Engine temp

[DCerebrate]

Depends more on age of radiator and on total number of months stationary. Has it ever been replaced / recored? Here is a thread on recores
https://www.pistonheads.com/gassing/topic.asp?t=86...

Other thing to check would be any signs of dreaded head gasket failure. Mayonnaise in oil or hydrocarbons in coolant.

Best of luck!

[Jooles81]

Hello!

Radiator is 3 years / 2000 miles old. It's an alloy one.

Head gaskets are 5 years / 5000miles old. No signs of gunk in oil or coolant.

I took some time this morning to try to bleed it again. Got to the point that the passenger side is not spitting any air even when running. Only when I give some gas, the flow stops and upon release of the pedal it spits again for a second and the there is a nice regular flow. Here is a video, it was even better after a few minutes :

https://youtu.be/QOK7vUwyfjs

Here is the driver side for reference :

https://youtu.be/4AIUBAytjME

This succion effect can be also done on the driver side but you have to give it more gas. I think this is due to the coolant flow not splitting evenly between both banks (driver side is closer to the pump after all) and the flow of the driver side is sucking the passenger side, if this makes sense. And when the coolant flow is increasing, it's sucking air. All this with the cap off, so system not under pressure of course.

I'll let the car cool a few hours and I'll do the same again to check. Will maybe even go for a drive if the car is willing to co-operate...

Any thoughts? Ideas?

Julien

[Thunderroad]

Could you connect a couple of clear plastic pipes to the bleed nipples on each coolant bank an run them up to the expansion tank (take the fill cap off and just wedge them into the hole).
This way you won't loose any coolant as it bleeds and you can add water when required.

If you can also get manual control of your rad fans by by-passing the ecu with a supply from the battery with a fuse and a switch you can prevent the water from boiling, but you will need to let it get hot enough to open the thermostat. Take care not to let it overheat!

Obviously you can't leave it like this but if you can just leave it running like this for half an hour or so, constantly monitoring the levels you should eventually get all the air out, or perhaps reveal other symptoms which may help to diagnose what is going on?

[Jooles81]

The clearing pipes is a very good idea. I'll source some tomorrow and try this way. Moreover, this will let me see what happens exactly when I give some gas.

I've let it warm enough this morning to open the thermostat. I run it half an hour letting air go out with the cap open, as you say. I'll do it again tomorrow. I went for a short spin half an our ago, which was not very successful, and I want to check the level before anything else.

Thanks!

Julien

[Incognegro]

Sorry if I sound totally stupid. I once had the steam situation from boiling over and hitting the manifolds when the thermostat only read 95 then upon switching off it would swiftly rise??

This was due to me simply not screwing my expansion cap on flat, have you ruled that out? To me even though it would lock down the angle was off allowing pressure to be uneven and it caused all sorts especially when stationary.

I was advised initially to screw cap on backwards till you hear click/snap (thread locating at the start point) then screw down as normal.

Never had a problem since

Sorry if I've told you what you already know.

[Jooles81]

Don't worry, that's helpful. BTW, I think I'm the biggest fool. When I got the car on Friday evening, there was probably water everywhere, and it steamed out and I panicked. Quite the same as you say. A few months ago, the cap was worn and spilled water everywhere...

I rechecked the level this evening : ok. Checked the bleeding in the radiator : there was still some air, now ok. Checked the rails while running : some bubbles and then ok. Go the car warm enough to start the fans several times : ok, including fast cooling when giving some help with the throttle. And... Lots of steam coming from the heat insulation under the coolant tank.

Conclusion :
- the car was probably working properly on Friday evening, it was just the insulation that was soaked from changing the coolant, and I panicked
- cooling system was probably cooling enough, only had to give it a bit of gas
- I was a fool. I still am, just a bit less so
- I think I got pretty good at bleeding the Thing (it's its nickname, btw), or at least understanding it.
- I used this time to check and set the throttle pots and it's running even better...

Plans for tomorrow : Checking level, bleeding again, let cook a little to check if any steam gets out, and go for a drive to the closest cleaning station...

Thanks for your inputs. This has been helpful indeed. I'll let you know what happens tomorrow (if it isn't boring to you, of course)

Julien

[jamckeown]

Hi Julien

Just a thought - I had a similar problem a couple of years ago and it turned out to be a hairline crack in the expansion tank. Easy to change and not to expensive.

[Jooles81]

Hello!

Well, cooling looks good. I've driven it in some hotter weather lately, and everything seems to behave properly there. The car doesn't ho below 80, which is fine with a standard thermostat and cools pretty fast if you give it some revs. Upping the idle to proper 950rpm seems to have helped too.

Relating to this, the car runs very poorly, stutters, and goes like st stuck to a shovel. Not good. All plugs on the driver bank have seen poor ignition with heavy, are black with lots of gas remaining on them. Left bak is better. So the car is due new coils, leads (which have perished, and one is clearly missing some insulation) and plugs. Should be fine after that...

Julien