Overheating - Looking for troubleshooting steps

[surfkernow]

Hi Doone, g8dhe and Jules Martin. Thank you for your replies. Oh, I understand the reasoning behind freezing the pipe now

Thanks for the warning about the difference in diameter of the turbo pipe. Currently in my Volvo investigating a CEL ....when it rains it pours. i hope to get back to the Bongo early next week and will update the thread.

The plan is still to bleed the hell out of the Van, then investigate the turbo issue. Thank you as always for the replies.

[surfkernow]

Back to square one I am afraid. My van still overheats even with a new cylinder head.

Fitted the new 3 way adaptor into the cylinder head, bled with system using the 3 part Youtube method for an hour and a half...getting the temperature up to 92 , lower radiator warm.

Took for a test drive to see if the power issue had resolved itself. It hasn't ! Coming up a slight hill and the cylinder head gauge started to rise...it got to 98 , and I pulled over to let everything cool down. It is programmed to go off at 101.

Pressure tested the cooling system via the expansion tank ...why that is 1.1 bar and the radiator 0.9 bar I don't know. Found a drip coming from the pipe that goes from the 3 way adaptor on the cylinder head into the turbo housing? It was not the at the end of the newly changed adaptor but leaking where it joins the metal turbo pipe. Will upload a photo in a sec

So, I don't know. A massive air lock? It has had a new thermostat, radiator, water pump, cylinder head, all 4 major front hoses replaced....and it will over heat after a mile or so of driving.....

[surfkernow]

New leak location. I was using the paper to confirm coolant was dripping. Maybe the lack of power on acceleration and lack of a turbo could be related to this leak

https://photos.app.goo.gl/y8P9Lcas3iyh1DHGA

[JulesMartin]

What a pain!! search on here for "Radiator pressure cap" for a few posts on why you have the two different caps. Where do you have your temperature censor connected? mine is bolted to the back of the cylinder head and mine runs mid to high 90 and will easily pop up to 105 when going up hill. I have my alarm set at 110 at the moment. When I bleed mine I wait until the cooling fans cycle twice before boxing it all up and this seems to work really well it's just a pain waiting and waiting for the fans to come on and you do need at least one well insulated glove and a patient assistant. As per the video's are you giving it a good long rev at 2000 as this seems the best way after the thermostat has opened to get the coolant moving.

[rita]

What a pain!! search on here for "Radiator pressure cap" for a few posts on why you have the two different caps. Where do you have your temperature censor connected? mine is bolted to the back of the cylinder head and mine runs mid to high 90 and will easily pop up to 105 when going up hill. I have my alarm set at 110 at the moment. When I bleed mine I wait until the cooling fans cycle twice before boxing it all up and this seems to work really well it's just a pain waiting and waiting for the fans to come on and you do need at least one well insulated glove and a patient assistant. As per the video's are you giving it a good long rev at 2000 as this seems the best way after the thermostat has opened to get the coolant moving.

Both the header tank and the radiator tank have 1.1 bar pressure valves.

[surfkernow]

In terms of temperature. When my Bongo was working it hovered around 88, on a hill or a long run the highest I saw was about 93. Even when it was overheating the highest it got to was 105 on the cylinder head temperature alarm. By the time it has got around 98 it was usually throwing out a litre of coolant out the expansion tank.

It is a pain. On my new radiator (not original) the cap says 0.9 but on the original expansion tank it says 1.1. I was just curious. I have a pressure tester kit now and I am just bringing it up to under 0.9 to see if it holds pressure.

The cylinder head temperature alarm is bolted to the back of the cylinder head as well.

[g8dhe]

why that is 1.1 bar and the radiator 0.9 bar I don't know

The radiator cap has a sealed outlet, so the pressure cap doesn't do anything - make sure you do have a sealed/no outlet, some replacement radiators do have an outlet in which case you need a 1.1Bar cap fitted (or greater, you don't really want it releasing from the radiator).

[Doone]

As Geoff said, if there's no outlet on your radiator, that rad cap is OK.

You could try a clip on the pipe to see if it stops the leak. If not you'll have to change it.

If the turbo isn't connected, the engine will work harder and could be raising the temperature? Though it shouldn't raise it that high!

2 easy things to check re power loss:
Theres a vacuum pipe from the top of the diesel pump to the elbow at the front of the inlet manifold - check its connected.

Also there's a clamp on the turbo, that connects it to the exhaust manifold. Check that's there and connected.

[surfkernow]

Changed the thermostat today and bled the system again and this time the lower radiator pipe got hot not luke warm ; it appears to be doing a better job of regulating the temperature. 94 on a hill outside the garage but the temp did come down and go up depending on the gradient. It did not just keep rising !

When I used to bleed the cooling system, the lower radiator pipe got hot, thermostat was open and when I revved the engine from this point on , the coolant no longer disappeared down the funnel. This did not happen with the last thermostat or the new one since the head was changed. But the lower radiator pipe is definitely hot and I got the bleeding temp to 85 by this point. The thermo opened at 82.

I still have no power and no turbo, but [Moderators] should I open a separate thread to discuss this? I think this thread is already getting huge and should concentrate on over heating in case it helps people in the future? Let me know

Don't worry about the radiator cap, that was just a question out of curiosity rather than a troubleshooting question.

In terms of the vacuum pipes from the fuel pump and the turbo. Could anyone identify the relevant pipes from these two diagrams? Everything looked connected today but I was not completely sure what I was looking at.

https://lushprojects.com/bongoparts/pag ... l).html#14
https://lushprojects.com/bongoparts/pag ... l).html#18

Thank you from a cold and windy Cornwall

[surfkernow]

At least I have a nice view when I work on my Bongo....the sea is there in the background...it is just very over cast

https://photos.app.goo.gl/y37g2qfYw3VM3nHa6

[Doone]

Nice view!
.
That sounds promising.
Sometimes people test the thermostat in a pan of hot water.

We tend to change the thermostat whenever the engine overheats.
"If the engine overheats for any reason, this can cause the thermostat to fail. The components inside the thermostat are only designed to handle normal operating temperatures, and overheating may damage its components."

[Flanners]

Straight to the point...I think taking your van to a Specialist is long overdue unless you (unlike me) enjoy an elongated saga of ignorance, bodging and throwing money at something that appears not to be getting fixed. Good luck.