S16 Pressure (Water & Crankcase)

[lpr1981]

Hi all,

As you may know from my previous threads here I am trying to bring a '94 306 S16 back to life.

I have rebuilt the cylinder-head including a pressure test and a skim and the engine is now running!!

But, I am getting a huge amount of pressure from the crankcase ventilation system e.g enough to blow the dipstick out just by revving the engine in neutral. The water system built up so much pressure when I removed the radiator cap the water blew out 2-3m high (and it burnt my hand boo-hoo) for a good 5-10 seconds!

The head is good so I am now think (worst case) cracked block? Any suggestions would be great fully received.

Many Thanks.

[Seb_Ryan]

If the head is spot on and gasket is fitted correctly it looks that way..

[Alastairh]

To get both water and oil pressurising like that, I can't help but think the head gasket isn't fitted correctly / is wrong part. Either way it's going to be coming apart again, but I would hope that's your problem

[Ben_w]

I'd agree with the head gasket not being fitted correctly if its pressurising the coolant system that much. I'd also be wondering about the state of the rings. Heavy crankcase pressure often results from the rings being shot. Have you compression tested it at all? I suspect you'd see secondary leaks from a cracked block?

[bashbarnard]

Could just be a blocked breather pipe causing high crankcase pressures and an air lock in the cooling system. Don't jump to bad conclusions until the basics have been checked I say.

[lpr1981]

Thanks for all your responses, I cleaned all breather pipes whilst the head was off and they were not really that gunked up to be honest.

I am currently thinking the thermostat did not open even though this is new but I will take it out and try again.

How did you fit a head gasket incorrectly?

To me it seemed as easy as one of those toys you give a child with all the shapes you put through the holes (cannot remember what they are called).
The Head Gasket in the end was ordered from Peugeot as to begin with I did consider a cheaper option, all the head bolts were new and torque and angle tightened to the specs in my bible (Haynes manual). The two locating dowels were in place before the gasket was sat on the block so the chances of the gasket slipping was pretty much impossible.

[Seb_Ryan]

Ive had it where the head hadnt been skimmed correctly, where you have the precups it skipped over them as they are harder, and it caused the same problems..

[lpr1981]

I took the thermostat out earlier fired the beast up and all seemed to be normal. Even crankcase pressure was normal.

Very strange as it is a new thermostat, I guess it is a bad one.