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Ron & Dee · 04-26-2009, 01:07 PM

I have posted about this before when I had my radiator flushed and new coolent and thermostat installed and now my temperature gage reads higher than it did before. I am also having to add coolent more often than before.

I took the motor home back to the people that did the work to have them check for a leak and see if they could find out why my temperature gage is reading a little higher. They couldn't find anything wrong so I took the motor home to a qualified Workhorse Service center to see if they could find anything. They could not find anything and said the temperature was running normal.

I am getting ready for another trip to the west so I'm seriously thinking about getting a scan gage to monitor my engine temperature. What kind of readings should I be looking for.

Thanks,

Ron

edgray · 04-26-2009, 02:42 PM

Ron: on my stock 03 8.1L, with original radiator cap and thermostat, my OEMY-programmed Scangauge II reads (after full warm up ) from 195F to 106F, at which time the FCA pulls on the big roaring fan and the temps go back down to ~ 198F pretty quickly and quite running returns. Recently, while coasting down a prettty long descent in ambient temps below 40F, I saw the SG display 185F, which has me thinking the thermostat isn't closing completely. Since I'm a firm believer in not breaking things that don't need fixing, I do have a plan to not do anything about the potentially "leaky" thermostat.

The best part about the OEMY-SCAN Gauge is that you can observe engine coolant temp & Tranny temp, plus two other "less important" readings, all simultaneously. I don't leave home without it. ED

dieselclacker · 04-26-2009, 02:53 PM

Ron, as I see it, there are a couple of possibilities here for the higher operating temps after the flush coolant and thermostat change you had done on your rig. First possibility is just a slight variation in degrees between the two thermostats involved, perhaps the new stat is reading a bit higher than the old one. Second possibility, how much was the percentage of coolant to water that you had installed. A higher percentage of coolant than was previously installed will also cause engine to run a little warmer than it did before. Check and make sure a mixture of 50/50 coolant to water was installed in your rig.
As to having to add coolant more often than before, you should very rarly if ever, have to add coolant to your engine. I would have a pressure test done on the cooling system to see if there is an external leak such as at a hose clamp, block plug etc.

Dieselclacker

Ron & Dee · 04-26-2009, 05:13 PM

Ed,

Thanks for the temps to look for.

Dieselclacker,

They did put in 50/50 coolant, and the system has been pressure check twice with no apparent leak.

Before the coolant and thermostat change I very rarely had to add coolant but now I have to add quite often.

I'm hoping that the temperature change I'm seeing is because of the new thermostat, even though seeing the change on my temperature gage is driving me crazy

Thanks,

Ron

DriVer · 04-26-2009, 08:40 PM

Quote:

Originally Posted by Ron & Dee

Before the coolant and thermostat change I very rarely had to add coolant but now I have to add quite often.

Ron & Dee, I have been told by many techs that if this condition exists check for a leak. I had a leak from my block plug that would only leak under way. Sitting, there were no drips, runs or errors.

Quote:

I'm hoping that the temperature change I'm seeing is because of the new thermostat, even though seeing the change on my temperature gage is driving me crazy.

I am curious but where are you seeing the temperature change? If there is any upward movement on your IP needle there is something definitely going on that requires more investigation.

Although this many not be likely, we have spoken about burping the system so that it doesn't contain air. Air can be introduced by replacing the coolant and thermostat but that event is not all that easy to recreate.

edgray · 04-26-2009, 08:57 PM

RON: If you can find no sign of an external leak, then the need to keep adding coolant is most likely due to air that got trapped in the system when they did the flush. As this air works it's way up and out, the level in the recovery jug may or may not go down. There is actually a WCC bulletin out on this subject, so this is not just my theory.

The proceedure is to wait until the unit is cold, then remove the radiator cap. IF you don't find coolant up into the neck of the radiator, it is low and you should fill it with a 50/50 blend to top off the radiator. It may be this low coolant condition that is causing you to see a sightly higher temp on your gauge. At this time you should also fill the recovery jug to the "cold" level and replace both caps. Make sure you align the arrows on the radiator cap so they point inline with the rubber hose going over to the recovery jug. If the cap is not properly aligned, the fluid may not flow to and from the jug as needed. After driving the coach again, re-check the radiator level again, even if the recovery jug is unchanged. You may need to repeat the process several times to ensure all the air is finally "out" Please be sure to wait until the radiator is cold before removing the cap each time-this is for your saftey and to give the system time to "suck back" from the recovery jug---if it can. Eventually, you should have no more need to keep adding coolant, and maybe your temps will return to "normal" too. Don't forget to align the radiator cap with the overflow tube. Good luck, and please let us know if this works for you. Thanks, Ed

edgray · 04-26-2009, 09:04 PM

DriVer: I must have been typing mine when your reply posted. Sorry.

I'm guessing Ron has the analog gauge on his 02, and thus he would be seeing real temps, not programmed "normal" like the later models. ED

DriVer · 04-26-2009, 09:19 PM

Quote:

Originally Posted by edgray

I'm guessing Ron has the analog gauge on his 02, and thus he would be seeing real temps, not programmed "normal" like the later models.

ED, I do recall seeing some movement in the temp gauge on my 01 now that you mention it.

Good job in presenting the burping process. Usually I just throw them over my shoulder and pat em' on the back.

Ron & Dee · 04-27-2009, 02:52 AM

Quote:

Originally Posted by DriVer

Good job in presenting the burping process. Usually I just throw them over my shoulder and pat em' on the back.

that's a good one

I'm well aware of the burping prpcess since my wife has an in home daycare. Surely the air should be gone by this time after several hunderd miles of slapping on the back

The air pockets is one of the first things that was mentioned by the people that did the change. I will have the Workhorse Service Center check the block plug.

As far as the change in the indication on the dashboard gauge, it is only one needle width higher, but being a gauge watcher like me it's driving me crazy.

Ed,

Taking the cap off of mine is no easy job. I have to loosen the air horn and move it out way every time I take the radiator cap off, and that's no easy job for a short guy like me

Ron

John350 · 04-27-2009, 02:43 PM

I copied this from my post on April 2007. Hope this would help.

A few coolant facts.

Installed coolant gage. (Instrument Panel Factory)
1st mark = 147 deg F.
2nd mark = 167 deg F.
3rd mark = 189 deg F. This is the halfway mark. It will stay there until bad things are happening.

Workhorse minimum engine fan engagement spec. = 178 deg. F.

Engine fan comes on when outside temperature is around 86 deg F. Fan will come on with engine coolant temp at the 206 to 208 deg. F range. The engine fan reduces the engine coolant temp from 208 to 201 deg. F. When the radiator out (Backside of radiator) air temp reaches approximately 180 deg. F at the fan thermostatic coil, the fan energizes reducing the radiator outlet temp to 150 deg. F. In the high 80 deg. ambient temp range, it does not matter whether the AC electric fans are on or not. If the AC electric fans are on, the radiator out air temp increases. No engine misfires are occurring. Radiator is full of coolant. This is for the most part flat level ground driving in the 65mph range. I am reading the radiator outlet temp using a thermocouple. The balance of the data is from the engine computer.

I have directed the inlet airflow to the radiator by blocking the airflow from open gaps but leaving airflow around the PCM and TCM. This seemed to have little or no affect on improving airflow through the radiator.

Going to a cooler thermostat in my mind is a waste of time whereas it appears that the production 190 deg. F stat is full open. It appears that the radiator capacity is limited for the engine loads.

Is there anything else I can do to minimize the engine fan coming on? Or am I stuck with it???

2003 W22 Chassis with Tiffin Allegro Bay coach.

John

JimElliott · 04-27-2009, 03:26 PM

Is there anything else I can do to minimize the engine fan coming on? Or am I stuck with it???
2003 W22 Chassis with Tiffin Allegro Bay coach.

John

John, A 6 inch "air dam" spread across the lower bumper OR just in front of your radiator will create a lower pressure in the engine compartment and force more air through the radiator.....
I placed every item that created some turbulence/blockage of the airflow on the side panel totally away from the radiator.
With the summer temps of 115º plus in the lower desert the cool down starts around 35 MPH and at 60 MPH the engine fan stay off even when climbing the majority of hills.....
The engine fan picks up speed at a stop signal but within a few moments of driving I can hear it drop off.....Good luck with you project..

Jim

Father Mulcahy · 04-27-2009, 05:39 PM

Jim can you explain more on the low pressure idea??

JimElliott · 04-27-2009, 05:58 PM

Quote:

Originally Posted by Father Mulcahy

Jim can you explain more on the low pressure idea??

Most cars today have the "air dam" right below the radiator or in the vicinity, Blocking the air down low builds up a high pressure zone on the nose of the vehicle then it passes through the radiator while creating a low pressure in the engine compartment......

On my older RV (83) the gaps on the radiator sides just allowed the air to bleed through sooooo with a 4" gap on the passenger side and a 3" gap on the drivers side a strip of rubber was screwed on each side and along the top of the radiator another 3" was bolted the entire width......Everything now goes through the radiator.....

Ever notice the "Nascar" machines?
Their front ends are just above ground level and at certain tracks the nose clips get ground down a dab

The heat here is a perfect testing ground plus the east & west bound I-10 out of the Coachella valley works the cooling hard....

Jim

John350 · 04-27-2009, 06:52 PM

Jim, thanks for the info on airflow. My w22 chassis with a 2003 Tiffin Allegro Bay has a U channel just above the stabilizer bar. It is about 36 inches in length. You mentioned 6 foot??? If I attach to the U channel, this is located just underneath of the fan shroud it would give about 36 inches. There is much stuff on either side of the ends of the channel. How did you get 6 ft??? I would think you would want the air dam not in front of the radiator.
Thanks again. John