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MP8 running hot up hills and mountains

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Hey guys, I've been battling a new issue with my truck running hot up hills. The coolant will get up to 230⁰ and the oil also reaches 250⁰ and will derate. I think the problem has been around for a month and progressively getting worse, but the truck did get a new injector and cup (#5) and the running hot issue seems to be a lot worse. The dealer that did the injector said an injector or cup wouldn't cause an issue like that, and as I said, it's been going on for a little while, but is there a chance the problem is with the work they did?

I think it's probably gonna be something simpler like a slipping impeller inside the water pump or a sticking thermostat, maybe a dirty (outside) radiator, but is there anything else to check? Radiators won't just gum up inside for no reason right? I'm going to replace the water pump and thermostat this weekend. Let me know if there's something else I can check. Thanks.

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Note, the fan does come on and try to cool it down, and it seems that if I run lower RPMs that the temp stays lower - longer than if I run past 1,400 rpm. 1,600 is usually where I shift.  Seems to me it's a pump but some insight is appreciated. 

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Have cleaned out between intercooler and radiator?    terry:MackLogo:

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Nope, I'll add that to my list. Just take the condenser off with the lines on and flip that over and take off the CAC and clean front of the radiator and CAC while it's out?

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Blow from the fan side out towards the front with compressed air. How is your air filter gauge? Is your air filter clogging? That'll run your pyrometer up.

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Once apart if real dirty, mix up some dishsoap and water in a spray bottle and spray down real good and let set for a bit , then rinse out with a garden hose, you will be surprised the dirt you get out.     terry:MackLogo:

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Posted (edited)

The condenser looks fine, not really any dirty in the fins, but I guess it's first to see the rain. As far as my air filter, it's most likely past point needing to be replaced. I'll try just those two things and see what happens next week rather than throwing parts at it. Today I took manual control of my fan, it does cool better with it running, at idle I put my hand in front of the condenser and it's not pulling a lot of air, but I'm not sure what would be concerned normal either. Should it be sucking my hand off? I'm buying a new air filter and taking the radiator, cac, and condenser off for through cleaning tomorrow.

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Edited by Keffer inc

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Not pulling air might be plugged radiator or air to air or both.    terry:MackLogo:

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It's pulling some air through. Can you set the idle in high in neutral using the cruise? It won't suck your hand hard, but it does need air flow.

Just blow air through from the fan side with compressed air. It'll tell you real fast how much dust there is in there. Blow out as much of the radiator as you can this way before tearing things off.  Get what you can out of there that way and run it for a day, see if it's any better.

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I think it’s a good ideal to replace the thermostat and coolant pump. These items are easy to replace and not super expensive and will fail not to much farther down the road if they haven’t already . As others have said the fan clutch/ air flow through the radiator is also a high on the list on possible cause of overheating. There is a good chance you have the much hated Borg Warner Cool Logic fan clutch. It’s easy to tell if you got the Cool logic fan because it’s super huge with heat sink fins all over it . They were a total failure and are no longer made . They actually leak oil and start slipping and gradually fail to the point that the issue only shows up on hot days . As others have said I’d first take the grill out , raise the hood and take the condensed loose and lay to the side . Pull the charge air cooler / after cooler and wash out the radiator. We replaced a couple of fan clutchs when it really just needed a radiator fin cleaning. Theses were farm trucks though. https://www.fanclutch.com/PicsDocs/BorgWarner_Cool_Logic_Diagnostic_Guide.pdf

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9 hours ago, Mackpro said:

. There is a good chance you have the much hated Borg Warner Cool Logic fan clutch. It’s easy to tell if you got the Cool logic fan because it’s super huge with heat sink fins all over it . They were a total failure and are no longer made . They actually leak oil and start slipping and gradually fail to the point that the issue only shows up on hot days .

Yup some one got sold a bill of goods when they were building  these trucks the Leader in cooling tech! YUP You bet! they started flinging oil out prior to the PDI or shortly there after! They probably bought up the seconds that the borg warner had or something!

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Well guys, looks like I may have found the issue, and I found by a freak accident. I broke a quick connect fitting off while trying to use several extensions to remove the fan belt (bad place for it) and broke the plastic tab off inside the hose. The hose I think goes to the DEF doser or the return from it. Anyways, coolant was only coming from the doser and not from the engine side and I thought maybe it's a check valve, but the brass fittings for the connector is plugged solid. Do you think this could be reason enough for running warm on flat ground and overheating 3/4 ro the top of the mountains?

As far as the radiator goes, I took the CAC off (heavy bastard too, thanks for that warning ;) ) and it's pretty clean, few bugs but looks normal. I'll wash it since I've done the work but I'm changing the pump and thermostat now anyways because I'm halfway apart now. 

Main thought is all this is because of the brass being plugged up?

 

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Not familiar with the MP engines, but the engine coolant is through the upper and lower rad hoses, which you'd have to try pretty hard to plug up. If the fitting you mentioned is clogged up it may indicate a sludge problem that could be clogging up your radiator core internally, not allowing enough coolant through to cool the engine when working hard.

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I suppose it also depends where your water temp sensor is mounted. Usually they're near the thermostat? But if Volvo was dumb enough to put it by whatever circuit you've stumbled on it could be reading hot there even though the main water jacket itself is at normal temp?

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Just now, JoeH said:

I suppose it also depends where your water temp sensor is mounted. Usually they're near the thermostat? But if Volvo was dumb enough to put it by whatever circuit you've stumbled on it could be reading hot there even though the main water jacket itself is at normal temp?

But your oil is running hot too, so the engines gotta be overheating.

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Yep, I thought about the radiator being plugged up if that 1/8 hole brass fitting was clogged. I'm changing everything else and hoping for the best. But if it still runs hot, then I'll try a new radiator or get it cleaned by a radiator shop if that's possible.

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Posted (edited)

Radiator shops here won’t touch them. If any part is plastic composite they tell you to pitch them. 

Don’t imagine DEF “tank thaw” coolant matters right now, but, in terms of internal corrosion blockage.......a clogged capillary means a clogging artery. 

Edited by Mack Technician

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Do you ever miss the older truck you had before this one?

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8 hours ago, 880joe said:

Do you ever miss the older truck you had before this one?

Damn sure do. It was cosmically nasty (interior) from the last owner, but pretty reliable. Rears needed to be reman so I parted ways with it. Should have just bought a cut off for it.

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On loaders and such we have "scrubbed" the coolant system with cascade dishwasher soap and had pretty good results.  But that is also heavy duty steel radiators, dont know if that would work in this application. 

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On a bunch of internationals at a place where I used to work at on replacement radiators, the fins were so flimsy a hard stream of water at the wrong angle would bend the fins over.    terry:MackLogo:

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18 hours ago, OldRedMack said:

On loaders and such we have "scrubbed" the coolant system with cascade dishwasher soap and had pretty good results.  But that is also heavy duty steel radiators, dont know if that would work in this application. 

I was considering trying that, but with coolant running in tiny hoses to DPF And DEF equipment, I'm scared the powder may jam up flow and create more issues?

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Doing my first load since I replaced the water pump, thermostat, cleaner the radiator fins, changed the coolant filter, and the truck is running 210-215 with a 20 foot container with a 1 ton load on flat ground. It seems to have gotten worse. I noticed if I'm at a traffic light, it's coolant down to 200 when we get going and climbs back to 210 in a minute or two. Think it's possible it's an EGR blockage? I'm assuming these trucks have oil coolers, but not sure where they are located? 

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I’ve seen radiator hoses collapse inside  that will drive you crazy also. With no external signs at all.   Have you check the hoses inside top and bottom 

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10 hours ago, mrgumby said:

I’ve seen radiator hoses collapse inside  that will drive you crazy also. With no external signs at all.   Have you check the hoses inside top and bottom 

Not yet. Brake hoses on my pickup did that so I can understand that. I'll check that. 

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