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Topic: ‘96 U295 Engine Temps (Read 1866 times) previous topic - next topic

Re: ‘96 U295 Engine Temps

Reply #20 –
Sorry for the slow update, but we didn't have any data, phone, or Wifi where we went in San Isabel, Colorado.

Coolant and fluid levels were good upon check. Nothing obvious in radiator area. Not sure how to test thermostat. Coach made it up to 9200 ft without incidentt pulling the Liberty, next time I'll deploy the dinghy if I have I have another driver.  If I saw temp creep up over 205ish I pulled off and let it cool down. Set throttle to 1100 rpms for a minute or two to run fans up.

Coming down, I drove using tach not speedo (new concept for me never having driven anything like this nor mountain driving)....1750 rpm did well, 185-195 until we got to Channing to Amarillo. I saw 200 on 87 S and 205, once, pulled over to rest.

Trans temps were fine going up and coming down from CO 165, saw 210ish but had been on retarder. I also deployed dinghy coming down.

Talked to Risch and he thought with outside temps it might be running a little hotter. He's noticed his own pickup running hotter lately. 

I think the valuable lesson I learned, thanks to my coaches previous owner, Elliott Bray, was 1700ish rpms. This is my first class A pusher and learning to drive the tach is obviously important! Im not mechanically experienced like you gurus, and y'all are one of the reasons I love my FT!

I'll have MOT investigate when we are there for service first part of August. May be time to proactively consider new radiator and hydraulic fan. Elliott thought they were impending when I bought it three years ago. So far so good.

I am curious though, someone mentioned the p3 carrier bearing, my coach is in the age  range of that being a problem, and on the rare occasion I get close to 70 mph (without a dinghy), I think it may be an issue (at PDI Risch said I should watch and plan on having Stewart-Stevenson?? Replace it  ....so could this be causing the higher engine temps (remember, I'm not mechanically minded)? At my typical cruising speed 55-65 (without dinghy-63 mph or less with dinghy) it's smooth, but notice more vibration 68 mph+.

I suspect it's a combination of age, miles, and p3. 180k probably time for cooling system overhaul and time to address the p3.

Any further thoughts and suggestions (again, I'm learning only from Forum, I have no one to help teach or guide me in person, I'm not mechanically minded but trying to learn)?


Re: ‘96 U295 Engine Temps

Reply #21 –
Quote from: jhardman –
1. May be time to proactively consider new radiator and hydraulic fan.

2. I am curious though, someone mentioned the p3 carrier bearing, my coach is in the age  range of that being a problem,
2b....so could this be causing the higher engine temps

1. Unless the fins are rotted out on the bottom few rows of tubes you can just have the core cleaned and new tank gaskets installed.

2. P3 bearing could be loose or failing. Only way to be for sure is to pull the tail shaft and check.  If you can get to S & S in Longview they are who does trans work for FOT and know what to look for.
2b. No not unless the trans was seezing up but you would have all kinds of alarms if that was to happen to a world transmission.

Mike

Re: ‘96 U295 Engine Temps

Reply #22 –
One way to check the P3 is to block the coach level and insert a pry bar or large screwdriver between the balancer on the output of the trans and a secure spot.  Gently pry up and note how much movement you get.  It should be very slight, a few thousandths at most.  More than that, better to get it tended to before it escalates. 

Re: ‘96 U295 Engine Temps

Reply #23 –
If the P3 bearing is failing the bedroom door will vibrate in the pocket when it is open and you are driving on the interstate, will not be able to hear it from the front. Have the DW go back and listen

Re: ‘96 U295 Engine Temps

Reply #24 –
The motor is not running hot enough for me to spend much on it considering ambient temps and the elevation your in. Unless you see something obvious that Mike mentioned.likely when you get to flat country temps will go down.. I would be watching it same as your doing.

Re: ‘96 U295 Engine Temps

Reply #25 –
Agree with Dub, but I would replace the thermostat and its gasket.  Inexpensive and a DYI job.

Thermostats wear metal to metal and can fail to fully open (or close).

Re: ‘96 U295 Engine Temps

Reply #26 –
Amarillo to home Temp was 195-200, one stretch probably 202-205. I drove a little more aggressively today at about 2000 rpms, 68-70 mph. Generator had a problem so we didn't have any air today, thus the increased speed. Plus I was experimenting with what y'all were saying.

We were on US 287 S.

1850-1950 yields 64-65

Transmission did some hunting and pecking at 68-70 in the hilly areas but temp remained pretty stable at 200.

Saw two other FTs north bound on US 287 N today too!

Re: ‘96 U295 Engine Temps

Reply #27 –
Temps seem high, ran south today on I-29 down to Kansas from South Dakota running into a quartering wind temps 180-185 @ 70 mph grossing 34500, outside temp middle 90s, 7.5 mpg avg.

Re: ‘96 U295 Engine Temps

Reply #28 –
Quote from: bbeane –
Temps seem high, ran south today on I-29 down to Kansas from South Dakota running into a quartering wind temps 180-185 @ 70 mph grossing 34500, outside temp middle 90s, 7.5 mpg avg.

You think the extra ten degrees in ambient air could make that big of difference?

I think I'll replace the thermostat for good measure, but do they partially fail? I thought they either failed open or closed?

How does one clean the radiator? Does the grill come off easily?

Re: ‘96 U295 Engine Temps

Reply #29 –
Hey you are learning what exact conditions the mechanical device you are driving will allow you go go.  Whether it's right or wrong is a separate subject.  Seems slightly low in capacity.  So you pushed it slightly less.  Exactly what I do on every drive.

It to 210 0r a half dozen times.  Trans to 220 max. 

36,000 pounds at 75+  Coach would go down to 60 on long medium steep  grades.

I downshift a lot and run near 2,000 rpm plus a bit or retarder

By the time the grades over the temp maxes then goes down.

Not sure I would have pulled over or removed the tow.l

Not saying you were wrong.  Great choices.

My experience is you are not nearly at the  coaches limit. 

Re: ‘96 U295 Engine Temps

Reply #30 –
Jhardman, yes thermostats can fail to open completely. Walking the radiator out can help, you can do it without taking the grill  out. Be careful and spray straight through it to avoid  Distorting the fins.

Re: ‘96 U295 Engine Temps

Reply #31 –
 Probably, as others have suggested, some incremental improvements, cleaning radiator, new t-stats, will drop your operating temp a few degrees.  And, sure, ambient air temp makes a significant difference.  Basically, what I'm reading, and I'm driving same year and engine coach, you're running a 24 year old engine on the pins in high temp weather, heavily loaded, pulling a heavy toad in hilly country, with 300 hp.  Can't really expect her to run cool in these conditions.

I swapped out the banjo bolt fuel overflow valve on my rig with a stock Bosch replacement and am pleasantly surprised with the increased power.  Nothing monumental, but definitely more twist. Might consider this if you havent done already.

Comparisons to 320's with 50% more hp are invalid. 

Re: ‘96 U295 Engine Temps

Reply #32 –
Quote from: Chuck Pearson –
I swapped out the banjo bolt fuel overflow valve on my rig with a stock Bosch replacement and am pleasantly surprised with the increased power.  Nothing monumental, but definitely more twist. Might consider this if you havent done already.
Smart move. All Bosch P pumps have this fuel return valve. It develops microscopic channels in the little ball and also the seat from the fuel passing by so the pressure is less inside the pump. It's easy to change and will return the internal pressure back to what it was originally.

Pierce

Re: ‘96 U295 Engine Temps

Reply #33 –
You can easily check for end play for the P3 bearing,put a prybar between the transmission harmonic balancer and the frame,on mine it's about a 1/2 inch gap where you put the pryer,if you get 1/8" play you have a loose bearing,many of us have had this problem,had mine retightened and inspected for 1K.You need to find a good Alison repair shop to do this,if it's caught in time and they save your bearing it's a whole lot less expensive.PS,not knocking "Risch"but what does his pickup have to do with yours running hot.

Re: ‘96 U295 Engine Temps

Reply #34 –
Quote from: John44 –
You can easily check for end play for the P3 bearing,put a prybar between the transmission harmonic balancer and the frame,on mine it's about a 1/2 inch gap where you put the pryer,if you get 1/8" play you have a loose bearing,many of us have had this problem,had mine retightened and inspected for 1K.You need to find a good Alison repair shop to do this,if it's caught in time and they save your bearing it's a whole lot less expensive.PS,not knocking "Risch"but what does his pickup have to do with yours running hot.



I was referring to the effect of the ambient temps.

What is the banjo bolt they're talking about, David? Where is it??

Re: ‘96 U295 Engine Temps

Reply #35 –
Quote from: jhardman –
What is the banjo bolt they're talking about, David? Where is it??
It's usually between the block and the injection pump. Normally takes a 17mm to loosen it. It will have a copper washer on each side. Here is the perfect illustration on the location and how to test it.

Check / Replace Fuel Return Overflow Valve | Cummins Diesel Engine Service

Pierce

Re: ‘96 U295 Engine Temps

Reply #36 –
Will look it up but there is an aftermarket place that sells a kit to beef up the fuel pressure at idle,a few of us have done this,they also
have a fitting to install that you can put a gauge on to check fuel pressure,is good idea. Research,Tork Tools,they have the info.

Re: ‘96 U295 Engine Temps

Reply #37 –
If return valve is OK, the Cummins lift pump has a higher than normal problem rate. Pressure gauge will pinpoint problem. A lot of Bosch P pumps on smaller engines have the lift pump mounted on the side of the main injection pump and some even have the manual prime pump as part of the lift pump. Never seen one of these fail. Not so much on larger diesels as the lift pump is usually between the primary and secondary fuel filter and with large filters, the line routing would be more challenging.

A new stock fuel return valve will allow the injection pump to produce the full pressure/volume for full power.

Pierce

Re: ‘96 U295 Engine Temps

Reply #38 –
Even though our coaches have differing drive trains. The effects of how one pulls a hill are the same for any diesel pusher. We were coming back from Idaho last week and had a long grade of 5 miles and average of 6% with an 8% section. It was 90 degrees. We had lots of fluids on board and a 3,000Lb car out back. I slowed down from the posted 60MPH limit to 45-50MPH and manually put it in 4th gear. Boost never got above 17PSI (I have seen 27PSI) revs were about 1700-1800. Water temp never exceeded the upper 180's, Oil temps never exceeded 212.  ^.^d 

Further down the road. I had another hill to pull. But not as steep or long. I had a pickup with a loaded car trailer going pretty slow. So I used the HP of the M11 and let her rip to pass him. Turbo boost was 25PSI, Water temp went up to 200, 15-20 degrees higher than the steeper pull. The oil temp went up by 5-6 degrees. Still not close to dangerous temps.  However, It was a perfect illustration of why you slow down and gear down for steep grades. Forget about those nascar dreams of passing everyone. We are in RV's, No one waved a green flag.

Re: ‘96 U295 Engine Temps

Reply #39 –
Quote from: John44 –
Will look it up but there is an aftermarket place that sells a kit to beef up the fuel pressure at idle,a few of us have done this,they also
have a fitting to install that you can put a gauge on to check fuel pressure,is good idea. Research,Tork Tools,they have the info.

Replaced my stock Cummins valve (broken spring) years ago with a Tork-tec adjustable valve years ago.

https://cppdiesel.com/adjustable-p7100-overflow-valve/