Club 80-90 Forums

Hello there.
Long time reader, first time poster here. Please forgive me for non-posting and please be gentle
My name is Kieron and my wife and I have owned my T25 for 7 years now.
When we first got her, she was running a 1.9NA diesel from a 90's SEAT and it was woefully inadequate as the van is a full camper conversion, so really heavy. Sooooo, we decided to upgrade and decided to go for a Mk2 Golf GTi. We ran this for 6 years and it was good. Very reliable and moved the van along well...comparatively speaking.
Earlier this year, we decided to upgrade again as we have a small caravan and wanted more power....so we embarked upon the journey to switch to Scooby power, choosing a SOHC EJ25 from a Legacy.
We went down the semi-DIY route, but using existing components from specialists. We went down the different flywheel route, with plumbing kit, engine bar etc, rather than chosing the revised bellhousing route. We got a great loom too and fabricated an exhaust.
The engine install itself was relatively easy and the van fired up fine.
However, the water system is a nightmare and it just feels wrong. We are using the standard coolant manifold. We do have a heater bypass right up the front of the van, close to the heater matrix, for the extra cooling.
We have a 84-90 coolant tank installed in the engine bay and we are running the normal "overflow/filling" tank behind the number plate. Currently we are running the system with a black cap, not a blue one, as it seems to prefer that.
I have scoured the forum, but can't seem to find a definitive layout for the coolant system, when running the normal coolant manifold.
There are two heater pipes at the front (of the van) of the engine, plus the top hose comes round from the coolant manifold and joins the rad hose on the van. The other rad hose comes from the thermostat.
We have linked the expansion system with Tpieces. Firstly from the rad hose that goes to the thermostat and goes into the top of the expansion bottle. Second Tpiece comes from the left hand heater matrix and goes to the bottom of the expansion bottle.
I have seen references to getting the radiator hoses round the wrong way. Could this be causing issues?
Please can anyone offer any assistance, please? Love the power of the engine, but we really need to get the cooling system right as it feels overpressured and it runs hot (even with the right resisitor in the coolant gauge circuit, so we can run the VW gauge from the ECU).

Can anyone help, please?

Thanks in advance

Oh dear! I think if you post up a clear picture of the engine bay, we might be able to help further. I run the reversed coolant manifold which lines things up very simply and has all coolant pipes running to the front of the van from the back right of the engine bay, but i know not everyone uses that method. I'm sure you've seen that option from rjes?

I also run the reverse coolant manifold as its far easier to set up than trying the plumb the standard set up ,,, my van runs very cool and iv got a turbo dohc engine that can cause things to run much hotter,, so the rjes set up works very well and my advice is to swap over to that set up

Check your rad hose set up first, you may have them on the wrong way . My 3.3 conversion does not have the cut and reversed coolant manifold but is still set up with mostly RJES coolant system parts and warms up nicely and holds a very stable temperature.

Struggling to post a picture - probably me being a numpty.

I have the rad with both pipes at the bottom, but can't find reference to which is flow and which is return. How do I tell?

I think I will be getting the revesed manifold, to make things easier....still need to ensure the main rad is the right way round though...I think.

Brain hurts with sooooo much research and not really getting a very clear idea

There's some pictures on my thread that show what I did, runs fine and keeps cool.

https://club8090.co.uk/forum/viewtopic.p ... 9&start=30" onclick="window.open(this.href);return false;