1997 MGF help needed!

[roger_owens_47]

Hi everyone

I'm hoping someone on here might be able to help me and more importantly my very poorly MGF!!

Having been stored for the winter, I got it out last week, got it serviced and MOT'd - hurrah I thought...

Well on her first run down to work this morning, trip of 80 miles, she started to struggle with power, requiring more and more rev's to keep any speed, which increased the engine note, and eventually caused me to pull over on to the hard shoulder. Opening the boot I was met with a VERY hot coolant bottle boiling away nicely, with steam coming out of the lid - immediate thought was HGF, however there are no other signs, no big spikes in engine temp on the dash, coolant once cooled was clear, and after sitting there for half an hour, when I started up again she picked up speed and carried on as if nothing had happened.

Before returning to the road, I checked the coolant level and looked for signs of any puddles under the car - no leaks and coolant to the right level. So off we trundled, roof down enjoying the sunshine.

It wasn't long though before the same problems started to occur, slow loss of power needed more revs to keep going, out of curiosity I put it in to neutral to coast down one of the hills and I quickly came to a complete stop even though I hadn't touched the brakes.

So our first trip back ended up being towed home

Has anyone got any idea what could have happened - my only thought is that something in the engine is seizing causing lots of friction, which in turn makes the engine work harder and hotter causing the coolant problem - but I'm drawing a blank as to what it could be...

[ZSx]

I would have thought brakes to slow you down in neutral, which effectively disconnects the engine from the wheels, sounds like a binding calliper for that.

As to the boiling coolant, id get the engine pressure tested and check for air locks in the coolant, as a first point of call

[RobboMC]

A simple test, when the problem surfaces, park quickly, put the car in neutral and give it a push.

These little cars roll with the slightest nudge, even my son can easily move the car a few feet by just pushing a wheel around.

That will tell you if it's the brakes or not. perhaps it could be the handbrake jamming on, just an idea to check.

The usual tell take sign of HGF is coolant in the oil rater than the other way around,
the oil ends up looking like mayonnaise.

[Rob Bell]

A binding caliper is generally easy to diagnose: the smell of burnt friction material, and even a little smoke, will give the game away!!!

A brake problem would not necessarily explain the boiling coolant either.

When the engine gets VERY hot, you will loose power and the engine will eventually stall and cut out (ask me how I know ).

What interests me is that the engine speed was increasing, but the power and road speed was dropping (have I got that right?) This sounds more like a slipping clutch? Has the clutch release arm seized/sticking preventing full clutch engagement after a long lay up over winter?

The boiling header tank with steam may point to a failing header cap. They are known to fail, are cheap to replace and that is what I would do next...

[roger_owens_47]

thanks everyone

As soon as I arrived at the office yesterday I placed an order for a new cap!

Sorry it probably was me not being clear - when it started to slow, I was having to push harder on the accelerator leading to a louder engine note to maintain any speed.

[Rob Bell]

So loosing power rather than increasing rpm?

[roger_owens_47]

Yep

Garage have of course diagnosed a HGF, which has already been replaced once, perhaps I'm being an optimist but I really don't think it's the HG.

Going to try and get confirmation that the brakes aren't binding, get a bottle of steel seal, replace the coolant pipes with Stainless Steel ones and replace the Coolant cap. Before I condemn the old girl to the race track in the sky!!

[RSR92]

Just to nip this in the bud; do NOT I repeat NOT use any kind of gasket sealant in the 1.8 K series...there is many a thread on this but the long story short is that the coolant galleries and jiggle valves are much too thin for these products and they will gunk up your engine and pipes and exacerbate your existing problems

Also if you go to a garage and tell them your mgf indicators aren't working they will also diagnose this as HGF...an exaggeration for sure but the point is you are being wise taking that with a pinch of salt but please please please do not put a gasket sealant through as the horror stories are endless. There are people who have bought their F and put a lot of care into it just to get engine problems because some twonk has put a gasket sealant through it! Have a google or a search on this forum for MGF Gasket Sealant and I'm sure you'll find a story or two to chill your bones

[daz]

get a bottle of steel seal

FUXAKE NOOOOOOOO!!!!!!!!!!!!!!!!

[ashleyfrazer]

Roger. Where are you in the country?

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[roger_owens_47]

Hi Ashley

I'm in Northants - I was driving down to Stevenage when the probs started.

[ZSx]

A binding caliper is generally easy to diagnose: the smell of burnt friction material, and even a little smoke, will give the game away!!!

A brake problem would not necessarily explain the boiling coolant either

Agreed, but this bit:

out of curiosity I put it in to neutral to coast down one of the hills and I quickly came to a complete stop even though I hadn't touched the brakes.

Made me think its a combination of issues maybe, one of which sounds like a wheel/brake issue to me? Although I'm no mechanic, so happy to be corrected if wrong

[talkingcars]

After some spirited driving s sticking caliper will make that wheel hotter than the others.

[ashleyfrazer]

Hi Ashley

I'm in Northants - I was driving down to Stevenage when the probs started.

Hi. I was thinking it might be good to get it to a specialist assuming the garage who say it HGF are not. Trouble is the guy I use is at Chesham. From what you say it would be a trailer job to get there. Ash

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[talkingcars]

Call out one of the mobile specialists?

[roger_owens_47]

Thanks everyone for the help and advice - it was very subtle but I feel theres not much love for gasket seals!

I've just come back from Trophy Cars in Stamford - outcome is that the Radiator has dropped, coolant pipes corroded and HG failed. I'm no mechanic so I know I'm going to have to pay to have this work done. They do have a more expensive alternative - upgrade to a TF160!

Haven't decided yet what to do!