I've been wrestling with an overheating issue for quite sometime and thought it was time to get some ideas from the forum... **Warning this thread may get quite long as I want to paint an accurate and complete picture**

I am from Virginia but currently working on some projects in Cairo Egypt where I picked up a 1995 Disco which has been great in dealing with the 3rd world roads here. I always joke that everything here is "offroading" including just getting into the neighborhood where I live.

So early in my ownership of the car I overheated while far from home and figured that I had caused some major damage so I had a "Landrover" mechanic "fix" it just to get me back on the road so I could continue on my way. Once I had a minute to check out his work I realized that he'd somehow locked my viscous fan clutch to the fan and so the fan was always running at full blast - not sure why I thought my engine sounding like an airplane was normal but let's not get into that now. Additionally I found that the thermostat was removed and so I realized that the way these guys here operate is to get you back on the road with no parts - they love to just bypass stuff which drives me nuts.... With this configuration (although dangerous) kept the engine cool no matter what conditions I faced on the road including extended trips and 100 degree weather.

So the first thing I did installed a real water temperature gauge (Glowshift) which reads off the top radiator hose heading into the engine and had a machine shop create a custom adapter that would allow me to slice my hose and connect the 2 sides of the top hose to it to get better readings as I realized that the Landrover temp gauge is useless.

After this, I got the following:

1. rebuilt radiator ( this is a bit strange but here they will actually will take aftermarket radiator grill components and weld them onto the Landrover radiator chassis which basically occupy the left and right sides of the radiator - let me know if this makes sense)

2. Thermostat 195 degree F (I have a 180 F thermostat being brought over by a friend from the US now as I couldn't find the 180 degree one here)

3. New Viscous Fan Clutch

4. New water pump

5. Replaced the head gasket as I figured this was shot from the original overheat and I had the engine heads machined and new rings and bolts as well.

So I figured now the car was back to normal and all the work around techniques this mechanic did were gone. Just to begin testing I just am using 100% water because I had a feeling that it was going to overheat and leak again and I'd get an opportunity to flush things out a few times.

Started driving the car and once warmed up runs about 210 degrees consistently.... After about 20 minutes on the road i found it started going up slowly the longer I drove. I must add that this summer has been about 95 degrees F without a break here. After the engine would reach about 230 I would pull over and let it idle where it would seem to recover back down to 210 - at this point the fan clutch is spinning the fan but it's not roaring like it used to and I can hear the electric fan run as well...

So I found that I had tightened the hose going into the thermostat manifold at the same place where a small metal nub was preventing a tight seal and thus was leaking, fixed that by moving the hose into the proper place and no more leaks. The engine then ran 212 degrees pretty consistently and then would creep up after 40 minutes into higher temps. Traffic would send it up higher than driving along at a slow speed.

After another road test I got home and found the cheesy plastic valve on the top of the radiator (passenger side) was cracked and shooting water straight up just as the engine began to heat up again - the timing was great as I had just pulled into my driveway. Replaced this with a brass plug and figured that was the end of my woes but checked over all my hoses and found one more leak around a hose clamp which I fixed as well.

So tonight I took it out and found that I will start off at 195 and it will quickly settle in at 212 again, 15 minutes in starts to creep up slowly to the point where I have to stop and let it cool down which it does ok when I allow it to idle... Again the clutch fan isn't roaring (but its spinning fast) like I am used to but I can hear the electric fan kick in too.

I realized that after the major leak from the top plug of the radiator I never bled the air from the cooling system so I may have so air in there.

At this point I am suspecting a few things but wanted to run it by everyone:

1. the rebuilt radiator isn't really doing a great job so I want to get a thermometer tomorrow to measure the temp difference between the top and bottom of the radiator.

2. That running pure water through the system is a bad idea?

3. That I purchased a bum viscous fan clutch, perhaps the vendor here didn't store them vertically like you are supposed to?

4. That I have some hidden leak somewhere that I've missed - I've been trying to rig up a cap with a air value on it to do some type of pressure test as the mechanics here don't seem to have a clue when I ask them to do this...

5. Could this be as simple as bleeding the system? I am going to do this tomorrow morning and spend the entire day trying to find any issues with the hoses in daylight.

6. Could we have put the head gasket on wrong and already ruined it? I had help from a good mechanic on this and we were extra careful in every step so I don't think this is it but don't want to rule it out.

As far as limitations here, I've never seen water wetter for sale but of course I have access to regular antifreeze as well as distilled water...Pressure testing seems to be to rocket science for the mechanics here as well as any test to test for exhaust gases in my fluids.

Is there another way to check for leaks in the system and would you guys suggest that I put in stop leak into the coolant just as a preventative measure? I had really wanted to find the true source of the problem and not guess by pouring in the stop leak right away.

Thanks for hearing me out, would blame you if you skipped this long post! I read through the overheating summary in the Disco I section which I thought was great but just wanted to see if my write up would narrow things down a bit.

 

Quick thoughts (sorry, I didn't read through all of that, just skimmed
Euro thermostats are classified at the temp they're fully open. American thermostats are classified at the temp they begin to open. So, in actuality, a 195 Euro is equivalent to a 180 USA, if that is indeed what you have.
Thermostat goes into your intake manifold with the spring towards the block, and the tiny air hole at the top. If there is no air hole, you can drill your own with a 1/16" bit. This prevents air pockets from forming in the system, which might be your problem.
If your coolant resevior is original, it's probably leaking at the seams and needs to be replaced. Also the cap has its own spring & vent in it, which helps keep the system pressurized. That may need to be replaced as well.
Double, then triple-check your belt routing. It is easy to get confused.
Fan blades should be curved towards the engine, so that while running a sheet of paper will get sucked against the grille. If it's backwards, your fan will be working against you.
I'd advise against the stop leak. You risk clogging up your radiator that way.

 

If you have access to an infrared thermometer, after truck warmed up and off, test temp of radiator fins top to bottom. More than 10F spread indicates radiator has sludge in bottom rows.

I ran my 97 D1 with no stat in 95-100F waether, and it will run about 150-160F. I run the 180F stat with hole at 12:00. Spring end of stat goes in the block.

Fan clutch not an issue at 50 mph, forward motion through air is a lot more feet per minute. But if blades reversed, belt route wrong, that is an issue. My previous owner wired the AC condenser fans to run backward, so they subtracted air flow, they can be tested with key in position 2 and AC on, hold paper toward grille.

Also, remove any strip and check spaces between AC condenser and radiator for trash in the fins.

You can heat stat in a pan of water to test temperature it operates at.

If available, Chevy fan clutch of late 90's early 2000's will fit. I run one with a deeper fan pitch.

 

more thoughts -

distilled water OK, cools better than coolant mix. If available, products like Water Wetter or Purple Ice will boost cooling of plain water. Need to have a good working coolant cap.

You may have to flush existing rad by driving with radiator flush, or white vinegar, etc. to loosen up some gunk. If you can look inside via the top threaded hole, and see ends of tubes, and see white stuff coming out of them it is time to have rad rodded out, or replaced. On ebay there is a company that sells D1 aluminum radiators for $240 US.

The thermostat determines how cold the engine will operate. Once you have gone to 20F above start to open you would be at wide open temp, and the cooling system then is pushing water thru the radiator with no flow control, it does not pause for cooling, etc. So your cooling is basically how much air can carry away heat from the radiator. If radiator is compromised this will be reduced.

If your heater core is also bypassed, would advise a "loop" as opposed to separate "stub offs".

 

Water boils at 212F. I would suggest using coolant. Your system is running way too hot and it's over pressurizing blowing hoses, the radiator plug, soon the expansion tank, freeze plugs and you'll be redoing the head gaskets eventually. Water Wetter doesn't provide but maybe 1F of difference as was tested by a fellow forum member on another site. It's nothing more than alcohol. You mentioned air in the system, that's what happens when you boil water, steam. It's creating the pockets of air.

I am suspicious of the radiator fix. How many core rows are there? You should have 3 to 4 rows.

Also I don't know if you have air conditioning but if you do and it doesn't work remove the condenser to allow more radiator air flow.

Do you have a fan shroud around the fan? Not having one decreases the fans efficiency.

I don't hear much complaining in the American South West and they've been having upwards of 100+F days for a few months now. So temp and locale are moot to me.

Check your engine timing. It has an effect on engine temp.

Stay safe..... I would not trade places with you right now.

 

Water boils at 212F .... at sea level.

Water wetter and coolant is maybe 1-6F change. But water wetter and distilled water is a bigger change. I am running that at this point with a slightly compromised radiator, have seen temps of 221F, and no boil over.

That is because we have coolant caps that hold until 18 PSI. That pressure by itself raises the boiling point of water to above 240F. Before coolant was invented people may not have had antifreeze in their cars. Coolant cap has to be in good condition. And cooling system as a whole has to hold that pressure.

Now, all the other points are spot on, especially about fan shroud and removal of anything that blocks air flow. Radiator repair may vary from place to place.

 

Ok very good points and thanks for your thoughts, I actually went outside and found that you were correct (along with SB) about pretty much everything. So I pulled out the thermostat and it's definitely Euro ( purchased from Britparts ) and it's stamped 88 which I know is 190.4 F. So I think I am ok there BUT the hole with the plastic jingly thing was at 9 o'clock and not 12 - I also took it out and put it in a pot of water with a thermometer and found that it was taking well past 92 C to open so I grabbed my new spare and tested that. Worked right at 85 so I swapped it in making sure that I put the jingly thing at the 12 o'clock position.

I also replaced the cap this morning and I examined the tank for leaks and didn't find any. I'll order one anyhow but just wondering if the $15 one I found is decent (found at BritParts which is much easier for me to order from).

I'll do the paper to the grille test when I can and thanks for the advice. I think it would be best if I replied to each persons post individually as everyone put up great posts..

After road testing, I got a bit farther before the overheat but it still overheated which makes me want to do the paper test and makes me suspect some of the items that SB mentioned.

 

Ok, so there are 4 core rows in the radiator fix but I am with you and SB, I suspect that there's something going on with the radiator. Believe it or not the air conditioner works ok for now. I do have the fan shroud in place. I'll double check the timing which I recently adjusted.

I completely agree that it's running way too hot, since it's a '95 I don't have access to all the fancy meters but my Glowshift Temp gauge allows me to quickly respond to overheats by pulling over and letting the car cool down.

Thanks for the concern, luckily I am in the suburbs away from where the craziness has been going on and after being here for 3 years I am finally getting used to things.

 

I could have probably done a multi quote but I just wanted to make sure I addressed each of the points here...

I am definitely gonna head out to Radio Shack here (we have them) where I saw an IR thermometer the other day and check the radiator which based on the comments here I am starting to suspect more and more. I just spoke to Britparts (they are just easy to work with since they are closer to me) and they have ESR2630 which is an aluminum rad with plastic tanks, for around $200 US - rather than continuing with my re-cored one which I think was done incorrectly.

I found that my stat was mounted with the jingly thing at 9 o'clock so I corrected that this morning along with getting new cap for the expansion tank. I can get about 10 minutes longer before overheat which leads me back to the radiator. I'll do the paper test as well but I did do your fan clutch test cold and hot and the fan clutch is fine which is good because its only a couple of months old.

When I had the radiator out it allowed me a chance to check for debris and build up and clean it out...

I'll try the IR thermometer and get back to everyone, thanks for all the help.

Any thoughts on the radiator that I found, I think someone mentioned a similar one on ebay... If i could get 10 years out of the rad I probably would be quite happy.

 

I assume you bought a Gasser,I would have looked for a diesel I have read comments how cool they run,
there is probly a reason the mech locked the fan clutch
Mixed coolant does heat slower and stabilizes temp easier then water plus increased boil temp
Not sure on the distilled water, wetter water is good but masking the problem
My opinion of the rover fan and clutch is trash,look for an s10 setup and cut 1" off each blade more blades better pitch more air flow
If you can see through the fins of Rad and condensor and have a "Saudi grill" and you are confident hg and wp were done correctly I would lean to new Rad or you are running too lean, timing off?
Ihscouts and buzz are both very knowledgeable hope you figure it out and let us know, carry lots of water desert is not a place to overheat and break down