First of all whom ever designed this motor must have been a sadist. Honestly one of the MOST difficult motors I have ever had to work on… Just because of poor design, and the fact that whomever put it together in the first place seems to have purposely put the spring loaded hose clamps on backwards to prevent any tool from getting to them and releasing the pressure on the hose… One fuel line in particular took me almost an hour !!!
With all that said I got the tstat out about 3 hrs later…
First thing I did was heat up some water on the stove to see if it was bad… Dunked it in with the water at around 180 and nothing… WOOO HOOO said I, then I grabbed the new stat to check it… It started to crack open right around 170 like it should… Then I heated the water up higher to about 200 and dropped the old stat in, to see what would happen… To my shock it opened (high temp I saw in my OBD2 scanner was 230)… Ok now I’m nervous. Cool the water back down to 180 and put the old stat back in and low and behold it cracked open…
So is it possible it’s not opening far enough at the lower temps?? Or that the hot water cleaned/freed it and now it works?? Or do I have another problem??
What do you guys think??
PS Honda has apparently disenvowed all knowledge of this truck, and no longer carry parts for it…
That’s because this truck never ever was a Honda in the first place. It’s simply a re-badged Isuzu. Take a close look at the emissions decal and some other parts.
Dunking the thermostat in a pan of water is not the correct way to check it. You stick a thin wire through the seat and the valve so that the closed thermostat can be hung by this wire. Then you suspend the thermostat in the hot water by the wire, as soon as teh thermostat starts to open, it falls off the wire.
When you just drop it in the pan, you may be heating the thermostat by metal to metal conduction.
@keith I did almost that, I hung it from a wire not touching the sides of the can… Just water. The old stat seems to work just fine. I will tell you this if I did all this for nothing I’m gonna be ticked, but all signs pointed to it.
Old thermostats can get sticky.
That first time in the pan it didn’t open until 200, then it opened at 180: inconsistent.
It might have been worse sitting in the engine, then got freed up some when removed.
In the past when I changed a thermostat for PM I worked the plunger by hand to compare old to new.
The new t-stat always felt smoother than the (4 year) old one.