Astra H VXR Sprint

…..and the odd teething trouble!

Today the front bumper was refitted ready for the first road test after the winter’s rework. Really just an opportunity to have a brief shakedown and check engine oil and gearbox oil coolers and temperatures. After the fuel pressure was adjusted using a new 4 bar regulator, the ecu was mapped and a brief check on the rolling road showed a safe but not fully optimised map giving a ‘useful’ 327bhp. On the road the car wasn’t driven in anger as the mapping has not yet been fully optimised, but it was instantly apparent that the power and torque gains are massive across the whole rev range. Even driven at ¾ throttle the acceleration is immense, compared to a Stage 3 300bhp car and the transformation is unbelievable. You have to experience it to fully appreciate it.

It was also an ideal opportunity to check the new engine and gearbox oil coolers. The engine oil cooler and temperature all seemed fine. Gearbox oil temperature rose to about 73 degrees C so it was time to try the new oil cooler. Back at base the switch was flicked on……. Nothing! No pump noise, no green LED to indicate power to the pump. Very strange as I had checked, double checked and triple checked all the wiring before everything went back together. So it was time to do a bit of investigative diagnostics.

The first thing was to put a live feed from the battery to the switch feed on the relay; this would power up the pump and check if the issue was a faulty pump or something to do with the switched side of the wiring. So on investigating the relay, ready to put some power to the switched terminal, it became immediately apparent that one of the relay earth connectors had pushed back out of the relay housing…… that would do it!!! Carefully pushed it back into the relay housing and refitted the relay. Bingo! LED illuminated and gearbox oil pump whiring quietly to itself. Fantastic because I was convinced there were no wiring issues, so a misconnected relay pin was a simple fix. And dare I say it easy to overlook when the relay was originally pushed into the housing.

Upon further checking round I then noticed a very slight weep from the banjo union back into the top of the gearbox, despite being sealed with copper washers. Clearly the face on top of the gearbox isn’t quite 100% square. So plan B for this union…. None of the other oil fittings using the same banjos and banjo bolts was leaking. So to get at this union it was a case of quickly popping out the battery  and bracket – it all comes out as one unit once the three bolts are removed and the battery clamps are disconnected – nice and straight forward now, unlike with a factory battery and battery tray. Unscrew the banjo bolt and clean everything down using degreaser. Refit with a pair of dowty washers which incorporating a rubber seal as well should seal better onto the gearbox face. This was in place of the copper washers which were originally used, despite the fact the chosen copper washers are the same as the ones used on the turbo oil drain to the block. Once all back together, flick the pump back on. The moment of truth…… sorted. Pump fully operational as before and oil flow back into the gearbox……. and no leaks.

So next it will be onto finalising the mapping, and an overdue wash and detail. And a new set of Pagid RS29 brake pads for the front alcon calipers and a new set of tyres.