... But I would have thought this would have caused bigger problems?.. and at temp?
.
My car is on a T plate, 99 make.. has 10 bolt heads and is fitted with fibre head gaskets?
.
Although this is no great loss over 150 miles… any thoughts on why it’s happening.. especially at cooler temps??..
Your comments would be appreciated... Cheers
If the system has been drained you can find air bubbles coming out months and thousands of miles later. Obviously the worst of the air will come out fairly quickly.
It's completely normal for the level to change with temperature and revs, if you have the pressure cap off.
Keep an eye out for scum in the coolant, or large quantities of froth coming out if you rev it with the pressure cap off, but if you don't see those symptoms and the engine hasn't overheated there's no reason to suspect head gasket failure or a dropped liner.
It's a good idea to keep an eye on the heater temperature. If that ever stops blowing hot air it's possible that you have no coolant circulation, in which case regardless of what the temp gauge says you should stop and check immediately.
It's completely normal for the level to change with temperature and revs, if you have the pressure cap off.
Keep an eye out for scum in the coolant, or large quantities of froth coming out if you rev it with the pressure cap off, but if you don't see those symptoms and the engine hasn't overheated there's no reason to suspect head gasket failure or a dropped liner.
It's a good idea to keep an eye on the heater temperature. If that ever stops blowing hot air it's possible that you have no coolant circulation, in which case regardless of what the temp gauge says you should stop and check immediately.
Yes.. should have said... no oil in water / water in oil / steem from exhaust etc.. but when I got the car last year, it had a leaking rad, only 1 fan running and had just come back for a 1500 mile trip around France.. So don't know if it's ever been overheated... I did a few miles last year before putting it away and doing the chassis, and have only really done these two run's this year so far... but did think air would come out in this time.. No bubbles when you rev it or anything...
But why would escaping air take coolant with it?? and half a cup is no small amount for an air bibble.
But why would escaping air take coolant with it?? and half a cup is no small amount for an air bibble.
Edited by TVR Beaver on Monday 27th April 13:12
Half-way up the expansion tank is overfilled in my Griff. It always finds its own level which is about an inch above the bottom of the tank. Any more filling than that and the system just "loses" it and I end up with a very humid & steamed up cabin! System has been pressure tested and there are no leaks.
That's just the way they seem to be!
That's just the way they seem to be!
Have talked with people who say they run close to the bottom... But it ran okay last year at 1/2 way mark for the couple of hundred miles I did... and this year on the first 'hot' run where it was on the fan's a lot.. and came back at 1/2 way?... And that's another good point you make... I didn't smell it when it came out.. usually you get a wiff of coolant when they blow... mind you... I did have the top off!!
TVR Beaver said:
But why would escaping air take coolant with it?? and half a cup is no small amount for an air bibble.
The air bubble acts like a big spring and makes the coolant volume change more than normal with temperature and pressure. Even without air in the system you will find the volume changes a lot as the revs and temperature change, but having air bubbles in there exaggerates this effect. 
HRG said:
Open the big brass screw when it's cold... That's the highest point in the system.
Make sure the header tank is full to the brim. Take out rad. drain plug while filling from there & check only coolant comes out.
Mine runs with expansion tank level about 1" from bottom - any more & it has a dump on my garage floor
.Thanks Guys... but Rad full of coolant and swirl pot to top (I did both these when I fit the new rad).. and I ran the engine whilst filling and squeesed all the air out of the top hose etc, ect...
.
No, think may be 3 options...
.
Air has been stuck in heater matrix
.
Level is differant now with new coolant type and will settle lower
.
I have a micro-gasket leak
.
The last option I think I will have to let get worst before tackling it.. when I say gasket I cover porosity / liner slips etc.... I pulled engines down before and could not find the problem.. so will wait till it shows it's self propper before delving in.... Just drive around with a buckett of water in the boot incase it throws a wobbler...
.
Had a XR2 once that would go week with no problem.. then for some reason it would dump all it's fluid... A skim and a new head gasket sorted that.... But how much is this operation on a RV8?.. any thoughts??
.
Cheers....
.
No, think may be 3 options...
.
Air has been stuck in heater matrix
.
Level is differant now with new coolant type and will settle lower
.
I have a micro-gasket leak
.
The last option I think I will have to let get worst before tackling it.. when I say gasket I cover porosity / liner slips etc.... I pulled engines down before and could not find the problem.. so will wait till it shows it's self propper before delving in.... Just drive around with a buckett of water in the boot incase it throws a wobbler...
.
Had a XR2 once that would go week with no problem.. then for some reason it would dump all it's fluid... A skim and a new head gasket sorted that.... But how much is this operation on a RV8?.. any thoughts??
.
Cheers....
On my 97 Griff there is another point where you can bleed air from the system. On the N/S cylinder head, near the oil filler cap is a hose about 3" long blanked off with a bolt stuck in the end of it. This is the hose which, in the engine's original application, goes to heat the plenum.
Hi TVRBeaver
apart from the water level changing about and inch or so I dont think you have anything to worry about. There arent any other symptoms. The water temp may be slightly different now but when you emptied the water system you may have had a 'wetter' in there and most defineately a different antifreeze with a different volume percentage. THis would explain why it is different to before.
If you had a head gasket problem I would expect you to loose more water. It can take a time to get all of the air out.
I will find out this week as I will be putting in a recored rad.
Trev
apart from the water level changing about and inch or so I dont think you have anything to worry about. There arent any other symptoms. The water temp may be slightly different now but when you emptied the water system you may have had a 'wetter' in there and most defineately a different antifreeze with a different volume percentage. THis would explain why it is different to before.
If you had a head gasket problem I would expect you to loose more water. It can take a time to get all of the air out.
I will find out this week as I will be putting in a recored rad.
Trev
HRG. the swirl-pot has the big brass cap... I've removed this a number of times and it's always full... so that's good news...
As Trev says... I have diff coolent in now and diff % so that may make an inch or so... Also interesting about the 'old' plenim feed... I've not seen this so will have a look tonight!
Thanks for all your inputs.....
Cheers...
As Trev says... I have diff coolent in now and diff % so that may make an inch or so... Also interesting about the 'old' plenim feed... I've not seen this so will have a look tonight!
Thanks for all your inputs.....
Cheers...
Edited by TVR Beaver on Tuesday 28th April 17:15
AlanKSG said:
Half-way up the expansion tank is overfilled in my Griff. It always finds its own level which is about an inch above the bottom of the tank. Any more filling than that and the system just "loses" it and I end up with a very humid & steamed up cabin! System has been pressure tested and there are no leaks.
That's just the way they seem to be!
Mine tooThat's just the way they seem to be!
Well.. I've done a few hundred miles more now and needed to nip up a couple of pipes due to leaks... I made a cap that I put on the header tank and connected to a pressure gauge and the air line... I put about 20PSI in the system and overnight id dropped to about 15 PSI?... This is how I found the leaks and nipped them up....
Having done 100 miles last weekend, it's gone from 45mm in the tank to 40mm??
If it's heading for the 1" mark as other suggest here, would it not get there quicker?.. how long does it take to hit the 1"???...
I sometimes smell something that's like coolant also... but I'm buggered if I can find it leaking anywhere else?... and nothing appears on the garage floor....
If it was a head gasket / crack / small hole I'm sure I'd see scum or slight bubbles... but nothing??
I know it's not a huge amount but is annoying... What about block seal?.. anyone tried it?.. Any other thoughts before I pull the engine in bit's!!!
Having done 100 miles last weekend, it's gone from 45mm in the tank to 40mm??
If it's heading for the 1" mark as other suggest here, would it not get there quicker?.. how long does it take to hit the 1"???...
I sometimes smell something that's like coolant also... but I'm buggered if I can find it leaking anywhere else?... and nothing appears on the garage floor....
If it was a head gasket / crack / small hole I'm sure I'd see scum or slight bubbles... but nothing??
I know it's not a huge amount but is annoying... What about block seal?.. anyone tried it?.. Any other thoughts before I pull the engine in bit's!!!
Before you go 
over an internal fault I would suggest you get a chemical cylinder leakage test kit or go to a local garage & ask them to do a 'sniffer' test with an emissions testing machine.
With either method what you are looking for are hydrocarbons (unburnt fuel) in the cooling system which will only be present if you have an internal leakage i.e headgasket. Both tests are not 100% accurate with very small leaks but from the sounds of your coolant losses if there is an internal leak it would be enough to register.
There does seem to be alot of variance to the levels that the Tivs run at in the expansion bottle. My Griff seems to be happy at about half way but a friend of mines Griff runs with less than an inch of coolant in the bottle & never has any problems
, if he adds coolant it just chucks it back out
Bodders
over an internal fault I would suggest you get a chemical cylinder leakage test kit or go to a local garage & ask them to do a 'sniffer' test with an emissions testing machine.With either method what you are looking for are hydrocarbons (unburnt fuel) in the cooling system which will only be present if you have an internal leakage i.e headgasket. Both tests are not 100% accurate with very small leaks but from the sounds of your coolant losses if there is an internal leak it would be enough to register.
There does seem to be alot of variance to the levels that the Tivs run at in the expansion bottle. My Griff seems to be happy at about half way but a friend of mines Griff runs with less than an inch of coolant in the bottle & never has any problems
, if he adds coolant it just chucks it back out Bodders
Gassing Station | Griffith | Top of Page | What's New | My Stuff