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How to test cooling system
pekwah1 - 7/2/13 at 06:55 PM

Hi GUys,

What's a good way of testing a cooling system or water pump?
I have a 1300 xflow with a header tank, but when it's running, i'm not convinced the coolant is circulating properly as the rad doesn't seem to get massively hot, and the coolant lines are different temperatures...

Is this normal or does it sound like a bad water pump / airlock?

Cheers,
Andy

carlknight1982 - 7/2/13 at 07:07 PM

Check your thermostat

jossey - 7/2/13 at 07:09 PM

There are a few ways.

Drop the coolant from the bottom n fill back up as far as you can... then start the engine of the pump works the level will drop.

Or get the fan started n see how long it takes to warm up it should take a long time.

Last try turn the water pump by hand ....

rusty nuts - 7/2/13 at 07:25 PM

Do you have a hose from the inlet manifold to the water pump possibly via a heater ? Inlet manifold is often the highest point of the cooling system in the engine and will trap air if the hose connections are blocked off

Andy S - 7/2/13 at 07:30 PM

The rad should not get hot until the stat opens if the block temp is at 100+ and the rad s cold you have a problem -

How to test if the block is at 80 wait...... if the block is at 90 wait..... if the block is a 100 turn it off you have an issue.

Andrew

britishtrident - 7/2/13 at 07:35 PM

What temperature is the cylinder head outlet elbow reaching ? or what temperature is the by-pass hose reaching ?

pekwah1 - 7/2/13 at 10:38 PM

it's been a while since i ran it really hot but i'm sure i got it up between 90 and 100 a while back, my rad fan never started but i'm not sure what temperature my rad switch is set for.

Also the rad was never 'that' hot....

As for the inlet manifold, no the connection is blocked off, is this particularly bad? Where should i route it to if i should have this?

britishtrident - 7/2/13 at 10:59 PM

quote:
Originally posted by pekwah1
it's been a while since i ran it really hot but i'm sure i got it up between 90 and 100 a while back, my rad fan never started but i'm not sure what temperature my rad switch is set for.

Also the rad was never 'that' hot....

As for the inlet manifold, no the connection is blocked off, is this particularly bad? Where should i route it to if i should have this?


The inlet manifold should connect back to the small inlet on the water pump, this circulates water round the block which warms up the bottom of the cylinders and ensures an even temperature.

It also helps to drill a small hole or two (smaller than 1/8" inch) in the thermostat to ensure the thermostat opens quickly. Don't drill any more than two holes or the engine will never warm up.

Paul Turner - 9/2/13 at 08:53 AM

quote:
Originally posted by britishtrident

The inlet manifold should connect back to the small inlet on the water pump, this circulates water round the block which warms up the bottom of the cylinders and ensures an even temperature.



That works fine with one exception, if the hose is too big all the water short circuits the radiator and boils the engine. Ran a x-flow for 14 years in my 7 (last was an 1860 with 175 bhp) and I simply blocked off the manifold and water pump outlets, never had a problem. Engine always ran at 78 dgerees witha 74 degree stat, fan switch was 88 degrees.

quote:
Originally posted by britishtrident

It also helps to drill a small hole or two (smaller than 1/8" inch) in the thermostat to ensure the thermostat opens quickly. Don't drill any more than two holes or the engine will never warm up.



Drilling holes does not ensure the thermostat opens quicker, it simply ensures that a little water trickles through and theoretically reduces the thermal shock on the head when the stat does open. In 14 years I never bothered and as I said above I never had a problem. Having said that on Zetecs with the Raceline water rail and no heater its an essential mod.