[E_T_V]

Also worth pointing out that the main reason the head gasket fails is that the coolant is run low allowing it to overheat badly.

The small coolant capacity of the K series engine (one of its good and bad points), means that any coolant loss can be serious.

If you keep on top of the coolant system then they last pretty well. If you don't - well they don't.

[CV35Rover]

Don't feel its all Rover chaps, HG issues are common on many cars, just less well publicised.

I have a Porsche 944 and was advised when buying that unless the HG has been changed recently, budget for a new one and expect to redo every 80K miles - guess whats being done on the car at the moment?

Also BMW 6 cyl engines - look on ebay for the number of E39 5 series and E46 3series being broken due to HG failure some at less than 120K miles.

Of the 3 MGFs I have had, only one had HG failure (just before I bought it so was a bargain) - and that had over 80k miles on it.

[220 GSi turbo]

Early 'wet liner' engines were more or less bulletproof unless the engine was allowed to lose water (as mentioned above), usually due to poor servicing (not changing water pump at sensible intervals, not checking radiator for corrosion/leaks: both of these could happen with almost any car).
There was indeed a small batch of engines that were built with porous cylinder heads (1990-91 ish, I seem to remember) but that was a typical motor industry quality control issue.
I once owned a 1994 Rover 214 that had had a head gasket change (because previous owner didn't notice a leaky radiator) at 110,000 miles. This was repaired by a Rover main dealer using the standard elastomer gasket and I ran that car up to 201,000 miles before selling it on. MoT records show that it was tested 12 months later with 209,000 miles on the clock. In all that time, I changed the oil every 6,000 miles and the coolant (OAT) every two years and the only breakdown was caused by a tired alternator.

Later 'damp liner' engines did prove troublesome: I know of more than one case of a regularly-serviced 1.8 only lasting 4-5 years and 40,000 miles before suffering HGF, but BMW refused to admit there was a problem (sound familiar? do an internet search for BMW swirl flaps, MINI power steering) and left Ford, who were still buying the engines for the Freelander, to try to sort the problem out. And of course after BMW offloaded MG Rover to Phoenix, there was definitely no money left to try to deal with it

[crepello]

There's a fascinating account, probably on AROnline, of the exchange of the complete lines between Cowley and Longbridge, for Mini and 75 at the point of divorce.

Among the differences were that BMW had introduced their take on QC at Cowley, so those Cowley employees transferring to Longbridge with the 75 needed to be re-trained in the Honda-inspired QC practices MGR wished to perpetuate. This was to MGR's credit, and illustrates a difference of culture.

Honda/MGR attitude was that everyone was responsible for quality, and could call out problems as soon as found on the line, so there was a chance to proactively adjust practices.

BMW attitude was to get on and build it and let someone else do the checking, fixing and complaining once the thing was complete.

Places I've worked have tended to the BMW attitude, and I was the one tasked with reporting a continuous dribble of bad news. Very easy to feel under-appreciated in that mode.

Jaded, moi?

[Mr Teddy Bear]

Not a lot of love around for BMW

Who is going to recount the story of the plastic dowel then?

[961tat]

Here is a link with good information and piece on the quality when bmw were at the helm .
Bedtime reading for her indoors

http://www.sandsmuseum.com/cars/elise/t ... kingk.html

[Mr Teddy Bear]

So to sum up for our non technical members then:

open deck block is not a cause of structural weakness and promotes coolant circulation between block/head

high performance and or high load application's such as the Freelander need the thermostat moving to the cylinder head coolant outlet

the crankshaft is not dynamicaly balanced beyond 6500 RPM in standard form and is responsible for block flex' when extended

The stresses within the block sandwich are spread and managed by the design of the stretch through bolts

the bolts are designed to be torqued up and stretched to put the bolt into it's yield zone, so the bolt flex's with the block

liner to block deck stand proud height has increased from 3-4 thou to 4-5 thou

block machined faces will go out of tolerance over time as the heating cycle works manufacturing stresses out of the block

the plastic dowel caused head shuffle, resulting in the liner tops no longer sitting in the gasket fire ring, steel dowel re-introduced

early gaskets suffered failure of the elastomer used in the fire rings and oil feed orifices [not discussed but added to complete the picture]

early damp liner engines suffered from excessive manufacturing tolerances between the block and liner


Fitting a beefed up through bolt not operating in it's yield or elastic zone will result in the crank seizing in it's journals or the block cracking

The above conclusions are based on high performance engines fitted to light weight racing applications.







What are the conclusions to be drawn from the above for those of us running standard Rover designed damp and wet liner engines?

Fitting the modified oil rail and beefed up bolts plus MLS gasket is probably not necessary with wet liner engines. Always change the through bolts when replacing the head gasket. Making the block too stiff when it was designed to flex could be detrimental to engine long life?
Liner heights need to be carefully measured before rebuild.
The Ford designed upgrade to oil rail, MLS gasket and beefed up through bolt's seems at odds with the conclusion drawn above that crankshaft dynamic imbalance is responsible for excess block flex.

Please don't view this as a lecture by myself and feel free to offer your opinion if you think I've got part or everything wrong?

[RoverRevival]

My conclusion, don't drive like you stole it all the time and you'll be fine.

[961tat]

now that funny but true

but none of this explains why my lad add a 25 1400 for 4 years while at university ( they don't teach common sense ) , told me he add it service and 3 year later it was leaking oil on the drive and the reason was oil filter was rusting a way and then 6 months later turn up again with no oil in it and wanted filling up with kettle full of water , and it's still going and no HGF , so some of them must have been built right !!! 51 must have been a good year .

[Mr Teddy Bear]