What would happen if a heater matrix was blocked up ??

dutchman (dutchman ) gurgled happily, sounding much like they were saying:

Blocked up? You'd have no heat. That's it. The water can easily bypass that part of the cooling system.

dutchman formulated on Monday :

Probably the same as any other car....

The heater would not work, or not be so effective. You can easily check it, feel the inlet pipe and the outlet pipe. The second should be almost as hot as the first. If much cooler it is blocked.

The heater has never been very effective.

I thought that the matrix was part of the main cooling circuit (assuming thermostat was closed).

If blocked where would the hot water go too (before thermostat opens)

I am asking this question as I have just had a blown head gasket (oil in water) with the radiator cap blowing creamy gunge all over the engine compartment. Head did not look cracked, so I put it all back together again, new head gasket, bolts, pump, thermostat, all bolts torqued down.

The engine runs soo good and smooth, but it now seems as thou the cooling system is getting pressurised, as the rad cap drips water. After driving it a few miles clouds of steam from the cap with temperature light coming on on the dash.And it has lost most of its water.

I did not flush out the heater matrix, as it was too difficult to get too.

Any other ideas or guidance to narrow down the problem.

get a gas test above the coolant, this will show the presence of combustion (in all probability) then take the head off and try again. get the head skimmed and tested before refitting. it is very rare to be able to see head faults without specialist test equipment.

================================== Holt's 'Radflush' (or similar product) is worth a try and it often works. However, with the symptoms you're experiencing I would suggest that you replace the thermostat as a first step as it could be stuck.

Cic.

dutchman formulated the question :

By the sounds of it, the head gasket has gone again - but this time much worse than before. You cannot check for cracks by eye and it could well be distorted.

dutchman (dutchman ) gurgled happily, sounding much like they were saying:

Round the circuit.

You'll be getting good at the HG at this rate.

Cicero (Cicero ) gurgled happily, sounding much like they were saying:

He says he already has...

================================== Yes, I missed that bit. Looks as if he's got a problem!

Cic.

Could I give it a go at torqueing the bolts a bit more ???

Or do I get the head off and do a dye pen.

dutchman submitted this idea :

Once the gaskets gone, its gone.

It needed to be torqued down a little at a time, to the specified figure and in the specified order. It then should be retorqued down after a set mileage has been done. Did you use a torque wrench?

Dye should help find any cracks, but it will not show up any distortion.

No, you get the head off and take it to somewhere that can check whether it's warped or not.

Instructions are 20Nm in order then angle tighten 120 deg twice in order (giving 240 deg)

No mention of running then re tightening.

So they're stretch bolts. Did you use new ones or just reuse the old ones?

Conor (Conor ) gurgled happily, sounding much like they were saying:

Yup, definitely.

He did say "new bolts" in the original post...

Some people have been saying tighten to 270 deg.

Would it do no harm even now to retighten by a further 30 deg ( as I am at 240 deg)

dutchman (dutchman ) gurgled happily, sounding much like they were saying:

It wouldn't do any harm.

It won't do any good, either, but it won't do any harm...