Coolant stains on swirl tank
Discussion
Hi guys
Been getting staining on the swirl tank all of a sudden. I've spotted as well a small antifreeze stain on the rad in between the fans so looks like the rad is on the way out. I would have thought in that case the rad would be seeping coolant while the cap holds pressure though?
And although the rad is stained I havent been able to see any more coolant loss from it even after eye-balling the engine for a good while as it cooled down. Maybe the stain on the rad is a splash mark from when the old cap had its first ''episode'' lol.
I've tried a pattern VW cap btw. It's better but stil there a bit and the level isn't going down nor is it overheating
Been getting staining on the swirl tank all of a sudden. I've spotted as well a small antifreeze stain on the rad in between the fans so looks like the rad is on the way out. I would have thought in that case the rad would be seeping coolant while the cap holds pressure though?
And although the rad is stained I havent been able to see any more coolant loss from it even after eye-balling the engine for a good while as it cooled down. Maybe the stain on the rad is a splash mark from when the old cap had its first ''episode'' lol.
I've tried a pattern VW cap btw. It's better but stil there a bit and the level isn't going down nor is it overheating
Make sure the outlet from the expansion/filler tank isn't blocked. The alloy on mine had corroded such that I had to run a drill through it to clear it.
The coolant in the expansion tank looked nice and blue but beyond the expansion tank it was brown.
The coolant level was much lower than it should have been but the coolant from the tank couldn't get through hence it looked OK.
Also worth checking the rad from the front looking up from underneath. I saw a mates chim s few months ago where from the back the rad looked fine but from the front looking up it was a mess with most of the cooling fins missing and it was weeping in several places.
The coolant in the expansion tank looked nice and blue but beyond the expansion tank it was brown.
The coolant level was much lower than it should have been but the coolant from the tank couldn't get through hence it looked OK.
Also worth checking the rad from the front looking up from underneath. I saw a mates chim s few months ago where from the back the rad looked fine but from the front looking up it was a mess with most of the cooling fins missing and it was weeping in several places.
Great advise guys thanks.
It's reminded me of my old 635csi BMW, I had the same symptoms and in the end it was the rad return to the header tank that was blocked which I guess will be much the same as if the alloy outlet from the swirl tank is blocked.
Yes the coolant is nice and blue which has always amazed me.
It's reminded me of my old 635csi BMW, I had the same symptoms and in the end it was the rad return to the header tank that was blocked which I guess will be much the same as if the alloy outlet from the swirl tank is blocked.
Yes the coolant is nice and blue which has always amazed me.
Tyre Tread said:
Make sure the outlet from the expansion/filler tank isn't blocked. The alloy on mine had corroded such that I had to run a drill through it to clear it.
The coolant in the expansion tank looked nice and blue but beyond the expansion tank it was brown.
The coolant level was much lower than it should have been but the coolant from the tank couldn't get through hence it looked OK.
Also worth checking the rad from the front looking up from underneath. I saw a mates chim s few months ago where from the back the rad looked fine but from the front looking up it was a mess with most of the cooling fins missing and it was weeping in several places.
This happened to mine, thought the coolant level was ok by checking the expansion can, but didnt realise the swirl pot was getting lower due to a tiny leak on the rad until the car overheated, found the tube in the base on the expansion can blocked, check the swirl pot as well now to confirm level is ok.The coolant in the expansion tank looked nice and blue but beyond the expansion tank it was brown.
The coolant level was much lower than it should have been but the coolant from the tank couldn't get through hence it looked OK.
Also worth checking the rad from the front looking up from underneath. I saw a mates chim s few months ago where from the back the rad looked fine but from the front looking up it was a mess with most of the cooling fins missing and it was weeping in several places.
Hi guys
I haven't done anything to the car, haven't even driven much been so busy but the few times I have, i've been in heat wave conditions stuck on the North Circ in traffic, steady country drives, fast drives, well basically most conditions and even though it still stains the swirl pot it never overheats at all.
I wondered if that might help cement any of the great theories mentioned ubove before I get it apart..
Cheers!
I haven't done anything to the car, haven't even driven much been so busy but the few times I have, i've been in heat wave conditions stuck on the North Circ in traffic, steady country drives, fast drives, well basically most conditions and even though it still stains the swirl pot it never overheats at all.
I wondered if that might help cement any of the great theories mentioned ubove before I get it apart..
Cheers!
Happens to mine, but it ain't broke so why tear it appart ??
I use mine on the Hillclimbs & Sprints with TVR Speed Champs and I think it gets hotter after 1 and 3 quarters laps of Pembry and Castle Coombe than on the road!!
I have no loss of fluid and like you at a loss as to why, but I am not planning on pulling anything apart!!
HTH
Trev
I use mine on the Hillclimbs & Sprints with TVR Speed Champs and I think it gets hotter after 1 and 3 quarters laps of Pembry and Castle Coombe than on the road!!
I have no loss of fluid and like you at a loss as to why, but I am not planning on pulling anything apart!!
HTH
Trev
dog man said:
Yeah, I'm kinda thinking the same but I've noticed a tiny stain coming from the bleed screw which was never there before so it's getting over pressurized somehow I think. I wanted to start by changing the coolant and checking for blockages
If its being overpressured the it suggests that either the cap isn't realessing pressure when it should or there's a blockage in the hose or entrance to the expansion pot. Again, I suggest that you check the alloy pipe leaving the bottom of the expansion tank first. It's easy enough to do.
All sorted.
Drained the coolant and blew through the swirl pot to top hose section (removed at rad end) and some rather revolting brown crap came shooting out - must have been a build up causing bad flow or something. Refilled and bled, Goodwood done and dusted, then a trip into east London in the evening and it's not lost/spewed out a drop.
Drained the coolant and blew through the swirl pot to top hose section (removed at rad end) and some rather revolting brown crap came shooting out - must have been a build up causing bad flow or something. Refilled and bled, Goodwood done and dusted, then a trip into east London in the evening and it's not lost/spewed out a drop.
Hey guys
Just a quick Q regarding this.
Changing coolant seemed to improve things, so much so that when hot you can take the cap off without coolant shooting out - even from hot. Thats not normal is it?? I mean it's handy but no car I've had will ever let me do that from hot...
However, I still get the odd stain on the swirl tank and a bit of coolant loss AND a small amount of stainage from the rad bleed screw....All this pressure yet you can remove the swirl tank cap when hot and no/not much pressure is released???
Whats going on? could something be blocked near the thermostat/thermostat not opening fully?
Or is it simply the pattern swirl tank cap, but if it leaks past the cap how comes it also leaks past the rad bleed screw o ring??
Just a quick Q regarding this.
Changing coolant seemed to improve things, so much so that when hot you can take the cap off without coolant shooting out - even from hot. Thats not normal is it?? I mean it's handy but no car I've had will ever let me do that from hot...
However, I still get the odd stain on the swirl tank and a bit of coolant loss AND a small amount of stainage from the rad bleed screw....All this pressure yet you can remove the swirl tank cap when hot and no/not much pressure is released???
Whats going on? could something be blocked near the thermostat/thermostat not opening fully?
Or is it simply the pattern swirl tank cap, but if it leaks past the cap how comes it also leaks past the rad bleed screw o ring??
The pressure cap could be faulty by not letting the pressure rise.
As you have a pressure tester (swirl pot version?) you could test the cap via this. Also where pressure is getting to (or not) to identify where a blockage may be.
What temperature does you gauge show (its probably more relevant to ask if your temprature gauge is showing different to 'normal').
As you have a pressure tester (swirl pot version?) you could test the cap via this. Also where pressure is getting to (or not) to identify where a blockage may be.
What temperature does you gauge show (its probably more relevant to ask if your temprature gauge is showing different to 'normal').
Edited by Harrytsg on Friday 14th October 08:07
TVR Beaver said:
No.. not normal... is the rest of the system presurising?.. (does the top hose go hard?)
If yes.. then it sounds like your small tube to the swirl pot is blocked (again?)... or may be breaking down inside and acting like a valve... I'd get it replaced for what it is and try again...
A point for clarity sake;If yes.. then it sounds like your small tube to the swirl pot is blocked (again?)... or may be breaking down inside and acting like a valve... I'd get it replaced for what it is and try again...
On my '98, the swirl tank is mounted on the front of the engine (passenger side), and has a large brass filling screw.
The overflow tank is wing mounted (driver side) and has a blue pressure relief cap.
I have seen some pictures of (older?) cars where the swirl tank has a blue cap, and the overflow tank is frame mounted centrally. Which are we talking about in your case?
Agreed, definitely "not normal" (in either case).
Assuming yours is like mine;
Is the staining starting from the top of the swirl tank i.e. the brass filler screw?
I just replaced my tank because the weld around the centre of the tank had failed (hole was hidden under the big jubilee clip), and was leaking slowly (until I loosened the jubilee clip to look).
Try a new o-ring on that brass screw as well.
If working 'correctly', the pressure cap should 'go' first (in either configuration) in the case of overheating/extra high pressure situations.
BTW, swirl pots and overflow tanks are not cheap.
I can point you to two second hand swirl pots at a very helpful breakers, but given the weld failure (it ultimately failed in four places) on mine (after 13 years), I would be very reluctant to trust an old one.
I just spent two weeks chasing the leaks around the cooling system following installing a new radtech radiator and rubber hoses. While mine never gets overly hot (and to be fair it never did from new until my original radiator was smashed), it managed to find every weak point in the system to allow a drop or two to escape...
HI guys
Mines pre serp with just the swirl tank with the blue Vag cap. No small hose going to it, no brass screw.
As well as the obvious pressure coming from the rad bleed screw and cap, I've seen stainage in the core as well (rad not that old) so somewhere she's a bit under pressure??? (flushed rad on Wed with gdn hose too)
Temp doesnt go past the middle, traffic not a problem etc. Car seems happy in that respect.
Actually, previously (to Wednesday this week) it always went up to just under 90 then the fans would come in...
....strange though, I just changed the coolant again and now the fans come in earlier...is that common?
If I hooked the otter switch up backwards it would turn the fans on all the time no? (fans are definitely running the right way as well)
I'm pretty sure they went back on the right way around...fans coming in earlier cant be bad though! but why suddenly doing that after a coolant change?!
Mines pre serp with just the swirl tank with the blue Vag cap. No small hose going to it, no brass screw.
As well as the obvious pressure coming from the rad bleed screw and cap, I've seen stainage in the core as well (rad not that old) so somewhere she's a bit under pressure??? (flushed rad on Wed with gdn hose too)
Temp doesnt go past the middle, traffic not a problem etc. Car seems happy in that respect.
Actually, previously (to Wednesday this week) it always went up to just under 90 then the fans would come in...
....strange though, I just changed the coolant again and now the fans come in earlier...is that common?
If I hooked the otter switch up backwards it would turn the fans on all the time no? (fans are definitely running the right way as well)
I'm pretty sure they went back on the right way around...fans coming in earlier cant be bad though! but why suddenly doing that after a coolant change?!
dog man said:
HI guys
Mines pre serp with just the swirl tank with the blue Vag cap. No small hose going to it, no brass screw.
As well as the obvious pressure coming from the rad bleed screw and cap, I've seen stainage in the core as well (rad not that old) so somewhere she's a bit under pressure??? (flushed rad on Wed with gdn hose too)
Temp doesnt go past the middle, traffic not a problem etc. Car seems happy in that respect.
Actually, previously (to Wednesday this week) it always went up to just under 90 then the fans would come in...
....strange though, I just changed the coolant again and now the fans come in earlier...is that common?
If I hooked the otter switch up backwards it would turn the fans on all the time no? (fans are definitely running the right way as well)
I'm pretty sure they went back on the right way around...fans coming in earlier cant be bad though! but why suddenly doing that after a coolant change?!
If you have changed the coolant you need to be confident you have all the air out of the system, I followed the techniques on here and still needed to top up slightly for the next few days.Mines pre serp with just the swirl tank with the blue Vag cap. No small hose going to it, no brass screw.
As well as the obvious pressure coming from the rad bleed screw and cap, I've seen stainage in the core as well (rad not that old) so somewhere she's a bit under pressure??? (flushed rad on Wed with gdn hose too)
Temp doesnt go past the middle, traffic not a problem etc. Car seems happy in that respect.
Actually, previously (to Wednesday this week) it always went up to just under 90 then the fans would come in...
....strange though, I just changed the coolant again and now the fans come in earlier...is that common?
If I hooked the otter switch up backwards it would turn the fans on all the time no? (fans are definitely running the right way as well)
I'm pretty sure they went back on the right way around...fans coming in earlier cant be bad though! but why suddenly doing that after a coolant change?!
Regarding the otter switch, I think it is just a thermal switch that completes the earth path. (I'd need to confirm though).
Is it the Steve Heath pressure tester adapter you have?
Gassing Station | Chimaera | Top of Page | What's New | My Stuff