[KSP1]

I have a 320d M47 2005. For the past year I have noticed that the cooling system is pressurising more than it should. As I can see that the cap was throwing out coolant And I would need to top it up every couple of days, The car would never overheat.

I have finally got around to sorting the car, as I need my car for work I can’t take off the road for a couple of days. So I bought a secondhand M47 cylinder head, which was skimmed pressure tested new valve guides and acid dip. With the three hole gasket that was provided by the engineering firm.

I have done about 500 miles since fitting the reconditioned cylinder head and gaskets. I have noticed that the car is still losing a little bit of coolant, The pressure is nowhere near as bad as it used to be. But after spending all of this money on trying to fix the car it seems that I still have minor symptoms of the previous issue.

NOTE- car has DPF Delete, EGR system delete with blank

Can anyone provide some insight on this issue ?

Thanks!!!

[Andy198712]

Have you tried a new coolant bottle cap?

[therealdb1]

My guess is either the system is being overfilled and the expansion tank cannot take that quantity of coolant or, as Andy says, the cap is passing.

This could be because it has been subjected to higher pressures in the past and now the seal is passing.

Have you actually measured the pressure in the bottle or do you just assume that because coolant is leaking out the pressure is too high?

I cannot believe that a new plastic cap for the expansion tank will be very expensive so why not fit one anyway?

[KSP1]

hi guys, thanks for the input I’ve checked the reservoir and the coolant is at maximum amount allowed on the stick.

What you were saying about the Does make sense, because I can see some watermarks around the reservoir. I’ve bought a new cap from the dealer, and fitted it today. I’ll let you know how I get on with this!

[Andy198712]

fingers crossed.... if the cap is failing or starting too it will be blowing off at a lower pressure.....

[KSP1]

Fingers crossed indeed, I’ve spent enough fixing it. Just wanna enjoy the car now and not worry

[DriverLDN]

My E90 330i had a similar problem with losing coolant recently and I had a load of the coolant hoses replaced due their age as my car is a 2006 model. This seems to have resolved my coolant issues.

[BourneJack]

Originally Posted by KSP1

hi guys, thanks for the input I’ve checked the reservoir and the coolant is at maximum amount allowed on the stick.

What you were saying about the Does make sense, because I can see some watermarks around the reservoir. I’ve bought a new cap from the dealer, and fitted it today. I’ll let you know how I get on with this!

+1

[KSP1]

Update......I’ve replaced the cap and it seemed to work for a few days until I had to add nearly a 1 litre of water

Running out of ideas on what it could even be...