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Never forgotten
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Some engines came from the factory with lower than optimum liners, but damage can also occur in service. Engines that have overheated badly cause the head to go soft and when this happens, the material can no longer clamp the liners into position and they hammer up and down in the block causing the location to sink. A similar thing can happen if the cylinder block gets too hot and goes soft.

A block that has been damaged during an overheat is not salvageable and should be scrapped, but blocks with low liners from new can be corrected by machining. At one time, liners were available in two different lengths to obtain the correct stand proud.

Most people just rebuild with whatever they have unless the liners are below the surface of the block. They usually get away with this since the engine has already proved that it is capable of running for some time at the liner heights that it has. Most gasket failures are due to problems with the sealing rubber bead rather than liner heights. This subject tends to receive more attention than it really deserves. That is not to say that it should not be checked! ;)
 

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mg_zr
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Absolutely!

I did hear that one long running issue with low liners that affects a lot of cars was eventually traced back to the blocks being slighly over machined to accept the liners.

The reduction of 2 liner options from one was a bean counter led move I understand!

Once overheating sets in and the hammering action of everything trying to blow itself apart (which is what people often forget is really going on with an engine) its not long before the alloy parts (block/head etc) are damaged beyond realistic repair. Annealing, the softening due to over heating cycles can be reversed but its expensive and usual the alloy material has been damaged as a result of the softening.

We always get heads hardness tested before we do anything with them. The only mega overheat I am aware of on an engine we have rebuilt is one of our own road cars, and its so far holding up well on 167,000 miles in total and over 80k since its rebuild but critcally the liners all had good protrusion despite the engine being cooked to death!
 

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rover_25
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49 Posts
Great info. My R25 had an MLS gasket fitted following HGF 7 months ago at 78 000 miles. I have been checking coolant levels regularly since.
One thing that seems weird is the role of the heater. The thermostat can only open when it receives water from the by pass which is hot enough to open the thermostat. However this water is diluted by cooled water from the heater matrix when the heater is on. So on start up the engine will get hotter when the heater is on. The thermostat will not open until it receives water at 88 deg C from the by pass and this water is mixed with water that has been cooled by the heater matrix. The by pass and pipes to the heater are small compared with the main coolant pipes and so are not able to provide enough water on their own without the main coolant pipes.
The normal advice to have the heater on is wrong for the R25 because this will lead to delay in the thermostat opening.
 

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In practice it is not quite like that and the engine is perfectly happy to run on the reduced quantity of coolant that it sees from by-pass flow alone. The engine has run complete full throttle endurance tests with the stat closed and no flow at all through the main radiator cooling circuit.

It is true that the engine gets a little hotter than stat temperature at low speeds with the heater operating, but under full load conditions the engine temperature is well above this anyway. About 110C. When the engine is running at high speed the difference between heater on or off is insignificant.
 

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mg_zr
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Its very common engine design practice now since the K Series pioneered many of the lastest idea in engine design, to have very small coolant capacities and flows to aid engine warm up, which has significant effects on fuel effciency and also emission control.

The old priciples are quite different when dealing with cast iron blocks etc, alloy not only warms up faster but also cools by the same rate making if a more thermally efficent material and thus needing less fluid cooling.

Many people dont realise that until the thermostat opens there is only a very small coolant flow within the engine, via bypass and the heater circuit that themselves play on the thermostat to influnence opeing/closing. In reality in many driving conditions the thermostat can be opening and shutting many times.

Some engines now don't use wax type thermostats at all but electronically controlled valves taking signals from the coolant temperature sensors in the engine.
 

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mg_zt_t
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7 Posts
zt t 120+

well my ztt120 none turbo head gasget went at 39k so all sorted now but im selling dude to not being able to pay the repair bill . i love the drive of this car and i think it looks cool to.
 

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mg_zr
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K-series HGF! I know, shocking!

Hello! My first post on this site as I'm a noob! Signed up about 10 minutes ago! Right for the first time I'm going to attempt to fix the head gasket myself! But I'm just wondering is there any need to drain the oil before doing this or is it any easier without oil? I know an oil change is good practice when dealing with HGF and I've drained it already, changed the filter and now I'm just wondering whether to bother filling her back up before I get on with the big job! The Haynes manual doesn't mention it and I cant find anything online to suggest it needs to be done but you lot seem pretty clued up so I thought I'd ask! Cheers in advance peeps and sorry if it's a naive question! I just prefer to be over cautious!
 

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rover_200_95_99
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I found this technical article in an old issue (July 2007) of Practical Performance Car magazine.

The four pages below are low quality .jpg's, larger and more legible .jpg's can be downloaded from the links below.

My thanks to Grant Stacey and the team at PPC magazine for giving permission to reproduce the article here.

Page 1: http://www.sendspace.com/file/b3xfhq
Page 2: http://www.sendspace.com/file/o17hsk
Page 3: http://www.sendspace.com/file/0tsz3a
Page 4: http://www.sendspace.com/file/30psbm



REPRODUCED WITH KIND PERMISSION OF PRACTICAL PERFORMANCE CAR MAGAZINE
www.ppcmag.co.uk
Hello!
Could anybody please re-upload Page 4, as it's been already deleted from sendspace....
 

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Nip your bolts up!

Is it not possible just to "nip" the bolts up if there's misting round the head?
anyway on to the MGF (2000MY) 50,000miles 1.8 Freestyle Stepspeed - Vroom!
I've got a little floating oil in the coolant - it feels slippery to the touch, but doesn't smell. No 'oil pressure' displayed - was always <120. Water temp 'normal'. Doesn't appear to be any problem, dipstick reads 'max'.
Exhaust sensor failed - needs replacement, (unrelated but thought I'd slip it in) therefore yellow 'check' light on.
Other than that it is brilliant..............any tips/ideas/warnings?
Cheers


I found this technical article in an old issue (July 2007) of Practical Performance Car magazine.

The four pages below are low quality .jpg's, larger and more legible .jpg's can be downloaded from the links below.

My thanks to Grant Stacey and the team at PPC magazine for giving permission to reproduce the article here.

Page 1: http://www.sendspace.com/file/b3xfhq
Page 2: http://www.sendspace.com/file/o17hsk
Page 3: http://www.sendspace.com/file/0tsz3a
Page 4: http://www.sendspace.com/file/30psbm



REPRODUCED WITH KIND PERMISSION OF PRACTICAL PERFORMANCE CAR MAGAZINE
www.ppcmag.co.uk
 

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rover_25
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Just had Head Gaskett done!

Hi guys / gals,

Ive just had to have my head gaskett sorted on my Rover 25.
I was devestated today when I went to collect my car from the garage to be dealt a bill for £630!

Is this about right these days or have I been done up like a kipper!

Ive always thought they were a good decent garage, but this does seem steep. He said I was only charged £250 for labor and usually it would be much more? Thoughts??
 

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To be fair, thats not a hideous price for a head gasket change these days from a garage. At least you know now your 25 will give many more years service! Much less than the depreciation on a new one!
 

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My local garage said a HG replacement would cost me around £400 including VAT. But luckily they said my HG hasn't failed so I don't need to pay that yet. :)

Mobile mechanics tend to charge around the £300/350 mark.
 

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Hi guys / gals,

Ive just had to have my head gaskett sorted on my Rover 25.
I was devestated today when I went to collect my car from the garage to be dealt a bill for £630!

Is this about right these days or have I been done up like a kipper!

Ive always thought they were a good decent garage, but this does seem steep. He said I was only charged £250 for labor and usually it would be much more? Thoughts??

i like to see a list of parts fitted on that bill
what part of UK are you in as London rates are dearer than Yorkshire
 

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rover_25
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i like to see a list of parts fitted on that bill
what part of UK are you in as London rates are dearer than Yorkshire

Im in Manchester.
From what ive been told, ir seems it was a fairly average price for job.
Ive been told to take it back after a month to get it flushed again - Hope this is free and part of what ive already paid?

How long do you think i'll get now with the new gasket sorted?
Or is that like asking how long is a piece of string?
I only do low mileage in it, couple of miles to work and back and the odd trip.

Must say it does seem to have lost abit of power, not that it was ever a race car like!
 

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Hazel, contact one of the mobile mechanics on here.
They know the engines well and are mega cheap compared to a garage.
They will also do the job properly!

I always think of the HG like a fuse in an electrical plug and failure is 9/10 due to an underlying problem. In my case a knackered radiator on the 214 and a failed water pump on the TF.

Hgf therefore prevents further damage to the engine, if caught early.

On the 214 a second Hgf was due to the muppets at the garage not having a clue how to work on a K series.
 

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mg_zr
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mg zr 1.4 wont start

i have recently bought a mg zr 1.4 2003 we gt it half way home and it died on us there was a hole in the water rail and the head gasket went we replace the rail and my mate is a mechanic who replaced the head gasket we have put it all back together and checked over everything timing wiring etc just do not have a clue why it wont fire any ideas on why it wont go ????
 

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mg_zr
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I fitted multi layer kit from rimmers, 20 k ago, haven't topped up water, or run hot since. 2004 ZR 105. Has become totally reliable, nippy little car. Kit come with gasket, shim, bolts, modded oil rail, can't remember price, couple of hundred I think!!!!
 

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rover_75
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Rover 75 suppliers

Hi, I am currently doing research at Newcastle University looking at how the automotive supply chain has changed in the West Midlands.

Does anybody know where I can get access to a list of major components and their suppliers for the Rover 75 or any other car built in the 1990s/early 2000s.

Any help would be much appreciated

Thanks :)
 

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mg_zr
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Hi, I am currently doing research at Newcastle University looking at how the automotive supply chain has changed in the West Midlands.

Does anybody know where I can get access to a list of major components and their suppliers for the Rover 75 or any other car built in the 1990s/early 2000s.

Any help would be much appreciated

Thanks :)
I would have posted this plea under a separate topic item in order for it to get more prominence under the MG Rover discussion section. I presume your research is for a Business Studies or Economics related dissertation? You don't say which period you are focusing on for your research or which era it is starting from - the pre-MG Rover Group era, or life from 2000 and after MG Rover Group? There may be a number of individuals who might be able to point you in the right direction. However, I don't believe such a list of major suppliers would exist although speaking with companies such as Stadco in the Midlands and Pressed Steel at Swindon would be a good starting point.
 
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