As some of you have seen my Z gave up on me yesterday. After three years of it going from garage to garage, it lost power and covered half of Aberdeen in white sweet smelling smoke. Quickly pulled up and had my missus pull me back home. It has been years since i have been pulled by a rope and it is not a pleasant experiance. With the help of neighbours pushed back into the garage. Quick inspection today after work the front of the engine bay is all covered in fresh coolant. All hoses still secure on radiator and the hardpipes going to engine dry. Small green puddle inside radiator fan. Feels like the pressure have built up so high that it just started spraying through radiator cap, which is brand new Mishimoto one. Took the intake pipes off all clean no oil or metal residue so i reckon turbos ok. Checked oil dipstick. Oil is still clean. Coolant is clean aswell. Next step is to do compression test. I will use this thread to note all finding and progress. Any thoughts are encouraged and appreciated. It does feel like a major headgasket failure. Please bear with me as progress will be slow for the start.

 

Good luck hope you can sort it.

Unlikely if your rad cap is a new one, but my last coolant leak was caused by excessive pressure in the system and it was simply down to the rad cap not functioning correctly. £10 for a new rad cap and all was well again! (+ the cost of the replacement hose that gave in to the pressure!)

Unlikely if your rad cap is a new one, but my last coolant leak was caused by excessive pressure in the system and it was simply down to the rad cap not functioning correctly. £10 for a new rad cap and all was well again! (+ the cost of the replacement hose that gave in to the pressure!)

 

Do rad caps need to be replaced every now and then? Mine may very well be original, if not at least 10 years+ as it was garaged for a long time before my ownership.

If your coolant has ever been left to run bad yes. The rusty gunk will contaminate the valve preventing it from opening under pressure. For the cost, it's a no-brainer. New OEM caps are not expensive.

Do rad caps need to be replaced every now and then? Mine may very well be original, if not at least 10 years+ as it was garaged for a long time before my ownership.

 

I don’t think it’s a service item but if it does fail, it has potential to cause a catastrophic overheat. Might as well replace it for piece of mind. Buy 2 and have another as a spare.

Thanks guys, I’ll get on that.

Started doing a compression test just now on on a cold engine so i know it might not be very accurate. But stopped after 3 cylinders as i found it pointless to carry on. Cylinder 1, spark plug soaked, 135psi. Cylinder 2, spark plug dry, 60psi. Cylinder 3, spark plug wet, 205psi, also compression tester end was wet after test. Wiped it with white tissue which ended up green, so coolant. So one side clearly dumps coolant into. Ylinders the other is very low on compression. Should i still expect a headgasket or something cracked? Whats a better financial option? Look for replacement engine or try and fix this hoping there isnt too much damage done? One thing for aure it did not overheat.

Really short progress. Was sitting all this time in the garage. Managed to get a couple spare hours this weekend. Radiator out, plenum off. Cambelt coming off hopwfully today. Then heads will come off. Question. How do i drain coolant from the block? Risk snapping a bolt on the block or is there a hole i can stick a hose with a vacuum pump on it?

 

You will find a drain plug on the block.It is located on the passenger side above the oil rail that feeds the turbo.It is between the AC pump and engine mount bracket.If you are pulling the heads just remove the engine it will be easier than in situ imho.

Thanks for the tip., unfortunately i do not have the space or the equipment to remove the engine. Managed to get the belt off and did not destroy anything. Very stressful experiance. I have done the belt before with locking kits.

Before I took my engine out I wanted to drain the block to minimise the mess, found a bolt when I removed the alternator a lot of water came out can’t catch it all with engine in but did the trick.

 

Third bolt down in front of the engine mount nearest sump on the drivers side, was extremely tight.

Thanks for help everyone. What a f... job it is to get the heads off with engine in. Fingers and arms all scratched up to armpits... driver side is off. Looks like bad workmanship caused the problem. Head bolts have been reused. Might not have been torqued properly. 2 came off with little to none struggle. So i take it the head just lifted a bit with some boost. Found leak marks from two water ports on cylinder three and one water port on cylinder 5. Passenger side head still to come off. Nothing seems to be damaged so new gaskets and new bolts and will be good to go again. Any trade secrets on how to pull a dipstick tube?

The head bolts are re useable they are not like modern ones that need replacing.I always tap the tube out when the sumps off from underneath but you do not have that luxury.A pair of good quality Mole Grips will probably grip enough to wrestle it out.

they might be able to make it, but by the time they figure out the solution, theyll only have 7 minutes left on that torch. game over, man.