Waterwetter for diesel coolant [Chasing MCI engine heat]

[plyonsMC9]

Thanks Gary -
Water pump was replaced.  As you mention - could have been an impeller issue.  Kevin took care of that.  And he had an innovative approach to that troubleshooting; baby (TV) monitor in the engine compartment, which gave a view of multiple gauges, including the trans temps.  That temperature was within spec.  It was interesting watching all the gauges and temps from the driver seat.

Best regards, Phil

[plyonsMC9]

For the life of me I cannot find the automatic shutdown high temperature for a 111 my series 60-12.7 DDEC IV in the truck it would shut down at 228F and reduce power @224F and he is reading 230F.

If you need to add coolant on a regular basis with no visible leaks, then a compression leak into the cooling system comes into play,those engine had a service bulletin issued for new head bolts to stop that

Thanks Cliff - after J&R found a leak in the temp sensor I have no more issues w/ coolant loss.  Very nice to have that fixed. 
Using the bypass setup they installed, we drove through Desert Center & Needles CA yesterday when it was about 115 degrees.  I had much more success as long as I kept the speed down to around 55.  This is an improvement.  The bypass consists of putting the radiator fan in TEST mode.  TEST mode forces the fan to run continuously vs.  on/off depending on temp.  And a couple of valves which force the shutters (louvres) open.  Temps with bypass in place throughout the day and low speeds were 190-220.  I had to pull over once when we were over 220. 

I'm going to test w/ the tach to compare radiator fan speed vs. MCI spec.  Verify whether the fan is moving at the proper RPM. 

I remember years ago when this bus was the current model, watching them run passenger services, blowing by me on the freeway at high rates of speed.  What happened between the time when it was running passengers, down the freeways at 75 MPH and now when I'm messing around trying to keep it at 55?   I don't ever remember seeing DL3's slowly going down the freeway with flashers on...  heat or no.   I just wonder.

Thanks all!, Phil

[luvrbus]

Some one could have replaced the OEM fan with the wrong pitch and blades count to, those plastic fans were not very durable on the early D models

[plyonsMC9]

Thank you Cliff, that’s definitely something I had not considered.  I shall add it to my list of items to figure out. 

We’re in Colorado now and I had to pull over 3 times to keep from shutting down coming up from Grand Junction to Estes Park through Golden.  Long 6-7 percent grades, up to 10,500 & 11,600 feet elevation.  Definitely was not speeding.  🤨.

I believe heat is now just an issue at the more extreme conditions but not certain yet.  I’ll have plenty of chances to test in these next few weeks.  Want to get this resolved before journeying up to Alaska.

With best regards, Phil

[plyonsMC9]

Re:  Some one could have replaced the OEM fan with the wrong pitch and blades count to, those plastic fans were not very durable on the early D models

I heard from a tour operator up in Colorado that one of their "new" MCI's (F series) fan had a blade detach and shoot through the radiator, totaled the radiator for sure. 

Regards, Phil

[plyonsMC9]

Update:  Drove several weeks cross country.  From Colorado out to Kentucky, then back through the southern states to AZ eventually.  Never had a serious overheat issue again.  Though, heat does seem to accumulate.  And the radiator fan seems to labor.  I spoke w/ MCI tech for quite a while a couple days ago.  He'd worked on about 80 - 90 of them.  In his experience the air should about blow you off the ground when it is operating properly.  Well that isn't what I experience.  Air seems to leave up & towards the center of where the intercooler and radiator are position, if you're on a good sized ladder in back of the bus while it is running. 

I've never been able to override the radiator clutch and lock it on.  The tech suggested that a sluggish / slipping clutch could be an issue. He also suggested checking vales - if they are too tight could generate heat as well.

I did request the correct RPM speed of the radiator fan.  He said that was the first time he'd been asked that, and after a lot of searching he was not able to find that number.  Either way, he spent a long time w/ me on the phone.  Most of his suggestions, we had already gone through.  But it was a good confirmation.  Glad to have been working w/ the mechanics that went through a lot of that for me.  Along with the good suggestions from the forum.  And I'm likely going to have the radiator fan clutch replaced.  Possibly at the MCI shop in So. Cal.  And have them eyeball the bus per spec if I can get that done re: the engine cooling system.

Steve at International Bus Parts has vented engine doors for the DL3, but I'd really like to nail the overheating issue.  Ditto for adding a "mister" system. 

So that's the update after our cross country trip & back.  Thank you for any suggestions!, 

Kind Regards, Phil 

[Iceni John]

Last year while the engine was out of the bus I took the MultiWing 9-blade fan off the motor and changed its blade pitch from the original 37.5 degrees to 45 degrees (the maximum recommended by MultiWing) to pull in more air.   The first test drive showed that the opposite was happening, with temperatures no lower than before and with a lot more fan noise:  the hydraulic fan motor was working much harder, and its hydraulic fluid was 10 or 15 degrees hotter than normal.   (I can also read hydraulic/PS fluid temps on my transmission temp gauge, and I can also read oil temps on my coolant temp gauge.)   So, out with the fan again, a PIA to do when the engine's in place, and I set the blades to 40 degrees.   No more jet engine noise, much cooler hydraulic fluid, and most importantly several degrees lower coolant temps.   Yeah!   So, the moral of the story is to not pitch the fan blades too much or they'll just create inefficient airflow;  maybe that's what compressor stall is in aircraft jet engines?   Everything's a learning curve!

John   

[plyonsMC9]

Thank you John.  You motivated me to check the fan pitch.  Which following the following formula, is just shy of 22 degrees.  7 blades.  For width I used the widest part of the blade, as the blade is not as wide near the hub as it is near the outer edge of each blade, moving from about 4 1/4 " wide to 5 1/4" wide. 

Height / Width * (180)/ 3.14159
Height (2") / Width (5 1/4") * 180 / 3.14159


The fan does look pretty wimpy next to the intercooler fan, and the center of each blade has been chipped as if it had hit a shroud at some point.  But maybe this is a standard look for the MCI DL3-45 fans.  Not sure.

That's a lot less than your pitch John, but that could by design. 

If anyone reading this thread has a DL3-45 or similar could send a picture ?  I may also be able to call MCI back on this one. 

With best regards, Phil

[luvrbus]

Rough edges on fan blades do cause a lot of turbulence of the air flow ,the newer fans have a ring tip designed to prevent the end chipping and keep the pitch on nylon fans ,the D's when the fan is working right move a lot of air and you can hear and feel it. On the 2 fan setup on the MCI D you may have a problem with the CAC fan over powering the engine fan with the rough edges you spoke about 

[Dreadnought]

While I totally agree with Clifford that the root cause needs to be found (my mc5 is scheduled to get a major upgrade to the cooling system), I had to hit the road. Up gradients, pulling my ram 2500 poor thing starts to get very hot. It started to overheat from selligman  in AZ to Williams. Steeper gradients certainly have a much worse effect than ambient temp.i  ended up sealing the fan bay doors with rubber seals (now they barely shut! ) and I used water wetter- the HD kind. I put in two bottles.
It’s hard to tell, as there are so many variables, but I’d say it probably doesn’t get as hot. It almost touched 200 going from Williams to flagstaff.
It probably honours their claims and runs up to 10-20 deg f cooler.
In any case the interim measures of extra chamber sealing and water wetter did seem to help!
If drive and once it started to touch 200 I’d pull over. Once it spiked higher and the lube for the fan gear box puked all over the ground! But once cool again it only leaks slowly again. The 8v71 doesn’t endure heat well but it’s probably the better out of the two strokes with its solid closed deck 2 stroke design. The most amazing thing to me is that now I’m in the Midwest flat lands, the needles just stays at 170-185. I could imagine someone living in the flat lands, never travelling to the mountains, totally oblivious to the potential overheating issues, maybe even putting in a more powerful engine! My water pump was rebuilt in 2016, the little mc5 rads look fine and the engine is making 280 bhp with the little c60 injectors. It’s also a manual trans.

[plyonsMC9]

I'm going to post a summary of all the steps I've taken in a bit.  Still chasing the heat issue.  She's running cooler, but long grades even when not towing can still be an issue. 

Latest step was to remove the full / solid heavy mud flap that ran completely along the rear bumper, from driver to passenger side, and almost touched the ground.  Reading through the posts I understand that may block heat flow.  It's gone now and as I use the Roadmaster "Tow Defender"  I don't really need that huge air / debris block there. 

https://www.roadmasterinc.com/tow-defend-bx-demco-mx/

The wheels still have their own mudflaps.

Not sure that made a difference on the latest mountain climbs.
Going to have the radiator fan (thanks Cliff) & clutch checked out when I can figure out where to take it, maybe early next year.  That work is a bit above my pay grade.

Hope to be posting my cooling system checkup / review list soon - maybe help someone in the future.  Especially when I get the final issues resolved!,

Kind Regards, Phil 

[plyonsMC9]

Good evening bus folks!,

Reviewing the DL3-45 radiator, intercooler setup.  Behind the intercooler (driver side) and coolant radiator (passenger side) there are what looks like some air flow panels, directing air from each side of the bus, through the side louvers, to the respective radiator/intercooler/fan setups. 

I've read about the importance of seals and not allowing air to leak through. 

I took a flashlight to look behind the radiator setup, through the side louvers, and see any air gaps.  What I see is surprising but would like to hear whether this is actually an issue.   There are air gaps and a couple of places where rivets are coming loose.  Could someone please tell me whether there should be seals in these locations?

What I'm concerned about is that w/o seals (if there should be seals here?) that when the intercooler fan kicks on at some point, as it looks to be a much larger surface-area fan, that it could suck in air from the radiator fan path, resulting in higher coolant temps, and eventually overheating that I'm seeing after long/hot drives or steep mountain climbing.

If I'm grasping at straws, please let me know too!,

Thoughts, suggestions are welcome!, thank you, Phil

[epretot]

Phil,

I'll take pics of mine and post. I have to work for a few hours tomorrow but I'll do it when i get back.

[plyonsMC9]

Hugely appreciated - thank you Eric!
Kind regards, Phil

[oltrunt]

My MCI9 came to me with new radiators and a new water pump but still had an over heating problem.  It turned out to be a loose impeller on the new pump and once tightened properly the over heating problem was history.  Jack