Thermostats

[Iain]

Can anyone say what is the best thermostat to run on a 1994 6.5L? Is it better to run a cooler thermostat, say 180 degree F? I need to change mine but I am not sure what is best. Thanks!

[Billman]

This is a highly debated topic.

Do a search.

My opinion...195.

Only because I can't find 205's.

[charliepeterson]

I vote for 195*'s.

In the summer you could run a little hot. This is where some people will run with 180*'s. The truck should run better and get good fuel mileage at 195*. If it does run hotter than you have other issues. When the truck was new it came with 195*'s and it didn't over heat.

[MTTwister]

Billman - Checker Auto over here has the "Prestone" / RoberShaw 330-205's on the rack. If you get desperate, let me know and I could send you 1 or 2. Current cost is $12.99.

[LanduytG]

I run 205's and would run hot in the winter if I could get them. A diesel runs best the warmer you can run it.

Thermostats should have no affect on temps in the summer if everything is working the way it is suppose to. I have never had and over heat problem until the fan clutch went out. I gross 16,500 when towing my 5th wheel and have been al over the US including the rockies in Colorado.

Greg

[Billman]

That's the first time I've seen the part number posted. Thanks.

Is the '330 Series' their Hi-Flow?

[MTTwister]

Is the '330 Series' their Hi-Flow?

Affirmative... ='s RobertShaw's numbering scheme.

See what might be hanging on a rack near you smile.gif

[Billman]

Thanks Twister

I confirmed that against my 330-195's right after I posted last night.

Will comb the stores this weekend...

[quickv6]

I found a thremostat for a acura that fits the single stat 6.5 perfect. It is a 170 stat. I dont remember the number but go to a parts place that has a book with the stat dimentions. There is a stat for an acura that fits perfect.

Lonnie

[Billman]

Lonnie

I'll bet that thermostat is wrong for your application for a couple of reasons.

And dimensions have nothing to do with it.

I would be careful if I were you...

[quickv6]

Originally posted by Billman:
Lonnie

I'll bet that thermostat is wrong for your application for a couple of reasons.

And dimensions have nothing to do with it.

I would be careful if I were you... When I purchased this truck I noticed that if the temps went over 200deg the power would decline. So I started out looking for a way to get it to run cooler. After installing a new stat, 98 fan and clutch hub new hi efficency rad. etc etc. The truck would still hit 200-210 in 90deg heat on a hard pull with the AC on but would not go any higher and did not require a pull over for cool down. Much better than before where I would go over 230 when it was 50deg and would need to make a stop for cool down. So I started looking for a stat that would work. I have 11 months under my belt using this stat. My truck towing a gross combination weight of 19,600lb traveling Jellico MTN south bound in TN will not break 185-190 in the heat with AC on. I did notice that the MPG slightly dropped with the cooler temps. The stat has a larger openning where it opens and so far works great. I still have the 95 cooling stat set-up. Normal cruise temps are 165-170. It might be a little cool for these engines but after joining this sight I was scared to death of over heating or running my 6.5 at the temps I was seeing.

Lonnie

[ 03-12-2005, 12:23 PM: Message edited by: quickv6 ]

[Billman]

If it works for you, great.

Their isn't anything better than experience. You've logged 400,000 miles. You must be doing something right. 19k gross is heavy.

General consensus on this board is to upgrage the cooling system to 97+ status first.