+1 and yes OAT (orange / vaguely pink) coolant

 

Payam,

Did you bypass the aux pump, link it out with a hose/pipe?

This is a side issue, your Jaguar is/was overheating.

It is not rocket science, the water pump has to circulate water around the engine and the temperature is controlled by the thermostat. This water is then cooled by the radiator.

Now you seem to have replaced/checked most of the the big bits so it must be something else.

I have attached the cooling diagrams, check your one for the 4.2 and go through it.

From some of your posts it sounds like the radiator is not getting a flow some of the time.

I would start again and go through the basics.

Are you getting a flow of water through the inlet hose and the outlet hose of the radiator.

Remove these and blow through each way.

Blow through the radiator both ways with the hoses removed, is it clear.

Is the water pump pumping? turn it by hand with the hoses removed.

Is the thermostat sticking? are there shinny marks on the barrel?

You would appear to have a restricted flow of coolant. Go through page 9 and prove you have a flow through the pipe work.

What we have to find out is Where and How.

Sludge, rubbish in the pipe work blockage, mechanical defect, and sort it.

If not your going to have one dead cat on your hands.


RSPCTJ Hon. Member

 

Thanks I didn't use the OEM water pump but the original water pump was OK didn't need to be changed.

But I removed the Auxiliary water pump from the system completely. now the car is running much better. I just got over hit only once since past few days.to day I drove about 100 kilometres without over hit.

 

Thank you every body for your attention.

a few days ago I removed the Auxiliary water pump from the system completely. now the car is running much better. I just got over hit only once since past few days.to day I drove about 100 kilometres without over hit. I will check it more.

But now another problem is coming up. when I am driving, till 50k speed its fine but higher then that if I push the gas pedal the engine jerks and and doesn't accelerate smoothly looks like sensor problem!!!!

any Idea?

Thanks

 

Over the past year there has been a steady trickle, of dead cats,

4.2ltr 2004/05 mostly.

In them there parts.

Various overheating issues mostly going for scrap value, nice bodies, 155/180K Km but usually miles away from me.

I used to wonder how they managed to get into such a state?

Now we know!

RIP

 

Something wrong, like pump was wired backwards. It needs fixing.

Other fault may be misfires. Stop making it happen or expect a huge cost for new cats.

 

Here are two resolutions to problems with my 2005 STR that hopefully shed some light on your problems:

Overheating Problems
A) I accidentally installed a low temperature thermostat backwards and engine coolant did not flow as needed to maintain proper temperature. The coolant temperature would rise when sitting in traffic but was fine when moving.
B) Had to replace radiator fan due as the wires (near DCCV) getting chaffed and shorted.

Engine Misfires & Engine Bucking
Inconsistent (random) engine misfires were due to a clogged catalytic converter.