Hi all, went out shopping yesterday evening, a bit cold so had heater on. Noticed this morning that the top hose had sucked in. Could this be due to the header tank cap being off the 8 valve engine, and is now on a 16 valve ecotech?

Hi Andy....hope you are staying well?

Coolant pressure caps is important to be be in good condition and also the correct rating to allow the coolant boiling temperature to be raised by increasing the pressure in the system. Too high and it will pop at the specified pressure. If faulty it can draw air into the system and create a vacuum as you are experiencing.

I would be tempted to replace the cap with a genuine part from the local Vauxhall dealer (shouldn't be too much)

Hi, yes thanks I am keeping well, and hope you are too. I  going to get a new cap, but will put the original one on and see how it goes. Have got to do another flush through too, as don't think I cleared out all the crap. Coolant still oily, but not as bad as it was. 

Regards Andy.😁👍👍🙋

Well i put the original  cap from the 16v on, and it has cured the problem of the top hose collapsing. Going to buy some rad flush this week and give it a good flush through. Fresh anti freeze, and then its service time again. And try to get a filter for the auto transmission, and freshen the oil as some dips**t has put ordinary gear oil in and not proper trans fluid.  

Blimey!  that's bizarre with the wrong oil being in the transmission and still working.

Should work a lot better after a fluid and filter change

I certainly hope so. The strange thing is, the car runs so well, gears change without any problems. Next payday will see filter and oil for gearbox. 

I definitely won't be going to the garage the previous owner used.