A friend had her R25's cylinder head gasket replaced along with a replacement cylinder head recently. Within a few miles of having the job done, the car boiled over and had to be recovered by trailer.
I looked at the car and offered to replace the cylinder head gasket again with the multi layer type and its head saver shim. Actual replacement of the cylinder head gasket was a doddle. Cleaning all the oil-coolant mix from the engine and the whole of the coolant system wasn't ~ it was a lot of work.
What I found was during the previous repair, the essential dowel which not only locates the cylinder head correctly to the block, but also encloses the essential oil supply to the over head camshafts .... was missing! This allowed the engine oil being sent at high oil pump pressure to the Over head cams to be diverted into and around the cylinder head and its gasket. This in turn meant it was sent into the cooling passageways and the rest of the cooling system at oil pump pressure. I fitted two new steel dowells in place of the nylon ones which very positively located the cylinder head and, more importantly, enclosed that oil supply.
To the inexperienced, at first this would appear to be yet another misleading "They all do that ~ repeat HGFs are common ~ well known fact" scenario.
This is yet another example of incompetent repair workmanship. Apart from that one little (BIG!) omission, they had done an excellent job. Since I repaired the engine, the car has done in excess of 1000 miles including several long motorway speed runs so far without further incident. The odd trace of oil has appeared in the coolant bottle ~ I suspect that is remnants from the previous failure which no matter how carefully and thoroughly you clear out the old much from the previous 'failure', a few globs of the stuff still lurk in the corners of the cooling system. This is what the stuff looked liked when I flushed the totally blocked core of the radiator:
This is what I saw when i first lifted the bonnet:
and on removing some cooling pipes and radiator:
The stuff was everywhere and took several hours of cleaning to get rid of most of it from engine and cooling system.
The full story can be found on this thread:
Helping a Friend out:
This is one of the worst cases of incompetent repairs I've ever seen on a car and I've seen many such over the years I've been driving. In conclusion, please remember this:
THEY DO NOT
ALL DO THAT!
Only some.....Unfortunately, due to incessant K-Series media negativity overkill ~ that is a LITTLE known fact.