Water pump fixed - Now need to sort overheating!
Discussion
Well thought by now it'd be easy but how naive I was. New water pump fixed to the (V8) engine after last one was ejecting steam. Apart from sheared bolt all went fine. I'll deal with that later.
Now engine overheating rapidly. I'll try to give the clearest picture of what's happening and see if anyone else has had a similar experience and hopefully tell me what they did-
(all this is with car stationary)
-Start engine cold - runs fine apart from usual cold start very mild lumpiness.
-Temp gauge rises gradually to about 50-60degC.
-Rises quickly from here to 90+degC.
-Holding the top hose, it gets quite hot eventually but is still easily squashed by hand.
-Radiator is as cold as when engine started. Return hose off rad also.
-Heater for cabin is blowing cold.
-At this point I switch off as its starts tipping into the red.
Going to remove themostat this sat but whilst this would be the magic bullet, I'm sceptical cos surely the cabin heater matrix would provide heat as this isn't governed by the stat.
I took advantage of being AA member and had a guy over to test for air locks which he confirmed he didnt think so cos he used his own pump to circulate water round. Apart from that he was stumped and wished me luck!
Anyone had a similar experience and sorted it?
Ultimate mare scenario is head gasket or leak in block. But car never overheated into red before I took old pump off and rad/ fan worked fine. It was only the pump bearing/seal failure that prompted the change and nothing else.
Throw ideas into the hat please!
Now engine overheating rapidly. I'll try to give the clearest picture of what's happening and see if anyone else has had a similar experience and hopefully tell me what they did-
(all this is with car stationary)
-Start engine cold - runs fine apart from usual cold start very mild lumpiness.
-Temp gauge rises gradually to about 50-60degC.
-Rises quickly from here to 90+degC.
-Holding the top hose, it gets quite hot eventually but is still easily squashed by hand.
-Radiator is as cold as when engine started. Return hose off rad also.
-Heater for cabin is blowing cold.
-At this point I switch off as its starts tipping into the red.
Going to remove themostat this sat but whilst this would be the magic bullet, I'm sceptical cos surely the cabin heater matrix would provide heat as this isn't governed by the stat.
I took advantage of being AA member and had a guy over to test for air locks which he confirmed he didnt think so cos he used his own pump to circulate water round. Apart from that he was stumped and wished me luck!
Anyone had a similar experience and sorted it?
Ultimate mare scenario is head gasket or leak in block. But car never overheated into red before I took old pump off and rad/ fan worked fine. It was only the pump bearing/seal failure that prompted the change and nothing else.
Throw ideas into the hat please!
From your description it still sounds like an airlock regardless of what the AA expert says. Also you may wish to try with the thermostat temporarily removed. I would recommend you refill the system taking care to try and get all the air out, disconnect your top hose and fill through that as a starting point, and then continue to fil to the highest point in system which should be the swirl tank, lastly start the car run for a short time and top up the aim being to eliminate any air. Lastly if all else fails use a leakdown test to try and confirm gasket failure, or alternatively a gas detector kit - which basically detects the presence of exhaust gases in coolant and is fairly cheap- best of luck
Agree that it sounds like an airlock.
It appears that for some reason the coolant is not reaching the radiator. So either the water pump isn't pumping the water round or there is something stopping the coolant getting to the radiator.
So either an airlock, or thermostat problem. Possibly a blockage in the radiator. Have you bled the radiator?
When the engine is cold try running the engine with swirl pot open and look in to see if you can see the water circulating to ensure that the waterpump is working.
It appears that for some reason the coolant is not reaching the radiator. So either the water pump isn't pumping the water round or there is something stopping the coolant getting to the radiator.
So either an airlock, or thermostat problem. Possibly a blockage in the radiator. Have you bled the radiator?
When the engine is cold try running the engine with swirl pot open and look in to see if you can see the water circulating to ensure that the waterpump is working.
you should have bought this one no overheating problems 
http://go.redirectingat.com/?id=1044X509854&si...
http://go.redirectingat.com/?id=1044X509854&si...
Thanks for all the suggestions put forward so far. Kind of reassured that everyone's not instantly leaping to head gasket or cracked block conclusions straight away. I'll try everything in turn at the weekend to eliminate one by one from scratch. ie total drain down and go from there. Its not a massively complex hydraulic system so the laws of physics must mean that if there's enough pressure pushing down the system and the losses are less than the pump pressure, then water will circulate?! unless there's unknown leaks of course. Think I'll just remove the stat and run it without so I know for sure that water should be flowing out into the rad.
wish me luck. if none of this works I might call in a faith healer.
wish me luck. if none of this works I might call in a faith healer.
Dangle the stat in a saucepan of
water, should open just before the water boils
Most stats I've seen have a little jiggle thing to allow air to pass before stat opens, if stat is mounted vertically (think it is on a V8) that vent thing should be at the 12 o'clock position.
As others have said most likely an air lock problem, fill and vent from anywhere and everywhere you can and squeze top hose with engine running to move air/stimulate flow.
water, should open just before the water boils
Most stats I've seen have a little jiggle thing to allow air to pass before stat opens, if stat is mounted vertically (think it is on a V8) that vent thing should be at the 12 o'clock position.
As others have said most likely an air lock problem, fill and vent from anywhere and everywhere you can and squeze top hose with engine running to move air/stimulate flow.
The water pump vents up through the bypass hose into the water jacket at the front of the inlet manifold, and past the stat into the top hose. If you have a non-vented stat, you may never have got the air out of the water jacket so the stat is in air. You may even not have vented the pump so there is no fluid circulation. A very handy point to vent the water jacket is the throttle body heater outlet. This is a small spigot pressed into the water jacket in the inlet manifold above #1 cylinder, and the return is a spigot on the side of the cabin heater return pipe where it comes out underneath the intake manifold. Hopefully it isn't connected to the throttle body heater any more (if it is, sort that out right now) and usually they supply and return are simply looped together - alternatively they may both be blanked both off. Whatever they're connected to, if you remove whatever is connected to the spigot on the intake manifold it forms a great vent point when you're doing the initial fill from cold.
If you have a chance to get at the stat again, I'd suggest drilling a 1/8" hole through at the 12 O'Clock position. This helps it to vent when you're refilling (you may not need that help if your stat has a jiggle pin) and also ensures that there is a trickle of water past the stat when it is 'closed' which minimises the thermal shock when the stat starts to open.
If you have a chance to get at the stat again, I'd suggest drilling a 1/8" hole through at the 12 O'Clock position. This helps it to vent when you're refilling (you may not need that help if your stat has a jiggle pin) and also ensures that there is a trickle of water past the stat when it is 'closed' which minimises the thermal shock when the stat starts to open.
To get the airlocks out, jack the front of the car up, open the valve on the top left of the rad. Remove the swirl pot cap. Turn the engine on, and begin to pour water into the coolant system. Once water is gushing out of the rad valve, there should be no airlocks present. Be sure to get the rad valve higher than the swirl pot; air rises to the highest point, so it'll be forced out by you pouring water into the system via the swirl pot. Works for Nick everytime!
King Fisher said:
To get the airlocks out, jack the front of the car up, open the valve on the top left of the rad. Remove the swirl pot cap. Turn the engine on, and begin to pour water into the coolant system. Once water is gushing out of the rad valve, there should be no airlocks present. Be sure to get the rad valve higher than the swirl pot; air rises to the highest point, so it'll be forced out by you pouring water into the system via the swirl pot. Works for Nick everytime!
That approach relies on venting the engine via the stat, so it will only work well if your stat has a jiggle pin or vent hole and is the right way up. Otherwise, you will successfully bleed the radiator but not the engine. You also have to ensure that the front is lifted high enough that the top hose is not going downhill towards the swirl pot. That means lifting the front quite a log way.GreenV8S said:
Hopefully it isn't connected to the throttle body heater any more (if it is, sort that out right now) and usually they supply and return are simply looped together - alternatively they may both be blanked both off.
Peterwhat is the issue with this? First I have heard of it, will have to check mine later.
Cheers,
Paul
I've just drawn up a schematic of how I see the TVR V8S cooling system fits together. It is only schematically drawn and not to scale etc, but and comments on anything I've missed would be useful. Just want to make sure I understand it before I start working on it again at the weekend.
Thanks
Thanks
Edited by gizzardio on Thursday 29th September 12:35
Oldred_V8S said:
Peter
what is the issue with this? First I have heard of it, will have to check mine later.
Cheers,
Paul
The throttle body heater comes in handy when you are taking your Land Rover to Siberia and want to avoid the throttle icing up, but everyone else is interested in keeping the incoming air charge as cool as possible to get maximum power, so having your throttle body heated up is exactly the last thing you want. You should be aiming to get all the induction as cool as possible.what is the issue with this? First I have heard of it, will have to check mine later.
Cheers,
Paul
gizzardio said:
I've just drawn up a schematic of how I see the TVR V8S cooling system fits together. It is only schematically drawn and not to scale etc, but and comments on anything I've missed would be useful. Just want to make sure I understand it before I start working on it again at the weekend.
Thanks
That doesn't look quite right.Thanks
Edited by gizzardio on Thursday 29th September 12:35
The coolant flows through the engine and up through the heads, exiting the engine through the water jacket at the front of the inlet manifold. The main outlet from the inlet manifold is the stat housing, but there is also a smaller outlet which goes from the front of the water jacket to a spigot on the pump inlet; this is the main engine bypass. There is also a small outlet from the back of the water jacket which feeds the cabin heater matrix; the return from the cabin heater passes under the intake manifold and comes out the front close by the bypass and also joins into the inlet of the water pump. Finally there is a very small outlet from the top of the water jacket which goes to the throttle body heater, and the return from the throttle body heater is teed into the cabin heater return pipe.
The cabin heater hot/cold control operates a shut-off valve in the cabin heater supply. Between the engine and the shut-off valve there is an H piece which connects between the cabin heater supply and return and allows coolant to bypass the heater when the valve is 'off'. (It also cripples the flow through the heater when valve is 'on'.) This enables the cabin heater circuit to act like an extra bypass. This is useful when the car is driven hard in cold conditions because the stat will be closed so the only flow through the heads will be the bypass flow, and that's tiny compared to the main coolant flow.
Thanks mate for replying. I thought I may have made a few errors somewhere. I'll amend it and post it on there again. I get what you're saying about the heater matrix piping now. Couldn't really work that out from memory (car is at my dad's house where I left it after it overheated) so that's the missing piece of the puzzle sorted.
If I am to drain and refill where would be best to start to eliminate airlocks? I'm prepared to disconnect and fill rad, top hose, swirl tank etc separately working from lowest point back to top hose.
If I am to drain and refill where would be best to start to eliminate airlocks? I'm prepared to disconnect and fill rad, top hose, swirl tank etc separately working from lowest point back to top hose.
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