I would like some input from you all. The operating temp on my DD is as follows ambient temp at 82deg towing my jeep @ 62-65 mph 197-205 not towing 190-200. This last short trip which was about 60 miles back home the temp was steady at 190 for about 35 of the 60 miles then it creeped up to at one point 200 for no real reason then came back to about 197. Strange fluctuation and I am paranoid about overheating the engine. Temp range in the owner's manual states operating temp 160-205 depending on load hills etc. Additionally it states max temp before a shutdown commences is 215 deg. The water pump has been replaced the Alarmstat fans witch has been replaced to a 185 deg switch (from what I'm told it either on or off no lo and hi). My understanding is the DDEC computer dictates when the fan comes on and off? Both fans are operating I have checked that. Fresh coolant as well. Concerned when we have 95 deg days it will get considerably hotter. Cools down fairly quickly when you slow down too.
Thoughts?
Thanks,
Woodie
My dash gauge is not super accurate and varies with voltage, like when I turn on the headlights. I have shot my engine with an IR temp gun at various points, engine heads, block, radiator, oil pan and my temp readings are consistently several degrees lower than the dash reading and within Foretravel recommendations. I would recommend getting an IR temp gun, they are inexpensive and you could check your engine temp readings for peace of mind. Also useful for shooting tire and brake temps.
I agree with Peter. The OEM gauge after 20 years is not very accurate and it certainly doesn't have good resolution on the dial either. It works by measuring resistance and old wiring will start building up contact resistance. I switched my gauge to a Nordskog digital but it is still not very good since it's the same resistance technology. I have a Silverleaf (Welcome to SilverLeaf Electronics | SilverLeaf Electronics, Inc. (http://www.silverleafelectronics.com/node/1)) that reads the DDEC directly and the dash gauge always reads higher. In fact the delta between the two increases to as much as 15 degrees at the higher temperatures - just when need the accuracy the most. The temp sensor on the DDEC is considered to be much more accurate and is the value to trust.
In regards to the fan controller, I recall other side radiator guys talking about a thermo-valve in the hydraulic circuit. I don't think I have ever heard of the DDEC controlling it. I have no direct experience on this since mine is a rear radiator; no hydraulic fans. Hopefully other '92 and later 6V92 people will jump in here.
I'm sure others will chime in, but temp running between 190-200 steady ( if your gauge is right) is closing in on the hot side. I would think 180-190 steady would be better. Back in my trucking days 190 was hot on the 12v and 8V92's. You might try spraying your radiator with a soapy water let it sit a bit and wash it out good with a hose sprayer.
X2 on the radiator cleaning. I hooked my hose up to hot water, and sprayed it good, back and forth multiple times - a lot of crud came out...possible it had never been washed...
The v92 series detroits are wet liners with liner seals that are very sensitive to overheating. The normal shut-down temps of other diesel engines are likely too high. I've heard 210F is absolute do not exceed on the 6v92.
Besides an IR gun order a Amazon.com: AGPtek® Professional Digital Laser Photo Tachometer Non Contact... (http://www.amazon.com/AGPtek%C2%AE-Professional-Digital-Tachometer-Contact/dp/B004Q8L894/ref=sr_1_3?ie=UTF8&qid=1461725678&sr=8-3&keywords=rpm+meter). You have all the symptoms of low fan speed. The only way to know for sure is to measure it. Low fan speed usually means a failing hydraulic pump or fan motor.
I would also check the hydraulic pump for leaks. Look behind the pulley and follow the shaft back to the pump. Right at the seal is where you would see oily dirt attracted by a leaking seal.
Good luck. Post or PM me if you want more info.
see ya
ken
I see that. I wonder how inaccurate the dash gauge must be?
Or the conventional wisdom may be different with the light loading that a unihome applies?
Plus the heat was not for hours and hours.
After all these years would be fun and informative to hook a silverleaf up to see what was really what. I would for sure versus creep up hills?
Based on the dash gauge and factory safety setup I have tested these 50 times at minimum
Your setup sounds like the one Kent Speers has in his 93. The fan is always on and speed varies with engine speed. Easy to check. Verify fan spins at idle then have someone hit the throttle. Should increase to hurricane speed at full throttle.
see ya
ken
Woodie,
I have the same side dual fan setup as you with a Hi/Low(190 degree) fan speed switch. Normal temps for me is 187-190 checked with the Pro-Link. My dash gauge actually reads about 7 degrees lower. The fan speed will vary with the rpms and the thermostat will take over at higher temps when that threshold is reached. When that temp is reached even at idle it should kick in at hi-speed. My hi/low fan speed switch was disconnected to run on high all the time before I bought the coach. You can also pull the 10A AUX PUMP/HYD FAN fuse in the dash to set the switch to default(high at idle). I reconnected it to save hp and pump wear and tear. I've tested the fan speeds with a digital tach at various speeds and my results were less than the factory specs that Kenhat sent me. I believe this is a result of a twisted hose to the pump I discovered but haven't replaced yet. I haven't checked the pump pressure, but I did check the fans with the engine off for resistance to make sure they were working and the Hyd oil reservoir to make sure it was full.
Bill Chaplin changed his thermostats and it helped his fluctuating temps return to normal.
My hyd pump was replaced and fan motor pump rebuild kits installed back in 07 by the PO. The work was done by Ray Thompson Auto Service, Inc. in Dothan, Al (334-794-7272). Ray is a great guy, old school, and an avid motor-homer. He likes Foretravels and told me that he tried to buy mine from the PO back then! He said he would be glad to discuss your situation.
Jerry
interesting variations in the cooling system controls.
My 97 has no electrical low-high. Straight mechanical variable speed fans.
I changed the 190 max temp fan speed controller to a 210 unit recently.
Stock Fan is always on at idle speed. Ramp up starts at 175 and max at 190 as far as the charts I have seen.
New unit same idle rpm but starts its fan speed ramp up at 195 and maxes at 210.
Thermostat does not fully open on my m11 until 195.
Truck cooling fan electrical switch on the m11 does not turn the trucks front fan on until 210.
Cooling fan on fully takes over 40 hp. Up to fifty at high rpms and makes the oil in the system hotter according to my cummins shop foreman.
Probably does not help the fan motors life expectancy running on high all the time.
Oh well testing this summer may show something. Long term better mpg and not much additional heating indications would seem to indicate I may be ok.
Had intermittent much higher mpg on the silverleaf show. Cooling system was finally at idle low speed for long enough to jump up the mpg IMO.
IMO Foretravel over did the cooling systems on points and added a pre cooling circuit just to try to keep the dash gauge from moving as much as possible.
Too many phone calls any other way.
As the posts here show every diesel owner is very concerned about any heating indications.
I had as I have said had countless conversations with rightly concerned owners about these issues.
Frankly I am not concerned if the gauge moves quite a bit under hard use and high temps and a grade.
I have passed numerous Rvs pulled over on grades in the last thirty years probably because the temp gauge moved off the peg.
mostly unnecessary. And somewhat unsafe IMO.
Had a guy with a new rear radiator multi slide sob run with me two years ago coming up from needles on I40 at 102 ambient outside.
Long uphill grade. I was floored. My dash gauge hit 215- 220 or so and stopped rising.
I noticed he finally dropped back in the next lane. Bet a dollar his temp gauge moved enougn he got uncomfortable.
Turns out my dash gauge is high versus the silverleaf. 10-15 degrees.
I never really went past 205 internally.
Tested my own coach after purchase up from the east into the Grand Canyon from the desert floor.
Dash got to 230 or so and stopped. Turns out it really was 215.
Now, long term 6v issues may well be different but I doubt it. Was not when I tested them new.
The extra controls were later discontinued on my m11 it seems.
Ah. I have no idea if the radiators are differently sized or the heat output from a 6v is lower or higher.
Needs a silverleaf verification and careful testing maybe.
My old testing was with company and/or manufacturers engineering reps in the coaches at times.
Do not do anything you do not feel comfortable with.
Perfect condition cooling system is necessary obviously.
Fun learning. Scary I know but the better safer driving was important to a lot of my owners.
The story I did not like to hear was a different not as pretty route selection based on the engine temp gauge.
Valleys instead of the ridges stuff.
Seen that too many times for me not to speak up a bit.