Bus (T2 Bay Scooby Conversion) overheats when towing

[Baydreams]

Hello, can anyone give me the answer I am looking for? I have an EJ25 conversion (by Fellows Speedshop with the rad in the chassis rails). For two years (up until the heat wave in the summer of 2014), everything worked fine, even when towing my Eriba caravan. Then I had a rad change (due to stone damage) and a couple of weeks after that (last summer in the heatwave) I went on another trip, towing the little Eriba. The bus kept over-heating (105 plus) and I'm worried that the same will happen again this year. It only happens when I'm towing, and I need to tow because I have a big family and we can't all sleep in the bus.

Fellows Speedshop have not been able to resolve the problem. In fact they've been less than helpful to date; hence why I'm trying the question on this forum. A couple of independent garages have looked at the rad and said ''well that ain't going to work is it mate, seeing as it's mounted horizontally?''. But I don't think that's the issue here, as this style of conversion has been used throughout the world for many years without any issues.

I'm hoping that a full flush of the system, checking for any air locks will solve the issue. But I guess the first time I get to find out if the problem remains is when I set out on a hot day, family on board, towing the Eriba to Cornwall (from Birmingham). Our next trip is planned for 23 May 2015. Apart from going for a test drive beforehand with the Eriba hocked up, in as hot weather as possible, is there any other way I can find out if there's still an over-heating problem when under load? Or is there anything I can do to improve the cooling (bearing in mind that I only have the issue when towing the caravan in very hot weather)?

[Wilfred]

hello,

how many fans do you have?
Did you change the size of the radiator when you switched it?
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[Baydreams]

[Sydney]

Hi Baydreams. Long time since we last messaged on TLB.

I had similar problems with mine in hot weather even without a trailer. I made up a 2 inch spoiler (angled at around 30 deg) that I hang from the chassis rails ahead of the scoop to push a bit more air up into the scoop. I attach it with two bolts when the weather starts to warm up. I didn't want to attach anything to the scoop itself as it would increase the loading on it.

It might be worth checking the rear of the scoop for air leaks. I put Duct tape around the joints in mine to make sure that all the air that enters the scoop goes through the radiator. It might also be worth checking that there is nothing hindering the air flow rearwards out of the top of the radiator. Every little improvement in airflow might help.

One of he problems is that there is a lot of stuff underneath the van that makes the air flow between the chassis rails very turbulent. If you put your head where the scoop is and look forwards you'll see what I mean. I plan to extend the length of my spoiler by another couple of inches this summer to get some cleaner airflow. It'll also double up as a grass cutter.

[Baydreams]

Hello Sydney. I sent you a PM (well, I'm going to after writing this, so hope you get it).

[richbaker78]

have you tested for a head gasket? could be that its airlocking. Get it sniff tested at any garage who know what they are doing

Also consider water pump. Could be cavitating or faulty.

[Bugsy_malone 666]

Have you got some photos of the rad setup, might help us understand. I have tried 2 different setups, one was way more effective than the other and it was the same radiator pack, just a different scoop system.
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