BenTyreman
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| posted on 9/2/10 at 02:22 PM |
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Advice changing MG TF head gasket
Does anyone have any advice on the best way to change a head gasket on a 1.6 MG TF? Can it be done in situ, or does the subframe have to be
lowered?
Thanks, Ben
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t16turbotone
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| posted on 9/2/10 at 04:10 PM |
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Calling British Trident again.................
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marcjagman
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| posted on 9/2/10 at 04:12 PM |
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I have done a few, I would strongly advise dropping the subframe. Don't skimp on these engines, new bolts, head skimmed, cam belt etc. Make sure
you can get the rear suspension re-gassed too.
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ashg
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| posted on 9/2/10 at 06:30 PM |
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my only advice would be not to bother unless your fixing it to sell it
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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britishtrident
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| posted on 9/2/10 at 07:59 PM |
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Before stripping check for external water leaks -- pipes under car, inlet manifold gasket, water pump, thermostat outlet pipe on the water pump.
If the subframe bolts will move drop the subframe.
Head is removed at half stroke and don't turn the engine more than about 45 degrees with the head off.
Rover head bolts can be reused 5 times BUT the threads must be properley cleaned and the fitted length of the bolts checked before refitting the head
by screwing the bolts into the block by hand to see the screw down far enough to properly clamp the head. --- personally a wash them in
thinners then clean with a hex die nut lube with WD40 or diesel and allow to drip dry for an hour.
Do this even with new bolts as initial tighten torque is so low and stickiness in the threads will knock the angular tightening out by a mile.
Cam carrier & Camshafts don't need to be removed from the head.
The cylinder liner heights should be checked to ascertain if the best type of gasket to use --- the Freelander multilayer gasket demands a tighter
tolerance.
If possible use the Freelander gasket.
If using the Freelander gasker take extra care to clean the sealing areas on liners and head properly --- the Freelander gasket seals on different
places from the original Paynes gasket.
Even if using the Freelander gasket the upgraded block ladder isn't really required.
The initial torque setting before angular tightening is very low so it is vital use an accurate low range torque wrench or the whole angular tighten
sequence will be a mile out.
After fitting and angular tightening the head I always do a sanity check and run a torque wrench set a 35nm over the head bolts --- usually one or
two bolts move a little.
Always fit a new inlet manifold gasket --- very common source of coolant leaks.
A new water pump is also a good ide.
Optional change the thermostat for later PRT type -- actually a relatively cheap Landrover part but involves a fair bit of re-plumbing.
Alternatively fit a new original type but drill two or three tiny bleed holes in in the thermostats valve plate.
Bleed the cooling system from cold after filling the cooling system with the correct type of coolant-antifreeze. If the coolant is pink-orange OAT
coolant used on later cars the OEM coolant was Havoline Longlife which is sold by Morrisions petrol stations.
If may take two or three attempts to get all the air out the system, always best to start bleeding the system as the engine warms up from a cold
start.
[Edited on 9/2/10 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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BenTyreman
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| posted on 9/2/10 at 08:50 PM |
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Cheers. Will have a go tomorrow.
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Marcus
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| posted on 9/2/10 at 08:51 PM |
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Just to add, you say it's a TF, these had proper suspension, no need to re gas, the F had the hydragas.
Marcus
Because kits are for girls!!
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britishtrident
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| posted on 11/2/10 at 08:41 AM |
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I should also add don't skim the head unless it is in a bad way, check the head for pitting corrosion round the bores -- caused by not
changing the coolant. Warping is unlikely unlesss it has been really badly roasted but check for it with a good straight edge.
Also check the cam drive roll pins are safe to reuse and locktite the sproket bolts, if you do do the cam belt (nb two different types --- wider
belt and auto tensioner fitted 2000 onwards) take especial care with the bottom pulley as they can float on the D flat on the shaft -- give it dab
of loctite + make sure it is tight.
[Edited on 11/2/10 by britishtrident]
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BenTyreman
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| posted on 13/2/10 at 04:49 PM |
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All sorted and running  Thanks for all the help.
Replaced the Paynes gasket with the MLS + shim one. The head gasket looks like it's been gone for a couple of weeks.
The plumes of steam came from a split coolant pipe next to the exhaust downpipe.
The car already has the PRT thermostat. Is this factory fit on 53 reg cars, or has this been upgraded by the previous owner?
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britishtrident
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| posted on 13/2/10 at 08:33 PM |
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Usual history --- initial water loss owner is brain washed into thinking its the head gasket. Water loss becomes worse the system airlocks and the
head gasket actually goes due to over heating.
PRT thermostats were just starting to be fitted to MGs and 75s in 2003, and some were fitted under warranty.
MG_Rover also started to change all the cooling system hose clips to better quality types.
The very last TFs had a coolant level sensor this can be bought in kit form from Brown & Gammons and is I believe based on parts Ford introduced
on the Freelander.
Most MG-Rover parts suppliers such as Rimmers Bros and Brown & Gammons can now stainless steel coolant pipes for underneath the car.
There were a few silly mistakes on the cooling system in these cars nearly all to do with the installation rather than engine design flaws. The big
one that affects almost all MG-Rover models is that both the temperature gauge and the fan are operated by the ECU from a single temperature sensor
and the ECU steadfastly ignores the readings from the sensor and substitutes a default normal reading if it sees an unexpected increase in coolant
temperature.
Apart from modifying the thermostat the mod I would recommend is fitting a simple over heat warning light.
On the saloons and Freelanders where space is available an addition auxiliary cooling fan with its own switch is is a good idea. I have done this
to my own 75 and fitted a coolant presure gauge to give early warning of leaks.
[Edited on 13/2/10 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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