BMW M50 Compression
 

Hi Guys

Sorry if this was covered before :shifty

I have took my e36 320i for diagnosis and only one errror code = Tank ventilation electronics, they also did compression test, No 4 & No 5 next to the bellhousing there's no compression.
1. Can 2 no compression cylinders cause a car not to start?
2. What COULD be NO compression cause ( suggestions or opinions, I know the head must be removed to diagnose the problem)
3. Any idea what are the rates for top skimming, pressure testing?

It would be tough to keep a six cylinder engine running on only four cylinders, so it might not start. If the problem is intake valves, then it is a safe bet that the backflow through the intake manifold would disrupt it enough to keep it from starting.

Low compression is usually a burnt valve or cylinder wall damage. No compression is usually a broken valve and/or a hole in a piston, or a broken cam.

Under any of these scenarios, there is a good possibility that this engine is not worth fixing if you have any possible access to a running junk yard engine that will fit in this car.

No idea on rates, especially in South Africa. By top skimming, to you mean shaving the deck of the block or the head? Neither is a good idea on this engine. By pressure testing, do you mean a leak down test so see where the damage is? That should cost just a little more than the compression test cost.

Possibilities include a blown headgasket. That would cause compression loss. As Manolitio stated above, how have you been driving it? Any missed shifts or money shifts?