The V8 Owners Forum -

just fitted a rr 3.5 engine in a stag, ran it up but within minutes it started to run hot, would of expected this to take 10-15 minutes, the temp gauge was rising rapidly really quickly. The rad has a new 4 core matrix. This feels cold in every part of the rad top/bottom etc.
upon several start ups tried the old heater and blower trick but cold air only. The hoses to the matrix heater feel very hot.
I also undid the top hose from the rad and water didnt come out at all.
My initial feeling is 80% the water pump failure, or 20% air lock. Is there a way of checking the water pump? should it come rushing out from the topof the rad on turn over?
mick

It does sound like water isn't circulating.

Given the rarity of water pump failure, I would think you've not got as much water in it as you think you have. Has the thermostat got a bleed hole in it?

Chris.

Hi. As ChrisJC said water pump failure is rare so next check is the thermostat. Remove it and check in boiling water. In addition it's probable you have an airlock in the heater pipes.
regards Denis

the last thing I did last night was to remove the top hose from the rad, lift the hose high and secure it, and try to fill the engine block through the thermostat. the level dropped in the hose over a couple of hours so must be flowly slowly into the engine.
So I think both of you chrisjc and DEVONMAN are right, If this doesnt work then I'm going to remove the stat.

Thanks for your thoughts

mick

is your cabin heater on?

If it is there are times when the flow through the heater matrix is more than through the radiator

Try closing the heater off or "mole gripping" the pipe to the heater to force the water through the rad

IAn

Ian Anderson wrote:is your cabin heater on?

If it is there are times when the flow through the heater matrix is more than through the radiator

Try closing the heater off or "mole gripping" the pipe to the heater to force the water through the rad

IAn

Just removed the stat, didn't open properly, so replaced it, will do as above tomorrow.

A quick test for a stat I use....

Push the stat open and slip a piece of string through it. When 'er indorrs is not looking, turn on the kettle and drop the stat in. Hold it off the bottom and you will soon see if it opens or not.


Alternative method for more domesticated types,
Put some water in a saucepan (?) find the stove and carry on from the string bit......

If it involves a pan it's probably best to get your wife/ girlfriend to do it!
Mike

Seems to be a lot better now the rad is hot its getting scarily close to 190+ degc on the gauge though, think that its due to the megasquirt needing set up, seems to be overfueling, but thats another post.

Thanks for the help

check and make sure you havn't connected the hoes on the back of the water pump housing to the blanked off outlet .. on some there are 2 stubs pipes , only one is open ...

i only know becuse i did it

bodger wrote:check and make sure you havn't connected the hoes on the back of the water pump housing to the blanked off outlet .. on some there are 2 stubs pipes , only one is open ...

i only know becuse i did it

Ok now you've got me wondering. Looking down on the back of the pump there are 2 pipes, both connected, the RHS goes to the RHS cylinder head, the LHS is connected to a metal pipe that disappears under the plenum.