Cat thermostats

Your gauge is reading low more than likely, 192 stats are correct. If you hooked up cat et you could check temperature operation better. We used to put 200 stats at the dealer as Cat told us but after many headgaskets and cracked heads, Cat insisted that this was an improper procedure and would not cover repairs under warranty if 200 stats were used. Try a new set of 192 stat, make sure you replaced the inner seal also, this will prevent internal stat leakage.

 

I have the pittsburgh 185 stats, they are fully open by 185, the stockers dont fully open till 212*!!!!! They helped me a lot, when i started to build power it would quickly build water temps on stock T stats, now i cruise around 165-170* and hardly ever see over 195*. Like DDS said, dont get any hotter than the stock ones..... I go by the motto the cooler it runs the longer it lasts.

 

Cat is working on this issue and Thermostats may not be the problem. Check with your Cat dealer later this month. This article mentions TEN which is their (Truck Engine News) publication available for public viewing at http.ohe.cat.com​

Here is a copy of a recent Tech Tip they published August 13,2008:​

Problem:
​

• Engine Jacket Water Temp running cool on some chassis, contributing to
oil Emulsion build-up and loss of cab heat and low cooling system temp.
Resolution:
• Two Teams working issue; Cat team mtg twice/week,
PACCAR/FRTLR OEM team mtg w/Cat monthly.
• Looking at ALL chassis, two solutions identified to-date:
• Shunt line re-route-to- water pump-inlet, planned for Prod End of Sept
• Severe overcooling trucks to be reworked with Check Valve/Stop in Radiator vent line as needed
• TIB / TEN to be released to cover this procedure
• Will finalize all recommendations prior to end of Sept
• Field testing of fuel economy on number of overcooled
engines showed Minimal differences in fuel economy​

 

What is considered "Severe overcooling"?
Where can we find the results of this "field testing concerning the fuel economy"?
It is my understanding that the major reason for these engines running hotter than the older engines, is the fact that hotter temperatures will lessen the NOX emissions (taken from "Fleet Owner", June 2008), allowing the engine manufacturer to be in compliance. I have found NO evidence that an engine running higher water and exhaust temps will have a longer, or even the same expected life as a engine running cooler, (normal) temps.

I am also curious that if emissions would not have come into play, would manufacturers have redesigned their line?

In the past, engine manufacturers were oriented toward building a quality product for their customer.
Now the focus is just to be within compliance, with the customers needs and a long lasting quality product just a hindsight.

 

If your gauge reads 180 running down the road, what temperature does the gauge read when the fan comes on? Your fan will be turned on at 217 deg by the ecm. I would still put money on that your dash gauge reads 10 degs cold. Very common problem. The check ball in the vent line is a cheap add on when you replace your stats, I will find the ball part number for you, you take out the fitting for the vent line and drop in the ball. Cat claims it make a 10 deg difference, in the winter. May not help yours in the summer.

 

DDS
I am still puzzled as to a couple of things:
(1) The reason for this check ball in the vent line, could you explain please?
(2)If Spike 64's truck gauge is showing 10 degrees cooler, and IF the engine temp is normal, why replace the thermostats?

I have to be missing something here.
Going back to my previous post, it is my understanding that the reason for the newer engines running hotter is SIMPLY to reduce NOX emissions, NOT for fuel economy, and NOT for longer engine life. If I am wrong, please correct me.

 

The check ball prevents coolant from bypassing the stats by closing the vent with coolant pressure, when the engine is off and the coolant pressure stops the check ball falls down allowing trapped air out of the stat housing.

The stat would not have to be changed if gauge is wrong, he needs to have Cat et hooked up to check his running temperature. That is the only way to know what the ecm is reading.

As for the nox, nox is a product of high cylinder pressure and temperature. High cylinder temperatures are a result of advanced timing. Advanced timing makes more power with less fuel. That is why the low nox program reduced fuel mileage, the base timing is retarded to lower cylinder pressure and temperature. With retared timing you need more fuel to make the same power, higher exhaust temperature is the result. More fuel makes more heat in the head that the cooling system must remove.

Hope that made some sence, just a Tech not a engineer.

 

will this check ball work in a 3406c if it will work could some one give me the part number for it

 

That explains why my engine fan comes on at 110 and my high temp light comes on at 112. i felt like one of them was wrong