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Topic: Understanding 6V92 coolant flow (Read 2551 times) previous topic - next topic

Re: Understanding 6V92 coolant flow

Reply #25 –
When I bought my coach the fans were running on the default hi-speed all the time.  I noticed the blue wire on the fan switch was disconnected.  Re-connecting it made the fan slow down.  Don't know why it was disconnected but I've had no problems since re connecting it.  Also my coolant temp reads about 7 degrees higher  with the Pro-Link than what shows on the dash gauge.

I have a digital tach and will get some reading at different rpms for comparison.

Jerry
The selected media item is not currently available.
Jerry and Cindy Maddux
1993 U300/36WTBI DD6v92TA
build 4271  "Miss Lou"
1995 suzuki sidekick 4x4 toad
Gulfport, Ms

"Pride of Ownership"

Re: Understanding 6V92 coolant flow

Reply #26 –
Quote from: Pierce & Gaylie Stewart –
Looks like the one. Does it have a red wire and black wire close by? I don't have a part number. Since one of the connections is unused , I can post a photo of mine for the connections after you find one.

P
Yes there is a red wire and a black wire with eye terminal ends not attached to anything
91 GV U300 Unihome 40' Build 3811
6V92TA Detroit

Re: Understanding 6V92 coolant flow

Reply #27 –
OK, here it is. I can't get the split loom off to see the colors but I don't think it makes any difference.  Remove the old one and try NAPA with a photo of mine too.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Understanding 6V92 coolant flow

Reply #28 –
Quote from: Pierce & Gaylie Stewart –
You have the single fan and vertical radiator as I remember on your 1992 coach? Ours does not seem to default to high speed.
Yes mine is the single fan vertical radiator. I assumed all would default to high speed as a safety measure. Makes sense to default to max cooling not min cooling. Yes you will burn more fuel but you are less likely to burn up your engine. (for the inattentive)

see ya
ken
The selected media item is not currently available.ken & dori hathaway & Big Agnes
🍺1992 U300 GrandVilla WTBI #4150 FOT FBP 2011
✨6V-92TA DDEC Parlor Coach 350HP Series 92
🏁2011 Nissan XTerra Pro-4X

Re: Understanding 6V92 coolant flow

Reply #29 –
Looking at the switch picture it is normally closed. Ths would let fans run on slow speed until temp opened switch and fans should then run high.In Tonys coach switch is disconnected which should make his fans run on high all the time. Which leads me back to my original diagnosis of clogged radiator. Temp difference on supply tubes to return is almost 60 degrees  return being 110 to waterpump.
91 GV U300 Unihome 40' Build 3811
6V92TA Detroit

Re: Understanding 6V92 coolant flow

Reply #30 –
I am not familiar with the Detroit, but my knowledge of cooling systems tells me you are seeing what the radiator is supposed to do. The water comes in the top hot and goes out the bottom cooler otherwise the engine would just keep getting hotter.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Understanding 6V92 coolant flow

Reply #31 –
Quote from: craneman –
I am not familiar with the Detroit, but my knowledge of cooling systems tells me you are seeing what the radiator is supposed to do. The water comes in the top hot and goes out the bottom cooler otherwise the engine would just keep getting hotter.
The coolant tube going to the radiator only get hot about 3/4 of the way down to the radiator.  At that 3/4 point temp drops about 35 degrees .there are 2 inlet tubes one from each head t stat housing.  It is almost like yhe coolant cannot enter the radiator. The two tubes that come to the radiator the upper tube us hotter than the lower tube by  quite a bit. The return tube never got over 110 on BBC temp gun.you could hold hand on lower rad  hose.
91 GV U300 Unihome 40' Build 3811
6V92TA Detroit

Re: Understanding 6V92 coolant flow

Reply #32 –
 
Quote from: stump –
It is almost like yhe coolant cannot enter the radiator. The two tubes that come to the radiator the upper tube us hotter than the lower tube by  quite a bit.
Stump,

This is starting to sounding like the impeller in the water pump is slipping on the shaft or has eroded away and has lost some of its discharge volume.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Understanding 6V92 coolant flow

Reply #33 –
Yes, sounds like poor circulation.  Water pump missing fins, restriction, etc. 
 Remove the cap , fill it right to the lip, start the engine and rev it a little . Water should push out some if the pump/system is moving water.

Re: Understanding 6V92 coolant flow

Reply #34 –
Quote from: stump –
Looking at the switch picture it is normally closed. Ths would let fans run on slow speed until temp opened switch and fans should then run high.In Tonys coach switch is disconnected which should make his fans run on high all the time. Which leads me back to my original diagnosis of clogged radiator. Temp difference on supply tubes to return is almost 60 degrees  return being 110 to waterpump.
Yes, Stump and Ken are correct and with the wires off, it should run at high speed all the time. The solenoid valve should be checked to make sure it's operating correctly.

Stump, is that when you are at idle or have driven the coach until it's up to temperature before shooting with the IR gun?

Moderate difficulty removing both thermostats as while they are visible, you have to remove a few things above to R&R them. I remember Ken looking at removing his at Q a couple of years ago.

Water pump is internally driven and not a big deal to change.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Understanding 6V92 coolant flow

Reply #35 –
To remove thermostats you need to remove the bolts from the EMS and lift it up a bit. Some of the bolts are a bitch to get to IIRC.

see ya
ken
The selected media item is not currently available.ken & dori hathaway & Big Agnes
🍺1992 U300 GrandVilla WTBI #4150 FOT FBP 2011
✨6V-92TA DDEC Parlor Coach 350HP Series 92
🏁2011 Nissan XTerra Pro-4X

Re: Understanding 6V92 coolant flow

Reply #36 –
Quote from: kenhat –
To measure fan speed you can use one of these cheap tachometers. You place a provided reflective strip on the fan blade and point the device at it. Do idle and WOT. Post results here for group feedback.  >:D

see ya
ken

Ken,
Here's my results from todays' test.

I have a cheap Cen-Tech tach from HF ($40) and it does the job.  Digital Photo Sensor Tachometer
Fun part is crawling under a hot coach with it idling at 1000 rpms and holding the tach close enough to the fan blade to get a good reading with no ear plugs!  I used the Pro- Link to get fast idle and I have the twin side mounted fan blades.

                                                                                         

(cold)  Engine RPMs      Fan RPMs low speed (blue wire connected)    Fan RPMs Hi speed default( blue wire disconnected)
                  600 (idle)                              87                                                                    775
                1000 (fast idle)                      154                                                                  1245

(warm)        600 (idle)                              92                                                                  1245
(180 deg)  1000(fast idle)                      188                                                                  1245

(after 50      600 (idle)                            775
mile run      1000 (fast idle)                  1245
187 deg) 

(after 5 min    600 (idle)                          270                                           
cool down)                                                         

Jerry                         

                         
The selected media item is not currently available.
Jerry and Cindy Maddux
1993 U300/36WTBI DD6v92TA
build 4271  "Miss Lou"
1995 suzuki sidekick 4x4 toad
Gulfport, Ms

"Pride of Ownership"

Re: Understanding 6V92 coolant flow

Reply #37 –
Quote from: coastprt –
Here's my results from todays' test.
Those numbers look pretty good to me. I would add a WOT test so you know the max possible and use that number as a basis to compare future numbers. Max rpm possible is the number I would worry about. Only do this after you are completely warmed up. Rest stops on the Interstate are a good spot to test. Don't recommend doing it in the campground. :)

see ya
ken
The selected media item is not currently available.ken & dori hathaway & Big Agnes
🍺1992 U300 GrandVilla WTBI #4150 FOT FBP 2011
✨6V-92TA DDEC Parlor Coach 350HP Series 92
🏁2011 Nissan XTerra Pro-4X

Re: Understanding 6V92 coolant flow

Reply #38 –
What temperature do you see on each coolant tube going to the radiator. And what temp do you see on the return tube to the  water pump? After engine is at operating temp?
91 GV U300 Unihome 40' Build 3811
6V92TA Detroit

Re: Understanding 6V92 coolant flow

Reply #39 –
Quote from: stump –
What temperature do you see on each coolant tube going to the radiator. And what temp do you see on the return tube to the  water pump? After engine is at operating temp?
I don't have those numbers. Can get them next time we are on the road but that won't be until end of October. :(

Edit: Or were you talking to Jerry?

see ya
ken
The selected media item is not currently available.ken & dori hathaway & Big Agnes
🍺1992 U300 GrandVilla WTBI #4150 FOT FBP 2011
✨6V-92TA DDEC Parlor Coach 350HP Series 92
🏁2011 Nissan XTerra Pro-4X

Re: Understanding 6V92 coolant flow

Reply #40 –
Ok guys, i ran a test today on coach. I started her up today with the outside temp at about 86f, i put a pair of vise grips on the two eye terminals and the fans went to the low mode. so the siloinode works as it should. just need to get a switch. after running for about 2 hrs. the temp gauge showed 184. the inlet for top of radiator was showing about 198f bottom of radiator was about 192. i then took the vise grips off to turn fan to high speed which it did. t stats seem to open about same time. inside gauge dropped to 178. top radiator was about the same bottom about 130. not sure if the t stats are working properly ( maybe sticking) not sure, or the radiatior might be partially plugged.
Tony n Denise 1994 U-300 SE detroit diesel 6v92 jake

Re: Understanding 6V92 coolant flow

Reply #41 –
Quote from: stump –
What temperature do you see on each coolant tube going to the radiator. And what temp do you see on the return tube to the  water pump? After engine is at operating temp?

Stump.

Here's the readings I got yesterday after a fifty mile run with ambient temperature outside about 90 degrees:

After cool-down at 1000 rpms and idling at 600 rpms:

Coolant temperature checked with the Pro-Link was 187 degrees.
Temperature at the Hi- Lo fan switch was about 184.  Fans running at low speed.
The tube on the right side about 171.
The tube on the left side about 159.
Temp at the water pump was about 168.

After idling back up to 1000 rpms and the temp on the Hi- Lo fan switch reached 190 the fans kicked into the high speed.
When the temp went back down to 187 the fans went back into low speed.

Jerry


The selected media item is not currently available.
Jerry and Cindy Maddux
1993 U300/36WTBI DD6v92TA
build 4271  "Miss Lou"
1995 suzuki sidekick 4x4 toad
Gulfport, Ms

"Pride of Ownership"

Re: Understanding 6V92 coolant flow

Reply #42 –
Quote from: Old phart phred –
My cheap IR gun is also a little wall eyed and sensor doesn't quite line up with Lazer pointer, especially on round targets.
Especially on pipe targets,  lots of beam scatter, i use it quite often on pipes and it's really tough to get a consistant good reading.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake