Failed water pump

[jackb_ms]

Good evening everyone

 

I have an issue with the cooling system in my car.

It's a 1996 1.8 vvc fitted with a rover prrt. The engine has been rebuilt by DVA, last year and fitted back in the car in March 2011. It has only run a few minutes at any one time due to the overheating issue.

When Dave rebuilt the engine, he found a lot of radwell residue inside the block.

 

The engine overheat very quickly when idling, looking at the water temp on gauge, it seems that there no coolant flow.

I say it seems as when I look inside the header tank I cannot see any water coming out of the engine return outlet and I can feel any air movement when I put my finger in.

 

The radiator stays stone cold but the inlet and outlet are hot, all pipes are hot

 

Are those tests valid to diagnose a failed water pump?

Is there a way to test the water pump without running the engine?

Do I have a massive air lock somewhere?

 

Can I assume the water pump is a standard K series item and not a “special” Caterham?

 

Thanks for your input

 

Jack

 

[Stationary M25 Traveller]

Standard Rover pump.

 

Sounds like you could have an airlock.

[Sheds Moderator]

My money's on an airlock. Even with a couple of cans of radweld in it the thing will work. Water pumps don't just stop working, the standard failure modes are (a) that they start leaking on the gland so the thing p*sses coolant everywhere. If you are really lucky then the coolant loss overheats the engine and you end up replacing the HG. That's fun. The other (rarer, fortunately) option is that he WP bearing siezes, the cam belt snaps and you bend valves. That's great fun, and gives you the opportunity to replace the HG again because you have to rebuild the head. Lovely. Fortunately either of these joyous scenarios is presaged by a good deal of squeaking and rattling or a gentle decline in coolant level that normal maintenance picks up. Ignore either of these at your peril, or if it's an old car, sell it.

[oldbutnotslow]

An air lock is one cause but DONT run it and overheat the engine or you will wind up replacing the HG!

 

Bleed the system (lots of posts on how to do this)Fitting a bleed T in the top heater hose if you have a heater will allow you to "back fill " & bleed the system more easily. I am a fan of these and fit them almost as a matter of course.

 

Its a 15 year old car that seems to have had heating problems before. Some water pumps have plastic impellers which can break. Similarly impellers do come lose from the shaft. Both will cause either reduced or no water flow.

 

If it were my car I would replace the water pump and the Tstat. They are not expensive and you then have the certain knowledge that they are not the cause.

 

Also check the hoses. If one de-laminates you can get a "flap" that will restrict water flow.

 

Other than that you are back to an air lock!

[jackb_ms]

What I did is bypass the heater matrix, and back filled the system from the pipe the heater pipe and still no joy.

 

If I had an air lock somewhere, should I see aerated water or air coming out of the outlet at the header tank?

 

Can someone confirm that?

 

Cheers

 

Jack

 

[CageyH]

Is your temp sender working properly? Does the fan kick in?

With a PRRT, you should get heat into the rad when you need it, and not before.

You may have a PRRT failure, but overheating in a couple of minutes does not sound right.

 

My bet is the temp sender is duff for the gauge.

If you have an Emerald, check this by looking at the water temp on the Emerald settings.

[Midlifecrisis2001]

Are you sure the thermostat is opening? Sorry if that has been covered already I just read the first post and rushed to reply - other half is trying to drag me out of the door!

 

Clive