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Topic: Overheating 1992 U240 with Cat 3208 (Read 2978 times) previous topic - next topic - Topic derived from 94 8.3 Cummins overhe...

Re: Overheating 1992 U240 with Cat 3208

Reply #20 –
So, normally aspirated 3208??

Again we are having to do a lot of guessing here.

Please confirm:

Rear radiator?

Normally aspirated?

Turbo with no after-cooler?

Turbo with after-cooler= CAC?

Yes 1992 was a huge transition year for Foretravel mechanicals as the new in-line engines replace the older generation V8's.

Re: Overheating 1992 U240 with Cat 3208

Reply #21 –
According to reply $5, it's a 3208T so turbo charged. It could either have an intercooler in front of the radiator or none at all.

Some CATs had air to liquid intercoolers but this is more costly so probably air to air.

Our Detroit has an air to liquid aftercooler mounted below the turbo and blower so you can't see it as it sits down in the valley of the V6 diesel.

Air to liquid intercoolers are smaller in size but more expensive. You can mount them most anywhere.

Both intercoolers and aftercoolers may be referred to as CAC in the RV community.

Here is a good site: Air To Water Intercooler Tech 101: What It Does And What You Need | Technolog...

Pierce

Re: Overheating 1992 U240 with Cat 3208

Reply #22 –
250 hp is turbo , no charge coolers
That's mine

Re: Overheating 1992 U240 with Cat 3208

Reply #23 –
Rear radiator with no other coolers attached.

Turbo charged but do not know if it has intercoolers as I don't know what they look like

There is a large tank with a big metal hose going to the turbo. I am assuming that this is where the turbo gets it's air from, and I need to know if there is a BIG filter in there, and if there is I'm sure it needs to be changed. If it is really dirty would it affect the temperature?

I am going to take Brett's advice and put a new thermostat in. Does anyone have a Cat part # and a place in mind where I can get one, and what temp should I install?

I thank everyone of you for your input to this discussion I am really learning a lot here.

Rick

Re: Overheating 1992 U240 with Cat 3208

Reply #24 –
Check the air cleaner first,won't cost anything,you can get the thermostat(regulator) at a Cat dealer but they will want the engine serial number,look on Ebay you can sometimes find a parts book.Just looked,plenty of books and regulators,plus you will need all the associated gaskets.

Re: Overheating 1992 U240 with Cat 3208

Reply #25 –
Thanks John, I see a lot of parts books, but not sure they will cover my 1992 3208t motor. Most of them are from 1967-1974 and so on.

Rick

Re: Overheating 1992 U240 with Cat 3208

Reply #26 –
The cover of the book will usually state which serial numbers it covers,some Cat engines also have what they call an arrangement number.

Re: Overheating 1992 U240 with Cat 3208

Reply #27 –
Yes, the correct thermostat(s) would be specific to your engine serial number.

I would NOT try to order over the internet-- too much chance of getting a "designed to replace" of unknown quality. The internet is full of knockoff parts.

Said another way, GET THE CATERPILLAR CORP PARTS.

And, as several have mentioned, have you taken a strong flashlight and shined it on the front (from engine room) of the radiator.

BTW, very easy to determine if you have a Charge Air Cooler:  Locate where the intake air goes into the engine.  Follow that plumbing back.  It will either go to a CAC OR it will go directly to the turbo.

Re: Overheating 1992 U240 with Cat 3208

Reply #28 –
There has been discussions on the Forum about REAR radiator Foretravel coaches, that originally came with fans that move air from outside rear to inside engine compartment. Some have improved cooling by replacing fan with one that has the blades curved differently so with the same rotation it now moves hot air from inside engine compartment to outside.

Drawing air in from rear of coach is also disadvantaged by the lower air pressure caused when driving down the road.

Re: Overheating 1992 U240 with Cat 3208

Reply #29 –
Quote from: Barry & Cindy –
There has been discussions on the Forum about REAR radiator Foretravel coaches, that originally came with fans that move air from outside rear to inside engine compartment. Some have improved cooling by replacing fan with one that has the blades curved differently so with the same rotation it now moves hot air from inside engine compartment to outside.

Drawing air in from rear of coach is also disadvantaged by the lower air pressure caused when driving down the road.

Agree, it makes no sense trying to pull air from the low pressure/high vacuum area behind the coach and "pulling it" forward against natural air flow.

Certainly no other rear radiator chassis do this. 

Are you sure there are Foretravels that were set up that way (vs improper later fan installation)?

Re: Overheating 1992 U240 with Cat 3208

Reply #30 –
The intercooler has to be on the coolest side of the radiator or it defeats it's purpose. In other words, if the air goes through the radiator first, might as well take the intercooler off.

Pierce

Re: Overheating 1992 U240 with Cat 3208

Reply #31 –
Quote from: Pierce & Gaylie Stewart –
The intercooler has to be on the coolest side of the radiator or it defeats it's purpose. In other words, if the air goes through the radiator first, might as well take the intercooler off.
Pierce

Absolutely correct. The objective of an inter-cooler/CAC is to bring intake manifold temperature down to close to ambient temperature.

Re: Overheating 1992 U240 with Cat 3208

Reply #32 –
Hmmm now this poor old Cowboy/Preacher is plumb befuddled ! Am I right in assuming that the fan pushes air out rather than pulling it into and over the motor? If so, where does the cooler air enter the engine compartment from?

Re: Overheating 1992 U240 with Cat 3208

Reply #33 –
Yes, air goes from the engine room OUT THE BACK.

Lots of openings below engine for air to enter the engine room.  Ideal, NO.  Does it work on the majority of the diesel powered motorhomes on the road-- YES.

Re: Overheating 1992 U240 with Cat 3208

Reply #34 –
This large round item takes air from the outside and routes it to the intake on the turbo. My question is there a large filter inside this can and do I access it by taking the end off?

IMG_20220908_174722532

Re: Overheating 1992 U240 with Cat 3208

Reply #35 –
Yes, that is your engine AIR FILTER.

Sorry, no first hand experience with the U240 and Cat 3208.

Might remove the bolts in the picture and see if the filter element is removable.

If you have an AIR FILTER MINDER what is its reading???

Re: Overheating 1992 U240 with Cat 3208

Reply #36 –
Thanks Wolf I didn't want to take the wrong thing apart and have washers, bolts, and springs jump out at me 🤣

I will take the end off and see what is in there.

Rick

Re: Overheating 1992 U240 with Cat 3208

Reply #37 –
Can anyone tell me where to point the infared thermometer to check the engine temp against the dash temp gauge?

Rick

Re: Overheating 1992 U240 with Cat 3208

Reply #38 –
Rick,

While that is a valid question (and someone with more Cat 3208 experience will weigh in), not sure how relevant it is to your issue.

Much more important is that your temperature goes from "whatever" to high reading with the slightest extra load.

So, correcting the "limited cooling capacity" is the issue.  That is why the suggestions of cleaning the front of the radiator and changing the thermostats.  Both are inexpensive and can basically be considered Preventive Maintenance.  Sure there can be other causes, but start with the basics.

Re: Overheating 1992 U240 with Cat 3208

Reply #39 –
The hose into the top of the radiator is a good bet for temp reading.
  Did you verify that the shroud is in place ?
  If the Tstat is faulty then it will overheat with any load.IMHO
 Your temp issue seems to be load related and that points to thermal exchange problems . Plugged air flow at the core,  shroud missing, wrong fan,  loose belts,  Small core even possible .