Under heating and question about oil temperature.

[Chester]

My 1989 LE van has no codes (I fixed the water temp sender) and the temperature gauge on the dash starts really low and barely gets to about a quarter. From reading these forums, it sounds like my thermostat is stuck open. We had a cold day for us this am in Seattle and the heat was paltry.

Is there a way to test the coolant temperature or should I just replace the thermostat? I bought the van in the summer and have put about 1000 miles on it, runs fine. I replaced front shocks and got a mechanic to replace differential pinion seal due to a differential leak. Additionally, I put a speedometer cable in (housing and all) from an 87 van and odometer and speedometer seem to work fine.

My oil temperature gauge will get to about halfway when I am driving, but when I am stopped at a stop light, it will drop to about one quarter. Had oil changed when I got van, no codes related to oil, oil idiot light comes on in the dash when I turn the key and start the car. It has not changed in the 3 months I have had the van. What do I need to do to evaluate/ fix this? Or can I leave it alone and just get involved if it develops a change?

Thanks for replies.

[potatovan]

me again I also have this issue but I also have luke warm heat do you? other than that its not over heating so when I see quarter on temp I am just in bliss. (Past problems) no oil gage in the potato so can't speak to that. Scott

[Chester]

See the thread called "possible thermostat issues" Timrv says that if the heat blows cool and the temp gauge doesn't move much, replace your thermostat. I am just trying to figure out if there is a test I can do to check the thermostat, so I can avoid replacing if it is OK.

[timsrv]

If the heat won't blow hot and your gauge shows low, then I'd just replace the thermostat and be done with it. Don't mess around with aftermarket junk, get a Genuine Toyota t-stat (several of us here have learned this lesson the hard way). The thermostat doesn't come with the rubber gasket/seal, so be sure to get that too while at the dealership.

If your heat won't blow hot and your gauge shows normal, then climb under the front of the van and check the valve attached to the heater hose there (driver's side & usually has a blue cable going to it). Have somebody turn the temp lever up & down while you make sure the cable moves the valve full travel. If it doesn't, then disconnect the cable and change the valve position by hand. This should give you heat but you'll have to climb back under the van again to turn it off . Tim

PS: To my knowledge Toyota never put an oil temperature gauge on the van. Unless it's an aftermarket installation, I think you are talking about an oil pressure gauge. If so it's normal for oil pressure to drop when engine RPM is low & go up when RPM is high. I'm still a little confused though as Toyota didn't put oil pressure "idiot lights" in vans equipped with oil pressure gauges. There is an "oil level" indicator lamp in some of the higher trim level vans. This light is typically amber (oil pressure light is red). The oil level indicator system is flawed and it's not unusual to see this light illuminated even when the sump is full of oil. Please recheck your equipment and report back with function of gauge(s) (is it pressure or temperature? is it (they) factory or aftermarket?). Also please recheck you warning light(s) & verify function. FWIW, the ECUs on our vans do not monitor the oil system & will not store/display codes related to oil temp, level, or pressure. Tim

[Chester]

Timrv, thanks, my van is an 89 LE and has a gauge next to the water temp ( to the left) with an oil can symbol. In between the speedometer and the tachometer that I thought was oil temp because the water was a temp gauge. It goes up and down, and nice to know that it is normal for the oil pressure to drop when the van is idling. Sounds like I don't need to fix that.

The oil light on the tachometer is amber, and lights up when I start the van, then goes away. I was worried that there was something wrong with the oil sensor. From your description it is working fine.

[timsrv]

Okay, that makes sense. Yes, that's your oil pressure gauge. As long as you regularly check & confirm oil level then I'd disregard the oil level light. These systems are known for giving constant false alarms. If it's important to you the system can be repaired, but it's not necessary for those who check oil the way you're supposed to. I think Toyota only put it there to remind the people that drive their rigs into the ground. IMO It's useless if you're already on top of things. Tim