V8 Overheating issues

[Jetprovost]

Hi, 

I hope someone can steer me in the right direction. I have 2002 Esprit V8 that let a piston loose through the block a few years back. Engine was rebuilt and all was well, but then it started suddenly overheating. If you leave the car running it will happily sit at temp all day and kick the fans in and out as it should. However when I drive it it will (seemingly randomly) suddenly overheat. I mean the temp gauge pegs to the right in one fast movement. If I don't stop immediately the car will loose all its coolant - So it is not a gauge issue. If I stop the car and wait ten minutes and restart it everything is good again until another random spike. radiator has been inspected, restored, and refitted, Thermostat has been swapped out, Water pump also checked and given OK. I do not know what to try next - Any ideas? Could it be a turbo cooling issue somehow???

At my wits end - Two mechanics familiar with these cars also are stumped. 

 

Thanks in advance,

Stuart

Edited August 1, 2019 by Jetprovost

[Jetprovost]

Hi,

I hope someone can help as I am at the end of my tether with this problem.

I had an engine rebuild a few years back when a weak piston decoded to go for a trip through my engine block. 

Anyway all fixed eventually and off we go again. Then, a few years later, I have a serious overheating problem. 

If I leave the car running but not moving all is well. Fans kick in and car keeps its temp.

However, when I am driving it, it will randomly (seemingly) suddenly - and I mean suddenly - overheat. The gauge pegs right and I lose my coolant if I don’t pull over. If I stop and let it cool down and restart things are fine again for a while then boom, it goes again.

I have had the radiator restored and checked, Water pump checked, thermostat replaced.

I am out of ideas, as are the dealer mechanics here in Seattle. Could it be turbo cooling issue? Anything else to check?

Thanks in advance,

Stuart

 

 

 

 

 

 

Edited August 1, 2019 by Jetprovost

[Barrykearley]

Is it dumping coolant?

this could simply be an airlock and the radiator needs to be fully bled 

[mike_sekinger]

Have you had your coolant checked for exhaust gases?

[Guest modifiedv8engines]

Could also check and verify the header tank cap rubber seal is okay.

An inexpensive part and something simple to check and rule out.

[MD355]

Do you have the original radiator ? I think it is insufficient...

When I bought my car, I decided to rebuild the turbos because they were worn out...

After that my engine worked well, but over time it started overheating, exactly as you are describing !!

When I let it idle, everything is fine. As soon as I drive and the turbos spool up, it would randomly overheat... I would lose between 1,5-2 liters of coolant...

We decided to replace the heater tank with an aluminum with a screw type cap...

The problem was not solve...

Therefore, we decided to replace the head gaskets... Expensive task, but necessary...

We also installed a switch that manually turns on the radiator fans..

This second solution solved the problem !! The temp is always below 80 degrees Celsius..

But if I switch this off and let it on automatic fan, I am scared that the temp will creep up again !!

Good luck fixing the problem. Maybe try the fan switch...

[steve930]

Not ideal to be running at such low temps.. Engine & fueling won't be running at optimum levels.. 

My car always ran at 87-90 °c no matter how hard I drove it 

[MD355]

2 hours ago, steve930 said:

Not ideal to be running at such low temps.. Engine & fueling won't be running at optimum levels.. 

My car always ran at 87-90 °c no matter how hard I drove it 

Well 80 degrees is more like 80-90 degrees... Just the right temperature to allow me now to be looking at the temperature gauge ALL THE TIME when I come to a stop !!!

It is frustrating in 2019 to drive a car where you have to check all the time if it is going to overheat !! Sure I enjoy the experience of the Esprit, but this is definitely something spoils the fun !!

So anything that can take the overheating stress away is welcome !!

[Guest modifiedv8engines]

It is surprising how much road debris including dust, bugs, flies,stones, mud, paper bags, leaves etc etc lodges in the front of the coolant rad and between that and the a/c condensor.

After my original coolant radiator corroded a few years back ( approx 17 years old at that time) and was removed, I decided to delete the a/c condensor and can report that with that removed, and maintenance like frequent blowing through with an air line, my engine temps are just over the 85 degree C mark on the gauge ( British spring/summer). And from a test with the Esprit software exel log, the gauge and that recorded were fairly accurate.

A Porsche 996 I have always ran slightly hot......bumper removed and a/c condensors and washing and blowing through with air line has reduced operating temps by a few degrees. Quick job on one of these cars but not so on an Esprit. 

The OP problem however with a temperature spike as described, sounds a bit like an air lock. There is a procedure covered in the manual for correctly bleeding the cooling system and involves releasing the plug near the thermostat housing and another on the near side/left hand side coolant rad top.  Check the manual for the exact procedure or ask the two mechanics or whoever did the work last time, the coolant bleed procedure.   If they cant tell you, then therein lyes the problem ...

Could also invest in one of those inexpensive infra red hand held thermometers and check best you can, the temp of the radiator (from the wheel arch area) and the inlet and outlet pipes and hoses on the thermostat casting. One should be cooler than the other by several degrees.  Good to check in any case to confirm if the gauge and actual temps are consistent. 

 

[steve930]

1 hour ago, MD355 said:

Well 80 degrees is more like 80-90 degrees... Just the right temperature to allow me now to be looking at the temperature gauge ALL THE TIME when I come to a stop !!!

It is frustrating in 2019 to drive a car where you have to check all the time if it is going to overheat !! Sure I enjoy the experience of the Esprit, but this is definitely something spoils the fun !!

So anything that can take the overheating stress away is welcome !!

My evora doesn't have a temp gauge, so it's quite nice not knowing what's going on  🤪

I never had issues with the esprit but like you I watched the gauge like a hawk 

[Guest modifiedv8engines]

Are there Darwin Awards for car manufacturers ?

 

[jonwat]

15 hours ago, steve930 said:

My evora doesn't have a temp gauge, so it's quite nice not knowing what's going on  🤪

Same as my Jag XKR.