Hi there,
Its a standard 89 rst. I'll try'n keep it short....


ok so first thing, in two weeks out of the last 3 it has lost the amount of water between max and min in the expansion tank and have detected a bit of scum under the oil cap when in 3.5 years ive never seen before, but no oil in the expansion tank. The dip stick seems clean and yesterday drained and strined the oil to find nothing unusual. I topped the water back to max 7 days ago and seems to have lost very little upto toady, but still a bit of scum under oil cap
After a journey and the car is cooled a bit there is still good pressure when undoing the expansion tank...if that means anything

things that have happed

unusual thing was the oil light on start up one cold evening was like slow pulsating for about 15 secs then dimmed and went out. During those 15 seconds a few times gave a few more revs but light carried on pulsating.
But really thought it was the cold.

second thing about 2 weeks later, driving home and after about a mile the tappets or something started making quite a loud tapping noise so slowed to a stop and the noise carried on for about 5 seconds about 10 in all.
I gave some small revs but made no difference just made the noise faster. Then after the 5ish seconds the noise stoppedand went back to normal.
I carried on home with no other probs. and hasnt done it since.

So now im hearing water like running through the heater matrix or something from inside the cabin. I checked the expansion tank and is on the full line and am hearing it more when there are more revs. Im also getting hot and cold from the heater

The car is used daily for short 4 mile journeys to and from work
I serviced it about a month ago and am using Comma Syner.G 5/40w fully Synth oil.
The last long journey was about 90 miles of motorway about a month ago

Sorry if written a bit randomly but do you think for sure its the head gasket and or do I have other problems.

Many thanks for reading and any comments