My car as developed a slight water leak there is no signs of antifreeze leaking. Had it pressured test still no signs of leaks.

Could this be the egr cooler leaking internally? There is no visual signs coming out of the exhaust.

Its took approximately two months to drop from high to low on the radiator expansion header tank. No loss in performance. Temp gauge reading normal.

Booked it in for investigation. Is there anyway of testing the egr cooler to pinpoint the fault.

Thank you for you're assistance Scooby.

7 minutes ago, Scooby-do said:

Its took approximately two months to drop from high to low on the radiator expansion header tank. No loss in performance. Temp gauge reading normal.

Far more likely that you have either a faulty cap on the expansion tank, or that you have hairline cracks on the underside of the expansion tank.

Personally I'd replace the cap as they are well known to fail.

By the time you've removed the EGR cooler to test it, you might as well replace it regardless.

If the original pressure test was done on a cold engine, then the next test should be done on a hot engine, as that's when metal expands and cracks open up in metal parts.

But for the sake of a few quid, I would also try a new cap first.

Thank you Tom. I've changed the cap. Pressure test done on a hot engine.

I suspect it may be the E.G.R cooler. 

Thank you once again Tom. I think I will take the bull by the horns and get it done. 👍🏻 

22 hours ago, unofix said:

Far more likely that you have either a faulty cap on the expansion tank, or that you have hairline cracks on the underside of the expansion tank.

Personally I'd replace the cap as they are well known to fail.

Thank you. I have replaced the cap and had it pressured test hot.Thank you once again.