1994 Toyota Previa - Page 3 - Answered Questions & Fixed issues

Check if the fan is running. You may also have blockage in the radiator or coolant is not circulating properly. I suggest first draining the radiator and inspecting if there are debris in the liquid that comes out.

1994 Toyota... | Answered on Aug 07, 2011 | 553 views


You night have a bad head gasket leak wish pushes the water up.

1994 Toyota... | Answered on Aug 07, 2011 | 358 views

The engine is kept cool by a liquid circulating through the engine to a radiator. In the radiator, the liquid is cooled by air passing through the radiator tubes. The coolant is circulated by a rotating water pump driven by the engine crankshaft. The complete engine cooling system consists of a radiator, recovery system, cooling fan, thermostat, water pump and serpentine belt.

Check the coolant level in the recovery bottle or surge tank, usually mounted on the inner fender. With the engine cold, the coolant level should be at the FULL COLD or between the FULL HOT and ADD level. With the engine at normal operating temperature, the coolant level should be at the FULL HOT or HOT mark. Only add coolant to the recovery bottle or surge tank as necessary to bring the system up to a proper level. On any vehicle that is not equipped with a coolant recovery bottle or surge tank, the level must be checked by removing the radiator cap. This should only be done when the cooling system has had time to sufficiently cool after the engine has been run. The coolant level should be within 2 in. (51mm) of the base of the radiator filler neck. If necessary, coolant can then be added directly to the radiator.

While you are checking the coolant level, check the radiator cap for a worn or cracked gasket. If the cap doesn't seal properly, fluid will be lost and the engine will overheat.

Worn caps should be replaced with a new one.

Periodically clean any debris; leaves, paper, insects, etc. from the radiator fins. Pick the large pieces off by hand. The smaller pieces can be washed away with water pressure from a hose.

Carefully straighten any bent radiator fins with a pair of needle nose pliers. Be careful, the fins are very soft. Don't wiggle the fins back and forth too much. Straighten them once and try not move them again. It is recommended that the radiator be cleaned and flushed of sludge and any rust build-up once a year. If this has not been administered within the stated time, this may be why your vehicle is overheating at this time. Have the Radiator flushed asap if this is the case.

Now, if the coolant level is proper and, the cap is in fair or good condition, i would advise to move in the direction of the cooling fans and sensors as well. These fans are vital to the cooling process as well. The cooling fans must cycle in intervals to keep the coolant cool during stop and go driving or, long idle. They are also very important during the operational period of the AC during travel as well. i recommend inspecting the cooling fans while the engine is running. they should cycle during the running period. if this is not the case, you will need to test the operational value of these devices. The test procedure follows below


1. If the fan doesn't operate, disconnect the fan and apply voltage across the fan terminals. If the fan still doesn't run, it needs a new motor.

2. If the fan runs, with the jumpers but not when connected, the fan relay is the most likely problem.

3. If fan operates but a high current draw is suspected continue with the following ammeter TESTING.

4. Disconnect the electrical connector from the cooling fan.

5. Using an ammeter and jumper wires, connect the fan motor in series with the battery and ammeter. With the fan running, check the ammeter reading, it should be 3.4-5.0 amps; if not, replace the motor.

6. Reconnect the fan's electrical connector. Start the engine, allow it to reach temperatures above 194°F and confirm that the fan runs. If the fan doesn't run, replace the temperature switch.

Ok, Now we will move on to the next possible issue. The water pump. ok, due to the fact that your pump is driven by the drive belt, you will need to start the engine and listen for bad bearing, using a mechanic's Stethoscope or rubber tubing.

* Place the stethoscope or hose on the bearing or pump shaft.
* If a louder than normal noise is heard, the bearing is defective.

Replace the pump in this case.

You will also notice leakage around the pump housing if the seal has failed as well. this will strain the impeller and, ruin the pump.

Now. the last area of concern will be the thermostat. this is the most common issue that will inflict overheating in many vehicles. The thermostat is used to control the flow of engine coolant. When the engine is cold, the thermostat is closed to prevent coolant from circulating through the engine. As the engine begins to warm up, the thermostat opens to allow the coolant to flow through the radiator and cool the engine to its normal operating temperature. Fuel economy and engine durability is increased when operated at normal operating temperature.

There are several ways to test the opening temperature of a thermostat.

One method does not require that the thermostat be removed from the engine.

* Remove the radiator pressure cap from a cool radiator and insert a thermometer into the coolant.
* Start the engine and let it warm up. Watch the thermometer and the surface of the coolant.
* When the coolant begins to flow, this indicates the thermostat has started to open.
* The reading on the thermometer indicates the opening temperature of the thermostat.
* If the engine is cold and coolant circulates, this indicates the thermostat is stuck open and must be replaced.

The other way to test a thermostat is to remove it.

* Suspend the thermostat completely submerged in a small container of water so it does not touch the bottom.
* Place a thermometer in the water so it does not touch the container and only measures water temperature.
* Heat the water.
* When the thermostat valve barely begins to open, read the thermometer. This is the opening temperature of this particular thermostat.
* If the valve stays open after the thermostat is removed from the water, the thermostat is defective and must be replaced.
* Several types of commercial testers are available. When using such a tester, be sure to follow the manufacturer's instructions.
* Markings on the thermostat normally indicate which end should face toward the radiator. Regardless of the markings, the sensored end must always be installed toward the engine.
* When replacing the thermostat, also replace the gasket that seals the thermostat in place and is positioned between the water outlet casting and the engine block.

* Generally, these gaskets are made of a composition fiber material and are die-cut to match the thermostat opening and mounting bolt configuration of the water outlet.
* Thermostat gaskets generally come with or without an adhesive backing. The adhesive backing of gaskets holds the thermostat securely centered in the mounting flange, leaving both hands of the technician free to align and bolt the thermostat securely in place.

1994 Toyota... | Answered on Jun 21, 2011 | 1,016 views

you must look under the motor you will find a oil pan it looks small at one end then curves
down to a bigger part thats ware you will find the plug it looks like a nut in the middle or
at one end on the big part

im going to find a pic for youbigguy810_18.jpg

1994 Toyota... | Answered on May 29, 2011 | 74 views

Does the heater control appear to work correctly, as in it is not too loose or very tight? If it is working correctly, it is common for the heater pipes to become clogged with rust & scale on this model, due to the distance between the radiator and engine combined with lack of cooling system servicing.
If the heater control feels loose or tight, It is likely a problem with the cable controlling the heater tap. If tight, then likely the tap is faulty. If it is loose, the cable could have come off or snapped.

1994 Toyota... | Answered on Mar 10, 2011 | 180 views

Dexron 3 is sufficient for this transmission

1994 Toyota... | Answered on Mar 10, 2011 | 37 views


Check that you have correct vacuum to booster and no leaks or lines off any where, try gravity bleeding the system . To check vacuum at booster connect the Gauge to the booster line, a reading below 16 might indicate a hose leak or obstruction, a blockage in the exhaust like a plugged catalytic converter or bad muffler or an engine problem such as head gasket or manifold vacuum leak. You need to check your vacuum with a Gauge should pull 20 to 22, if it doesn't your problem is the booster, but most probably your vacuum is low.

Please get back to us if you have further query else please accept the suggestion.

Thank you for contacting fixya.com

1994 Toyota... | Answered on Feb 24, 2011 | 80 views

remove the little cover from the combination meter and push the little button with a small screw driver its on the dash on the left side of the cluster. heres a pis to help guide you. hope this helpsonetufshoppe_57.gif

1994 Toyota... | Answered on Jan 27, 2011 | 136 views

change the heater core! pretty easy to do! buy a replacement at orileys, or autozone, etc!

1994 Toyota... | Answered on Jan 09, 2011 | 155 views

fuse block under dash, hood, or in kick pannels

1994 Toyota... | Answered on Jan 06, 2011 | 365 views

Maybe check for a fuse that is blown, or maybe the heater control has burnt out.
Is it a digital display one or is it just a simple fan switch?

1994 Toyota... | Answered on Jan 01, 2011 | 217 views

Check for pieces of straw, paper etc in the MAF sensor. The mouse nest may have flown apart and bits are residing on thew sensor....

1994 Toyota... | Answered on Apr 02, 2014 | 158 views

looks like you have it full. it should hold between 4 and 5 quarts. your problem is elsewhere.

1994 Toyota... | Answered on Dec 12, 2010 | 145 views

Sounds like the radiator cooling fan isn't turning on, i would unplug the fan and run 2 jumper wires direct from the battery to the fan if the fan kicks on the fan is good, if it doesnt the fan needs to be replaced, if the fan checks out i would check the fan relay and make sure the relay is good, if the relay turns out to be ok then the coolant fan thermo switch is most likely the culprit for the fan not engaging when the engine reaches a certain temperature....

1994 Toyota... | Answered on Nov 26, 2012 | 318 views

Your engine does not have an idle adjustment like an older vehicle would have. The idle is controlled by the PCM (computer). If you have a high idle issue, then there is a vacuum leak. The most common cause for a vacuum leak that will attribute to a high idle is a loose or broken vacuum hose. A missing vacuum cap on a vacuum port on the engine. Lift the hood and inspect all vacuum lines and ports for loose or cracked hoses's or connections. Sometimes, you can actually hear where the leak is coming from with the engine running, due to the pull of air being drawn in the leak. Also check the rubber intake boot going to the throttle body for cracks that can occur inbetween the ribbed sections of the intake boot.

1994 Toyota... | Answered on Nov 17, 2010 | 338 views

possible sway bar bushing and or sway bar links in front and worn out shocks in rear

1994 Toyota... | Answered on Oct 30, 2010 | 238 views

yes there is a engine core plug and its behind and inside of the bell housing,, sorry its a gear box out job to fix it,,,or you could try
"block weld!" that may stop the leak for a short time,,,

1994 Toyota... | Answered on Oct 18, 2010 | 317 views

If you have 150k or more, you probably need a water pump, which is under the seat next to the sliding door. You may not be able to hear it going bad, due to location. I would also switch to 20w50 motor oil. If you live in a high altitude area, it is definitely the water pump. I have two of these, with a combined total of 900k.

1994 Toyota... | Answered on Oct 14, 2010 | 171 views

Here is a firing order diagram to help assist you.


1994 Toyota... | Answered on Sep 13, 2010 | 328 views

The speed sensor on the transmission maybe bad, replace it and see if that is the problem.I had the same problem with my previa and replaced it and it worked great!

1994 Toyota... | Answered on Aug 30, 2010 | 168 views

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