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Servicing Tasks
Maintenance Home

There are a few common problems with the Renault 5 GT Turbo Blown Head Gaskets, Knackered Turbos and Knackered Clutches all of which are pretty expensive to replace and/or fix. Under each sub heading I will mention how to maintain a 5 and keep these problems to a minimum.

Head Gaskets
Head gaskets blow for a reason for which there are two reasons either the Boost has been turned up too much or the car has overheated. If you are going to turn the Boost up either using a bleed valve or adjustable Boost control on a standard head gasket you can really only turn it up a little bit. The Boost can be turned up by winding in the nut on the wastegate actuator arm remembering the more you wind it in the more Boost you will get out of the Turbocharger, but this puts more strain on the headgasket, thus causing it to blow. If you want to turn the Boost right up then you are going to need an uprated head gasket to cope with the added strain put on it. Also turning up the Boost will make the Turbo work harder thus shortening it's life span unless it's a hybrid Turbo manufactured for running higher Boost.

Turbo Boost

If you do turn the Boost up above 15psi then really the fuelling needs to be adjusted to pump in the correct ratio of fuel into the engine by maybe using bigger carb jets or a Group A carb. If you do not increase the fueling to match the higher Boost then you will get "PINKING" or "DETONATION" as it is called. This WILL damage pistons which are expensive to replace as the engine has to come out and the engine be rebuilt.
  Bar PSI
Another cause of a head gasket to blow is the car overheating and considering that 5's run hot as it is there really is no margin for error. So if you're driving a 5 always keep a watchful eye on the cars temperature gauge. Driving along a five should read just below to halfway on the temperature gauge under normal driving conditions and maybe rise a little on the motorway and when putting your foot down where the Turbo is being used alot. While sitting in traffic the Cooling Fan should cut in just before the 2 3rd's line on the gauge. If you notice that the fan doesn't cut in when the temperature gauge gets to the 2 3rd's line switch the car off and let the car cool down. "NEVER LET THE CAR OVERHEAT" "NEVER LET THE CAR'S TEMPERATURE GAUGE GET INTO THE DANGER ZONE AND WAIT FOR THE RED LIGHT TO COME ON AS BY THEN THE DAMAGE IS PROBABLY ALREADY DONE" You may have a dodgy thermostat or Fan switch which isn't working properly which may be the reason the fan isn't cutting in.


Maintaining the Cooling System
Keeping the cooling system on a 5 Turbo in good working order is a must. An £8 fan switch not working could cause your headgasket to blow and/or warp your cylinder head and end up costing you £400.

Temperature Gauge Guide
Maximum driving along at a steady speed
Maximum Radiator fan cut in point
This may rise slightly when driving the car hard, ie using the Turbo alot. Idealy the cooler they run the better so if yours run slightly lower than this then its a bonus. I would not let a GT Turbo run much over this point as it is likely to cause damage by warping the cylinder head.

On a regular basis

The cooling system on the 5 gets air in it from time to time and this can cause the car to overheat so to overcome this and get the air out you do the following.

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1. Unscrew the Coolant Tank cap and unclip the strap holding it to the side of the inner wing and lift it up as high as you can get it with all the pipes attached.
2. On the top hose there is a plastic screw in the top of it. Get someone to stand by this and undo this.
3. Now with you standing holding the Coolant tank over the top of the wing and another person holding the srcrew from the top hose put your mouth over the top of the coolant tank making it air tight blow holding in the pressure and not letting go. Keep the pressure on until you see out of the screw hole pure coolant flowing out with no air in it. While the coolant is flowing out air free get the person to screw in the plastic screw back in all the time you are holding in the pressure. Once the screw is back in you can remove your mouth from the coolant tank.
4. Now you need to follow the same procedure for the screw on the top of the the pipe coming from the top of the water pump and remove any air from this side of the cooling system.
Once you have done the same for the water pump pipe screw you can put the coolant tank back in place and screw on the cap. Hopefully your Cooling system should be free from any air locks.

Also on a regular basis leave the car running and wait for the Cooling Fan to cut in while watching the temperature gauge and make sure that it cuts in where it normally does. If it starts to go above the 2 3rd's line then switch the car off and investigate what the cause is before driving the car. Likely causes are air in the cooling system, blocked radiator or cracked radiator, faulty water pump, faulty thermostat, a hole in one of the water pipes, faulty fan switch or incorect coolant mixture.

Do not let the car overheat
Never let the car overheat or let it get into the danger zone where the little red light on the temperature gauge comes on. If your in traffic and the car goes above the normal temperature where the fan cuts in pull over and switch the engine off. Call someone out and have the car towed home or to a garage and investigate the problem before driving it again.

Turbo Failure
Because the turbocharger on a Renault 5 Turbo is a small T2 Garrett it spins up quickly, partly the reason 5 Turbo's are so quick, but this also means that they really are on the go all the time that is why the life expectantcy of the Turbo is roughly about a year. But there are a few things that you can do to prolong your Turbo's life.

1. Change the oil regularly (Maximum every 6000 miles/Recommended every 3000 miles). Because your engine oil is what lubricates the bearings inside your Turbocharger and if the quality of your oil is poor this is going to have an effect on these bearings, thus causing them to seize up (New Turbo Time NOT CHEAP £250 Recon + Fitting). So the rule is change your oil as often as possible and use a high quality Engine Oil Semi-Synthetic minimum.

2. Also you can prolong the life of your Turbocharger by getting in the habit of every time you finish your journey and want to switch off your engine, let the engine idle for about 2 minutes then switch off the engine. This allows the Turbo to stop spinning before the oil supply to the Turbocharger is cut off by you switching off the engine.

Another Factor that will make your Turbo's life shorter is by turning up the Boost (Meaning the Turbo spins at a higher RPM that normal thus wearing it out quicker).

A Dump valve may improve the life expectantcy of your Turbo though this may only be true of hybrid Turbo's running higher Boost im not sure. Any way the dump valve releases the pressure left in the the inlet pipe when you release the throttle, otherwise this pressure causes the Turbo to stall and when you apply the throttle again it has to spin up from start again causing Turbo lag. Where as if you release the pressure via a Dump Valve the Turbo keeps spinning and picks up speed again when you apply the throttle after gear change. It doesn't neccessarily make the car quicker or make the cars BHP figure any greater but maybe give the Turbo a bit of extra life.

Fitting a dump valve guide

Worn Clutches
Worn clutches are a big problem for the 5, because they're a common problem and they are not cheap to replace. The reason being because these cars accelerate so quickly it puts alot of stress on the clutch. So having an uprated clutch will be a better bet than the standard renault clutch especially if you are running higher Boost. To have the job done properly you are looking at around £400. That is with the engine being removed. You can do the job the same way as with other cars by just removing the gearbox but because of the limited space chances are that it will not be alligned properly so probably won't last very long. So to make your clutch last here are a few tips.

1. Do not ride the clutch as this will cause it to wear.

2. Try not to rest your foot on the clutch pedal as this could stretch the clutch cable or wear the thrust bearing.

3. Sudden accelaration from a standing start all the time will wear your clutch so if your game is traffic light grand prix's then your probably best off having an uprated clutch.

Rule of thumb with the GT Turbo
This is where having a deep pocket comes into it. If something goes wrong with a 5 Turbo try to fix it as soon as possible because before you know it you'll have another problem then you'll find it hard to get back on top of them. Bottom line is treat them like a baby as they can be very temperamental cars when not treated right !