Just needs bleeding properly?

[Geoff130]

My ZT190 came with an engine that was replaced at 75k miles and had done 125k when I bought it. The previous owner had replaced and skimmed the heads he said and it doesn't leak oil or water. It does leak a bit of oil and although it doesn't leak coolant it does get rid of water somewhere though. Initially the steel pipes to the oil cooler were weeping so they were replaced with the stainless ones. There has become more and more evidence that oil and water are mixing somewhere, never oil in the water but a bit of mayo in the oil filler cap. Temperature as monitored on diagnostic was always high so I changed the water pump and belts (pink leak stains and dripping down that the engine). Better but not fixed. I have since found the fan wasn't working right, so I replaced the resistor and fan motor brushes. Temperature is now much more stable but still losing water, about half a litre every 100 miles. Oh and I did replace the expansion tank filler cap with a new one. Can someone tell me what magic cure there is rather than take the heads off and have a look inside.

[SD1too]

I'm really sorry to say this Geoff, and other members may well disagree, but your experience is what can happen with replacement engines. The fact that the heads were skimmed is also a warning sign. It was either done unnecessarily or because the originals had warped, and the latter case indicates that the engine has not had a good life.

On the positive side "a bit of mayo in the oil filler cap" may be the result of condensation due to lack of use. Could this be the case?

Coolant stains below the water pump were, in my case, the result of drainage from the 'V' due to leaking plastic component 'O' ring seals. Have you checked your engine for this?

However, a 500 ml loss over 100 miles is not insignificant. Are you overfilling the expansion tank? You should be able to see the 'max' marker within the tank. I don't see any justification for removing the cylinder heads.

Simon

[Geoff130]

I had the same thought regarding the mayo but it seems to be getting worse although it may just be me. The vee has always been dry with none of pink stains found around the water pump. I may have overfilled it on occasion but from just touching the full mark it will be out of sight the next day, about 30 miles use in two journeys. I am considering an oil cooler leak at the moment.