Looking at buying a V6 Contemporary SE tomorrow

[trikey]

Originally Posted by racing green rover

I'm going to buy some tubing tomorrow and bypass oil cooler iv'e fitted a new thermostat and flushed the engine again for 4th time and I flushed the heater matrix from the small hose which goes into the thermostat loads of k seal came out. Now the engine isn't overheating now it takes a good minute for it when the fan kicks in to bring it back down to 95c also the heater warms up now only when you rev it on idle it cools back down

Sounds like an airlock if the temp drops when revs are applied.

[racing green rover]

No the heater cools down with no revs it gets hot when you rev it this is when the temperature of the engine is around early 90s

[Ched]

You still have an airlock

[buchanan]

Water pump, if the thermostat is ok, and you have flushed everything, it might be the water pump, to bleed the system you need water pressure if pump faulty you won't get it.

[SD1too]

A review of Pete's thread shows that this car is suffering from the effects of K-seal, not a straightforward air lock. We know from other members' experiences that it is not an easy task to get rid of this dreadful product. Pete's report that the heater output fails at idle, but is restored as revs increase, suggests that K-seal has infiltrated the heater matrix (and/or associated pipework) and is impeding flow.

Originally Posted by buchanan

... to bleed the system you need water pressure if pump faulty you won't get it.

Roy; MG Rover's refilling and bleeding procedure does indeed require water pressure, but from the raised expansion tank not from the water pump. The engine should not be run until the air has been expelled from the bottom radiator hose and the bleed screw refitted.

Simon

[dave lincs]

Originally Posted by racing green rover

No the heater cools down with no revs it gets hot when you rev it this is when the temperature of the engine is around early 90s

Had few of these with cold heater till you rev it up wa oil cooler every time

[vitesse]

Originally Posted by SD1too

A review of Pete's thread shows that this car is suffering from the effects of K-seal, not a straightforward air lock. We know from other members' experiences that it is not an easy task to get rid of this dreadful product. Pete's report that the heater output fails at idle, but is restored as revs increase, suggests that K-seal has infiltrated the heater matrix (and/or associated pipework) and is impeding flow.

Roy; MG Rover's refilling and bleeding procedure does indeed require water pressure, but from the raised expansion tank not from the water pump. The engine should not be run until the air has been expelled from the bottom radiator hose and the bleed screw refitted.

Simon

Simon,

If we accept that pressure is applied by the height of the raised coolant tank, and if this pressure then fails to dislogde the air lock or K-seal, would not more pressure help to unblock that which is blocked?

Had my own car not given me my previously described belch then my next plan C or D (I forget) would have involved small bursts of compressed air in through the expansion tank to attempt to dislodge the blockage.

I’ve often used compressed air, first to drain the coolant as releasing the lower radiator hose produced no more than a mere trickle, with air behind it the bucket filled in no time, accompanied by graining debris.

I’ve also use compressed air when bleeding “unbleedable” clutches (Saab V4 / Rover 820) and even on brake circuits.

In normal circumstances the car’s not difficult to bleed but mine had defeated the experts with their vacuum filling and the OP’s car seems similar.

Would not the use of one of those radiator pressure tester be beneficial? Any thoughts?

Mike

[racing green rover]

I've flushed the system again extensively also tried to bypass the oil cooler but the pipe i had was too big and it kept on kinking the rubber hoses so I've ordered a new oil cooler will update after fitting it

[racing green rover]

Iv started working on the car again I was waiting 3 week for the oil cooler to be delivered but it didn't turn up so the supplier refunded me what sort of piping do I need to bypass the cooler I got some copper pipe but couldn't bend it without it snapping most of the k seal is gone now I don't think I will get it all out I have already flushed it about 10 times. The heater is working now blowing hot on both sides at idle no overheating the only issue is with the water rising immediately to the top of the expansion tank when I start the car up from cold it doesn't vent through the cap when it's fitted.
Thanks

[SD1too]

Originally Posted by racing green rover

... what sort of piping do I need to bypass the cooler ..

I've never done it myself Pete but it will be obvious what is needed when you remove the undertray and have a look.

From what I've read on the forum, ten flushes isn't unreasonable. That's really good news that the heater is now working properly.

... the only issue is with the water rising immediately to the top of the expansion tank when I start the car up from cold ...

Make sure that you're following MG Rover's refilling and bleeding procedure exactly. Take particular note that the expansion tank must be raised and the engine not started until the bleed screw is refitted.
If you're already doing both these things then it sounds as if there's air trapped by remaining K-seal.

Simon