I just got back from my trip with my 5000 lbs travel trailer. Tows great but when I run at 75mph my truck runs at around 210-220 degree. Going up steep hills does the same thing. If I slow down to 65mph it runs at 190 degree. It never goes over 220 degree. Is this safe for the diesel? I have a 96 crew cab C3500 with the 6.5. All stock with water wetter. I have the single T-stat.

Also, how much do these truck smoke under load? normal crusing I don't see any smoke but hit a hill or accerate hard and black smoke comes out and doesn't seem to stop till I let of the throttle.

Without the trailer I run at 180 degree all day and never see streams of smoke. Just puffs.

Dave

Cooler is best especially with low flow single stat system system, back of engine gets very hot, if on a budget start with exhaust, downpipe, airbox, and recalibrated fan clutch, then EGT, boost and then a fooler or turbo master. Some will say fool first, I say no to that as unfooled the PCM will keep you from damaging the engine, some additional boost is what you need as indicated by black smoke, heavy black smoke while loaded is not a good thing.

Diesel engines are designed to run in the 210-215F range. At that temp they make the most power and best mileage, sounds like your cooling system is doing an outstanding job.
As far as the black smoke, a boost gauge would be the best place to start, see what the turbo is doing, that might reveal lower boost levels than desired and there's any number of remedies for that.

Were he running a 97+ set up I'd agree with you TDG, at 220 on older style water system back of block is pretty darn hot, my opinion and just that; from comments I've read on early model engine failures multipleweb sites hotter they are; more prone they are to over heat problems.

Gages area great addition anytime, my thinking though if he was on a budget, and was looking for some cooling relief and performance benefit was to unchoke the system 1st with intake and exhaust flow improvements, do both pipes and gages and you won't be disappointed toss up chicken or egg which comes first. Gage will help to sort out if you are having boost problems causing excessive smoke, I'll 2nd that advise. If he knew someone with a scan tool that would be best to watch all parameters while he or an observer logged all the data generated by the PCM. GM T2 or clone or Snap-On MT2500 can capture what you are after.

220 is kinda of hot for the transmission to if you expect it to last. How cool can you cool the trans if the water temp is 220?

I already order the air intake from SSdiesel and will make an alum box for it. I use to make airplanes so alum is easy for me to work with. I was thinking of getting the 4" exhaust from them as well but my truck needs to pass emissions.

I get those things and I have heard of the turbo master.. Just have no clue what it is. What does it do? I get a feeling that my boost isn't that high. I can't hear the turbo at all and the black smoke tells me that the turbo is not catching up with fuel. What can I do about that?

Also, I notice that you never mention the dual T-stat kit. Is that something that is overrated? I know on most engineering projects that the weakest link will always hold you back so is this one of those situations?

I just want my truck to tow reliably. I already have enough power to pull the hills here in BC with ease. Also, I get about 15mpg towing. That's 50% better than my last truck with a 5.7 gasser. I want to keep this feature.

Thanks

Dave


Cooler is best especially with low flow single stat system system, back of engine gets very hot, if on a budget start with exhaust, downpipe, airbox, and recalibrated fan clutch, then EGT, boost and then a fooler or turbo master. Some will say fool first, I say no to that as unfooled the PCM will keep you from damaging the engine, some additional boost is what you need as indicated by black smoke, heavy black smoke while loaded is not a good thing.

Oversight on my part, dual thermostats are a worthwhile longevity mod, wasn't sure where you were in your build or power load requirements, 97+ mods are an integral part of running cooler, but I'd do them after breatheability mods, the recalibrated fan clutch is a easy bolt on mod that will help with lowering temps, 97+ cooling is a little involved. Turbo Master is a spring tensioning device used to keep wastegate closed, if you got too far with waste gate closure and TM only you may need to fool PCM from throwing codes. If vac system is functioning already, try just fooling alone for more boost. My personal preference is to not add any boost or fuel until freeing up the engines ability to flow any extra fuel & air addeded, and gauges are really a must IMO before doing it as well. $" exhaust should not prevent passing emissions 3.%" is all that is needed so if you can find that for less I'd go for that.

IMO, everything about an engine should be able to handle 220F all day long the limitation of running at that tempurature is hotspots. Once you get 50/50 up around 220F it starts vaporizing at small spots inside the heads. Where this vapor exists coolant is not comming in contact with the heads causing two problems. 1. the heads inconsistent heating leads to distortion and cracking. 2. the vapor from the hotspot is super heating your coolant because the vapor is much hotter than boiling 50/50.

This is a geometeric self feeding problem.
Your engine is getting hot and creating hotspots due to load so the part of your head that needs the most cooling is now getting NONE! At the same time the vapor from the hot spot is super heating your coolant, while your cooling system is already having a hard enough time trying to keep the engine cool as you climb the hill. So you can see how fast your engine can go from normal operating temp to over heat to destruction as the combination of hill and trailer weight increase.

I would try water wetter, it is suposed to coat the inside of the cooling system to resist hot spots. I don't know if it works because my engine has never overheated before, I never tow anything and my vehicle is relatively light@4400lbs I have also installed the 97+ cooling upgrade and I'm running water wetter. I run daul 195 t-stat's and cannot get my engine over 180 for me it's about the insurance, I don't plan on losing this engine to cooling issues.

All stock with water wetter.
I think he's already got this covered, this is from his original post...

I missed that when I read the original post, Thanks TDG

Let me get this straight. Smokes under load and high ECT's? That sounds like low boost. If your running the vac pump, start there.

Are you saying that water wetter reduces the hot spots problems with these heads? That's what I read too, but have never proved it. It works well on my dirt bikes so that is why I use it in my truck.

Oh, and my truck has never overheated before too.. Just runs hot underload.

Dave

I would try water wetter, it is suposed to coat the inside of the cooling system to resist hot spots. I don't know if it works because my engine has never overheated before, I never tow anything and my vehicle is relatively light@4400lbs I have also installed the 97+ cooling upgrade and I'm running water wetter. I run daul 195 t-stat's and cannot get my engine over 180 for me it's about the insurance, I don't plan on losing this engine to cooling issues.

Can you give me something I need to look at? How much smoke is too much? It isn't a cloud.. This is my first diesel so I'm not sure how much is too much. So, I'm assuming that the turbo is vac control? or is that the waste gate? How can I test to see if it's working?

Thanks

Dave

Let me get this straight. Smokes under load and high ECT's? That sounds like low boost. If your running the vac pump, start there.

I agree with QM, if you have low or no boost fix that before digging any deeper into the problem. If your still running hot there's a whole laundry list of things you can check and/or change: Check for junk between radiator and ac condenser up front, Get the radiator cleaned/serviced, 97+ cooling system, there's more........ If there's anything wrong with the radiator like being clogged internally or blocked externally, the 97+ cooling will not help till those are fixed. You might want to to do some or all of the cooling items mentioned even if the bosst issue is corrected.

Dave2001,
You have to pull the vac line at the turbo and check for ~15 " Hg of vac at idle. Then proceede to the wastegate solenoid from there. It should have ~23.5" at idle on the hose from the vac pump.
Usually the lines break and crack leaking the pressure, The WG solenoiud gets rusty and pitted and the internal check ball can't move or the vacuum pump goes out.

I prefer a spring to the vac set up. You can make your own or buy Heath's Turbo Master then the vac system can come off on a HD.