I think its the Head Gasket...help!

I have very recently taken ownership of a 1994 Supra Twin Turbo Manual,

Yesterday i must admit did drive it slighlty hard, however as i was driving on the motorway i realised a slight rise on the temp gauge, then after 10 minutes (was driving at 70 mph), i puuled up and opened the bonnet and the overflow bottle was pushing water out.

I then got back in the car and put on the heaters on full and started driving at 50 mph, the temp stayed below middle,

However got home and left the car to cool down, today i put approx 1.7 litres of water in the rad and let it settle down, i then started the car with the rad cap off, i realised after about 2 minutes on tickover the water gradually started to pour out....

Is it the HEADGASKET!, and how much will it cost?, anybody had any HG problems since their ownership?

I've rang a few perfromance specialists & they all seem to be fully booked,

Any advice & personal experience would be apreciated,

Regards

First thing to do mate, is take off the spark plugs and do a compression test.

Get a mechanically-minded mate to help if you don't know how to do it. Then post the results here.

its normal for the water to start pouring out when it gets hot as it expands.

might be worth just getting a new rad cap first. as they do tend to fail.

Max, don't panic yet, the most common cause of what you have described is simply a worn radiator cap. If the radiator cap is not holding the pressure, the water will boil over as you've described and blow out of the over flow bottle.

Get a good quality, new rad cap and make sure the seat where it sits against the radiator is clean and free from crud. Refill the system through the rad cap opening and rev the engine for a few minutes to make sure fluid is circulating and to get any air out of the system. Keep topping up as necessary until you get rid of all the air and the fluid is hot, then fit the rad cap. Leave it sitting there and keep the revs up, to get it up to running temp, if all is well, go for a short test drive, take it steady and keep an eye on the temp gauge. Hopefully all will be well and problem will be solved

If it is still running hot, then the next thing I would check (once the engine is off!) is the viscous fan. If the viscous connection on the fan is worn (very loose) it may not be spinning up sufficiently to cool the radiator. If it is not this, then it could be that the radiator is past its best or the water pump needs replacing.

Head gasket failure is rare on the 2JZ engine, so I would check the cooling system as described. My money is on a knackered rad cap

True, a knackered rad cap would produce similar symptoms and is easier to check too.

But since you've just bought the car, do a comp test anyway, it will highlight any other issues you might have later.

Forgot to say to the club Max and the joys of Supra ownership

Where abouts in Yorkshire are you? As you've just bought the car I would recommend getting it checked over by a tuner who specialise in Supras (a lot won't have a clue!) It may be a bit of a treck for you but I would highly recommend you paying Chris Wilson a visit see details [user=54]HERE[/user] I gaurantee that you'll agree it was worth the journey, on your way home.

Ok, some good new,

Borrowed a friends rad cap from his n/a supra, as it was too late to go out and buy one. After filling up the rad with water i took the car for a drive, keeping an eye on the temp. Drove for approx 20 minutes, on boost for the last 10 minutes, seemed to cure the problem, got bak home and checked for any overflow leaks, NONE,

What a relief!,

A big thanks guys,

Good news indeed. I had a similar panic last week. Damn cars.

Sent you a PM too.

I wonder why the radcaps go though.

Could it be that it is because the coolant hasn't been changed for years, or do they just 'expire'?

I wonder why the radcaps go though.

Could it be that it is because the coolant hasn't been changed for years, or do they just 'expire'?

The plastic/rubber seals perish over time and the springs become weaker/corrode, eventually leading to pressure loss, which is the cause of the fluid boiling over. Just one of those parts that expries over time.

That's what I'd think Nic.

However, my supra radcap is 8 years old and looks almost new inside out. I've got FTSH and they are keen to charge washers and nuts, so I doubt that they'd leave out a component like the radcap.

My thinking is that if the coolant has been changed regularly (like fully flushed every 2-3 years, nothing obsessive) then the acidity will never reach critical levels and nasty deposits will not have a chance to form.

Just a theory, as I've never had to change the radcap in any of my vehicles, but I change coolant often (every year or two, partly because I vary the strength winter vs summer)