overheating roadblock 3000m
Discussion
When you have found and fitted the replacement inlet manifold you could check mixture with a ColorTune plug. For the helicoils they need a very small chamfer at the top of tapped hole before fitting. Then fitted a 1/4 of turn down from surface. Don't use Loctite on Helicoils.
Imho the crack in the inlet manifold would make a very lean mixture and high temps.
Alan
Imho the crack in the inlet manifold would make a very lean mixture and high temps.
Alan
i absolutely agree with neil. when you changed your head gasket did you have the head crack tested if it overheated prior, and did you get the head skimmed? you mention a stream of bubbles visible in the water flow, that in itself is the most significant observation, look deeper!!!! best regards and luck keith
We had big compression variation initially on one side. This all became even following head gasket replacement on that side only.
Dollyman1850 said:
Is the header pressurising after a short time on the drive??
I'm not quite sure what you mean? My ignorance more than anything! Water pressure or cylinder compression?V6Pushfit said:
Also heater hoses - are they looped over in a way to cause an air lock and lack of circulation.
Water seems to be flowing fine throughout entire system. Heater hoses are getting hot with rest of system so doesn't appear to show the symptoms of an airlock. plasticpig72 said:
When you have found and fitted the replacement inlet manifold you could check mixture with a ColorTune plug. For the helicoils they need a very small chamfer at the top of tapped hole before fitting. Then fitted a 1/4 of turn down from surface. Don't use Loctite on Helicoils.
Imho the crack in the inlet manifold would make a very lean mixture and high temps.
Alan
We have a new inlet on the way so no need to worry about the helicoils. Hopefully this one has original threads that have not been destroyed! The cracked inlet is only a new development and the car was overheating long before this. It was only on wednesday that the inlet gave up and the damage is not in a place that would affect mixture. Once we get the new manfifold on we can try to tackle the overheating issue again.Imho the crack in the inlet manifold would make a very lean mixture and high temps.
Alan
chassyman said:
i absolutely agree with neil. when you changed your head gasket did you have the head crack tested if it overheated prior, and did you get the head skimmed? you mention a stream of bubbles visible in the water flow, that in itself is the most significant observation, look deeper!!!! best regards and luck keith
We haven't had the heads crack tested and only removed one side to sort the head gasket for the low compression cylinders. Head has not been skimmed. The stream of bubbles from the swirl-pot we assumed was the system working the air out still from when we flushed the system. Is there an easy way to check for head issues without taking the engine to bits. We will if we have to but don't want to go down that route before we've tried all other easier options. I've just removed the Core Plugs on the outside of the Block on my 3000M because one was leaking.
That's 2 each side and cannot believe the amount of crap, sludge, debris inside Waterways.
If you recore Rad and some of this debris moves it could easily block your nice new recored Rad.
Before i fit the new Core Plugs i will flush out the Waterways. The most debris is next to n°4 Cylinder.
For sure this will not help the cooling with lots of debris. Imho without removing the Core Plugs it's impossible to flush correctly.
Alan
That's 2 each side and cannot believe the amount of crap, sludge, debris inside Waterways.
If you recore Rad and some of this debris moves it could easily block your nice new recored Rad.
Before i fit the new Core Plugs i will flush out the Waterways. The most debris is next to n°4 Cylinder.
For sure this will not help the cooling with lots of debris. Imho without removing the Core Plugs it's impossible to flush correctly.
Alan
plasticpig72 said:
I've just removed the Core Plugs on the outside of the Block on my 3000M because one was leaking.
That's 2 each side and cannot believe the amount of crap, sludge, debris inside Waterways.
If you recore Rad and some of this debris moves it could easily block your nice new recored Rad.
Before i fit the new Core Plugs i will flush out the Waterways. The most debris is next to n°4 Cylinder.
For sure this will not help the cooling with lots of debris. Imho without removing the Core Plugs it's impossible to flush correctly.
Alan
Thanks for all your help so far. I bought a new set of core plugs from Burton Power, Ilford this week. For now I have just flushed system to get any loose bits out. A little bit more crap from the block came out but nothing significant. That's 2 each side and cannot believe the amount of crap, sludge, debris inside Waterways.
If you recore Rad and some of this debris moves it could easily block your nice new recored Rad.
Before i fit the new Core Plugs i will flush out the Waterways. The most debris is next to n°4 Cylinder.
For sure this will not help the cooling with lots of debris. Imho without removing the Core Plugs it's impossible to flush correctly.
Alan
We are going to put everything back together with the re-cored radiator and if it is still overheating then the only thing left to do is remove and check the heads again and do head gaskets again. Saying this it will probably make sense at this point to remove the engine completely and strip it down and do the core plugs at the same time. I would have liked to do core plugs now but there is no way I can remove (let alone replace) any of them whilst the engines fitted
tom_609 said:
Thanks for all your help so far. I bought a new set of core plugs from Burton Power, Ilford this week. For now I have just flushed system to get any loose bits out. A little bit more crap from the block came out but nothing significant.
We are going to put everything back together with the re-cored radiator and if it is still overheating then the only thing left to do is remove and check the heads again and do head gaskets again. Saying this it will probably make sense at this point to remove the engine completely and strip it down and do the core plugs at the same time. I would have liked to do core plugs now but there is no way I can remove (let alone replace) any of them whilst the engines fitted
Last time you did your heads did you re-use your head bolts?We are going to put everything back together with the re-cored radiator and if it is still overheating then the only thing left to do is remove and check the heads again and do head gaskets again. Saying this it will probably make sense at this point to remove the engine completely and strip it down and do the core plugs at the same time. I would have liked to do core plugs now but there is no way I can remove (let alone replace) any of them whilst the engines fitted
Its a common engine building mistake when changing gaskets not to ensure that your head can clamp down. I have known and seen many times a combination of stretched bolts and thinner replacement gaskets be the cause of a head which pulls down but bottoms out on the thread… You can measure this but an alternative (cheap) method of ensuring you are not bottoming out is to take a couple of mm from the bolt end . Also make sure your thread holes are cleaned out
N.
Dollyman1850 said:
Last time you did your heads did you re-use your head bolts?
Its a common engine building mistake when changing gaskets not to ensure that your head can clamp down. I have known and seen many times a combination of stretched bolts and thinner replacement gaskets be the cause of a head which pulls down but bottoms out on the thread… You can measure this but an alternative (cheap) method of ensuring you are not bottoming out is to take a couple of mm from the bolt end . Also make sure your thread holes are cleaned out
N.
Yes we did re-use the head bolts, we only replaced the head gasket on one head which had weak compression on 2 of the cylinders. We did a second compression test after changing the head gasket and all seemed fine so definitely clamping correctly and we re-torqued the head bolts after driving a few miles. Gasket looked like it was a like-for-like replacement and we cleaned both the bolts and threads before reassembly. Its a common engine building mistake when changing gaskets not to ensure that your head can clamp down. I have known and seen many times a combination of stretched bolts and thinner replacement gaskets be the cause of a head which pulls down but bottoms out on the thread… You can measure this but an alternative (cheap) method of ensuring you are not bottoming out is to take a couple of mm from the bolt end . Also make sure your thread holes are cleaned out
N.
Thank you for the advice nonetheless, worth considering for future engine work
Update for all
Just collected re-cored radiator. I've had it done with standard 4-core crossflow setup but instead of curved fins (6 fins per inch) we have gone for straight fin cores with 12 fins per inch. This is supposed to dramatically increase cooling as the surface area of the fins is effectively doubled, helping with heat dissipation. Adrian also recommended having a 22mm fan switch boss installed which we have had done. Very happy with the results!
Upon collecting the rad we were shown the original core. Approximately 1/3rd of all channels were blocked at one end and many of the remaining water channels that look clear from the pic were actually blocked at the other end or in the middle of the channel. A flow test showed that the radiator was not able to get water out at the same rate it was taking it in. The shop reckons it is highly likely the rad was the source of the overheating problems but even if it doesn't fix it, this will definitely help and would've needed doing very soon anyway.
I cannot recommend the work of Commercial Specialists in Luton enough. They are 2 guys in a small radiator shop who have produced rads for Aston Martin and been going since 1982. Happy to discuss your needs in length and the moment I mentioned the TVR he knew the dimensions off hand! Was very impressed and over the moon with the quality of their work
Just got to wait for the inlet manifold to turn up and I'll put the cooling system back together and see where we are at!
Just collected re-cored radiator. I've had it done with standard 4-core crossflow setup but instead of curved fins (6 fins per inch) we have gone for straight fin cores with 12 fins per inch. This is supposed to dramatically increase cooling as the surface area of the fins is effectively doubled, helping with heat dissipation. Adrian also recommended having a 22mm fan switch boss installed which we have had done. Very happy with the results!
Upon collecting the rad we were shown the original core. Approximately 1/3rd of all channels were blocked at one end and many of the remaining water channels that look clear from the pic were actually blocked at the other end or in the middle of the channel. A flow test showed that the radiator was not able to get water out at the same rate it was taking it in. The shop reckons it is highly likely the rad was the source of the overheating problems but even if it doesn't fix it, this will definitely help and would've needed doing very soon anyway.
I cannot recommend the work of Commercial Specialists in Luton enough. They are 2 guys in a small radiator shop who have produced rads for Aston Martin and been going since 1982. Happy to discuss your needs in length and the moment I mentioned the TVR he knew the dimensions off hand! Was very impressed and over the moon with the quality of their work
Just got to wait for the inlet manifold to turn up and I'll put the cooling system back together and see where we are at!
Update on events
replacement Inlet manifold turned up. An attachment on the new manifold wasn't required but when we tried to remove it the metal snapped clean in two due to corroded threads. We managed to cut out the metal left inside the thread and re-tap it so that is all good now.
Yesterday we also noticed the carburettor spacer had completely disintegrated and also been bodged by a previous owner. Managed to source a replacement from a guy around the corner and picked it up early afternoon today.
Got home from work and switched the inlet manifolds over using new gaskets all round, connected up all the hoses, flushed the system once more, rewired the messy wiring to the new radiator and our new fan switch and topped up with water.
We started the car and topped up the water whilst air in the system was 'burped' out. After 10 mins we thought the fans weren't wired up correctly but to our joy the car just wasn't hot enough yet! We then felt the thermostat open and 5-10 minutes after that the fan kicked in. The car is maintaining a good and stable temperature Been out for the longest drive in my ownership and no overheating whatsoever! Temperature cools nicely as the speed increases and sits perfectly in traffic even with 1 fan (we have a second fan wired to an override switch just in case).
After a year of ownership we have finally sorted this frustrating issue. I believe it to be mainly the recored radiator however everything else will have certainly contributed too: installing an 82 thermostat (no thermostat before at all), new water pump, system flushed. I've bought a bottle of water wetter which should give me a couple more degrees flexibility too. Also need to drain some water and top up with actual coolant/antifreeze as the winter will be here soon and to save my precious new rad cores Just time to sort out my very temperamental throttle cable now which slips and takes away all pedal control with it. That's for a different thread though I reckon 
We are overly grateful to all of your help and if I ever meet any of you I owe you a pint
Finally got there!!!
replacement Inlet manifold turned up. An attachment on the new manifold wasn't required but when we tried to remove it the metal snapped clean in two due to corroded threads. We managed to cut out the metal left inside the thread and re-tap it so that is all good now.
Yesterday we also noticed the carburettor spacer had completely disintegrated and also been bodged by a previous owner. Managed to source a replacement from a guy around the corner and picked it up early afternoon today.
Got home from work and switched the inlet manifolds over using new gaskets all round, connected up all the hoses, flushed the system once more, rewired the messy wiring to the new radiator and our new fan switch and topped up with water.
We started the car and topped up the water whilst air in the system was 'burped' out. After 10 mins we thought the fans weren't wired up correctly but to our joy the car just wasn't hot enough yet! We then felt the thermostat open and 5-10 minutes after that the fan kicked in. The car is maintaining a good and stable temperature
Been out for the longest drive in my ownership and no overheating whatsoever! Temperature cools nicely as the speed increases and sits perfectly in traffic even with 1 fan (we have a second fan wired to an override switch just in case).After a year of ownership we have finally sorted this frustrating issue. I believe it to be mainly the recored radiator however everything else will have certainly contributed too: installing an 82 thermostat (no thermostat before at all), new water pump, system flushed. I've bought a bottle of water wetter which should give me a couple more degrees flexibility too. Also need to drain some water and top up with actual coolant/antifreeze as the winter will be here soon and to save my precious new rad cores
Just time to sort out my very temperamental throttle cable now which slips and takes away all pedal control with it. That's for a different thread though I reckon We are overly grateful to all of your help and if I ever meet any of you I owe you a pint
Finally got there!!!V6Pushfit said:
Bloody good news got there in the end. You did today's work pretty quick too!
Yep, got home from work early and managed to go collect the spacer then it was solid work from 3-7pm. It was more putting everything back together more than anything but as we all know "I've just got to switch that for that" is never a simple job haha 
TVRMs said:
Hop that's the problem sorted 
I hope so too Gassing Station | TVR Classics | Top of Page | What's New | My Stuff