20w50?

 

To what degree would a non functioning viscous fan have to an otherwise perfectly working cooling system? I'm guessing little to none on the highway and quite significant in traffic? Catastrophic or just warm?

 

If radiator is in good condition, fan can be removed at high way speed. Have driven 30 miles home with wobbly water pump pulley, took fan off to keep it from chewing up radiator. I happen to have a suspected marginal radiator, and I am using an extra heavy duty fan that gives me a little more cooling while I go about getting a radiator or re-core the one I have, even while driving.

At low speed or idle is where the viscous fan comes into play. If the fan has any fluid inside, that settles to one side overnight. When you crank up, it will engage at 99%, and "roar". That drops away in a minute or so as fluid is circulated inside the fan clutch, and warms up slightly, coupling reduces to 20-30% in most cases. When face plate of fan warms up above 170 F, clutch startes to re-engage, slowly for visocous only models and all at once for thermal element models . Roar may return, but air flow increases even if no roar. This extra cooling is needed because you are not moving. Same thing for bulldozers, road graders, etc., that move slow but rev high; also for Disco's playing in the sand, rock crawling, etc.

If engine is cold, and fan will spin more that a short part of a turn, it is probably shot. If it freewheels it is certainly shot. When warmed up, it may turn a little more, but you don't want it to freewheel spin.

Problem in traffic or idle would be catastrophic if not dealt with. No, it is not like an oil filter punctured by a road hazard. But long term over heat can warp heads, fail head gaskets. Severe over heat, perhaps just once, can cause the steel cylinder liner to come loose and become the dreaded "slipped liner", which requires even more major repair or engine replacement.

If you see guage headed upwards, select new traffic route to keep moving, switch off AC (cuts heat headed toward radiator), roll down windows, switch on heat to max (adds extra water and extra dissiapation surface to cooling system). In some cases you can shift to neutral and rev engine up to 1500 or so and see an improvement. Got a cooler full of drinks? Put ice on top of radiator, pour cold water in front of radiator.

Better to make the passengers angry about too hot with windows down than too hungry next month because you had to buy head gaskets.

A non-functioning fan is fairly cheap to fix, a bolt up replacement is in the tech sticky area, it goes for about $49. If you want something just to verify your diagnosis, a six inch reverse rotation clutch from a late 90's GMC/Chevy truck should bolt up also, about $10 at junk yard.

 

Got it. Thanks. I'm ready to go with my SD and metal fan over the weekend!

 

My oil gauge post:
https://landroverforums.com/forum/di...-instal-43603/

 

OK, we did the replacement of the Imperial SD clutch with metal fan. It sounds and looks great. We'll see how well it works this week in traffic.

A few things. 1) I had the fan cut 3/8" by the machine shop. They used a plasma cutter and charged me $40. The fan is a lifer for sure. The clutch can be easily replaced at any time. 2) You need new bolts to fit the fan clutch. They are bigger than the original. 3) You need to make the holes slightly bigger on the fan to accommodate the larger screw. I think.

While cutting the fan and changing the screw diameter could send the fan off balance, it is heavy weight and I had the work done as professionally as I could. I think we'll be fine. I could not imagine cutting my own and being precise.

I did a few other things as well to improve drive.

Thanks guys for your help on this one. I appreciate it.

 

Looks good. And the holes won't disturb the balance very much, as the shoulders of the mounting location on the clutch for the fan force it into the center.

 

i'm not sure the holes were even necessary...if the fan goes with the clutch you would think they would be the same sized. My mechanic told him to bore out the holes a little while we were at the shop without the clutch.

 

Since this thread has gotten a bit convoluted I thought I could enlarge it to include other cooling system optimization "opportunities". We did SD fan clutch and metal fan. There are a couple area I would like to look at and hopefully can get some more great help here.

From what I've been reading about and considering my tropic climate:

1) Coolant. I'm going to switch to 'green' (Peak) as per Mike and others advice here. I'm going to add WaterWetter. I will flush as well. QUESTION: Should I go with 50/50 PEAK Long Life and a bottle of WaterWetter?

2) Thermostat. Tom you said a 180 right? That's the standard one I order from AB? They don't state temp on the web page. QUESTION: Would a non standard thermostat with different temp operation help me under my conditions?

3) Air Conditioning fans. The A/C is used infrequently. Unlike Tom, I would like to use it a lot. It works pretty well. Do improvements or tune ups help the A/C performance and assist the engine in keeping cool.

Anything else you think I should look at?

 

Truck still overheats. I need to confirm that it is overheating without A/C but I'm gonna assume it does as basically I have the same problem as I've had for awhile now. According to the "criteria" here it qualifies for head gasket replacement.

BUT, I need to rule it out before I go there. This is what I'm pretty sure I did right:

1) oil bits (oil/filter/pump)
2) water pump
3) viscous and rad fan (SD and correct orientation <actually have a look at the pic in my prior post and let me know that it is correct. please.>)

This is what I'm not 100% sure about:

1) thermostat (it could be older than I remember and up to 6 or 7 years old so obviously I'm getting a new one immediately.)
2) radiator quality (my mechanic took it to the rad place and they "fixed it up." He said he would buy it from me if I ever wanted to sell it. But it was not rodded or recored or acid bathed to my knowledge.
3) the truck had a "mod" done by an unknown mechanic. there was a problem with the heater (i don't even remember what it could have been as I surely would not need a heater. He did a bypass of sorts. The car worked fine for a long time after so I don't think it was that.
4) did savannah's plastic bag test on the grill while AC on and engine off. Hard to tell but it did pull the bag towards the grill.
5) expansion tank is old opaque version and was replaced with cap about 7 years ago. While there doesn't seem to be a leak anywhere she'll get condensation if she gets hot.
6) haven't had codes read so I guess I should do that ASAP as well.
7) Coolant mixture. We've been adding coolant and distilled water all summer. A little here a little there. I really don't know what the current mixture is and I haven't added the water wetter yet. My plan is to flush and add the right mix but if I'm pulling things apart I didn't want to have to lose another batch of coolant.
8) Pressure test. haven't done it. Guess I should.

So I guess I'm looking for some order on how to progress now. Any help would be appreciated.

I have that young mechanic that goes from part to part and assumes everything is fixed each time we replace something. That's the best I can do for now here. That and learning everything I can from the pros here.

So what's the labor charge on head gasket replacement? The AB kit with bolts is $200.