MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - How many skimmings can you have..

Hi yas,

long time no speak. My beloved MGF died last week; Went to start engine and lots of lovely metal noise (HGF) and coolant disappears into the engine. Strange, as engine was fine and coolant level was perfect the day before. Does this mean engines suffer as much stress when turning on as they do if you were to try driving at 100mph+?

The problem is, the car had HGF a year before I bought it and HG was replaced and head skimmed. So, now my baby is resting in my local garage before I get the bill for its repair, and I wonder should I get a new head or is it safe for the existing head to be skimmed again? Will i get another HGF in the next year? Would a new head be so designed that the likelyhood of another problem be minimised to that of any non K6 engined car? Lots of questions... And how much should i expect to pay for repairing the existing head/replacing the head gasket or supplying a new head and gasket.

Appreciate your swift response. My life is empty now..:-(
JANINE ELLIOT

I would guess yes to your 1st paragraph question.
But the HG shouldn't cause a metal noise when it goes, but a cambelt breaking or slipping a tooth or two, might do. (eg caused by bolt or tensioner failure) although that might also damage the head such that it is written off.
It depends how long you have had it as to whether the LR gasket may have been fitted previously, and it has been known for sellers to claim that a head has been skimmed when it may not have been. Sounds like it didn't get overheated, which is a plus
B&G aren't a million miles from Bedfordshire and will be able to assess it's options with great accuracy.
If all else fails the prices for Fs are so low that replacement may be cheaper.
Best of luck and let us know.
Charless

> or is it safe for the existing head to be skimmed again?

The answer is it depends on the head. There's a max amount that can be taken off, if after skimming it's still within the tolerance you're fine.
Leigh

As Charles points out, gasket failure doesn't usually cause metallic noises. I'd be interested in what your garage's diagnosis is once they've investigated.

If it is indeed the gasket that has failed, a second head skim shouldn't be a problem, provided the first skim was a light one. In many cases it's not necessary to skim the head at all, but that's largely dependant on what caused the gasket to let go.

Engines suffer different stresses at different points - for example on a cold start, the oil circulation takes a while to build up so for a short time metal-to-metal surface wear occurs, regardless of engine or driving speed. At 100mph the oil is circulating properly, however the engine will be producing a lot of heat (which thins the oil) & the internals are spinning at quite bewildering speed and trying very hard to make contact with each other, so the oil has to be in good condition to prevent the surfaces meeting.

Buying a shiny new head is no guarantee that you'll have no more trouble - it'll be the same design as the existing head, just a bit newer. And shiny. The issues that cause gaskets to let go are rarely directly the fault of the head

A garage cost for gasket replacement is anywhere from £500 to £800 depending on what work is needed (i.e. skim or no skim) and the hourly rate. There are mobile technicians that specialise in head gasket repairs and seem to quote much lower prices, so perhaps worth looking into that. The demise of MGR led to a lot of well trained & experienced mechanics suddenly having to find a new source of income 8-/
bandit

Hi,

Thanks for your concern and advice. Having visited the garage looking at the car it seems one of the cylinders had cracked and a piston had been damaged, so looks like it needs a new engine as well. Where can the garage get one from, how much, is it worth it for a 51 MGF? Or should I just buy a bicycle. Sensible advice welcome. The garage is quoting me anything up to £2000 to get car on the road again.

Ta,
JANINE ELLIOT

Hmm, that'll explain the metallic noises 8-(

A like-for-like engine swap isn't as challenging as it might seem, an experienced mechanic in a MGF specialist workshop should take max 8hrs, I've seen a transplant done in well under 6. What hourly rate are your garage quoting?

Most salvage & breakers yards are hooked up to a nationwide parts network, so if you Google 'car breaker' you'll find lots of websites offering search facilities. The price will vary according to mileage & age, but I'd be surprised if you can't get a suitable low-mileage replacement for under £1000. Most will offer a warranty of some sort, but if you get one from a crash damaged car it's unlikely you'll get a dud. eBay is another source, usually a few engines for sale there, sometimes as low as £400.

Has the cylinder head been damaged? If not, you may be able to find someone selling just the engine block, i.e. re-use your cylinder head/manifolds/etc, which would be cheaper and shouldn't be much different on the labour costs.

Bicycles would be great if they had 2 more wheels, a roof, a boot, and an engine...
bandit

Hi Bandit,

Many thanks for your reply. Yep one of the cylinders has gone completely, as well as the piston. Plus the head gasket. I've given the garage the go ahead to replace the whole engine, do a complete service and MOT. I expect it all around £1500. The engine is guaranteed.

Sure I can get it cheaper elsewhere, but by the time i pay for work already done to the car and towing to another garage I'd be paying more. Ce la vie (I think..)

I'll keep u all posted as to what happens next.....
JANINE ELLIOT

Hi all,
Just collected my MG. All in all I had new engine (since the last one had HGF, cylinder crack, broken piston and worm out rod thingies that move the piston up and down), new clutch, full service, MOT (which of course it passed) and valet.

My god it looks stunning and runs soooooo well. Having made do with borrowing a Renault Scenic lorry for the last month, going back into the MGF was worth the wait. It steers so much better than the Scenic and obviously doesn't roll when i go round corners like the lorry did. It is such fun. Now I just hope HGF's are a thing of the past. Any tips on putting MGFCentre Lexus style rear lights on (are they legal), and upgrading the brakes (which are not anywhere as responsive as the Scenic's) would be gratefully received. Anyone agree with me that Top Gear is getting more and more boring?
JANINE ELLIOT

'Con rod' thingies, I suspect.
If you had a cylinder liner crack and a piston broke (usually spelt pissedandbroke) too, I think the HGF can be forgiven as a 'secondary' problem! It certainly explains the 'metal noise' in your original post.How many miles had it done before that major upheaval?
Anyway glad to hear you are back on track and heartened you still want to spend more money on her(?) !!!!
Charless

Hi Charless, Not sure if it's a boy or a girl. Like to think it's a boy, but he's very cute :-) Yep, thanks for your post - I agree it was a lot more serious than the HGF. It was the con rod thingy that the garage mentioned. They were really good, though they took a lot of money off me! The 2001 MGF has done 58,000 and already had HGF before I bought it. I have already replaced pipe work with stainless steel so hope coolant loss won't happen in the future. Most other essential parts (alternator, battery, water pump) are still almost new now, so I'm hoping I can have a few trouble free years now...
JANINE ELLIOT

Ouch! Good to hear that you've got the car back in one piece and all is now once again well :o)

May I ask which piston failed? Was it Number 1 per chance?

Hopefully the new engine will be more reliable - and certainly I am sure that you'll benefit from the peace of mind offered by a guarantee!
Rob Bell

This thread was discussed between 10/07/2009 and 05/08/2009

MG MGF Technical index

This thread is from the archives. Join the live MG MGF Technical BBS now