High engine temp under load

[80t0ylc]

After finding that the OFNA silicone oil that I got is 30, 000 wtg, not 30, 000 cst, I've done a little more studying. This site helps a little. Landtank made reference to it in his blue hub clutch thread. I thought this was discussed somewhere on here, but I can't find it . Anyway, the link has as good a explanation as I've seen. So, I think, I'm going to back my target down to 25, 000 cst. Here's a link for a handy silicone fluid viscosity calculator if you're doing any mixing.

 

[landtank]

IIRC you set your modded clutches temp @ 95°. Being from AZ with daytime temps rarely dropping below 95° for several months would that mean your modded clutches are open before you start your engine?

Not so much. The bulk of the drive on the blue clutch comes from the second stage which doesn't come on until some time later.

 

[gtfour43]

My truck will idle all day at 193 w/ ac on but climbs to 207 on a short steep hill. Is it in need of a upgraded clutch? Should I be lower at idle? Still on orig radiator too.

 

[80t0ylc]

My truck will idle all day at 193 w/ ac on but climbs to 207 on a short steep hill. Is it in need of a upgraded clutch? Should I be lower at idle? Still on orig radiator too.

Are you in Hawaii? I imagine ambient (air temp) is high 80s or low to mid 90s. I think that you're alright. If you'll be doing long hills or much towing, you might think about upgrade. Most important to have complete cooling sytem in good order, not just fan clutch. And drain and flush yearly, or at least every other year. Don't mix coolant types & don't let it go.

 

[BlackLS1]

change the water pump, i have seen water pump blades become flat and useless from acids in the coolant and rust.

 

[80t0ylc]

change the water pump, i have seen water pump blades become flat and useless from acids in the coolant and rust.

Interesting idea. But we're talking Land Cruiser water pump. Cooling system would have to see a lot of negligence for that to be a factor. Other components would show similar symptoms. Thanks for input!

 

[BlackLS1]

yea forgot to mention, this was in other cars, not a landcruiser. but still worth a shot, thats all thats left in your cooling system to replace.

 

[80t0ylc]

yea forgot to mention, this was in other cars, not a landcruiser. but still worth a shot, thats all thats left in your cooling system to replace.

Yup, if upping the fan clutch fluid viscosity doesn't help, that's my next step. Just hate the thought of tearing into the engine again. It's got fresh coolant. Seriously though, about a year ago, my original fan clutch locked up solid. That could of caused water pump problems if it had gone unnoticed for a while. But it's not noisy and looks solid - no vibration watching it while engine is running and it's not leaking coolant. But, I do consider it a serious possibility. Thanks!

 

[80t0ylc]

Old 10k fluid drained and new mixture put in. It took 35 ml to bring the level to the bottom of the holes. That's all I put in because I didn't want to overfill. Drained for approx 3 hrs. Figured 10k that was still in would mix with my new mixture which was approx 28k. I figure the current effective is between 25k & 28k which should be sufficient for my needs. Initial test ride did not reveal much change in temp gauge. Fan roar on start-up lasted much longer - over 2 minutes, but eventually subsided. So hopefully the steps are working correctly. This clutch still has factory setting on it. In my research, I feel that overall, that's best - at least for now.

 

[FastCarGuy]

Just curious...I thought fan roar comes from the fan "free-wheeling" until the clutch engages. So if yours roared for a longer amount of time would that not indicate it's going to take longer to come up to temp to fully engage?

 

[gtfour43]

Are you in Hawaii? I imagine ambient (air temp) is high 80s or low to mid 90s. I think that you're alright. If you'll be doing long hills or much towing, you might think about upgrade. Most important to have complete cooling sytem in good order, not just fan clutch. And drain and flush yearly, or at least every other year. Don't mix coolant types & don't let it go.

Yup hawaii. Mid 80's here only. I pulled the same hill in my ls400 this weekend and it reached 215 so I think the cruiser is fine. My ls just had the complete 90k dealer service. Both vehicles using toyota red fluid.

 

[fullybalanced]

Yup hawaii. Mid 80's here only. I pulled the same hill in my ls400 this weekend and it reached 215 so I think the cruiser is fine. My ls just had the complete 90k dealer service. Both vehicles using toyota red fluid.

yep, sounds ok to me. I had been running 186deg in winter, now that's it getting in the 80's I'm running 193deg. Pulling up about 2000ft over about 2 miles of cut backs, the temp got up to 215deg. After roughly 5 min gong back down (about 300ft) temp was down to 198deg. Then I was "there" so I turned her off. I had just flushed everything the weekend before. I'm running green, not red for the past two flushes.

 

[LandCruiserPhil]

A properly set up cool system on an 80 should be able to pull hills in 100°+ temps at ~200°...mine does it all summer long.

 

[Land Shark]

This sounds just like mine a couple of weeeks ago. I since have put a LT modded blue fan clutch but have not tested it fully yet.

 

[80t0ylc]

Just curious...I thought fan roar comes from the fan "free-wheeling" until the clutch engages. So if yours roared for a longer amount of time would that not indicate it's going to take longer to come up to temp to fully engage?

No, just the opposite. The "fan roar" at a cold engine start-up comes from the fan clutch being fully engaged. As I understand it, after sitting, the fluid in the clutch is not in its normal running location in the clutch. The clutch handles it as fully engaged until the fluid can be dispersed and handled normally. Then you will hear the fan step down to its lower steps which is less drive and moving less air and quieter. In other words, roar = moving lots of air.

 

[FastCarGuy]

Thanks! Now that I think about about it...that makes a lot of sense

 

[gtfour43]

A properly set up cool system on an 80 should be able to pull hills in 100°+ temps at ~200°...mine does it all summer long.

Yea second time I did the hill I hit 202 only.

 

[BlackLS1]

what do you guys moniter the temps with i have a 1994 so i am obd1 a data reader is not an option for me

 

[80t0ylc]

what do you guys moniter the temps with i have a 1994 so i am obd1 a data reader is not an option for me

I have same problem. What I did was modify the temp gauge (check this thread). You can get an aftermarket gauge at a parts store, also. Beware, your temperature will fluctuate a LOT more than with the stock gauge. So be ready for it. There's a chart in the 1st post under the "Results" heading. I copied and printed it and stuck it in my sunvisor as a reference. I checked it with an infrared (laser) thermometer and if you've modified the gauge successfully, it's real close - close enough to keep track.

 

[80t0ylc]

Just an update for those searching and pulling up this thread. It's been a few years in testing (lol), but I got the best result in lowering my engine temps under load by replacing my copper/brass CSF radiator with a TYC aluminum with plastic tanks. It was recommended to me by a few Copper State Cruisers and I figured, WTF - the price was not that bad - what could I loose? It turned out to be the trick that worked. The Landtank modified fan clutch from Wit's End helped, too. My '94 came stock with a copper/brass 3 row and that's why I replaced it with the all metal CSF when the plastic tank split figuring not have to fuss with plastic tanks anymore. Turns out the 2 row aluminum TYC cools a hell of a lot better. One other thing that I've experienced in off road travel, especially towing my trailer, when ambient temps are 85*F or above, is using lo-range more often than necessary. It's hell on fuel mileage, but it keeps the engine happy or more to the point, it doesn't have to work as hard on hills, for example. I've found that lugging the engine under load causes the temp to rise quickly, but I can watch the temp come back down and stay there using lower gears and higher rpm just as quick. YMMV, but it works for me. HTH any '93 or '94 80 owner (early 1FZ) that is on the fence about switching to an aluminum radiator. I've come to the conclusion that the extra weight above stock with the mods I've done, plus running bigger tires exceeded the cooling capacity of any copper/brass radiator that's available for an 80 series. And this is especially noticable trying to use A/C. The most annoying thing when I had the CSF was that when it was hot out, that's when I really needed the A/C. But when I'd crank on the A/C, the engine temp climbed towards the red causing me to shut it back down and suffer. Bone stock rigs are probably fine with the copper/brass radiators. To be honest, I think if it hadn't been revealed to me on this forum about the stock OEM temp gauge and it's tendency to stay in the center until it was too late, I would have fried my engine.