Before I get started with the issues, heres the details on the truck that some of you may already know, 95 F350 crew cab, 6637 filter, 3" dp, 5" exhaust, 6" tip, ts 6 pos chip, truck has 24" wheels running 295/40/24 tires, and carries about 80+ gallons of diesel.

Pulled my new vendor trailer for the first time this weekend from north Louisiana to mid Missouri which involved going thru a few mountains. Trailer is a 20'x8.5' v-nose enclosed trailer, im guessing somewhere in the neighborhood of 5,000 pounds.

Here are my issues with the truck, first of I am constantly battling high exhaust temps and now high engine temps. Never had any issues with the engine temp until pulling this trailer and it has all brand new antifreeze and hoses. First noticed it the day after I got the trailer when I jumped on the interstate and was trying to run 75. Truck acted like it didnt have enough power to maintain 75 and when i looked at gauges truck was at almost 1400 egt and past the L of normal on the temp gauge....slowed down to 60 and it went back to normal. Then while on my trip I finally figured out that the truck can stand 65mph to keep engine temp perfect and egts under 1200 at all times. Im not trying to race but id like to be able to go at least the speed limit.

Second issue was pulling some of the bigger hills in the mountains. Ive never driven a diesel in the mountains before so I wasnt sure what to expect but i was not impressed at all. The truck seemed to struggle at times on some of the bigger hills, would go from 65 all the way down to 35 to make it up the hill. Some of the smaller hills it would do pretty decent but would always lose speed. Now granted I was feathering the throttle sometimes watching egt's and engine temp but other times it was to the floor the whole hill hovering at 1250-1300 egt, and just seemed to struggle a little. It never let me down and always got me up the hill fine but i was expecting a lot more.

Truck got 9.2 mpg on the way there and I havent checked it yet but I think I got over 10 on the way home.

Also truck blows black smoke the whole time it climbs hills, everytime it downshifts, and sometimes when im trying to push it hard. Not a lot and not a thick cloud just enought to faintly see it.

So my questions are, is all this normal? Am i expecting to much out of this truck? What mods should I look into to help? Im thinking intercooler first to cool it down. I plan on driving this truck all over pulling this trailer so I need to get it all lined out but am on a tight budget. Sorry for being so long winded just really looking for help and opinions.

Thanks

 

Are your up pipes good and sealed up?
Those tunes canned or custom?

 

No clue on the up pipes? How would i know or check? Tunes are still canned, was gonna wait until after intercooler and injectors

 

What mods do you have now? I have added power over the years but have always battled high EGT's but I pull a 65' train. What I don't understand is the coolant temp being so high. Mine will climb a little but not that much. Maybe you need a good flush and a new fan clutch?

 

All i have is 6637 filter, ts chip on 75hp setting and 3"dp, 5" exhaust, 6" temp. Just had fresh flush antifreeze and hoses

 

Sounds like you have either an up pipe leak( look for soot around the backside of the turbo) or an boost leak. That should help egt's. You exhaust shouldn't be that hot with stock injectors. It also sounds like you have either a plugged rad, sticking thermostat, or worn out water pump. You can check the rad with a infrared thermometer, if it has cold spots then it's plugged.

 

Can you hear the fan 'sing' when its hot, if not the clutch is bad.

 

With the tires you're running, how accurate is the mph? What gears are in the differential? Tranny cooler? What rpm's are you running at 65?

 

I use the gps for my mph and to figure my mpg. But the stock cluster is off my 5mph and gets furthur off with increasing speed. Believe they are 4.10, believe there is a trans cooler, i was told thats what the smaller looking radiator thing on the front of the radiator was. Trans was 190-210 the whole trip. And i believe pulling the trailer at 65 i was around 2k rpms, but im not 100% on that. I know 75-80 empty on interstate pulls about 2500 rpms

 

Your expectation are not too hi at all. You have something else causing issue. The fact you cant pull 5000 lbs around over 65 through mountain passes at low elevation says enough. Try pulling with the chip off next time and see what happens with your EGTs. If you still push over 1200 with such a light load then start looking elsewhere. Other have already mentioned your up pipes, regarding the coolant temp - new fluid and hoses doesn't mean much considering the mechanics that keep that motor cool can be failing ex thermo, fan clutch, plugged radiator (internal or external), or water pump. Pumps usually fail fairly quick, but I have replaced quite a few that do exactly what you say, truck runs fine unloaded on the flats, and when hooked up, they run very hot on hard pulls... a new pump usually solved the issue if the other issues checked out. They typically weep out, but I have seen some that failed and did not. An old 2000 ford F150 with the old NA 5.4 can pull 5000 lbs up a pass faster than 35.

The fact your pulling at 1400* is going to make the truck coolant run stupid hot as well, on top of a pre existing cooling issue. Keep it up, not only will you melt your pistons, but the motor will toast out even under 1200 running that hot. I bet your power loss is due to heat. It will feel like she is seizing up (because that its exactly what is happening due to thermal expansion)

I'm guessing 4:10s are in your rear end, running that tire size is not all that bad. Is the truck a manual? If so it will help even more if driven right. If you have 3:55s then yes you will be lugging the crap out of the motor at the 60-65 mph mark in OD if it is an auto.

There are a lot of guys on here that pull heavy with your setup, some have additional mods for power but in stock form these trucks are more than capable of pulling 5000lbs over any mountain pass maintaining 50 mph.

On a side note, my personal experience is once you start throwing fuel at these trucks, and towing heavy, the stock turbo is not up to the task. You can put a billet wheel, and drop 600 bucks into modding it, porting the inlet, etc., but its still a turd. Just doesn't move the air quick enough or efficiently. Yes custom tunes will help, but I went through 3 reburns and a different chip manufacturer to try to just get the stock sticks and a chip to not run hot when towing heavy. Once I put in stage 1s in I couldn't even run cool enough in a stock tune with an intercooler and light load in tow, only water injection helped remedy the issue. Once dropping in a bigger turbo it was night and day difference. I do not even need the water any more. I simply use it time to time to clean carbon. That's just my two cents, but unless you can get the truck live tuned, you will always battle with the tuner considering there was an issue with your truck vs the tune being off... they may be right...they may not. Either way I was still running hot....

Other may have mentioned to boost leak the truck from the inlet of the turbo. If your intake plenums are leaking or anything else for that matter.... she is going to run very hot.

Pic of up pipe leaks....on a newer style SD, but its still going to look the same when they leak on our OBS trucks.

 

So, at 65, you're actually going 70? Are you running stock injectors? I almost never got smoke with stock injectors and tunes once above 2000rpm's.

 

At 65 is probably more like 72, stock injectors yes. Only time it smoked at low rpms was when it was struggling. Otherwise it was when it down shifted and got up to 2500 or so

 

Agreed with everyone else. Check for exhaust leaks around manifolds, up pipes, and back of turbo. And, as stated above, I have seen water pumps not circulate like they're suppose to even though they aren't leaking. Clutch fan, dirt build up in the radiator, a number of possibilities.

 

These guys have got you pointed in the right direction. 5000# on the level should be easy to pull at 75 mph. I don't have much mountain towing experience, but I'd expect better than what you're experiencing based on what I've read.
When the trailer is loaded what does it weigh?

 

Agreed. Pay attn to the pros above, something isn't right.

Mine is completely stock, except for 1"oversized tires. I have 3:55 gears and a manual trans. I pulled a 7000# trailer up a 2 mile 6% grade (Not a pass) a few months back. Was doing 70 at the bottom with the cruise on and crested the hill still going 70, never took the cruise off. Boost hovered around 7 lbs (2000rpm) and egt's topped out at 1120. You should handle a 5000# trailer with ease, especially a v-nose.

Good luck.
Bob