BX GTi - now I've got no compression

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BX GTi - now I've got no compression

Post by martinwiseman » 26 Jun 2002, 04:09

It just goes from bad to worse. Earlier I wrote about my problem with it running very rich. Now it's totally dead, the engine just spins round with no compression but once again it doesn't appear to be any of the obvious things.
I was making some measurements on the ECU whilst cranking the engine (*see below) when all of a sudden it just started cranking over much faster and more steadily as if there was no compression. A check with a compression tester verified that there was indeed no compression.
I've had the rocker cover off and the camshaft is going round just as it is suppose to.
I've checked that the timing marks on the crank and cam pulleys line up with their respective marks - so the timing belt hasn't jumped.
I've checked as best I can that the valves are going up and down (the tappets certainly move up and down as the cams push on them)
I've checked that there is clearance between the back of the cams and the tappet. The only clue here is that it seems a bit excessive, unfortunately I didn't think to measure it exactly. A 7 thou feeler gauge slipped in with no resistance - that's all I know.
So what the hell is wrong????
My best guess is that the valves are sticking open very slightly - but why would all 4 cylinders go simultaneously?
Cranking the engine over for an extended period of time hasn't freed things up, neither has letting the engine cool completely.
I'm pretty much resigned to scrapping the car unless anyone has any miracle solutions.
Martin (somewhat pissed off) Wiseman.
(*) The investigation I was doing at the time was admittedly a bit bizarre, but I can't actually see why it should bugger up the engine. I was cranking the engine over with the manifold pressure sensor disconnected. The intention was that as soon as it fired I would use a syringe to draw a vacuum in the sensor however I was a bit premature and drew the vacuum before the engine fired. It was while I was drawing the vacuum that the engine suddenly lost compression.