I thought Land Cruisers didn’t overheat ever (1 Viewer)

[Eiji73]

Beautiful Cruiser and scenery!

Yes just ease off the skinny pedal going uphill until we get to the bottom of this overheating issue.

BTW if you haven't already, consider changing to a Toyota low temp thermostat. If your overheating occurs while you are moving at a good speed (say above 50km/h) then the incoming air volume and speed should be sufficient for adequate cooling. But that's only if the coolant, radiator, cap, thermostat, pump and passages are in very good shape

Keep us updated.

Hello @Tigris and all. It’s been a while but I have found the time to look deeper into the cooling issue on my LJ73. I did come back from central France up to Belgium, 600 km, with the truck as it was. I had checked the coolant level in the expansion tank, was a bit low, topped it off. Didn’t seem to make a difference. On that trip it got hot crossing the Morvan hills (a very old mountain range, peaks around 1,000m) so I stopped a couple of times. Rest of the way was on surface roads, I took it easy, and once in Northern France the outside temps made it safe to drive 90-95 km/h without an issue. Once home, I received the advice of a mechanic friend from the Netherlands (who swears by Toyotas — he worked for the roadside assistance for years) that the radiator didn’t look well — some of the surface was dented in, which may have prevented optimal cooling. Cutting the crap, I bought a new radiator and we installed it yesterday. Whilst at it, we also checked the thermostat operation and it was NG. Did not open in hot water. So we replaced that too. Drove home from Holland (250km) and the temp gauge stayed in the smack middle despite me verging on 110 km/h most of the time. Bingo!

 

[Tigris]

@Eiji73

It's always a good feeling when you get to the bottom of issue and get it fixed! Especially things that bring a lot of anxiety like overheating issues.

Yes, a defective thermostat won't permit good flow or won't open until the temps are already in a runaway trajectory. I have PTSD from overheating ever since I killed an FJ80 with a 3F and an FZJ80 both due to overheating, the 3F had a catastrophic leak in the radiator and stopping was not an option (for real), and the 1FZ died due to the stupid PHH, but really that is my fault for not doing the recommended PM.

What radiator did you go with and what are your impressions on it?

Cheers!

 

[Eiji73]

@Eiji73

It's always a good feeling when you get to the bottom of issue and get it fixed! Especially things that bring a lot of anxiety like overheating issues.

Yes, a defective thermostat won't permit good flow or won't open until the temps are already in a runaway trajectory. I have PTSD from overheating ever since I killed an FJ80 with a 3F and an FZJ80 both due to overheating, the 3F had a catastrophic leak in the radiator and stopping was not an option (for real), and the 1FZ died due to the stupid PHH, but really that is my fault for not doing the recommended PM.

What radiator did you go with and what are your impressions on it?

Cheers!

What is PHH?
I went with a standard replacement, not OEM (no longer available) but copper, just a normal replacement. Toyed with the idea of an aluminium performance radiator but availability was questionable for an ‘89 — info on sites all quoted for ‘90 and beyond. It went in perfectly, dimensions being exactly correct for the screws and nuts. So far so good. I used a Belgian site, delivery was prompt and cheap. Made by International Radiators, it was on promotion, luckily, less than 300€ instead of €450 for most of those I found elsewhere.
It’s a relief to have fixed it, but I am still nervously watching the temp gauge… Perhaps scarred for life as well

 

[Tigris]

Sorry, the PHH is an IH8MUD made up term that stands for "Pesky Heater Hose" lol which is a short rubber coolent hose that feeds into the intake plenum area IIRC. This is a specific thing and only applies to vehicles with the 1FZ engine. But because people here considered it the Achilles heel of the engine (because it's prone to drying out and cracking with time, leading to loss of coolent/head gasket failures) it became notorious.

The 80 series section if full of horror stories on the topic. That being said, the 1FZ is an incredible piece of engineering fit for the Land Cruiser name, but I suppose nothing is truly bulletproof and everything can manifest itself into an Achilles heel under the necessary circumstances.

Our trucks don't have PHH, but to be fair, any piece of rubber under the hood of a 25+ year old truck is a sort of a PHH, and a potential liability if not preventatively replaced.

Thank you for the radiator input, that is certainly useful information for the rest of us. I also think you will continue to watch your guage like a hawk for a while lol. I still do and I haven't even seen mine ever move past N.O.T.

Cheers friend!