OVERHEATING 350 Cat

fergo27 · 10-02-2014, 03:20 PM

I have a 2005 Journey with a 350 Cat engine, and I tow a Honda CRV. Normal flat ground is no problem, even in 100 degree weather. However, when climbing a steep grade my temp gauge goes to high. I had the radiator cleaned (blasted) and my fluid levels are good. Before it starts to overheat I shift down, and at times have even had to go to first gear. My last trip, coming out of the desert east of San Diego, I had to pull over and stop. I'm wondering if the transmission could be overheating, thus causing the engine to overheat? As far as I know, this Cat doesn't come with a transmission cooler. HELP. i'm starting to get pretty HOT. Any suggestions would be greatly appreciated.

Fergo 27

skigramp · 10-02-2014, 04:08 PM

I have travelled from Yuma, AZ to San Diego on I-8 multiple times ... there are some pretty good pulls on that route.

I make sure that I shift down to keep the RPM's near 2200 on the long pulls.

This keeps my engine from overheating.

I use a garden sprayer with Simple Green on my radiator twice a year.

BFlinn181 · 10-02-2014, 05:06 PM

Quote:

Originally Posted by fergo27

I have a 2005 Journey with a 350 Cat engine, and I tow a Honda CRV. Normal flat ground is no problem, even in 100 degree weather. However, when climbing a steep grade my temp gauge goes to high. I had the radiator cleaned (blasted) and my fluid levels are good. Before it starts to overheat I shift down, and at times have even had to go to first gear. My last trip, coming out of the desert east of San Diego, I had to pull over and stop. I'm wondering if the transmission could be overheating, thus causing the engine to overheat? As far as I know, this Cat doesn't come with a transmission cooler. HELP. i'm starting to get pretty HOT. Any suggestions would be greatly appreciated.

Fergo 27

If your radiator is clean, the next things to check would be the fan, thermostat, and water pump. Make sure that when hot, the fan is running at full speed. The thermostat and water pump can only be checked by replacing them, so start with the fan. If it's direct drive, make sure the belt is good.

dnystrom · 10-02-2014, 05:07 PM

Trans cooler is on the rear left side of the coach with 2 electric fans.
How HOT are you running???
I will get up to 205 on a long steep pull.
Also normal operating temp for that engine is 190.
Like gramp said, keep the rpm's up. Don't lug it at 1500-1600.
When is the last time you had the radiator flushed???? (Every 4 years)

cbeierl · 10-02-2014, 08:09 PM

Quote:

Originally Posted by dnystrom

Trans cooler is on the rear left side of the coach with 2 electric fans....

Actually, I suspect that that's your engine A/C condenser on the left rear side of the coach.

RKL · 10-02-2014, 08:21 PM

I agree. Rkl

dnystrom · 10-02-2014, 09:39 PM

Well raise my rent! I ass u me d that it was the trans cooler!
Does the trans get cooled from the radiator?
I learned something new today and as usual the hard way.....

Skip426 · 10-02-2014, 09:51 PM

Question for the OP.
No trans temp gauge in your coach ?

I don't think any Allison equipped coach comes without a cooler; mine is in the lower rad hose; oil to water cooler. I've seen other post with members replacing oil to air coolers for their transmissions.

EDIT: The trans fluid to the cooler lines , on Allison transmissions , run from under the drive shaft yoke to the cooler , and they are huge, easy to trace.

Re-Edit: Another question. By too high, what temp is being displayed on the gauge? Any chance your cooling fan is not ramping up to full RPM ?

stink · 10-02-2014, 10:00 PM

Rear radiator? If so, may have lots of stuff between rad and cac.

FIRE UP · 10-02-2014, 10:49 PM

Quote:

Originally Posted by fergo27

I have a 2005 Journey with a 350 Cat engine, and I tow a Honda CRV. Normal flat ground is no problem, even in 100 degree weather. However, when climbing a steep grade my temp gauge goes to high. I had the radiator cleaned (blasted) and my fluid levels are good. Before it starts to overheat I shift down, and at times have even had to go to first gear. My last trip, coming out of the desert east of San Diego, I had to pull over and stop. I'm wondering if the transmission could be overheating, thus causing the engine to overheat? As far as I know, this Cat doesn't come with a transmission cooler. HELP. i'm starting to get pretty HOT. Any suggestions would be greatly appreciated.

Fergo 27

fergo27,
Well Sir, I assume you're talking about "Mountain Springs Grade" if you're heading west from Yuma/El Centro to San Diego. It's a pretty good grade, about 7% at various locations and, based on application speed, it will take the average coach, about 10-12 minutes to climb it. Now first off, can you actually verify that your radiator and, your CAC are both REALLY CLEAN?

Sometimes, it's pretty difficult to do a bang-up job and get both of them really, really clean. I had to remove both my radiator and CAC in order to get them thoroughly clean. Not a fun job, to say the least. And, based on what you reported as your model year and manufacture of coach and engine, you WILL have a solid drive fan. About 99.9999 % of those coaches did NOT come with fan clutches. Especially in rear radiator design.

Side radiators, well that's a whole different story. But, on yours, do make sure your radiator is, in fact, really clean. Second, I've known way more the a few that have had those factory plastic fan blades on both the 3126 CATs and, the C-7 330 and 350 HP versions, break apart and before you know it, you're missing quite a few fan blades and, sometimes you actually don't see it happen and, there's no damage to the radiator or CAC.

But, third, do check your serpentine drive belt for the fan. The factory spring loaded tensioner "should" be doing its job in terms of keeping the belt tight and therefore, making sure the fan is turning at full speed, based on engine RPMs at a given time.

Of course, you may have to dig into the thermostat(s) and make a change on those if you have to. And, if your coach/engine is anything like ours, an '04 Itasca Horizon 36GD with the C-7 330HP CAT and Allison MH3000 Trans, you have what's called a "heat exchanger" in place as a transmission cooler. It's just like the average car built in trans cooler in the bottom of the radiator only, a lot bigger and, it's out in the open, not inside a radiator.

But, like stated, I'd start the investigation with a real close look at the CAC and, the Radiator fins to be proof positive that they're clean and free flowing of air. Now, one thing here, another point to check is the outlet for the infamous "slobber tube" or, aka the "Blow-by" tube. See where it's at. I don't know how long you've owned this coach and or, if the blow-by tube outlet has been re-located to a point at which its exhaust will do no more harm to the CAC and radiator. Something else to check. Please report back if you find a "for sure" cause of your issues.
Scott

bsamole · 10-03-2014, 08:33 AM

The IRV2 cat forum is a great source for information on the cat engine. My rear radiator had to be pulled in order to properly clean and the blow by tube extended to prevent future clogging.

Iron Horse · 10-05-2014, 06:39 AM

I just got through removing the radiator and cac on my motorhome, 2007 Winnebago Journey 36G with 27000 miles. We bought it in 2007 used (8500 miles). I have cleaned this one as best I could every year but could not get all the gunk out, plus somewhere along the line it ingested a trash bag. It was super filthy, you wouldn't believe. I have replaced all the belts and hoses, tensioners, idlers and thermostats while I was in there. I don't see where anyone mentions the water pump belt (separate from the serpintine belt) as these tend to go bad/get loose guite regularly. You need to check this out too since this belt, if it is slipping, can seriously slow water circulation. My water pump belt had severe cracking. I knew to look for this since I had one go south on my company truck (3116 cat) leaving me stranded on the interstate.
Hope this helps, Iron Hors

FIRE UP · 10-05-2014, 10:31 AM

Quote:

Originally Posted by Iron Horse

I just got through removing the radiator and cac on my motorhome, 2007 Winnebago Journey 36G with 27000 miles. We bought it in 2007 used (8500 miles). I have cleaned this one as best I could every year but could not get all the gunk out, plus somewhere along the line it ingested a trash bag. It was super filthy, you wouldn't believe. I have replaced all the belts and hoses, tensioners, idlers and thermostats while I was in there. I don't see where anyone mentions the water pump belt (separate from the serpintine belt) as these tend to go bad/get loose guite regularly. You need to check this out too since this belt, if it is slipping, can seriously slow water circulation. My water pump belt had severe cracking. I knew to look for this since I had one go south on my company truck (3116 cat) leaving me stranded on the interstate.
Hope this helps, Iron Hors

Iron Horse,
I certainly applaud you if you did the R&R on the radiator and CAC yourself. I did it on our '04 Itasca Horizon 36GD with the C-7 330 and, while I was not in any hurry, it did take me about 6 hours to get both of them out. No biggie. I replaced about everything I could with the exception of the fan bearing. I could not, for the life of me, break those little, flat head, ALLEN screws loose that held that fan bearing hub cover on.

I tried and tried but, all I was succeeding doing was, bend the Allen wrenches. Oh well, next time. But, as you say, you've cleaned and cleaned your radiator and CAC and still, when it was out, it needed extensive cleaning. Well, mine was that way too. It took a whole un-diluted gallon of ZEP citrus based degreaser and, a 2500 psi pressure washer to get them both clean. That stuff was IN THERE! But, after all the cleaning I did on the radiator, I replaced it because of a leak that was in the lower left corner anyway. A reputable radiator shop said there was no chance of repairing it so, I ordered up a new copper/brass one. Works perfect.

Anyway, as you well know, it's not easy getting those units out for service but, in my opinion, it's seriously well worth it when it comes time for service of the fan area, bearings, belts and, anything else in that area.
Scott

mel s · 10-05-2014, 10:57 AM

Quote:

Originally Posted by fergo27

I have a 2005 Journey with a 350 Cat engine, and I tow a Honda CRV. Normal flat ground is no problem, even in 100 degree weather. However, when climbing a steep grade my temp gauge goes to high. I had the radiator cleaned (blasted) and my fluid levels are good. Before it starts to overheat I shift down, and at times have even had to go to first gear. My last trip, coming out of the desert east of San Diego, I had to pull over and stop. I'm wondering if the transmission could be overheating, thus causing the engine to overheat? As far as I know, this Cat doesn't come with a transmission cooler. HELP. i'm starting to get pretty HOT. Any suggestions would be greatly appreciated.
Fergo 27

fergo27
How "high" is to high and how "hot" is pretty HOT?
My Safari Owners Manual states that a coolant/water temperature of 190 to 215 degrees F..... and a transmission fluid temperture of 140 to 250 F..... are "normal/acceptable".
Mel
'96 Safari, 250hp 3126 Cat, M3060 Allison

1ciderdog · 10-05-2014, 01:07 PM

Quote:

Originally Posted by fergo27

I have a 2005 Journey with a 350 Cat engine, and I tow a Honda CRV. Normal flat ground is no problem, even in 100 degree weather. However, when climbing a steep grade my temp gauge goes to high. I had the radiator cleaned (blasted) and my fluid levels are good. Before it starts to overheat I shift down, and at times have even had to go to first gear. My last trip, coming out of the desert east of San Diego, I had to pull over and stop. I'm wondering if the transmission could be overheating, thus causing the engine to overheat? As far as I know, this Cat doesn't come with a transmission cooler. HELP. i'm starting to get pretty HOT. Any suggestions would be greatly appreciated.

Fergo 27

Out of curiosity is your temp gauge accurate? Is it really overheating? Do you get shutdown or overtemp alarms? Does it boil over? On my CAT I will get a shutdown alarm if/when it overheats such as when the fan pulley came apart a couple of years ago. I now have a scangaugeD and it reads engine temp digitally so I don't need to worry about how high the dial gauge gets.

Mekanic · 10-05-2014, 02:04 PM

Quote:

Originally Posted by fergo27

I have a 2005 Journey with a 350 Cat engine, and I tow a Honda CRV. Normal flat ground is no problem, even in 100 degree weather. However, when climbing a steep grade my temp gauge goes to high. I had the radiator cleaned (blasted) and my fluid levels are good. Before it starts to overheat I shift down, and at times have even had to go to first gear. My last trip, coming out of the desert east of San Diego, I had to pull over and stop. I'm wondering if the transmission could be overheating, thus causing the engine to overheat? As far as I know, this Cat doesn't come with a transmission cooler. HELP. i'm starting to get pretty HOT. Any suggestions would be greatly appreciated.

Fergo 27

When you say you had it blasted clean,....... did they remove the rad and CAC from the vehicle ?

Or did just point the nozzle at it where its at. ? BIG difference in how clean they get.

Gary CA · 10-05-2014, 11:20 PM

Fergo 27, My 2004 had the same overheating problem. I can tell you that between the radiator and air-charge unit you have probably the same collection of crap I have removed; plastic bag, leaves, even duct tape that was sucked up off the road and forced in between the coolers. Research the overheating topic and follow the lead by a member that cut a access panel in the fan shroud. Take a cell phone or camera and take a picture between the units, it is a mess in there. Drill a one inch drain hole in the bottom, soak the units with Dawn, simple green and what ever will cut the crud and using hot water spray for hours and take pictures until you can see the bottom. By the way you will need a 27 inch grabber tool, $15 or so from Pep Boys, because every on else on sell 24 inch tools and you can't reach the bottom to pick out the debris. Good luck be patient and give it two days for this project. My local CAT dealer wanted $3000 to R&R units and send cooler out. Give it time yours will look like new and I have not overheated since my cleaning and that is with a 2000 mile trip up and down the Western states this summer while towing. Invest the time and save the $$$ for fuel.

Iron Horse · 10-06-2014, 05:35 AM

Fire Up, Yes I did the removal and cleaning myself. I tried to take it apart in pieces but discovered that it comes out as a unit, I think it is refered to as a "cool pack" from Freightliner. The allen head screws I found out are metric and very stubborn to remove. I used an impact driver. You put a allen wrench socket on it and hit with a hammer. Allen wrenches come in all different hardness. An Allen Wrench is a true allen wrench brand, guess they invented them, most others are china knockoffs. I replaced the hub bearing from Cat for 58.00. The newer bearing has a different seal. My Son and Grandson helped put it back in. If I do it again I will disconnect the water and cac hoses from the engine instead of the radiator as they are very difficult to access.
Iron Horse

mel s · 10-06-2014, 06:58 AM

Apparently we are all wasting our time.
fergo27, the OP, is not responding!
Someone check for a pulse.

Jupiter · 10-06-2014, 09:17 AM

".... follow the lead by a member that cut a access panel in the fan shroud. Drill a one inch drain hole in the bottom, soak the units with Dawn, simple green and what ever will cut the crud and using hot water spray for hours and take pictures until you can see the bottom."

C-7 350... Yup, this process works. I did this procedure while on the road tripping in the Rockies. Not at all a fun job but it removed a lot (certainly not all) of crud off the entry side of the radiator. Enough so that it never overheated again for the remainder of the mountainous journey. Steam cleaning would have been best but in a pinch the simple green, dawn, long bottle brush and hot water did the trick.

cheers,
Joopy