Any ideas on why my Series 60 runs so hot?

belfert · January 01, 2019, 03:31:58 PM

Quote from: luvrbus on January 01, 2019, 12:54:34 PM
Test the inter cooler sounds like it is leaking 25+ lbs should be normal under a load or it will heat didn't you bump it up to 370 hp ?

The inter cooler was tested and some repairs done when I first got the bus. I could certainly have it tested again as the inter cooler is fairly easy to remove. The HP was bumped up slightly more than five years ago, but the heating hasn't changed from what it was before that.

I found my thread about turbo boost from years ago. In that thread I noted that under 100% engine load I was maxing out at 18 PSI. You mentioned that 19.2 PSI is max for the 11.1 with 55 injectors and standard turbo.

thomasinnv · January 01, 2019, 03:50:28 PM

My 11.1 would hit 25 to 26 psi under full load. Obviously different turbo and injectors could change that, as well as bad ddec programming. When you turned the power up did he flash a oem program? Or did someone do their own adjustments to the fueling tables? You can flash all kinds of programs on that ecm but if it doesn't match the components you actually have in the engine you won't get the expected result, and in many cases can actually end up going backwards instead of forward.

belfert · January 01, 2019, 06:22:37 PM

To be clear, my heating problems and turbo boost issues started long before I had the DDEC flashed. I really never noticed any change in power after the DDEC was flashed.

The DDEC work was done by a Detroit Diesel dealer locally and it is an authorized upgrade.

luvrbus · January 02, 2019, 10:10:16 AM

Check your boost sensor the hose could be broken or the sensor is bad

Scott & Heather · January 03, 2019, 05:06:05 AM

Brian,

So on my 8v92TA, I had it flashed from a 400hp program to a 500hp program. I never noticed the change at all. My bus still felt slow. More smoke, more heat and no joy. I finally this past summer realized my turbo was bad and after having it rebuilt gained huge amounts of power, eliminated my overheating issue, and stopped the smoke. I'm wondering if you have some sort of mild boost issue...if you had a reflash, you should be able to tell/feel it in the seat of your pants.

belfert · January 03, 2019, 11:21:29 AM

There is a lot of talk about a possible turbo issue, but could there be something else with my cooling system causing issues? One of the few things on cooling that has not been replaced is the fan clutch. It is a two speed electric clutch. The strange thing is it locks up as soon as the ignition is turned on. I thought it is supposed to freewheel until around 160 degrees, and then a second stage at a higher temperature.

How can my turbo be tested before I spend money either getting it repaired or replaced?

chessie4905 · January 03, 2019, 03:45:56 PM

You could pull the inlet hose off at the turbo and look at the impeller. It should look perfect and no slop if you try to wiggle it side to side or up and down. And easily spin like a small fan blade. Check with your finger, not a screwdriver, so you don't damage the fins. They are somewhat delicate. It is just two impellers connected to each other by a shaft. The exhaust flow spins one end causing the other end to spin and pressurize the air coming from the air cleaner or intercooler. To thoroughly check, remove exhaust pipe from outlet and do the same visual inspection. I would do this with the engine turned off.😵

thomasinnv · January 03, 2019, 05:12:08 PM

Scott, depending on what he went from/to for power he may not notice anything in the seat of the pants on an 11.1. For example going from say 330 or 350 @ 1250# to 365 @ 1250# you wont notice it all all. The 330/350 was usually @2100 rpm and some of the 365 were @ 1800 rpm. If you extrapolate that out on a graph you will find them very close to the same tq value up at 2100 rpm. On a series 60 the torque curve is basically flat from 1200 to 1500, and above 1500 it's a fairly straight line to whatever the hp rpm is. Torque curves look quite different compared to a 2 stroke.

Scott & Heather · January 05, 2019, 07:29:43 PM

That makes sense. So it begs the question, why even get reflashed at all then? But still, we have his overheating issue...

belfert · January 05, 2019, 07:57:07 PM

I went from 350 HP to 400 HP. I doubt the local Detroit dealer would have done the upgrade for me if it wouldn't work with my existing cooling, turbo, and such. i thought about going outside to look at the turbo today as it was 46 degrees, but I decided to work on other things.

thomasinnv · January 06, 2019, 08:05:53 AM

Back when the 12.7 started replacing the 11.1 in otr trucks the dealers had an incentive program going to try to sell the older used trucks with the 11.1. They would bump the power to 375 or 400 to try to compete with the newer trucks running the 12.7. If it was done at a Detroit shop chances are it was reflashed to one of those programs.

belfert · January 06, 2019, 03:34:36 PM

One other note on the turbo. For the past few years I seemed to have a minor exhaust leak I couldn't find. I looked all over at all the clamps for the exhaust and nothing was loose. I had the bus to a different shop than usual in early September to get some routine work done and they said they found a bad clamp on the turbo which I had them replace. Wow, what a difference! The noise from the engine dropped substantially and I am pretty sure the minor exhaust leak is gone now. Not sure which clamp they replaced as I had checked the exhaust side clamp multiple times.

Unfortunately, no change to the heating issues, and no change in power or boost.

belfert · July 04, 2019, 06:59:32 PM

Resurrecting an old thread of mine.

I finally got around to opening up the exhaust side of the turbo. The fins looked good and no play. I spun it several times with my hand and it didn't seem to make it even a full turn before stopping. Is this normal without any oil flow from the engine?

thomasinnv · July 05, 2019, 08:32:52 AM

Quote from: belfert on July 04, 2019, 06:59:32 PM
Resurrecting an old thread of mine.

I finally got around to opening up the exhaust side of the turbo. The fins looked good and no play. I spun it several times with my hand and it didn't seem to make it even a full turn before stopping. Is this normal without any oil flow from the engine?

If you flick it with your finger it should spin freely with minimal resistance, should spin at least a few revolutions before stopping. What is your boost running under load? Should be upper 20's.

belfert · July 05, 2019, 12:31:50 PM

It sounds like I should be looking for a new turbo or a rebuild then based on the impeller not spinning much. Does it make sense to have a turbo rebuilt versus just replacing it? I certainly have time to get it rebuilt.

I am going to stop by the Detroit dealer after work to see if they can tell me what part number turbo I have based on the serial number for my engine.