rover v8 overheating problems
Discussion
I have just got my new engine in and running and it is overheating. It has a hufaker inlet manifold so there is no thermostat, it has a electric water pump and a big electric fan (ive tried drawing and pushing fan direction) A big thick jcb radiator it has 2 oil coolers and a bonnet scoop. I took it about 15 miles to get it mot`d yesterday and i had to stop about 6 times each way. I run a chevy th350 gearbox with a 8" torque converter. I know it will run hotter cause of the box and converter but it shouldnt be that hot. has anyone got any good ideas or has anyone tried that wetter water that you can get to help make it run cooler, if so does it make a diffrence ??
With that manifold, do you still have a bypass from the inlet manifold water jacket to the back of the pump? Without that bypass it would be almost impossible to bleed the pump.
Is the radiator new?
Have you fully bled engine and radiator?
Is the radiator air intake positioned so you get decent ram air through it?
What happens when it gets hot:
Does the top hose get hot?
Does the radiator get hot all over?
Do the fans come on at the correct temperature?
Do you feel air blasting out of the back of the radiator?
Is the radiator new?
Have you fully bled engine and radiator?
Is the radiator air intake positioned so you get decent ram air through it?
What happens when it gets hot:
Does the top hose get hot?
Does the radiator get hot all over?
Do the fans come on at the correct temperature?
Do you feel air blasting out of the back of the radiator?
Yes i still have a bypass in to the back of the pump. The radiator has been recored about 2 year ago but it is what i have used with diffrent size engines. Infact i belive it is what was put in the car when it was built in 1978. The temp guage just kept rising and i had to stop just before it got on H. The heat under the bonnet was red hot. Im going to cut the blades of my water pump to see if that makes the water flow better and it may stay cooler.
stevieturbo said:
it was a total POS.
Yes that's my view too. But despite all its shortcomings, it should be more than adequate to cool the engine when idling or driving gently. I suspect there's another fault here, most likely an air lock. It's the sort of thing that would normally be easy to diagnose in person just by feeling temperatures round the engine bay, but the '20 questions' approach takes longer ...I have checked and had it checked for me that there is no air lock. The electric pump is working on its own. When i switch it on you can see the water going around in the rad, With the standard pump you carnt so my electric pump must be good enough to do the job. Everything is plumbed in correctly. The fan is mounted engine side of the rad and it over heats which ever way i have it running pulling or pushing. The fan is on a switch and i have been putting it on as soon as i start the engine.
Yo say you can see water going around in the rad.... Is the rad clear to allow you to do this ?
A little sarcastic...I know. I dont think that by looking into the rad cap, which I assume that means, you would be able to see if the water was actually circulating or not.
Is the mechanical pumps rotor still in place, or is it removed ?
Do you have a thermostat, if so, does it actually work. Is it situated correctly ?
Not sure if it will help any, but do you have any pictures of your cooling system layout, and pipework ?
Does the rad and top and bottom hoses get warm at appropriate times...ie is teh stat opening and closing, a well as the water circulating.
Can you dump the POS electric pump, and re-fit a mechanical pump to test it ?
A little sarcastic...I know. I dont think that by looking into the rad cap, which I assume that means, you would be able to see if the water was actually circulating or not.
Is the mechanical pumps rotor still in place, or is it removed ?
Do you have a thermostat, if so, does it actually work. Is it situated correctly ?
Not sure if it will help any, but do you have any pictures of your cooling system layout, and pipework ?
Does the rad and top and bottom hoses get warm at appropriate times...ie is teh stat opening and closing, a well as the water circulating.
Can you dump the POS electric pump, and re-fit a mechanical pump to test it ?
I'm guessing how you have the pump plumbed in. My guess is you have it in line in the bottom hose, between the rad outlet and the inlet to the mechanical water pump (which is now inert). It's worth noting that the bypass and heater circuits are connected to the inlet of the std mechnical pump, but to the *outlet* of an EWP plumbed in like this. This means that there is a possible 'short circuit' round the radiator and bypass/heater circuit that bypasses the engine completely. I don't know if you've actually arranged it like this, but it seems quite likely to me. There might be enough restriction in the bypass/heater loop to force enough of the flow through the block to bleed the engine and then flow enough to cool the heads, but I wouldn't bet on it. Cooling circuit are funny old things and it's all to easy to mess it up.
Temperatures are the best way to get to the bottom of this. This first test is very simple: when it's hot, is the radiator hot all over and do you get a blast of hot air off the fans?
Temperatures are the best way to get to the bottom of this. This first test is very simple: when it's hot, is the radiator hot all over and do you get a blast of hot air off the fans?
That's encouraging. It implies that you have at least some water circulation through the engine and some air flow. The question now is why the cooling you're getting is not sufficient to control the temperature.
When it overheats, what are the symptoms?
Edited to add: unless you get lucky, you'll soon get to the point where you need to measure actual temperatures round the system. Can you get hold of a thermometer capable of reading 80 - 120 C? An IR thermometer would be ideal, but a bit expensive at around £100 or so. An ordinary cheap thermister based electronic thermometer would do fine and should cost less than £10.
>> Edited by GreenV8S on Wednesday 15th June 21:35
When it overheats, what are the symptoms?
Edited to add: unless you get lucky, you'll soon get to the point where you need to measure actual temperatures round the system. Can you get hold of a thermometer capable of reading 80 - 120 C? An IR thermometer would be ideal, but a bit expensive at around £100 or so. An ordinary cheap thermister based electronic thermometer would do fine and should cost less than £10.
>> Edited by GreenV8S on Wednesday 15th June 21:35
IMO buy a new mechanical pump and try it.
Altering the postions of the pump and how it operates by fitting an EWP can mess up coolant paths through other hoses, like the heater.
The suck and blow or flow and return paths become different, therefore everything could be messed up.
The instructions with the pumps dont seem to mention this.
I still stand by they are a POS. Mechanical pumps have been around and worked almost faultlessly for years. There's a lot to be said for them.
perhaps an EWP that actually replaces the mech pump might be different, but for a road car, Id go mechanical every time. Their reliability is proven.
Altering the postions of the pump and how it operates by fitting an EWP can mess up coolant paths through other hoses, like the heater.
The suck and blow or flow and return paths become different, therefore everything could be messed up.
The instructions with the pumps dont seem to mention this.
I still stand by they are a POS. Mechanical pumps have been around and worked almost faultlessly for years. There's a lot to be said for them.
perhaps an EWP that actually replaces the mech pump might be different, but for a road car, Id go mechanical every time. Their reliability is proven.
The ir thermometer is expensive, But ill ask about to see if someone has one that i can borrow. It is set up same as my mates and his works ok. im going to try setting my carb up as my jets might not be big enough. they are set perfect for a car 300cc smaller and it was spluttering when i took it for test the other day. The vehicle is used on the road but is used for drag racing too.
My mate has the same set up in his car and his car puts his set up to the test and he does not have any problems. He runs respectable times, so i would have thought if his car can cope i would have thought mine would. I know i need my carb re jetting to 1 or 2 sizes bigger so i will try that and see how goes.
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