MG TF Headgasket - or some other problem?

[Jaguar steve]

Mrs JS has a 40k mile 2004 1.8 TF. Been told the HG has already been done and no reason to suspect not as there's evidence it's been apart with new Jubilee clips on the head coolant hoses and scuffs and marks on the parcel shelf.

Coolant level has not changed since we've had it and there's no signs of mayo in the oil or oil in the coolant. Engine temperature is stable even on hot fast drives and the heater works all the time.

Noticed ofter switching off from hot a gurgling noise from the engine and the expansion tank was filling right up. Sounds like - hopefully - an air lock to me, so have bled out radiator but is there another bleed screw somewhere else?

Google says there is on the F as well as a automatic bleed valve too but no info on the TF.

Anybody help? Cheers Chaps

[jimbob82]

take the thermostat out and test it in boiling water

[itcaptainslow]

Three bleed points-one on the rad, one on the heater matrix below the scuttle panel (remove the black plastic trim in the front compartment under the bonnet) and one in the engine bay on the metal coolant rail running above the gearbox by the air filter housing.

[Jaguar steve]

Fantastic - thanks.

Will give it a go once caffene levels have normalised.

[Jaguar steve]

Update - turned out it was the coolant header tank pressure cap. New cap, system bled and topped up.

[nta16]

Jaguar steve said:

Update - turned out it was the coolant header tank pressure cap.

that common to many cars I'm surprised that isn't on more threads on this subject

there's quite a bit of info on F/TF on here so have a look at old threads or do a site search if you have other issues

these cars are also very tyre sensitive, plenty on that subject on here too

as with most things do read the instruction manual at the start too

now she should be tearing the road up in it

[simplesolutions]

just a short note to say if anyone with an MGF or an MGTF requires any good quality used spares try this place in glossop derbyshire.
http://www.mgfntfbitz.co.uk tel [phone]. or mobile [phone] also on ebay too.
they have a massive stock of every part you can ever want for you car and all laid out in an fully organised warehouse, everything from interiors to panels and switches n wheels n tyres in fact everything for your mgf and mgtf. and all at very reasonable prices. you can call in or shop online and they will ship them out to you.
derek jackson, time served city and guilds mechanic of 45 years based in manchester.

[MGJohn]

Jaguar steve said:

Update - turned out it was the coolant header tank pressure cap. New cap, system bled and topped up.

Cheap as chips fiver to fix...

Those worn valves in Expansion Bottle Pressure Caps along with a worn Water Pumps have probably damaged more cylinder head gaskets on K-Series cars from overheating than any other agency.

[Ex X Power]

disagree, i'd have said rotten radiators, no end of cars that I've repaired have come in with "Bloody Crap Rover Headgaskets" when what they should have said is "Bloody Crap Rover Radiators"
In my experience I'd have said the radiators outweigh the expansion tank cap at least 5 to 1

[MGJohn]

Ex X Power said:

disagree, i'd have said rotten radiators, no end of cars that I've repaired have come in with "Bloody Crap Rover Headgaskets" when what they should have said is "Bloody Crap Rover Radiators"
In my experience I'd have said the radiators outweigh the expansion tank cap at least 5 to 1

Five to one eh.... those are good odds....

You appear to be in the trade. I'm merely a keen amateur spannerman. Worn Water Pumps losing coolant in my limited experience is possibly the major cause of so called head gasket failure in these engines.

The alloy radiators in our cars appear to be in good shape despite their age. Premature radiator problems, again in my limited amateur experience, is often due to poor quality coolant mix or worst still, simply H2O only used. That is asking for trouble. Plain water accelerates engine and cooling system internal corrosion. That corrosion crud accumulates in the lowest part of the cooling system, usually the bottom of the radiator core causing all sorts of problems there.

A lady friend's Rover 25 showing 110,000 miles had the core of her car's rad crumble to dust allowing rapid coolant escape. Amazing! Fortunately, no harm done and a replacement alloy one surprisingly cheap at £40 delivered.

[nta16]

one of the biggest faults with most cars (certainly classics) is past and present owners and some of them consider themselves petrolheads too (whatever they are)