1.6 TDi CAY engine - oil pressure concerns.

[davegsm82]

Hi, I've recently bought a car with the 1.6 CAY engine, it's got a blown turbo, this had been replaced by the previous owner with a brand new unit and evidently failed very quickly.

When I started the car at one point it did have a flashing oil light so I shut it down straight away, suspecting oil pressure issues.
I bought a pressure gauge, attached it to the oil pressure switch port and started up, it showed about 15 Psi.
I then disconnected the turbo oil feed (bare in mind the turbo is ruined) and connected the pressure gauge there, it showed about 30-40 Psi.
Finally I blocked the turbo oil feed on the block with a plain bolt and re-measured the pressure at the oil pressure switch, still 15 Psi.

Google seems to suggest that all of this is normal, and I'm starting to think the previous owner either had really bad luck or bought a really cheap turbo which failed immediately and they subsequently gave up on it.

I've got another Turbo from another 1.6TDi, not exactly the same unit but it's from the same series of engines, all feed, return, boost and exhaust piping will bolt right up. I'm willing to put it all together and try it, but has anyone got any experience with oil pressure issues on this engine? am I missing anything obvious?

Have also checked the oil filter for sparkles, none found, only a tiny amount of sludge, can't even find any rubber from the wet belt. Other than the lack of turbo and the alarming oil pressure light, the engine starts and runs well.

[ORCoaster]

I have to ask.  At what RPM are you measuring the pressures at the various points?  I think that 15 psi at the head would jump considerably if you ran it at 1,000 RPM.  I think that is the Bentley spec, but don't quote me on that.  I think the 15 psi at idle is acceptable if it rises upon acceleration. 

[davegsm82]

The measurements were made at idle, but I did rev the engine a little and it didn't seem to make any real difference to the oil pressure.

The oil is fresh but also extremely thin, it flows like water.

I'm probably going to drop the sump and have a look at the pickup screen anyway, as well as inspecting the belt while I'm in there.

[fatmobile]

15 at idle when the engine is warm is pretty good.
 Even 7psi at idle is plenty good.

Not sure why it is so much higher at the turbo line.
 Except the oil line comes from the filter mount instead of the head so it is closer to the pump.

When it comes to bad oil pressure, I worry about the intermediate shaft bushings.

[davegsm82]

15 at idle when the engine is warm is pretty good.
 Even 7psi at idle is plenty good.

Not sure why it is so much higher at the turbo line.
 Except the oil line comes from the filter mount instead of the head so it is closer to the pump.

When it comes to bad oil pressure, I worry about the intermediate shaft bushings.

I think you must be thinking of the old IDI engines? as far as I know the TDi doesn't have an intermediate shaft.

The turbo feed is a lot closer to the oil pump on this engine though, it's half way along the back of the engine. The pressure switch is right up near the exhaust manifold.

[fatmobile]

Oh, you are right.
 I think the intermediate shaft bearing problem is probably why the TDI moved away from and auxiliary shaft.
I say 1.6 and missed the TDi part in the title.

I'm not very familiar with the 1.6 CAY block.