Urgent: Badly overheated. I don't dare turn off.

Nah unfortunately not. Little bit of hissing from the rad bleed pipe

blue beasty said:

Thermostat is likely but dont do anything until it's cool

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feeling top hose would give you an idea on that

when safe i'd also check your coolant levels, and to see if any water has leaked from the p gasket , right of block behind pump, or weep hole under water pump.

pump is high on a 300 and you need to watch your coolant levels.

I have faith in my baby. Off for some lunch at the cafe. Fingers crossed she'll survive. What am I looking for on the engine for signs of wickedness? Assuming it runs and cools properly once I'm done here.

Turn it off and leave it off. Leave the bonnet open to give it a chance to cool down. What may also help if you have a good battery is to put the ignition on and heater and heater fan to full. You'll get some, although very small, amount of thermo syphoning to circulate the coolant and help it cool down. But too be honest any damage will have already been done. Don't touch the expansion cap or try to undo a single cooling system component for at least an hour.

What to look for later.

1. Rough running
2. Missfires
3. Coolant loss
4. Oil and water mixing.
5. Expansion tank over presurising.
6. Chuffing sound from rear of block
7. Lack of power

Any of those could indicate failed HG. Which is the most likely thing to fail from overheating, if your really unlucky the head may crack or warp but the symptoms will be similar. I would also change the stat even if you find something else. Its good practice to replace stats on any engine thats overheated as they are more likely to fail afterwards.

Saying that mine overheated to the point it blue the cap of the expansion tank a few weeks ago. Replaced rad that caused it to overheat and she has been fine ever since, no signs of damage to the engine.

Everything looks dry however there is a bit of rust coming down from the top hose so a bit of leakage there. We'll see in an hour or so

The heater matrix is gone so can't do that. I've got an electric fan which I've had blowing over the engine to help things a little. Shallnt touch anything until I know it's compeltey cooled down.

Well topped it up at thermo. It was low and lost the water around the stat. Engine seems to be running ok. Though a little noise from the water pump. Will be swapping it out this week. Slow drive home and will se how she goes. Just driven a mile and its at temp and holding. No oil in water. Will check again when I get home. will check oil for water too once it's been sat for a while.

99 times out of a hundred a tdi head gasket failure or head warping will show as pressurisation of cooling system once engines hot 6 - 8 mile journey,might not show on shorter unless gaskets blown in which case it will pump water out of expansion tank with cap off, tdis need regularly checking they are full by removing thermostat housing plug and seeing its overflowing, unless head gaskets been done recently id think about fitting a new one soon

The head was replaced about 10,000 miles ago. I replaced the gasket and had the head skimmed about 4,000 miles ago. I'll have the head off with the water pump next weekend and give it the once over. Won't be getting any use this week.

Found the leak. Top pipe was catching on the bracket above water pump. Had this before. I usually twist the pipe a little to keep it off but it's obviously twisted back round recently.

in which case if head gasket seems fine after a 20 mile trip id probably leave it ,fix leaks check rad gets hot all over and check plug level regularly,expansion tank level doesnt necessarily mean engines full, which it needs to be

Awesome. Cheers man. I'll keep you posted.

Pull the thermostat out and leave to cool down.then continue with stat in and hope ot doesnt overheat again

Leak sorted and given it a good run. Filled heater matrix and topped up via stat housing and given it a good run. About 30 mile round trip. Definitely no oil in the water. Will let off the drain plug on the sump tomorrow after its been sat overnight to check for water but look like I might have got away with it

Cheers for the help guys. Didn't mean to come across as arrogant with the whole leaving the engine running thing but I was panicking a little. I guess the only time it's good to do that is if the cooling system is functional.

Cheers.

Larry365 said:

Leak sorted and given it a good run. Filled heater matrix and topped up via stat housing and given it a good run. About 30 mile round trip. Definitely no oil in the water. Will let off the drain plug on the sump tomorrow after its been sat overnight to check for water but look like I might have got away with it hew:

Cheers for the help guys. Didn't mean to come across as arrogant with the whole leaving the engine running thing but I was panicking a little. I guess the only time it's good to do that is if the cooling system is functional.

Cheers.

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Good news, keep yer eyes crossed and a finger on it....

Possibly the other way round

Just an update. Everything running fine. No sign anything ever happened however, and I'm not exaggerating here, the engine is running a lot better than before. Previously, 30mph on flat was a constant struggle between 3rd and 4th. Accelerating out of 30 in 4th was a struggle and strain. Now it pulls no problem. It will even sit in 5. Bare in mind I'm running 31" with a 1.2 box (for now). The whole performance has been increased 10-20%. It pulls very noticeably better in all gears and 3rd (my favourite gear on the disco) is pure torque.

I'm expecting one of you to tell me this is the first sign of complete engine failure..

What's going on here guys? It can't be my imagination.

Mine did that as well after I changed the rad and thermostat. Its probably simply that the engine is now running at the right temperature.

Larry365 said:

Cheers for the help guys. Didn't mean to come across as arrogant with the whole leaving the engine running thing but I was panicking a little. I guess the only time it's good to do that is if the cooling system is functional.

Cheers.

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Glad you got away with it, but, you really have some strange understandings on cooling

If EVER an engine gets hot, turn it off ASAP, there is never going to be a situation that leaving an engine on tick over will cool it more than just turning it off straight away. (Unless you have a separate waterpump system and can pump the water around the engine when it is off, that would help...) :scratching_chin:

Bump said:

Glad you got away with it, but, you really have some strange understandings on cooling

If EVER an engine gets hot, turn it off ASAP, there is never going to be a situation that leaving an engine on tick over will cool it more than just turning it off straight away. (Unless you have a separate waterpump system and can pump the water around the engine when it is off, that would help...) :scratching_chin:

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My mowers frequently over heat due to grass and debris and the advice is to let the engine tick over while clearing the rad filter. Warranty can actually be void if engine is turned off straight away if overheating for any reason. When the head blew on my Ransomes triple, I had to really fight to get it fixed under warranty as Kubota saw on the log that it had been turned off immediately.

So you get all these mixed opinons from different people, when in a panicked situation who knows.

Looks like all good in the end anyway.

Larry365 said:

Ok done. You sure not a quick start up ever 5 mins?

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If you were at the point you felt you needed to keep it moving to stop it seizing then it would have been toast already and running it every 5 minutes was not going to help.

Larry365 said:

I blew a head and seized a tractor before. Rad was cold too. Turning it off was what ####ed it so just asking.

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Keeping it running was going to save it?