[V8] Time for a new thermostat?

[Jeremy Ward]

Today's top story:

Portland man replaces thermostat and sees 20% increase in gas mileage.

 

OK, so when I bought the V8 4 years ago, I noticed it always ran really
cool.  On the freeway on a cool day, the needle was always about 1/3 of the
way between 50C and 75C.  My gas mileage was always 15.5 as reported by the
trip computer for 4 years.

 

Last January, Ingo flew out to Portland and he and I went for a ride down
the Oregon Coast to pick up his new 4.2.  On this trip, he complimented how
well my V8 ran and how strong it pulled.  He also told me that my water
temperature was WAY too low; guess that's why my mileage sucks and my
tailpipes are sooty.  

 

Finally this weekend, I had a chance to swap it out.  The hardest part was
trying to set a torque wrench to 7ft lbs (my 3/8 TW only goes down to 10ft
lbs).  I had to use the 1/4 TW and set it to 84in / lbs, use a 1/4 deep
socket with a T30 torques bit in it.  I have since purchased a 1/4 to 3/8
adapter from Sears so I could use my regular T30 socket (and others) in
times like this.

 

Now the water gauge rides between the 75C mark and the 100C mark (~87C just
like the thermostat says).  I guess my old one was stuck open and not
allowing the engine to get up to its sweet-spot.  This all makes sense; I
just wish I had put two and two together long ago.  I am now getting 18+ MPG
around town.  I am curious to see how many miles I get out of this tank, as
I have been getting 270 miles or so around town.

 

Moral of the story: if your water temperature gauge doesn't sit at 87C after
5min of driving, install a new thermostat! It will quickly pay for itself!
:-)

 

Cheers,

 

- Jeremy