CAT 350 Overheat

[jk_and_dog]

Well, my memory just isn't what it use to be. Another thing I had a little trouble with.

The CAT 350 in the MH seemed to be running a little high. It tipically runs around 192 while driving down the road and has been at that temp almost all the time even when running the hills of WV on I64. Typically it will auto downshift and keep on trucking with little issues.

last trip coming back from Indy while coming up the hill just inside VA on I64 the engine heat went up and finally it sent an overheat signal to the light board on the dash. I immediately pulled over and let it cool back down. Temps out side were running around 100 F.

I've noticed that the engine now normally runs around 194 on hot days but will vary significantlly while runnibg the light hills in VA. Week before last while headed to WV up 460 the engine temps got to 212 F. Never did light up but still I'm a little concerned. It was still hot outside around 97-100 but I've never experienced the temp range being so wide.

I flushed the fins on the radiator yesterday and let the engine idel for a while and temps remained around 185 F while in driveway.

My question is...has many of you guys or gals expierenced the radical rise in temps on your engine when the outside temp is in the upper 90's or low 100's?

Thanks
jk

[bellsharbor]

On my 2002 Journey/ 330 Cat, I had the same problem until I had the radiator steamed cleaned. After that, the needle didn't move much even in 100*. Good luck--

[teekay]

Drove the 36G with C-7 CAT in 88F temp 70F dew point for 5 hours today, mostly 190, few times up to 192. We were pulling jeep Liberty. I clean rad with simple green every year.

[smlranger]

Cleaning the radiator (that's on the outside) is far less effective than cleaning the charge air cooler (that's on the inside). You gotta get under the bed, soak that thing with Simple Green or something similar, then flush it good with a hose. You might have to do it more than once but most of the rear radiator DP's will run hot when the CAC and radiator get gunked up.

[Chuck 1935]

I just crossed the desert from Barstow to Kingman. It was 100 to 110 degrees all the way. Up hills down hills the guage never went above 1/2 way. On a long pull I will drop it into 5th and keep the RPM's at 2000 and it stays below 1/2 way. I do keep the radiator fins cleaned out with paint thinner (that will get thing stirred up, but it does a great job of dissolving any grease or oil that are on the fins) sprayed from a syphon gun. After that dries I follow up with a water and air sprayer that removes the remaining dirt and dust from the fins.

[skigramp]

I clean my radiator with simple green (this year I used Jungle Jake because my local supplier was out of simple green) once a year ... I use a garden sprayer ... I crawl underneath and spray it into the fan housing with the engine running ... and spray it from the outside too ...

[David W]

I have a 2005 Meridian Itasca, 350 Cat that is slightly overheating. I have cleaned the outside fins but can not get to the inside. Any secrete passages I should know about.

[jimmccreary]

There are 3 accesses that I have used to clean the inside of the radiator.
The most effective is under the bed raised and with the engine cover removed. From this position you look down onto the inside surface of the radiator. Soak well with 1:1 simple green (or other degreaser) and water. Using a garden sprayer with a long tip you can get most of the top half of the radiator. From the bottom front under the driver seat you can get about 25% of the radiator, you will have to squirt the liquid between the fan blades which must be rotated slightly to get it all. You may have to crank the engine. I have been able to rotate the blade by hand but is difficult. The 3rd access is under the passenger seat but again the fan blade will have to be rotated. After all of this is sprayed, I also soak the outside surface of the radiator by trying to squirt the cleaning fluid directly into the radiator fins. You can rinse with water but if you have a really thick build up you may have to use a pressure washer or car wash sprayer directly into the outside rear of the radiator to get it really clean. When doing this hold the sprayer far enough away from the radiator fins to avoid bending them.
You can tell when the radiator is clean. With the engine on, the fan should uniformly blow air through all areas of the radiator.
Also, if you dont have a closed crankcase, you may want the extend the oil blowby tube (crankcase oil vapor exhaust) so that it vents beyond the radiator.
good luck
jim & debbie, 04 Journey, suzuki toad

[JoeT]

My C7 normally runs at 185 degrees. I've never seen it above 192. I don't downshift on hills and, as CAT recommends, top the hills with the tach in the upper 1400's at times.
This is my second C7 and I can say the same about both of them. I do clean the CAC/Radiator with Dawn every six months.

[MrTransistor]

Hi All,

6 years, 90,000 miles and never cleaned the radiator. Temperature fluctuates between 198° and 204° (as seen with PocketTech, not the dash gauge) as the hydraulic fan kicks on and off. The engine has never overheated. Seems like the side radiator is the key. From what I’m seeing, it’s the rear radiator that has to be cleaned all the time.

Also, isn’t the same radiator used with all Freightliner chassis? Everything from 275 HP up to 400 HP. Seems like different HP’s might require different cooling capacities.

[David W]

Thanks for the input guys. I am new to all this, just trying to make sure I don't damage anything. Coach is DP, 350 HP Cat 2005 Meridian Itasca 39K WITH 42 k miles.

[richf]

I'm confused about Jim McCreary's post on access to the radiator under the "drivers" and "passenger's" seat. Need a little clarification. The radiator's in the rear of the coach chassis. ???

[jimmccreary]

Oh, so sorry, I am feeling really retarded now. That you so much for the correction and helping to keep postings accurate. Yes the radiator cleaning is done in the rear. Here is what I was trying to say. when you are under the coach and looking to the rear. The space on the passenger side (looking backwards under the radiator) is large enough to spray the cleaner on the lower left corner of the radiator. Because of the angel of the fan blades, this space allows a larger view to the radiator and therefore offers more cleaning potential. However on the driver side of the coach, still looking towards the rear under the coach, the view of the radiator is more obscured by the fan blade and offers a more limited area for cleaning the radiator.
I am so sorry if I misled anyone. Anyway, I stand corrected.

jim & debbie, 04 Journey, suzuki toad

[deffinba]

The Cat engines had a slober tube oil mist problem. Varify the slober tube has been extended past the radiator. Also the heat exchanger (inside radiator) is the one that plugs. It can only be cleaned from the engine side. I ended up having to pull the radiator on my '01 Journey because of this problem.