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edwin

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833
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Lichfield
Gentlemen. My Renault 1985 4tl has been running well, and we drove it back to the UK from France with no problems, and then back to France again, about 3000 kms in all, running beautifully. But just in the last day or two its started to have a flickering ignition light. The car starts well, the engine runs well. There is a slight problem of liquid coming out of the top of the plastic bottle under the bonnet on two occasions with long hills, hot weather and a trailer in tow. On those occasions there was a bubbly noise as well, which soon disappeared when you turned off the engine which I assume is the cooling liquid boiling. The liquid levels were always in the max min band.
I did not had time to look at this before I flew back to England yesterday. I don't know if these problems are related or coincidental, but the fan belts appear to be well tensioned, in good shape and do not appear to be slipping.
They don't make any noise.

It could be the battery, but I would expect that to result in a constant, not a flickering light. It could be the
alternator, and if brushes are wearing out that may cause the flickering.It could be a short somewhere, but we have done nothing with the electrics to start that happening.

I am off back to France in May and I want to take whatever bits I may need to to speed up repairing the car. Has any one a suggestion of a possible cause of the problems, and what to do about them and what bits to take.

I was thinking of getting some replacement brushes. I will check the acid level in the battery, and I will check the battery. Any other suggestions gratefully received. Thanks, Edwin.
 
If you have a decent voltmeter, check the voltage when the engine is running; it should be 14.4 volts, give or take a decimal point. If it varies drastically from this value the alternator may be at fault, so your thoughts regarding the bushes might be correct. This value shouldn't change when a load is placed on the alternator, such as main beam headlights, either. The fan belt might be worth checking, just in case it's slack-sometimes the most obvious things are overlooked! And check all the connections at the back of the alternator are all tight and bright as well
 
hi gentlemen, thanks for the suggestions. This is a photo of my engine bay, and I have looked at the alternator and compared it with pics and think that its a Paris Rhone model, can anyone confirm or otherwise. I was going get new brushes from Franzose, and I need to know the type. I sent the photo to them, and they replied that if it is a Paris Rhone model.. rather that it is a Paris Rhone model, which did 'nt help me. If someone can confirm it that would be great. Thanks. This ability to ask detail questions and get well considered answers is fantastically helpful, so thanks to everyone.
 
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Consider a stuck or failed thermostat to cause the coolant bubbling - this boiling should not happen!

Simply: Replace the thermostat (note which way around it fits!); flush whole cooling system using a hosepipe (forwards and backwards), including the engine block & head (don't be afraid of getting wet!); make sure that the radiator is clear of sludge etc at the bottom, and that the aluminium fins are in good condition. If the fanbelt is old, replace that too (they can become hard and not grip properly even when tight - this could be causing ignition light flickering and a drop of cooling-fan speed), otherwise double-check the tension.

I've had a few occasions (before a simple mod) when I have accidentally unplugged the electric radiator fan on my F6; it's amazing how quickly it overheats and boils - even at tickover it's only a couple of minutes once at working temperature.
 
Consider a stuck or failed thermostat to cause the coolant bubbling - this boiling should not happen!

Simply: Replace the thermostat (note which way around it fits!); flush whole cooling system using a hosepipe (forwards and backwards), including the engine block & head (don't be afraid of getting wet!); make sure that the radiator is clear of sludge etc at the bottom, and that the aluminium fins are in good condition. If the fanbelt is old, replace that too (they can become hard and not grip properly even when tight - this could be causing ignition light flickering and a drop of cooling-fan speed), otherwise double-check the tension.

I've had a few occasions (before a simple mod) when I have accidentally unplugged the electric radiator fan on my F6; it's amazing how quickly it overheats and boils - even at tickover it's only a couple of minutes once at working temperature.
Thanks very much. I did fit a new thermostat, because there wasn't one in the car when i bought it and I wanted the heater to work. I may have put it in the wrong way round but I did look at it very carefully at the time. I may also have bought the wrong temperature for the area possibly? Its very good of you to give me your thoughts everyone.
 
The thermostat 'pointy' end should be sitting inside the water pump housing when it is fitted, I believe (may be different for other engines), with the body of the thermostat secure inside the top hose.
Possibly I am suspicious of the reason for your car having no thermostat when you purchased it - could be blockages in the radiator or head causing overheating previously, hence someone was trying to improve flow by removing the thermostat ?
My themostat works fine and is 89 degrees temperature rating; it's a heavily-worked van so not molly-coddled but no overheating probs yet!
 
The thermostat 'pointy' end should be sitting inside the water pump housing when it is fitted, I believe (may be different for other engines), with the body of the thermostat secure inside the top hose.
Possibly I am suspicious of the reason for your car having no thermostat when you purchased it - could be blockages in the radiator or head causing overheating previously, hence someone was trying to improve flow by removing the thermostat ?
My themostat works fine and is 89 degrees temperature rating; it's a heavily-worked van so not molly-coddled but no overheating probs yet!
Hi Adam. You mentioned flushing out the rad and water system. I understand that its easy on an R4 to get an air lock when refilling. How do you avoid or overcome that?
 
There is a dead-ended little pipe coming out of the engine bulkhead (left side), which has a bleed knob in the end - undo that a bit/a lot until only coolant comes out. I usually unstrap the coolant header tank and prop it up high as far as I can to provide extra bleeding pressure. Start bleeding with the radiator cap, when that's full open up the bleed knob as above (this is actually connected to the heater, but is the highest point in the system). Open up the heater to 'hot' before you start.
 
Adam you are a mine of good info. I wondered what that was for. So after a good flush out, refix all the tubes, clips etc, and fill with antifreeze, leaving that bleed valve open till antifreeze comes out and then close it and bobs your uncle.
Where do you refill, top of the radiator? Or the big plastic bottle?
 
I'd fill everything from the plastic header tank, propped on the windscreen (or somewhere else as high as the pipe will allow) - it's not ultra-fast, but that gives you a chance to open and shut the radiator cap to check for fullness without losing too much coolant! 50% antifreeze/water (unless it's a premixed lot) - much more or less concentration reduces the cooling ability, aparently.
 
By the way, Edwin - flush the heater out a bit as well by removing the dead-end bleed knob and pushing water into the system until it comes out of the bleed pipe clean (and flush the other way around). I can't remember how effective this is, but I remember doing it!
 
Good advice here. Also, squeeze the top pipe (between radiator and engine) as air can get trapped in it.
 
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