1991 200TDI to R2.8--couple remaining questions


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yep. as Chris noted...this is a common occurrence with the R2.8 (not just Defender installs).
If i recall correctly - engine throws an error code at 225degrees (which I consider on the low side compared to my car getting to 280's w/o a problem). Also noted previously...this doesn't happen on flat land or low elevation or without load on the engine. The issues to crop up during summer time heat (ambient near 100F), sustained uphill (load on the engine), or towing (again load on the engine) and all that at 5000ft+ elevation.

I believe that the purpose of posting here is to share the learned knowledge and hopefully save others from additional spend / time for cooling package installs. If your install is space limited and requires an eFan - I get it - again hopefully saving others time & money by making informed decisions.
From my own experience - I would say its the heat soak and the EGR cooler adding additional heat to the system.
My cooling package efforts:
v1.0 was a single pass radiator (372 sq in surface) w/ 1600cfm 16" SPAL. (this was behind a FMIC also 272 sq in)
v1.5 was upgrade to a 2000CFM SPAL (front area fully sealed so all air was directed through radiator)
v1.6 changing to a 50% smaller FMIC so that the radiator had clean air passing through it
v2.0 was upgrade to dual pass radiator that was 522 sq in (40% bigger core) - this dropped temps, but still higher than I want to see. (2000cfm SPAL/original shroud)(original shroud left some un-shrouded area to facilitate highway speed free flow) smaller FMIC also ducted to "hot side" of dual pass radiator, leaving "cool side" clear
v2.5 was change to Mechanical Fan - When I first installed mFan - eFan and shroud were still in place - temps dropped to acceptable level
v2.6 - removed eFAN & shroud, running mFAN un-shrouded for testing -- while I build a new shroud - no problems with cooling
v2.7 - *coming soon* - in the process of building the custom fiberglass shroud to facilitate proper flow through radiator.

Why the mechanical fan makes such a tremendous improvement over the E-fan can be many factors - I also struggled to understand how an eFan was not up to par with mFan.
1. static pressure in the engine compartment - hood vents could possibly fix this (I didnt go this route)
2. Fan blades - w/o getting into blade pitch, rpm, etc...mFan blades have more surface area
2. M-Fan does push more air (even prior to full clutch lockup) than the eFan (this could also be clearing out hot air from engine compartment
3. Currently with 60-70 degree ambient temps, murphy gauge stays in low 170's, with only partial flow from thermostat to radiator. Where I would hit 212 consistently w/ eFan, now only gets to 189MAX. Like Chris...I will likely be running a radiator muff into the winter so that proper warm up happens

If anyone is interested, I do have some used FMIC's, radiator, silicon hoses and fittings...
For sure brother. Too bad the egr setup has to stay to keep it legal. I wonder if the water pump can be at fault as well.


Technical Excellence Contributor
Work has really been "comprehensive" is the best way I can think to say--- so over winter I didn't drive too much and when I did it was quite cold so not heat issues. But I was figuring stuff out. I decided, as I mentioned, to convert to a mechanical fan and that has been a journey. I thought of doing it out of fiberglass but was concerned with weight and PITA so opted for aluminum...which I don't really work with. So I bought a TIG set up, learned to weld thin ass aluminum over the winter (just good enough, for now), and made a custom shroud. I rolled a frame for the fan side, welded a frame for the radiator side, then made some connecting supports between the two and then skinned the full thing with 0.040" thin aluminum. Thought (other than the welds) that it came out great, but truth is, it is just the first iteration to get the truck on the road for summer and way down the line I will remake it all nice and pretty.

First I rolled a hoop and cut it on the metal chop and welded it up.
rolling hoop.jpg

To make it fit centered, I used pipe insulation on the fan blades that spaced the hoop about 3/4" from all sides of the fan:
Hoop fit.jpg

I welded the radiator side frame and then tacked support struts on the sides to keep the assembly in place.
tacking frame.jpg

Then I used construction paper to make the general templates for the 1mm aluminum skin.
Skin templates.jpg

I skinned it and welded it up. I probably should have just run small 1" tacks, but I used it for practice and did a full weld up.

The welds are mediocre. But welding 0.040" aluminum (1mm) to a 0.125" frame is quite tricky. Only burnt through a couple times, nice penetration and the shroud is stout. 5.6lbs all in. Then painted matte black


Recap---it works great. It was 72F yesterday, took it at 75mph and never got hot, just warm. Stayed at 180 at that speed. I will take it to the hills with the trailer to get the real world result and will follow up. So far, excellent cooling and super stoked.

When I remake it (since this is the first thing I see when I open the bonnet and want the welds beautiful) I will do it in two parts so the top half has a removable skin portion to aid in removing the fan. Just a little thing, but I want to do that. Maybe in a couple years. Maybe never. However, out of this process, I can now TIG aluminum :)


Technical Excellence Contributor
Started my last major mod, not engine related, but probably last mod for this thread. It’s my long waited rear seat conversion to the Disco2 black leather seat I got last year (took forever to find one in black).

I welded two 3/16” aluminum angle irons top and bottom) back to back to form the mounting tab, full length, for front mounts, and mounted with vertical and horizontal bolts through tub:

This moves seat forward a few inches enough so it doesn’t hit cubby, but allows as much load space as I could. I had to slice about 4” out of each side of tub making 8” wider for width (photo shows 3”, but wanted a little wider as it was tight), and seats fit great:

Now to tie in front tabs into mount and to make tub patches…


Technical Excellence Contributor
I welded a couple sides into the tub and out of position welding is HARD! Laying on my side trying to manipulate torch head, filler rod and squeeze / regulate pedal between my knees…damn. Welds started getting worse and worse, ruining all my work, then goddarn awful. Even though my tank read 0, I could clearly hear gas and my nozzle cone meter read 15cfh, the end-of-tank gas killed me. Picked up another 125cf tank and all is well…except a ton of repairs now necessary…. Guess I’ll be a grinder not a welder this weekend, lol.

once I got to this stage I knew what must be up…
But the gas gave out gradually. I will be able to spot it way earlier in the future. Always learning…


Technical Excellence Contributor
And the big mod crap is done! Today I finished welding and smoothing the rear cut outs and mounting the hold downs. If friggin pleased with how it came together and turned out. I have a little more work to button it up and finish the interior, but feeling great with what’s done!!!






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Well-known member
The Disco 2 seat conversion came out awesome! Very tidy and it looks like some decent leg room with them as well.

And welding aluminum is very tricky - the material and it's thickness, the cleanliness, and weld settings all make a massive difference (at least for me). Both aluminum jobs came out really good especially the design aspects!


Technical Excellence Contributor
Thanks so much! I got to learn new skills and enlarge by horizons — feels really nice. Buttoned up the back minus below window trims. Thinking hard about back speaker panel and putting together game plan before tackling that part. Might get one of Scott’s. Back cargo is getting the. Vertical sides cover cover bottom seam at tube, and wheel arch pad overlaps sides. Then secured top to sides with a simple method of 3 finish nails through tops into the edge of the vertical. Works great, nothing slips around. Might reduce to a thinner pad in future as these are a little thick (3/4”) and heavy (94lbs for 4’x6’). But fine for now.

Still debating on cargo management.
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Technical Excellence Contributor
https://www.amazon.com/gp/product/B004XOO0AK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1. I went with 17” Derale reverse direction fan. And it’s been night and day between electric and mechanical. This is commuting to Denver, 30 miles in 80F weather, then hitting stop and go. 0 issues.

I’m designing a louvered radiator gril that has rotatable grill blades that can rotate and shut to restrict/heat the coolant more in winter Without me having to put my radiator muff on. I NEVER removed, drained or changed my coolant or system between transformation from electric to mechanical fans, and all my issues are gone.

I couldn’t go bigger than 17” due to proximity to power steering and coolant hoses. YMMV. Dont feel I needed bigger and I‘m borderline too much!. I’ll pull the trailer up a pass this coming weekend to fully tax system but without trailer, 100% good.

Having it complete has allowed me to move on and not look back…. Cranked out back seat, just installed a gull wing rear window, finishing up some trim work…. And very soon….CAMPING!
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