This is my first post and I’m a first-time landcruiser owner (a life-long dream). Nice to e-meet you all.
Our little LJ70 is super fun & smooth to drive off road, but it’s also giving us overheating nightmares. Bought in 2020 and we’ve spent a year playing cooling system detectives and the temp gauge is still entering the red under minimal load.
We’ve scoured IH8MUD for ideas and have tried everything short of replacing the infamous 2LTE engine head. We know we’ll have to replace the head one day, we’re just hoping we don’t have to do it yet. (Especially if, like most of the things we’ve already done, it turns out not to have been the main problem.)
Does anyone out there have any ideas on what else could be the cause?
About the Victim:
About the Temp:
The temp shoots up abnormally high (even into the red) for short bursts of time, from 5-20 seconds at a time. Some drives there’s no problem; other times it keeps shooting up every 10 mins or so even in suburban driving conditions (especially bad during our recent Westcoast heatwave). Usually there’s a hill involved but not always. Not towing anything, no lead bricks in the back etc. We thought it could be related to inadequate revs, so we’ve been increasingly careful to turn off overdrive going up hills, and that seemed to help a bit but isn’t consistently preventing these temp spikes. Goal is to use this little beast for a lot more interesting off-roading than just trips around the neighborhood!
What we’ve done:
What we haven’t done: (Do any of these seem like they’d make more than a minimal difference?)
Engine Head Checks:
Thank you for any help, ideas, or general commiseration!
Our rad before vs. after because I always enjoy seeing folks' horror pics on here. (Fins crumbled with a slight touch and there was coolant leakage at the seams too.)
Our little LJ70 is super fun & smooth to drive off road, but it’s also giving us overheating nightmares. Bought in 2020 and we’ve spent a year playing cooling system detectives and the temp gauge is still entering the red under minimal load.
We’ve scoured IH8MUD for ideas and have tried everything short of replacing the infamous 2LTE engine head. We know we’ll have to replace the head one day, we’re just hoping we don’t have to do it yet. (Especially if, like most of the things we’ve already done, it turns out not to have been the main problem.)
Does anyone out there have any ideas on what else could be the cause?
About the Victim:
- 1990 LJ 70 (Prado), diesel, automatic, right-side drive, import from Japan, bought at 135,000km and have hardly been able to use it, used mostly for weekends/pleasure by previous owner.
- Thermostat needed replacing when we got it and it had under-specced coolant. Not sure if it was previously being driven while overheating.
- Drove it for a week on dirt roads before it suddenly overheated going up a minimally graded gravel road on a hot day and started madly leaking coolant out the overflow.
- Doesn’t have the typical Toyota fan “roar” when you start it up (even after clutch fluid replacement), seems some folks on here find that either normal or abnormal (...?)
About the Temp:
The temp shoots up abnormally high (even into the red) for short bursts of time, from 5-20 seconds at a time. Some drives there’s no problem; other times it keeps shooting up every 10 mins or so even in suburban driving conditions (especially bad during our recent Westcoast heatwave). Usually there’s a hill involved but not always. Not towing anything, no lead bricks in the back etc. We thought it could be related to inadequate revs, so we’ve been increasingly careful to turn off overdrive going up hills, and that seemed to help a bit but isn’t consistently preventing these temp spikes. Goal is to use this little beast for a lot more interesting off-roading than just trips around the neighborhood!
What we’ve done:
- Coolant system:
- There was massive coolant leaking but now we are 100% sure there are no more coolant leaks, thanks to the following:
- Coolant cap: Replaced
- Water pump: Replaced
- EGR: Deleted
- Cooling system: Flushed, no blockages, good flow. Sealed up some of the connection points that were leaking. Refilled with good coolant.
- Fan clutch: Fluid replaced. Definitely stiffer after.
- Radiator: Re-cored (it was ugly; before/after photo for entertainment below.) It does sit behind the A/C but surely it's not airflow that's the problem at this point.
- Gauges:
- Temp sender: Replaced
- Temp sensors: Replaced
- Thermostat: Replaced
- Fuel Gauge: No issues with it (saw some people reported flakey fuel gauges made your temp gauge needle wonky, but our fuel reading is always consistent & seems accurate.)
- Exhaust System:
- No power issues, no black smoke. Little puff of black smoke if you hit gas at idle; but it’s clean after.
- Other:
- Fuel Injection Pump: Rebuilt. We thought we’d fixed the whole cooling system and got 2 blocks into the test drive to discover we were spitting diesel. No fuel leaks since this was replaced.
- Oil: Replaced oil & filter, topped up oil (i.e. it’s not low).
- Air filter: Replaced.
What we haven’t done: (Do any of these seem like they’d make more than a minimal difference?)
- Could get new hoses (the current ones look fine; no cracks, and flow was good with flush)
- Turbo: could clean intake
- Rad output hose: could check the output temp (although we already know this is an issue so…); could get an adaptor to check temp of lower rad hose to see if coolant is still not circulating as it should
- Exhaust Gas Temp Gauge: we have the connection installed, just need to set up the display
- Engine Head Replacement
Engine Head Checks:
- No hallmark bubbles visible when we pop the coolant cap
- Overflow level stays consistent (since we got rad re-cored, new coolant, replaced clutch fan fluid, and had injection pump rebuilt)
Thank you for any help, ideas, or general commiseration!
Our rad before vs. after because I always enjoy seeing folks' horror pics on here. (Fins crumbled with a slight touch and there was coolant leakage at the seams too.)