Old Vehicle - Deadly Nevada Heat - Roadtrip!

Next week the misses and I are headed for San Francisco and the Bay Area, and will return back to Arizona over the holiday weekend. Leaving this Friday, hopefully by 5pm, and camping in Lake Mead overnight. The long hot leg of the trip will be the 5 hours from Vegas to Mammoth Lake.

Our choice for the 800 mile route is both cheap and heated. We'd like to take Rt 95 to 120 to cross through Yosemite. This takes us on the eastern side of Death Valley, with expected temperatures in the 100-110 range. We'll likely return the same way.

I'd like to take my 98 2.7l Tacoma with 193,000 miles as its ideal for camping and boondocking. Unfortunately, its got a 193,000 miles, and I haven't really had it long enough to drive it long distances in temps above 90 degrees. Helping the idea though is that I haven't had any issues with the truck. Aside from loud valvetrain noise when its hot, it doesn't have any issues.

I plan on taking at least 4 gallons of spare water with me. I may also have the spare replaced as it doesn't seem to great. Coolant was tested good 1000 mile ago and topped off. I have no idea when the coolant system, thermostat, or water pump was last changed. AAA membership is current.

Any suggestions on making this trip as secure in "backups" and piece of mind as possible?

Big hats and a pop up tent in case triple A is busy.... And more water.

If the temps ever rise from climbing hills etc, I'm thinking a performance-oriented coolant mix would be a good idea, if you're not already running one. The typical 50%+ mix leaves a lot of cooling power on the table.

In reply to GameboyRMH:

Could you elaborate?

For example, in my cars I'll run 30% Toyota Red or Prestone Orange with Redline Water Wetter (RP Engine ICE can work too) and distilled water. A "leaner" coolant mix conducts heat better.

It was my understanding that Water Wetter products don't really do much.

The effect is slight and most noticeable as the temps get dangerously high. Basically it improves the engine's capability to come back from the brink of overheating.

On that note, another mod you might want to consider if you have good fresh hoses is a higher-pressure radiator cap. This will increase the coolant's boiling point, again making it harder for your engine to overheat. Also good for reducing coolant cavitation on high-revving engines. The only downsides are the increased risk of springing a leak from a poor seal or blowing up a crusty old coolant hose.

I wouldn't worry too much about it.

The odds are quite good that it's got a cooling system capable of towing up Davis Dam when it's 110 outside. Or something really close to that.

And everyone has been testing cars in Death Valley (which does take special permits) for a long time. In the heat and all.

As long as there's no buildup in the radiator, or blockages anywhere, I'd suspect Toyota has done their homework.

Gameboy's right on when it comes to coolant mix. It's not coolant, it's antifreeze, and it has a lower specific heat capacity than water. Run 30% antifreeze in a street car. Water Wetter is best used with pure water, and it does help there by messing with the surface tension as well as offering anti-corrosion properties usually provided by the antifreeze.

I wouldn't crank up the cap pressure on an old street vehicle, though. Make sure you have a good cap, that's all.

Keith Tanner wrote: I wouldn't crank up the cap pressure on an old street vehicle, though. Make sure you have a good cap, that's all.

Make sure it's Toyota's spec. '98 isn't that long ago- and even back then, they should be capable of running coolant temps up to 250.

I'll put it another way- I would be STUNNED if Toyota could not run at 250F and not blow things up.

And I'll wager that it will run up to 220F (where the fans are running full blast for most cars) and not much higher. I know that the car ran those temps commonly during development, given how everyone does stuff.

"...loud valvetrain noise when it's hot..." doesn't bother anybody?

Not sarcasm. Just wondering what we assume that (loud) noise to be.

alfadriver wrote:

Keith Tanner wrote: I wouldn't crank up the cap pressure on an old street vehicle, though. Make sure you have a good cap, that's all.

Make sure it's Toyota's spec. '98 isn't that long ago- and even back then, they should be capable of running coolant temps up to 250. I'll put it another way- I would be STUNNED if Toyota could not run at 250F and not blow things up. And I'll wager that it will run up to 220F (where the fans are running full blast for most cars) and not much higher. I know that the car ran those temps commonly during development, given how everyone does stuff.

Agreed, run Toyota's spec and not higher. But make sure it's a good cap and not one that's failed.

I have no doubt the Toyota's cooling system would be fine if it's in new condition. But there's no point in handicapping it with over-antifreezed coolant or a bad cap. The vehicle's nearly at two decades and 200k miles, not everything will be quite the way the Toyota engineers intended at this point. A 1998-era Miata radiator is ready to blow out the end tanks, for example, and a high pressure cap (higher than OE specs) will ensure this happens sooner. Putting in 70:30 coolant and a new cap at stock specs are good maintenance, easy to do and cheap. So why not do it?

Try and do the driving early in the morning or later in the afternoon if possible.

I did LA to Vegas and it gets hot at noon.

Are you going to be towing anything?

If so, a larger transmission cooler may not hurt.

Nope. Fast and light.

chuckles wrote: "...loud valvetrain noise when it's hot..." doesn't bother anybody? Not sarcasm. Just wondering what we assume that (loud) noise to be.

First thing I noticed too.

I drove up the contintal divide at 103 degrees in a 00 explorer at 75mph and it didn't over heat. It has 230k miles on it. I think you would be surprised at how Good the cooling of newish cars is. Turn off the a.c. and watch the temp gauge

I'm not sure what the noise is. Valves out of adjustment?

I doubt its piston slap because that usually happens when its cold. This is the opposite. When I first start it, its pretty quiet. If its been running all day it'll make a racket.

What weight oil is in it now? Might increase the weight so that it doesn't thin out with higher temps. That can cause some valve clicking.

Keith Tanner wrote: Gameboy's right on when it comes to coolant mix. It's not coolant...

It transfers engine heat out, it's a coolant. Not the best coolant, but for the price, it works well enough.

OP, it's a Toyota. Drive it a bit to make sure it's ok and hit the road. About the only things I'd check and fret over would be the plastic radiator end caps, looking for stress fractures and the beginings of failing, and how scuzzy the radiator hoses look.

Nothing useful to add, but I thought the question was about an old vehicle! I don't consider 98 to be old and I really wouldn't worry about overheating on a late 90's vehicle as long as it's all in good condition. What do the hoses look like though?

Don't increase the cap pressure. The gain in BP of the cooling system will be marginal, and you'll stress things like freeze plugs and whatnot. Even with a 13 pound cap, which is pretty low, water boils around 230 degrees. Do you really want to be pounding on your engine that hard? Honestly, when temps get over 220 or so I assume there's a problem and pull over.

Yeah, expect to do that. That is, pull over and cool down. So, bring plenty of beer.

At 193,000 miles, your engine tolerances probably aren't as tight as they originally were, so a higher mileage type oil would be a good idea. Whether to go synthetic or not is up to you, but if Toyota recommended a 5W-30 for that truck, I'd absolutely go with a 10W-30 high mileage formulation. My wife's 2000 GMC Jimmy (which we drove cross country last Christmas to give to her brother in Pheonix) called for 5W-30, but it would consume about a quart in between changes. I switched to 10W-30 and it drank maybe a cup or two between changes. It had 170,000 miles on it.

Install a new cap and thermostat. They're cheap insurance. And make sure the radiator isn't all clogged with bugs and crap, the fan clutch works, etc. All the basic stuff. Keep your speeds reasonable, don't drive in the heat of the day, just generally be sensible and it should be fine.

I agree with everything put forth so far, but there is one critical thing that I didn't see mentioned yet.

A '98 surely has a plastic tank radiator. If it's never been replaced, it's on borrowed time at over 10 years old, pushing 20 in fact. If there is any sign that's original, or even if it's not, but the age is uncertain or thete is any indication that the plastic tanks are ageing, I'd replace it, along with hoses and T-stat.

My guess about the engine noise is that it's valve clatter from thinning, very hot oil. I wouldn't panic about it unless there is obvious power loss along with it. Try going up on step in viscosity at the next change.

I don't consider a '98 to be an "old vehicle" either. IMO by around 1990 manufacturers had really sorted out cooling systems. I remember when cars and trucks would overheat idling in traffic or climbing a long grade but I've given it zero thought in the last 25 years. If the system is in good repair (healthy hoses/radiator) a '98 Toyota should be fine pulling an infinite hill loaded to capacity at 120 F ambient temp.

Also agree about the clatter being a too-thin oil at temp. Manufacturers spec a thin oil to help mileage but as cars age and tolerances relax I like to thicken up the oil (10-40 for the summer is fine).

chuckles wrote: "...loud valvetrain noise when it's hot..." doesn't bother anybody? Not sarcasm. Just wondering what we assume that (loud) noise to be.

Most older Toyotas get that way.

Im in the dont worry about it camp. Look for pink fuzzies around the rad caps, my truck is at 220k and I wouldnt hesitate to take it.

Think that engine uses shim under bucket for valve adjustment, so it can rattle for a long time without incident. In fact, wouldn't be surprised if it's actually a leaking exhaust gasket at the head.