struggling. with the cooling. system
Discussion
Thought I'd done it.........no
Jusy keeps taking liquid.
Topping up thru the swan neck and must have put in ten litres.
When I run her the header tank dumps it all (catching it now tho in a bottle)
I imagine to. Rad takes several litres and the engine must take five(ish).
Any ideas lads.......worried for the fest !!
Fans kick in
Jusy keeps taking liquid.
Topping up thru the swan neck and must have put in ten litres.
When I run her the header tank dumps it all (catching it now tho in a bottle)
I imagine to. Rad takes several litres and the engine must take five(ish).
Any ideas lads.......worried for the fest !!
Fans kick in
Oil level OK? If it's rising, sounds like water is getting into the oil (in which case you may as well look for a new engine now as you'll have been circulating a nice, non-lubricating emulsion around the oilways).
Otherwise, either a massive airlock or one of the head gaskets is blowing.
Otherwise, either a massive airlock or one of the head gaskets is blowing.
Agree - head gasket. Assuming you still have EFi not carbs?
Then try disconnecting the injector connector one at a time so there is no fuel going to that cylinder. It will run lumpy.
The water passages are at the ends of the heads so try cylinder 1, then 7, then 2, then 8. If the water stays in (or the problem gets less) then I think you have found the culprit.
You can road test too using this method but as I said it runs lumpy and is quite uncomfortable to drive. I've done 40 miles at a time with no ill-effects.
If you have head studs installed (on the off chance) then you can re-torque these in situ which might fix it for a while. To check this look at the head in between the exhaust manifolds where the bolt heads (or studs and nuts) are sticking out - the easiest being between 4 and 6 cylinder.
Then try disconnecting the injector connector one at a time so there is no fuel going to that cylinder. It will run lumpy.
The water passages are at the ends of the heads so try cylinder 1, then 7, then 2, then 8. If the water stays in (or the problem gets less) then I think you have found the culprit.
You can road test too using this method but as I said it runs lumpy and is quite uncomfortable to drive. I've done 40 miles at a time with no ill-effects.
If you have head studs installed (on the off chance) then you can re-torque these in situ which might fix it for a while. To check this look at the head in between the exhaust manifolds where the bolt heads (or studs and nuts) are sticking out - the easiest being between 4 and 6 cylinder.
Pressure cap on the header tank?Well, according to my TVR Owners Handbook, the coolant capacity of the 350i is stated as 11 litres, so you may still need a bit more if you have only put in 10 and lost some already. Possibly still some air somewhere in there. Is your heater working, as on mine (though a 280, so a bit different) I had an air lock in the heater, and once that cleared needed to add more coolant.
Hi Gav, well I got a slap off Angela for coming in at 10.30 & not calling 
Keep in mind what I said, all that water has to be going somewhere.
"It's either replacing the volume taken up by trapped air as it's bled out, it's dumping it on the floor... or its putting it into the cylinders"
I would have thought the rad will hold 3 litres, the block 4 litres & all that pipework another 3 litres.
Perhaps another 2 litres if you include the heater matrix & piping, but we have isolated this now.
Lets say the entire system holds an absolute maximum of 12-15 litres, yesterday we put 10 litres in it.
Which means it was either more or less empty when we started, or.... all that coolant is going somewhere.
I know you dont want to think about head gaskets & slipped liners but if it takes much more coolant & its not dumping on the floor, we've got to start looking at other possibilities.
Don't give up just yet, let everything settle and have another crack at it this evening, make a note of how much more coolant it takes & we'll have a chat about it.
If it takes any more than another 3-5 litres & it's not dumping it on the ground you really need to three more tests.
1) Get it someone with a sniffer to check for exhaust gasses in the coolant
2) Ask them to do a pressure test of the cooling system
3) Ask them to do a compression test on all 8 cylinders
For correct & conclusive diagnosis of the problem it's important all three test are done, not just one or two of them.
The results of all three tests will tell you if you have a head gasket & or a slipped liner issue.
Unfortunately I must say that the constantly returning misfire at idle does potentially point to water getting into one of the cylinders, to check this remove each spark plug in turn to see if one looks steam cleaned.
But don't panic just yet mate, at the end of the day we were still seeing air coming out and I have to say the way the pipe work is designed it should be no surprise it's a massive pain in the arsh to bleed up.
Remember a mechanical water pump is just a stirrer, it doesn't really create a huge amount of positive pressure, getting it to produce a solid column of water around all that convoluted pipework is a real ask.
Compared with a Range Rover your rad is very low, the hoses go through the most ridiculous convoluted paths & there's no bleed screw on top of the rad we could see.
Add to this a mechanical water pump that was never designed for such an over complicated plumbed system & it actually amazes me it would ever work at all.
Standing back from it for a minute, looking at the way it's plumbed & the abilities (or lack of) of the mechanical water pump, I cant help thinking you need a far greater positive flow of coolant than the old Range Rover pump can ever hope to muster.
An electric water pump would solve that problem, but you really need to try one last time to bleed it then get the above three tests done before you throw any more money at it.
I'll call you this evening to see how you're getting on.
Good luck with it, Dave.
Keep in mind what I said, all that water has to be going somewhere.
"It's either replacing the volume taken up by trapped air as it's bled out, it's dumping it on the floor... or its putting it into the cylinders"
I would have thought the rad will hold 3 litres, the block 4 litres & all that pipework another 3 litres.
Perhaps another 2 litres if you include the heater matrix & piping, but we have isolated this now.
Lets say the entire system holds an absolute maximum of 12-15 litres, yesterday we put 10 litres in it.
Which means it was either more or less empty when we started, or.... all that coolant is going somewhere.
I know you dont want to think about head gaskets & slipped liners but if it takes much more coolant & its not dumping on the floor, we've got to start looking at other possibilities.
Don't give up just yet, let everything settle and have another crack at it this evening, make a note of how much more coolant it takes & we'll have a chat about it.
If it takes any more than another 3-5 litres & it's not dumping it on the ground you really need to three more tests.
1) Get it someone with a sniffer to check for exhaust gasses in the coolant
2) Ask them to do a pressure test of the cooling system
3) Ask them to do a compression test on all 8 cylinders
For correct & conclusive diagnosis of the problem it's important all three test are done, not just one or two of them.
The results of all three tests will tell you if you have a head gasket & or a slipped liner issue.
Unfortunately I must say that the constantly returning misfire at idle does potentially point to water getting into one of the cylinders, to check this remove each spark plug in turn to see if one looks steam cleaned.
But don't panic just yet mate, at the end of the day we were still seeing air coming out and I have to say the way the pipe work is designed it should be no surprise it's a massive pain in the arsh to bleed up.
Remember a mechanical water pump is just a stirrer, it doesn't really create a huge amount of positive pressure, getting it to produce a solid column of water around all that convoluted pipework is a real ask.
Compared with a Range Rover your rad is very low, the hoses go through the most ridiculous convoluted paths & there's no bleed screw on top of the rad we could see.
Add to this a mechanical water pump that was never designed for such an over complicated plumbed system & it actually amazes me it would ever work at all.
Standing back from it for a minute, looking at the way it's plumbed & the abilities (or lack of) of the mechanical water pump, I cant help thinking you need a far greater positive flow of coolant than the old Range Rover pump can ever hope to muster.
An electric water pump would solve that problem, but you really need to try one last time to bleed it then get the above three tests done before you throw any more money at it.
I'll call you this evening to see how you're getting on.
Good luck with it, Dave.
I should add...
With the rad fans running the car held a perfect 90, the exhaust from the rad fans was nice warm air.
Then with the fans still on the air started to blow cold but the temp gauge rose to 100+.
That can only mean one thing.
There was definitely a large amount of air still trapped in the rad.
Squeezing the hoses gave us more bubbles at the swan neck, further conclusive evidence there is still air in there.
This all tells me you shouldn't get stressed out with the possibility of head gasket failure or slipped liners just yet.
Keep at the bleeding mate, if you eventually get 12-15 litres in it then all the air should be removed.
If it still overheats after that we should look at getting the three tests done, but not before you're 100% sure all that air has been removed.
You're biggest enemy is the bonkers way the whole system is plumbed.
With the rad fans running the car held a perfect 90, the exhaust from the rad fans was nice warm air.
Then with the fans still on the air started to blow cold but the temp gauge rose to 100+.
That can only mean one thing.
There was definitely a large amount of air still trapped in the rad.
Squeezing the hoses gave us more bubbles at the swan neck, further conclusive evidence there is still air in there.
This all tells me you shouldn't get stressed out with the possibility of head gasket failure or slipped liners just yet.
Keep at the bleeding mate, if you eventually get 12-15 litres in it then all the air should be removed.
If it still overheats after that we should look at getting the three tests done, but not before you're 100% sure all that air has been removed.
You're biggest enemy is the bonkers way the whole system is plumbed.
I had a similar thing last year except the coolant was frothing up like champagne as it came out the expansion tank into the over flow bottle and it was the head gasket at fault. i now have it doing it again but without the frothing so its pointing at slipped liner but havent had it checked properly yet. What a bumer!!
Although we closed the manual valve on the heater pipe to isolate the heater, it isn't actually fully isolated.
To do that you need to join the two pipes I showed you at the back of the engine.
You shouldn't really have to do this, but with the current problems your having & the way it's plumbed, completely isolating the heater can only help to make your life a bit easier.
Keep in mind when it's up to temp the exhaust air from the fans should always be nice and warm.
If the temp gauge shows hot, but the air being pulled through the rad is coming out cool you know there's no hot coolant running through the rad.
That means there's definitely air still in there.
As I've said already the problem is the crazy convoluted plumbing, and that mechanical pump is just designed to help the coolant around.
The mechanical pump is most definitely not designed to drive masses of air out of very long pipe work that changes direction so many times .
To see how this engine is designed to be cooled with the light assistance of the mechanical pump we need only look at a Range Rover.
Look at the top hose and compare it with yours Gav, now compare the position of the radiator, and I haven't even got to the bottom hose yet.
In my opinion, and based on what I witnessed yesterday, I'm convinced you've still got air trapped in the system.
To drive all that air out with all your up & down pipe work & low mounted radiator, I would have thought you're going to need a lot more shove than that mechanical pump can ever hope to muster.
Just my personal opinion having been with the car yesterday, and dont take this the wrong way, but whoever designed the cooling system that way wants shooting.
My guess is they designed the body then tried to cobble in a cooling system to suit an engine that needs a far more straightforward in & out cooling system in a higher mounted vertical rad.
The low sloping bonnet makes this impossible, the result is they were forced to use all that up & down pipe work making the thing an absolute nightmare to bleed.
If you mount even a small booster pump to assist the mechanical pump at the back of the engine where I showed you can bypass the heater, it will really help get all that air out.
Even the above little booster pump will create over 50psi and shift 15 litres (the entire coolant capacity) every 60 seconds.
To do that you need to join the two pipes I showed you at the back of the engine.
You shouldn't really have to do this, but with the current problems your having & the way it's plumbed, completely isolating the heater can only help to make your life a bit easier.
Keep in mind when it's up to temp the exhaust air from the fans should always be nice and warm.
If the temp gauge shows hot, but the air being pulled through the rad is coming out cool you know there's no hot coolant running through the rad.
That means there's definitely air still in there.
As I've said already the problem is the crazy convoluted plumbing, and that mechanical pump is just designed to help the coolant around.
The mechanical pump is most definitely not designed to drive masses of air out of very long pipe work that changes direction so many times .
To see how this engine is designed to be cooled with the light assistance of the mechanical pump we need only look at a Range Rover.
Look at the top hose and compare it with yours Gav, now compare the position of the radiator, and I haven't even got to the bottom hose yet.
In my opinion, and based on what I witnessed yesterday, I'm convinced you've still got air trapped in the system.
To drive all that air out with all your up & down pipe work & low mounted radiator, I would have thought you're going to need a lot more shove than that mechanical pump can ever hope to muster.
Just my personal opinion having been with the car yesterday, and dont take this the wrong way, but whoever designed the cooling system that way wants shooting.
My guess is they designed the body then tried to cobble in a cooling system to suit an engine that needs a far more straightforward in & out cooling system in a higher mounted vertical rad.
The low sloping bonnet makes this impossible, the result is they were forced to use all that up & down pipe work making the thing an absolute nightmare to bleed.
If you mount even a small booster pump to assist the mechanical pump at the back of the engine where I showed you can bypass the heater, it will really help get all that air out.
Even the above little booster pump will create over 50psi and shift 15 litres (the entire coolant capacity) every 60 seconds.
Edited by ChimpOnGas on Wednesday 10th July 15:25
With some coolant circuits you need to be careful shunting the heater matrix, might need a restrictor to ensure good flow through the radiator. Has the existing coolant circuit ever worked OK in its current form? If so, that should be the starting point, otherwise there is a risk of reinventing the wheel.
V8 Fettler said:
With some coolant circuits you need to be careful shunting the heater matrix, might need a restrictor to ensure good flow through the radiator. Has the existing coolant circuit ever worked OK in its current form? If so, that should be the starting point, otherwise there is a risk of reinventing the wheel.
I would normally agree, and I'm not 100% sure Gav's cooling system is still 100% as TVR intended it.But looking at it (as it is), I have to come to the conclusion this particular wheel is/was broken in the first place.
Honestly it's like the boiler room on the SS Titantic in there, there's pipes going up & down & all over the place.
That aint the way to build a reliable cooling system, it's the way to trap air.
On all the liquid cooled cars I've ever worked on I've never seen anything like it.
Well that's not strictly true, I've worked on a Hillman Imp with a front mounted rad mod.
Being rear engined, it had the top hose running the length of the N/S sill, & the bottom hose running along the O/S sill.
Like Gav's Wedge that's a lot of pipe work & volume of coolant for the little mechanical pump to move effectively.
The front mounted rad mod on Hillman Imps is quite common, because the original rear mounted rad never got enough air through it and they regularly cooked their heads.
It's another case of reinventing a broken wheel, with an electric water pump that font mounted mod works great.
Without it you would stand no chance.
It's a bit like the rear suspension on these cars, sometimes you've just got to accept when a design is flawed, and then get on with solving the problem.
There's no shame in reinventing a wheel that was broken in the first place.
That's what engineers do every day.
Hi Dave, it's funny that 9 out of 10 wedges run OK and don't overheat every 5 miles then...
I'm not saying it's the best plumbed system but it is workable. Also, it only needs to be 3/4-full to work fairly well, and not boil. A bit of air here or there won't matter too much.
There are so many bits of advice in this thread already it's hard to suggest where to go next with this. Also there are a lot of unanswered questions:
- is the oil level constant or rising?
- do the hoses feel "pressurised" when it wanms up?
- if so how long do they feel pressurised before going "flat" after stopping?
I would fill it as cold and then make sure you catch all the runoff, wait for it to go cold again and see if it fits back in. If it keeps spewing out and burping more air too, you've got to ask yourself how that air is being pumped in, against the water pressure.
I'm not saying it's the best plumbed system but it is workable. Also, it only needs to be 3/4-full to work fairly well, and not boil. A bit of air here or there won't matter too much.
There are so many bits of advice in this thread already it's hard to suggest where to go next with this. Also there are a lot of unanswered questions:
- is the oil level constant or rising?
- do the hoses feel "pressurised" when it wanms up?
- if so how long do they feel pressurised before going "flat" after stopping?
I would fill it as cold and then make sure you catch all the runoff, wait for it to go cold again and see if it fits back in. If it keeps spewing out and burping more air too, you've got to ask yourself how that air is being pumped in, against the water pressure.
hallsie said:
get it up on the kerb, or a jack, or ramp on one side and see if you can get the expansion tank higher to get the air out.
then try it with the rad at the high point.
Then call the monkey round to sort it out!
Stu
Good call hallsie, I suggested the much the same, re the heater.then try it with the rad at the high point.
Then call the monkey round to sort it out!
Stu
When you bleed a bleedin Chimp it really helps to get her nose up in the air to put the heater at the lowest point.
In this case there's some things suggesting a head gasket or a slipped liner, but there's also a lot to suggest its still got air in the system.
I know denial is a terrible thing, but Gav is a mate and for his sake I really want it to be nothing more than a bit of trapped wind.
My guess is the old girl just needs to let a big one go and she'll feel a million times better.
http://www.youtube.com/watch?v=Swd-uJTsSCY
ChimpOnGas said:
But looking at it (as it is), I have to come to the conclusion this particular wheel is/was broken in the first place.
Honestly it's like the boiler room on the SS Titantic in there, there's pipes going up & down & all over the place.
The Skoda Estelle and Lotus Esprit manged to get their coolant all the way to the front of the car and back again without any drama, which involved going down, along and back up, then down, along and back up. The Estelle's water pump was about as far from the rad. as it was possible to get!Honestly it's like the boiler room on the SS Titantic in there, there's pipes going up & down & all over the place.
...and it was RMS, not SS, Titanic...
jmorgan said:
350 pipe work is somewhat different to the 400 but I fitted a bleed valve at the highest point for the heater, helped me a lot with bleeding it off.
Also have a 350 cooling diagram somewhere. Post it up?
Nice one, that's a real help.Also have a 350 cooling diagram somewhere. Post it up?
I tried to call Gav 20 mins ago for a progress report, but he's not answering, so I did the only decent thing & opened a bottle of wine.
Feckin TVRs, they try your patience some times, but I can tell you when its on song Gav's 350 goes like ship off a shovel.
Refurbished wheels look the nuts too
I'll try him again to see how the old boy is getting on.
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