Community Forums

Bonanza45D · 01-27-2012, 08:30 AM

Quote:

Originally Posted by RLS

You say that the thermostat is new, the 3126 has 2 thermostats. Are you sure that both were changed?

No, I wasn't aware of TWO Thermostats in this 3126 CAT. There was also no mention of that from Wagner, the CAT Service Company that worked on it. I'll investigate that more. I did move the Oil Breather hose immediately upon purchasing the Coach (it was placed poorly originally and easily fixed). Indeed, this Coach is a 1999 with 70K. I suppose the age could be contributing to crud build up, etc, so as to block heat transfer & cooling efficiency.

The one thing I DID NOT do is change out the Water Pump. Wagner said it appears to be moving water nicely. Still, how does one really know? I mean moving water 'nicely' verses moving water 'correctly' may be two different issues. I guess I don't really know how best to test the CAT's Water Pump my self to see if it is really doing it's job correctly. God knows, I've changed EVERYTHING else out thus far. Perhaps a visual inspection of the water pump's impeller is the only proof of condition and hell, by then, I might as well swap in a new pump, huh? THAT was a blunder on my part. I mean, I should have merely swapped out the stupid pump to eliminate that possibility, but upon giving it the visual, it just didn't appear to be an issue.

I don't know what 'dp' means, but according to Wagner, again, the engine is operating per spec, temp wise. The problem is that when the engine goes up into the overheating range (according to the instruments), its shortly followed by the Check Engine light, which is then followed by a de-rated engine computer or 'limp home' mode.

Since I generally operate at 6,500 ft, MSL, this is where I typically experience higher coolant temps. I can't say that I've had much problem with it at Sea Level (because I haven't run it much at Sea Level).

Well, there's a couple of things to follow up on and check out! I appreciate everyone's feedback. No magic bullets yet though.

LKL

Vegasdan · 01-27-2012, 09:11 AM

One other thought, could the temperature sender be defective?

Thewellz · 01-29-2012, 12:50 PM

Hi there I recently experienced your issues while travelling in a mountainous area, I overheated 3 times on one grade! I was a little discouraged... emediatley thought it was a sensor or thermostat issue, but everything was fine even in 34 degree weather on normal grades, I cleaned the rad thouroughly which I know you have done, but also my driving habits greatly contributed to the problem, I Found that keeping the rpms near 2000 was the key for keeping things cooler on mine, after cleaning the rad and adjusting my driving, the same trip back was much better, this is just my experience, on a side note I was shocked at the amount of black crud that came out of my rad when I cleaned it with simle green.

bachler · 01-29-2012, 02:11 PM

The only way that it can be verafied as to the real problem . Is to get under the bed and look at the front of the rad;/intercooler. They have to be cleaned FROM the INSIDE;; The Rad. and inter cooler have two differant Core patterns; And YOU CANNOT see through them.(maybe just a little). It was/is not oncommon for the fan to pick up the engine breather mist;; This is not a new problem; The only thing new is some of the ways of cleaning it out.. (most of them don't work) Only two ways . Cleanfrom the INSIDE . Or remove the Intercooler and clean it. Because that is what blocks up and keeps the air from the rad;; It is simple. Just clean it. >> NOT from the back. It can't be done.. I tryed it; IT cost me $3400.00

Kerry1 · 02-20-2012, 01:46 PM

Great discussion! I have basically the same issue. I have extended my breather tube, had the radiator R & R'd and I clean it using Simple Green from the inside. I downshift and slow down when climbing large hills / mountains. My coach still overheats. It's a '98 Tradewinds with a 3126 CAT. I am of the opinion that a water spray system over the top of the radiator is the best approach. I'd like to hear where you intend to tie into the coachs water supply and what type of valve you would use to turn the spayers on / off. Also, shouldn't distilled water be used for this? Won't tap water result in calcium buildup on the radiator fins?

01 Journey · 02-20-2012, 04:52 PM

Kerry1
Downshift is the key word. But what i think you are doing wrong is slowing
down. You need to remember these radiators do not breath from the front like a car
They only get air from the fan and I think most of your problem is not running enough
rpms when climbing a hill. With my 01 Journey traveling through west virginia not only
would i gear down once but depending on the hill and I would gear down a second time to keep my rpms up to push enough air through the radiator to keep the engine
running cool. Doing this I have never had a overheating problem.

01 Journey 3126 B
2005 Honda CRV Blue 0x

distaff · 02-21-2012, 09:10 AM

I saw a posting on this site about replacement fan blades that were lighter weight and pushed more air. Just did a quick scan and couldn't find it but one of the other readers may know about it. It is a specialized engineering firm.

distaff · 02-21-2012, 09:12 AM

Found it. http://www.irv2.com/forums/f115/sour...hes-86104.html

distaff · 02-21-2012, 09:14 AM

One other suggestion - try a different mechanical shop. Even a good mechanic will get stuck on a point of view and you need someone else to look at it to see what is wrong.

Vintage · 02-21-2012, 10:25 AM

I discovered on my coach that there was originally a piece of material that went from the top of the radiator up to the bottom of the engine bay roof and all along thr top of the radiator.

It had rotted away and was allowing the hot air that had gone through the radiator to recirculate back into the engine bay and then back through the radiator before it even had a chance to exit the grill at the back.

I installed a piece of old tarp material along the same mounting points as before and now I don't get hot even with the A/C on in 100+ temp climbing out of the Great Basin area last summer.

Don't know if you ever had this configuration but you might check.

p.s. Early 3126 CAT only has one thermostat. You can tell if you look at the housing and if it has two humps you have two t'stats.

There was also an early 3126 CAT mod to incorporate a 9 blade fan and shroud modifications to help cooling. See how many blades you have on your fan.

ninos · 02-26-2012, 10:48 AM

I have a 2006 discovery with a cat c7 and last year I took the radiator and cac out replaced all the belts and all roller berings fan bering and both thermostats and I had my cac and radiator tested and the radiator had a leack so I ended up buying a new radiator and it wasn't that expensive was around $950.00 and the old rad and cac had a lot of build up and I looked from outside it looked clean but inside it was very duty, it was quit a bit of work but I did it all and my engine never goes over 192 degrees and I had it on the dyno in hot sumer day and the temperature went to 194 for about five seconds and they push those engines hard on the dyno I spend some money but I'm very pleased with the outcome of the all thing, bonanza if you were a local I wouldn't mind taking the time to go over the all thing with you untill we found the problem because you have a problem some where in the cooling system, good luck with finding a fix to your problem. Joe

336muffin · 02-26-2012, 11:01 AM

Quote:

Originally Posted by Vegasdan

One other thought, could the temperature sender be defective?

I too would check this. Gauges also go bad. A after market gauge could be installed in bedroom, DW could keep an eye on it during a pull to verify.

Bonanza45D · 02-27-2012, 07:29 AM

Thanks for the reply guys.
I too have done just about everything one can do, in regards to the cooling system. What I DID NOT do was to change out the water pump and/or the cooling fan, neither of which have a fault, according to the CAT dudes. I don't believe the gauge is faulty, since so many things start to 'de-rate' when the temp zings up into the red zone.
I intend in following through with my 'water injection system' plans to spray house water down between the fan and radiator, on demand only. I expect I'll get 20-30 degree drops, when I need it most. I will report, on this thread, as to how well it works. LKL

Vintage · 02-27-2012, 10:56 AM

I re-read your OP and I think this is the most interesting thing you posted.

when the engine decides to run hot (which it does for no apparent reason at times on level highways

This seems to me that there is something more going on than what would be corrected by all the suggestions posted so far. It sounds like there is an intermittant blockage of the coolant flow, maybe a hose collapse, or the temp sender is having a fault.

I don't know, but to run hot on level ground and then go back to normal for no apparent reason is not due to a lack of cooling ability or restricted air flow.