Temp gauge issues

[Bad_Vision]

if your stat isnt fixing the problem then you may have other issues like a clogged radiator or even a fuel issue. try running a can of seafoam in your tank when you have about 5 gallons in it. you wouldn't beleave what a clean fuel system can do your truck.
keep in mind if you have a automatic your tranny fluid may be burnt and not reaching proper temp as well and that also heats the radiator and transfers heat to the coolant.

 

[supra6m]

Im NOT a mechanic, but I was raised by one so I gotta ask...wouldnt a clogged radiator make it over heat instead of under heat? I'll try the seafoam tommorrow.

 

[supra6m]

oh wait... right... the tranny cooler line. hmmm, maybe.

 

[supra6m]

So what would be a good move for the tranny? The truck has ove 170,000 so I dont think a tranny flush would be a good idea.

 

[Bad_Vision]

a new filter and some new fluid wont hurt it, but yes stay away from the flush.
as for the clogged radiator the cooling system is funny like that if the cores near the bottom are full of junk the coolant may be passing through faster then its supposed too and get to the top section of the radiator were it is cooled more then normal. the bottom is a heat soaking area and the top is the dispersal area.

you may need to think about a wind block also for highway driving a high speeds it will deflect air and keep the engine warm and at idle and slow speeds it will cause no effect.

 

[supra6m]

Ok, I must admit that makes alot of sense. Thanks Bad Vision, that gives me a very good place to start actually FIXING the problem.

 

[supra6m]

**update**

Over-cooling problem is FIXED. Solution? OE t-stat. It runs like it should, it idles like it should, it warms up in 2 minutes instead of 20. I will never buy an aftermarket t-stat again. So let it be written, so let it be done.

 

[rlpjw1959]

Supra are you 100% sure...! How long have you been able to run the truck successfully? That's great news for you...I have the same problem and man is it frustrating. (as you know)

I would like to pick up a Original equipment if it fixed yours. This will be my 3rd Tstat.

Hope this was not another false fix for you! Way to go and please let me know how long you have had the fix in place.

Thanks!

 

[supra6m]

Get an OE. It's funny but I went through 3 t-stats too. The one that was in it when I bought the truck, the new aftermarket 180* to replace it, and when that didn't work, the 195* to replace that. They were all junk. If the OE t-stat doesn't fix your problem, then at least you have completely eliminated one variables and can start from there.

 

[KBJ]

As far as temp gauge, my needle usually sits just below half way up, unless it is really hot and I am in traffic then it will creep up to over half way up. In both scenarios the a/c is running.

Good luck

Mark

Is this typical of this engine? Ever since I've had my 4R this has been a concern. My gauge also gets to just about halfway, and never seems to move from that position no matter what the conditions are. I can be pulling a long grade in 100 degree heat and no change. I had Yodaman rebuild the topend of the motor and this was something I asked him about and he said it's how this engine runs. I just have trouble accepting that, it seems that the gauge should vary somewhat depending on load and weather.

The truck runs just fine by the way, no indications there is an over-heating problem. Am I chasing shadows and should just not worry about it?

Thanks to all and anyone who can help.

 

[supra6m]

I would certainly hope that this is not "typical". I've had 2 other 88 4rnrs with the V6's, And neither of them did anything like this. I really am starting to believe that it's just a crap-shoot with aftermarket stats. It makes it very hard to diagnose an engine problem when the worthless, brand new stat you JUST put in is junk.

 

[Buck Bridges]

OE Thermostat

Thanks for the tip. I am having the same problem with my O/D and I have a leaking thermostat housing so I figured it would be best to replace the thermostat as well. This might fix my O/D issues. I bought the original equipment thermostat for 20 bucks just to be safe. It costs a bit more but if it solves the problem, I'm happy.

I appreciate all who contributed to the thread. I will post my results as soon as the parts arrive and I can install. Fingers crossed

** UPDATE **

Installed the OE thermostat and discovered that the previous owner pulled the thermostat for some reason. Put that baby in and got 20 yards down the road and got hit with a CEL, (5-2 knock sensor fault) and that is a whole new can or worms BUT my overdrive is working like a champ! Just wanted to say thanks for the ideas and suggestions. Now, I'm off to fix the new problem. Just gotta love these classic 4runners!