Overheating

[C20]

See signature for make and model. Isc 425 cummins.

Have overheating issues in stop and go traffic. Fine on the highway even pulling the trailer loaded. So I take it to the local Kenworth dealer and they replace the thermostat. Cost $2200. Damn! I told them I didn't think the fan was running because last time it overheated I was backing in the garage and didn't hear it running. I can't tell driving down the road if it's running or not but can usually hear it in the garage.

Seems to me if it was a thermostat it would overheat on the highway.

So on the way home get stuck in traffic on the interstate. Stop and go and guess what? Overheated!

Took it back to the shop and they are checking it out. Any ideas? Pretty pissed off about right now!

Btw, I cleaned the CAC twice so know it's not that.

[Mr_Mark1]

C20 wrote:
Update 2:

Picked it up today and all is good. MHC Kenworth gave me a full refund on the labor for the first fix. I paid for the parts, then just charged me for the temperature sensor and labor. I couldn't be happier with the outcome. I felt like I was treated very fairly and honestly. They made the offer to drop the labor.

That seems like a very good outcome. Let us know if it runs like before.

Safe travels,
MM.

[C20]

Update 2:

Picked it up today and all is good. MHC Kenworth gave me a full refund on the labor for the first fix. I paid for the parts, then just charged me for the temperature sensor and labor. I couldn't be happier with the outcome. I felt like I was treated very fairly and honestly. They made the offer to drop the labor.

[Ivylog]

"I'm saying I should get the money for the first work refunded."
While I agree with you, it ain't going to happen. I would ask for half of it back as they MIGHT do that. Keep us informed on what happens $$$$.
Hanko, thanks for letting us know you are glad you bought a gas coach... very helpful.

[wolfe10]

bluegypsy wrote:
Our overheating was caused by the fan clutch.

While a very few rear radiator coaches DO have fan clutches, the vast majority are direct drive.

Sure easy to tell-- with engine off, reach in from above or below and if you can spin the fan by hand, it is clutched. If not, direct drive.

[C20]

Update:
The shop called and its a bad temperature switch. So of course my question is I didn't need a thermostat? So I should get a refund on that and pay for the switch and labor. Long pause on the phone and say come drive it and make sure it's ok.

I'm saying I should get the money for the first work refunded. We'll see what happens tomorrow.

[ridin_with_the_]

Don't know about your coach. On my Alfa there is room between the CAC and the radiator for grass,wrappers,random******to be sucked up and acculate. This will reduce the air flow. Also both the CAC and radiator can get oil and road grime build up. Both of these make my coach overheat then suddenly work fine only to overheat again later. The fix was cheap but requires abit of crawling around. Use compressed air to remove the debris between the CAC and radiator then pray a degreaser on both the radiator and CAC. Let it sit for a few minutes, spray off from both sides. Use a strong spray nozzle.

[bluegypsy]

Our overheating was caused by the fan clutch.

[hanko]

Ivylog wrote:

hanko wrote:
$2200 to change a thermostat? That aint right

$2200 to put in a $48 thermostat, bend way over. $100 for new antifreeze so you paid for 20 hours of labor? And you took it back there?
You've owned it for over three years so this sounds like a new problem. Just using water from the wrong direction is not going to clean the radiator or the CAC.

just another reason I bought a gas coach.

[YC_1]

Ditto on the tip about putting the tranny in neutral when stopped for a time. I found this when waiting for an accident to clear. My radiator is pristine and have a new thermostat as well as a freshly flushed radiator.

[wolfe10]

Yes, if stopped in traffic, put the transmission in Neutral.

And, if it overheats then, use foot or cruise to bump to 1000 RPM or so (though this really should not be necessary).

[Ivylog]

If stopped in traffic for over a minute, you need to put the tranny in neutral. When stopped the torque converter is slipping creating heat and at idle you are not getting enough air flow.
Since this is a new problem and it does not do it at speed with the trailer, you need to clean your radiator/CAC better. Not sure if you have a crank case vent tube, but if you do you may need a slobber hose added to it to keep oil from getting into the radiator's fins. Do a search on cleaning and slobber tube for more info.

[wolfe10]

sch911 wrote:
I fail to see how the cleaning of the CAC helps engine cooling? On mine the CAC and radiator are in parallel. Wouldn't you need to be cleaning the radiator?

With a rear radiator (likely Freightliner chassis) the CAC is in front of the radiator. The two are in SERIES. Dirt is "filtered out" by the CAC. So the front of the CAC is what needs to be cleaned.

Usual way is to clean from above (bedroom/closet access).

Blocked air flow into the front of the CAC also blocks air flow through the radiator.

[C20]

I agree it's high. To access it they had to take the bed apart and use the panels in the floor. I know they had a lot of labor hours in it. Plus I didn't know they had to do that and had a bunch of clothes and in between trip stuff on the bed they had to move. Credit to them it was all put back right and even remade the bed. No greasy paw prints inside either!

When they get done if it turns out to be the fan switch we'll. be talking about a refund for the difference in labor hours.

[Ivylog]

hanko wrote:
$2200 to change a thermostat? That aint right

$2200 to put in a $48 thermostat, bend way over. $100 for new antifreeze so you paid for 20 hours of labor? And you took it back there?
You've owned it for over three years so this sounds like a new problem. Just using water from the wrong direction is not going to clean the radiator or the CAC.