First, let me slip on my flame suit. :mad3: Ok, I've got a '95 Disco that I'm slowly starting to build. Normally I'm a Jeep guy but I got this thing in a trade and, well, I like it more than I planned on.
Here's the thing. It's getting hot. Water pump is good, thermostat is new, radiator is fine, coolant is fine. I can start it and let it sit and the temp climbs to normal and stays there, I can drive it around and the temp stays normal, then for no really good reason, the temp starts to climb quickly. I have noticed that the temp begins to climb after a slow hill, but after cresting it continues.
So fan clutch? the fan turns but, after stopping the vehicle (with engine hot), I can easily spin the fan- making me thing the clutch is bad. Thought on this? Also, i noticed to small electric fans on the front of the radiator. When do these come on?
Understand, I'm a decent mechanic/ fabricator. I am , however, new to diso's and wonder if there is a common problem with them I am unaware of. This is bread & butter stuff, but any help would be appreciated. :shaking:

On the viscous fan clutch. If it works, you will here the fan "turn on". It is quite perceptible. If you don't here it and the temp keeps climbing the cutch is dead.

The electric fans are for the A/C system but should also come on if the engine is too hot.

I have a feeling the clutch is dead, that would explain why the temp climbs steadily after a slow climb. On the AC fan, I'll need to check them becasue they are not energizing-ever.

Listen to some good advice. Search this topic it has been beaten to death before. You need to replace your radiator or have it rodded out and cleaned. It is the radiator buttmonkey. Fix it and go break something we would interested in hearing about.

Buttmonkeys its what PBB is all about.
JP

My guess would be radiator also, i have seen too many that have the bottom half completely stopped up and don't cool enough. I think Southern Radiator downtown rods them for about $50.

Brad

Guys, I appreciate the advice and I did search but I really don't think it's the radiator. My reason; I checked the radiator for cool spots and there are none, this ussually indicates good heat exchange. Also, the temp remains constant for a long itme, even sitting at ide, then climbs quickly; a radiator would be a slow, steady climb (if speed and engine load are constant)?That being said, maybe it's a Disco thing. I know this is boring stuff, and believe me I hate asking, but this kind of crap is a fact of life. Hell, anything "interesting" I need to know, :flipoff2: I already know.

Guys, I appreciate the advice and I did search but I really don't think it's the radiator. My reason; I checked the radiator for cool spots and there are none, this ussually indicates good heat exchange. Also, the temp remains constant for a long itme, even sitting at ide, then climbs quickly; a radiator would be a slow, steady climb (if speed and engine load are constant)?That being said, maybe it's a Disco thing. I know this is boring stuff, and believe me I hate asking, but this kind of crap is a fact of life. Hell, anything "interesting" I need to know, :flipoff2: I already know.

Have it flow checked, just because there are no cold spots doesn't mean it flowing a 100%. It's a VERY common occurrence.

radiator

had the exact thing happen to me

Looks like I'll be pulling a radiator this evening. I appreciate you help. (BTW-I did search and found very few posts on this/ also tried Discweb, but they are down right now). On a more intersting not, I finished my SR and front spring packs on my CJ last night...but you guys don't care about that stuff.

Yeah, leaf springs are for losers. All the cool guys run coils.

J-L (not cool in so many ways)

Wait a minute...a little more information needed here. Does it lose coolant or over pressurize the system on the long hill? Could be a blown head gasket.

So far I haven't noticed any coolant loss, nor have I found any discoloration of the coolant. I was afraid of a blown head gasket,but becasue the problem was so intermittent I hoped it wasn't. I thought it was a thrmostat (and in fact had no pressure on my top hose). Changed that and had good pressure. So, start it in my driveway, let it idle to normal temp. Everything is good, no problems even with AC on. Drive down the road, maybe 4-5 miles, even hammer it coming back up a long grade w/ AC on; no problems. So slow down to come into neighborhood and after slowly climbing hill (and driving very conservatively) the temp begins to climb. I mean, it is like somebody flips a switch. When I park and the temp continues to climb. I did this three times with same results. Head gasket? Like I said before, the viscous clutch on the fan is easy to turn by hand even immediately after engine is shut off & temp is hot. Made me wonder becasue the temp climbed on a slow, steep climb. Engine runs like a champ, burns no oil, and had a valve job not long ago.

Leaf Springs kick ass...'specially Disco ass.

I think your thermostat is sticking...

OMG-you'd think we were troubleshooting a nuclear reactor, not a 1960's vintage engine with undoubtedly MANY miles.

Replace the water pump and viscous clutch. Then, the expansion tank (with natural color plastic), the thermostat, and finally, replace the radiator (have it packed very well).

If this doesn't cure it, do the heads :flipoff2: You know you want to, all the cool kids are doin' it.

How much could this possibly cost, a few hundred?

Peace,
PT

(Pendy is STILL my new best friend)

Yeah, leaf springs are for losers. All the cool guys run coils.

J-L (not cool in so many ways)
No you are very uncool because you will not share pics of the beast.

I think your thermostat is sticking...Have you verified that it actually *IS* getting hot? Landrover temperature sensors
are pretty persnickety, and are know to fail like that, its like under $20 bucks!

If you know it *is* getting hot, then forget it, your screwed :flipoff2:

TomW

Have you verified that it actually *IS* getting hot? Landrover temperature sensors
are pretty persnickety, and are know to fail like that, its like under $20 bucks!

If you know it *is* getting hot, then forget it, your screwed :flipoff2:

TomW

I second this - check the gauge- mine was showing in the red and I thought the thermostat was stuck and the head was cooking - turned out it was just the temp gauge.

OMG-you'd think we were troubleshooting a nuclear reactor, not a 1960's vintage engine with undoubtedly MANY miles.

Replace the water pump and viscous clutch. Then, the expansion tank (with natural color plastic), the thermostat, and finally, replace the radiator (have it packed very well).

If this doesn't cure it, do the heads :flipoff2: You know you want to, all the cool kids are doin' it.

How much could this possibly cost, a few hundred?

Peace,
PT

(Pendy is STILL my new best friend)


I thought you believed in the CB way of doing things. Randomly replacing parts that are probably fine doesn't seem particularly CB :shaking: .

Fellas, I'm not sure weather to be impressed or disapointed: this is PIRATE damnit! I want to troubleshoot it, not be a shotgun mechanic (replace verything and hope that fixes it!). Leet's look at the facts:
I just changed the thermostat (3 days ago) & I have good pressure on top hose. SO, chances are it's not the thermostat.
I seem to have good circulation and can feel pressure build up in the hoses, water pump is relatively new. So, probably not the water pump.
Radiator? Like I said before (though it may mean nothing), no cold spots (& I verified this w/ a temp probe). So, I suspect uniform heat exchange. Also, a clogged radiator exhibits different symptoms. It will show a gradual temp climb, especially at idle & high engine RPM (correct?). Also,I do not show overheating at highway speeds w/ is typical of clogged radiator.
What I do notice: my fan clutch may or may not be working. After the engine is warm, I can still easily turn the fan by hand-I would think the clutch would engage w/ more resistance than that? A bad clutch fan would explain overheating on slow, steep climbs. No airflow through the radiator to compensate, not enough draw from the fan to cool the engine. But, anyone know how much resistance I should feel when it's engaged?
Finally, the electric fans on the front do not seem to be energizing-ever. After talking to a LR tech, he informed me that those fans should come on 1. when the AC is on & 2. when the engine reaches a certain temp. If they do not, the Ac will go down on high head pressure & the engine temp will also start to rise (especially at low speeds). SO, I need to check the relay going to the fans (it is unlikely the fan motors as neither fans are coming on).\
I do not think it is a head gasket becasue I do not see the problem all the time, I do not see the problem during hard driving, my oil looks good, coolant looks good. -and I want to be optimistic!
I drove into work this morning, 15 miles stop & go traffic, with perfect running temps-Even on slow hills. BUT, the outside air was 50 degrees. During the other test drives it was nearly 90 & I wwas intermittently running the AC to see if it WOULD overheat (and it did-quickly and at the top of a slow hill, but never during hard hwy driving).
So, if I were a betting man I would say I have a bad clutch on the fan and may not have noticed the problem becasue we have only recently started to see summer temps around here. I would not see it at speed becasue air flow would compensate for the fans. Also, I think the problem may be compounded(at slow speeds) by non-operation of the AC fans. I think I will fix those first. If that doesn't do the trick, you guys were probably right about the radiator.
I really appreciate the help. I COULD fix this no problem if I wanted to throw money at it, but hell- that's no fun. :D

I thought you believed in the CB way of doing things. Randomly replacing parts that are probably fine doesn't seem particularly CB :shaking: .

Completley destroying your engine over known and recognized faults isn't very CB either.

On MANY occasions I have unequivocally stated that the last place to fawk with one of these vehicles is the fragile cooling system.

It is usually accepted as fact that these vehicles are very often neglected w/r/t scheduled maintenance and that the cooling systems can be difficult to diagnose. In this case, I suspect the first part to be replaced is the fan clutch... Mine was replaced at about 150 K miles after I heard the aux fans kick on while I was getting the mail-when I shut the engine down, I watched the fan freewheel down to stationary-sound familiar? Yep, MB's does the same thing. I even know where you can get the clutches cheap bastard style! (shameless plug)

Assuming this vehicle has some miles, the water pump will fail, sooner, rather than later. I will be replacing one later today that only divine guidance kept from tearing through the radiator-cheaper to replace the pump now than the hood, fan shroud, radiator (although subsequent investigation may indicate a need for this step).

I think we've all seen the carnage that can be caused by the failure of the old black expansion tanks.

If a build-up is planned for this truck, let's get the fundamentals under control before running off on a Dweb inspired springs/lockers/roof rack build up.

If I'm losing my OCB status, perhaps I'm getting tired of fixing cobbled together junk.

Peace,
PT
Survivor of Rover cooling system failure carnage

Fan clutch sounds likely.....next in line would be radiator cloggage.

I'm not sure if the disco is the same as the RRC in respect to the aux fans in front of the AC condensor. However, on my rrc the wire to the two fans snaked around the front battery. You'll find 4 wires there.....I was able to jump the two of the wires to get those fans to work. I've pulled the A/c condensor, so I toyed with the idea of wiring the fans up directly to a switch...but I haven't got that far yet....as one of the two fans isn't working. knock on wood, my cooling system doesn't need the extra help anymore.

Replace the fan clutch. Also have the radiator flow tested at a radiator shop. If they have any clogging, get it rodded.
The last suggestion is a band aid....Redline makes a product called Water wetter. Its an additive to the coolant. It reduces overall temps(not recommended for winter), I use it in my racing mini with excellant results.

Guys, I really appreciate the info. This is the kind of Rover experience I was looking for. Are ther any donor vehicles that can supply a fan clutch? I know this is a 50's style buick engine so I would guess several manufacturers use the same clutch. I will probably go ahead and wire in an in-line toggle on the AC fans. I have that on the electric fans on my Heep and it is a handy thing. Cheers! :)

While you are at it....forgot to mention this.
If you have the radiator out, clean out all the crud and leaves that tend to get stuck in there and the ac condensor. Pull off your front grill and do the same. I would expect paul could give you CB source for a fan clutch.
I have recently had luck with this guy in Vermont....grampa's (http://www.grampas.biz) He breaks down old rovers.

Thanks for the info, I'l definately do that. Any thoughts on swapping in an electric fan (like from a Ford taurus). It is a slick swap on a Jeep, but am not sure if it would fit a rover as I haven't paid much attention to the dimensions. Probably covered under search. Thanks gain.

if you look on www.d-90.com there is an FAQ on putting in an electric fan.
Better to solve the current problem before you add another new variable into the equation...just my opinion of course.

http://www.atlanticbritish.com/techtips_main.html#discovery


There's a section on engine overheat.

The way I always checked a fan clutch is: when the engine is good and warm, shut off the engine and watch the fan slow down. If it spins after the engine stops- bad clutch. It should come to a stop like there is a brake being applied to it- if that makes any since. It may even kick backwards a little when it finally stops as the engine hits a compression stroke and can't overcome it then settles to a stop. Hope this helps.

Welll, I have exorcised the demons. The clutch fan is fine, but the relay to the auxiliary fans is bad so they are not coming on. I've been driving to work all week with no problems, stop & go traffic, 15 miles each way, perfect temps (& I haven't changed the relay yet). What is kind of funny, every day , as I descend the hill to my driveway and turn in the temp negins to climb! I drive like a nut all the way home with no problems, coast into the driveay and the temp climbs! So, I think all of you were right who said the raidator needs to be flushed. I don't think it's really bad-yet. But I think the auxiliary fans might have been compensating for a partial loss of flow through the radiator. Anyway, I will take all of your advice eand go ahead and get rid of any prospective problems here. I know i have a new water pump & thermostat, so a radiator flush, new fan clutch (which has 135k & will probably go ouot soon anyway), and fixing the relay should do the trick and give me piece of mind. Thanks for the advice & the education. Now, back to more interesting topics!

Hey guy, you sound like a very intelligent, mechanically perceptive bro!, I am picking my DII up in Chattanooga tomorrow morning...you should hang out there until they get sick of seeing your face, and they will fix it for you, or at least tell you what they would do...They helped me, after I complained to two service departments, and when they know you are serious, they all help...especially at lunch time, if you bring a Pizza. Maybe see you there, Tony in Tennessee, red DII, mega warrior rack, leopard tire cover, cowboy hat, :smokin: Pretty blond wife. Remember, you don't need money, just a great story!

Thanks Tony. Not sure if you are speaking of the rover dealership or the new off-road shop off 58. I'll never make it into the rover dealership if I can help it (I'm cheap), but the guy off 58 is supposed to do some sweet fab work on Rovers so I'l probably get by there sometime. I'll definatly know who is driving your Disco if I see it; not too many fitting that description...if your wife is driving I'll be sure & wave. :D Give a month or so to finish up my Heep and we'll head to tellico. Cheers!

If your radiator and fan clutch are working, you should never need the fans unless your A/C is running.

Look elsewhere first (clutch/radiator)

You are correct, but if my radiator is partially clogged then the aux. fans could have been kicking on at slow driving speeds and compensating for the reduced coolant flow through the radiator (if they are actuated by temp rather than just whnen you turn the AC on). But, get this; My thermostat was originaly bad (changed that). BUt that didn't fix it! Relay to Ac fans bad, but that didn't fix it! Clutch fan (which I was unsure about) is definately bad. Hell, now I know why you guys just suggested changing everything. If I ever lose a wheel bearing I'm just going ahead and swap axles- that seems to be the only way to be sure with a Rover. So, what obscure american vehicle has a fan clutch that will swap onto a Disco? COME ON. GIVE IT UP!

As I stated at the beginning, clutch fan. If the clutch is working, you will hear the fan "turn on". It make a very noticable fan noise when locked up. I tyhink most people do not know this because:

1) They don't drive anywhere hot enough to make it lock up OR
2) There clutches are dead. From what I have seen most are dead.

Fix the cutch FIRST. Don't waste money on other bits.

I'm having the same problem as Monkeybutt on 95D1.

I replaced the thermostat, water pump (was leaking thru peep hole), fan clutch, hoses, coolant tank (BP had it for $29), no garbage between rad and fans, checked tranny fluid and coolant.

I notice that the electric fans won't turn on while the A/C is on. Guess I have to check relays.

I guess the rad is next, right? Remove it and have it tested. Any other suggestions?

radiator first....worry about the electric fans later.

Done, ordered a new rad ($347 delivered).... I should get it by Tuesday, I'll let you know how it goes.

I guess it wouldn't hurt to rechore the old one since it looks like it's in very good condition externally.

Thanks.

It was the Rad, it came in on Friday and I swapped it out this weekend and all is well.

Electric fans aren't working (with A/C on). I guess I'll check the fuses and relays.

Thanks Sachilles.