Buying A Cavalier Turbo 4x4
The Vauxhall Cavalier Turbo is a car many people will wish to avoid with the longest of barge poles. Stories and hear'say of problematic transfer boxes and weak turbos are enough to put many people off of purchasing one. However, a well cared for and maintained Cavalier Turbo should give you no more problems than any other car.
As with any other performance car though, the Cavalier Turbo requires more maintenance than your average family saloon. However, in doing so you will be rewarded with a very sophisticated and capable car worthy of the respect of any performance car driver.
Why choose a Cavalier Turbo? What other car can you buy for under £3000 that has a 204PS engine, six-speed gearbox, semi-permanent 4wd, leather interior, 16" alloy wheels as standard and more electrical trickery than you can shake a stick at?
The main issue with the C20LET engines is the fact the cylinder heads are prone to going porous. In a nutshell, there is an oil-way which runs within 6mm of a water channel. Due to poor casting this oil way erodes leading to oil entering the cooling system. Cosworth made some of the cylinder heads and in doing so they saw fit to sleeve this oil way to prevent this from occurring. Therefore having a 'CosCast' head will minimise (but not eliminate) the chance of it going porous whereas as with a GM head the risk is significantly increased. The problem arises when you consider that GM did not fit the CosCast heads to any specific model of car, it appears to be completely random as to which cars got them.
Therefore one of the first things you should check upon opening the bonnet is the coolant bottle. Look for a mayonnaise-like sludge, this will give an indication as to whether or not the head has gone porous (beware this could also be a blown head gasket). Secondly check as to whether or not the car has the Coscast head. This can be done as follows. In the picture below you can see that the core plug is arrowed. This denotes a GM head, CosCast heads do not have this core plug. There are other small differences between the heads but this is the easiest way to tell them apart. The pipe running above the plug is Couternays own porous mod.
The only other real worry with these engines is the turbo. The KKK-16 is good for well over 100,000 miles if looked after properly. Regular oil changes (3000 miles) using Vauxhalls own semi-synthetic oil, allowing the turbo to warm up (approx 10-15mins) before pushing it and allowing it to cool down for no longer than 1 minute will see it a long life. Does the current owner know this? For more information on how to look after the turbo go to Richies Owners Guide.
When was the cam-belt last changed? If the current owner doesn't know and there is no receipt or mention of it in the service history make sure it is the first thing you do once you have bought the car.
Sump gaskets often leak on these engines as does the distributor o-ring. These are common problems and even if a little awkward to put right shouldn't put you off buying the car.
The F-28 gearbox is pretty much bombproof, however, the synchromesh on second is often the first part to go as the boost is limited by the ECU in 1st gear. Listen for a crunch upon engaging 2nd. Replacement parts are now available for the F-28s through Regal. Don't worry if you find it hard to get the car into 1st, 6th or reverse gear. The chances are it's just the linkage which needs aligned.
As most people are aware the Cavalier Turbos Achilles heel is the transfer box. The first thing to check is that the accumulator carries a white ring. The plain black ones are a recalled item and are faulty. There are other accumulators that carry 3 white dots, these were an intermediate item and will now also need replacing. For reference the accumulator should be changed every 52,000 miles or 6 years, whichever is the sooner. There should be a yellow label on the cars slam panel denoting when the next change is due.
The first picture below shows a recalled accumulator with no white ring while the second picture shows where the accumulator can be found in the engine bay, you can just make out part of the white ring.
To check the functionality of the transfer box start the car making sure the 4x4 telltale comes on and goes out after a few seconds. The cars wheels should never spin (unless driving like a complete maniac in the wet!) and there should be no knocks or thumps from underneath the car when pressing the brake or clutch pedals whilst driving.
Another important test to do is the 'whoosh' test. Start the car and let it idle for a few minutes. Then switch off the engine and turn the ignition through 2 clicks (so the dash lights come on). With the bonnet open listen carefully, when you press the brake pedal you should hear a fluid squirt type noise coming from the accumulator area. This is the solenoid relieving the pressure from the transfer box, theoretically disengaging the 4wd. If the 4wd is not functional for any reason there will not be anything to disengage. The fluid-squirt should happen every time you press the brake pedal, up to around 25-40 times.
Other very important things to note: are all the tyres the same make and do they have the same tread depth? Does the current owner rotate the tyres every 3000 miles or sooner?
Be very wary of cars that are lowered. Lowering the 4x4 Cavalier induces camber on the rear wheels due to the IRS rear setup. This in turn reduces the rolling circumference of the wheel which is the equivalent of running the car with mis-matched or unevenly worn tyres. A camber kit is available to correct this, however many owners do not bother.
As with all Cavaliers with Independent Rear Suspension the rear chassis legs are prone to extreme rot. I have yet to hear of a Cavalier Turbo that has suffered this fate but many of the older GSi2000's have been condemned come MOT time due to this. The pictures below (click for a larger view) show the rear chassis rot that caused a Cavalier GSi in otherwise excellent condition to fail its MOT.
The design of the front lower arms was altered in May 1994 by GM to make them stronger. The earlier arms had a tendency to fail due to people using them as a jacking point. Most will have been replaced by now due to bush-wear although it would be prucdent to check them.Make sure to also check for the usual things such as bouncy shocks, leaks, and knocks caused by worn anti-roll bar bushes.
The brakes are largely ok on these cars. The 284mm front discs can be expensive though so its nice to see some receipts for recent ones having been fitted. A lot of people will upgrade the brakes if the cars engine has been tuned. Also make sure the ABS light comes on and goes out when starting the car.
The Cavalier Turbo shares the same basic bodyshell as all the other Cavaliers and as such it inherits the problematic rear wheel arches. Mud and dirt gets caught on the arch lip and if not removed will eventually rot through the arch. The lip needs to be rinsed clean regularly and many owners also apply waxoyl around the area as a preventative measure.
The thumbnail on the left shows how bad the arch rot can become if left untreated. The thumbnail on the right shows the first signs of rust taking hold. Idealy you want to be treating it before it gets to this stage.
Other than that normal things such as panel alignment should be checked and be fine.
Turbo interiors tend to wear very well. Look out for wear on the drivers seat bolster though. Also, the handbrake and gear lever gaiters are prone to the material cracking and flaking off. This is normal. Cars without electric windows or sunroofs are often ex-police cars.