2.5 Engine, Cooked it good and proper

[xmexclusive]

Earlier in the week the 2.5 estate that I am currently using lost a lot of coolant.
Took less than a mile for the temperature to go from 90 to 130 plus.
Only realised what was happening when first stage of limp mode cut in.
Was getting ready to turn right on a dual carriageway.
So suddenly restricted to little more than tickover.
Decided to make the turn as it was both my destination and the next place of safety.
While held at the lights waiting to turn engine temp went up to max on the gauge.
When I went to move round could hardly draw any power, just inched across.
Stopped and switched off.
A quick look under the bonnet, hoses rock hard with pressure, left it to cool down.
Later on I found a towel and eased the radcap just enough to release pressure.
When I got to look in the header the internal red plastic for level marking was gone.
Just a pile of burnt brown splintered bits in the bottom.
Called the AA to be resucued.
Patrol took 15 mins to arrive.
He thought the same as me, blown engine, need to trailer it to repair.
Still he had to go through the attempt a repair process.
We filled it up with water and rather to our surprise no sign of leaks.
Started it up and finished bleeding the system.
Still no leaks but a lot of water on the subframe under the rads.
Coolant temp came up to 90 and stayed steady.
Drove it gently round the block, no problems.
We decided that the leak must be in the small rad and only when the stat opens.
Limped it home on low traffic back roads keeping revs right down.
AA van following as neither of us expected the car to complete the journey.
Temp never went above 90.
Decided that the ECU limp mode had possibly protected the engine.
That evening drained off and got the coolant back up to strength.
It did not loose much coolant overnight so took it for a couple of gentle trips.
Not much coolant lost.
That evening I left the rad cap off and it lost about 2 ltrs by the morning.
Released the front panel and tipped the rads up passenger side.
This let me get at the smaller rad hoses and remove the small rad.
Quick and dirty low pressure test showed a small leak.
No handy spare so piped up direct to main rad.
Refilled the coolant , bleed then checked the cooling fans cut in.
Has been running like that for a couple of days now.
No sign of temperature problems or engine damage.
Hopefully I have been a bit lucky with this episode.
May well keep it running on one rad for a while just to check what difference it makes.
Ordered a new coolant header tank.
Item still stocked but design changed and needs a new type of rad cap.
Will see what the difference is when it arrives.

John

This post has been edited by xmexclusive on January 25, 2013 01:08 pm

[Peter.N.]

Hi John

You were lucky, although with your technical knowledge I would expect nothing less. I boiled two 2.1 engines and got away with it, one in France and the other in Weymouth, both because the radiator fans didn't work and I was stuck in a traffic jam, a very rare occurance for me, didn't fix them but didn't get in any more traffic jams.

Hope it stays good.

Peter

[nightmare]

The small rad in front is for the turbo intercooler so in the winter you probably won't notice any change BUT when the weather warms up you might loose some power,
(warmer air going into the engine) and possibly overheat.

HTH