Engine/Transmission (1994 - 1998) Need help lowering water temps & egt,s

[JBeasley]

I need need help figuring out how to cool my truck down. Whenever I'm towing 10-15k in 90+degree heat it runs warmer than normal and when I hit a hill and lay into it it will almost go to the red by the time I hit the top. I put a HTT 62/12 and exhaust manifold on hoping that would help my egt,s which in turn might bring down the water temp, but I think it made it worse. With my stock turbo I could hit a hill and just start letting off the throttle a little bit at a time to keep me from going past 1200 and I would never lug it down bad enough where I would have to shift. With this turbo the egt,s do come up slower to 1200 but the second a slightly start backing off the throttle it gets under the turbo and it falls on its face. Then I have to down shift and keep it on the floor at high rpm's the rest of the way up the hill. I hate towing with this turbo. At WOT I did see an egt drop but you can't tow at WOT. Any how I need any suggestions on lowering the water temps. egt's, keeping the turbo lit and making this set-up more towing friendly because that's all the truck is used for. I've replaced the water pump and thermostat and removed the radaiotor and pressure washed it. Sorry for the long post

 

[cro-magnum]

Are we talking about the 06 and or the 97?

 

[DonTX]

You are in the same boat as I, over on the Towing board. I have been having identical problems, doing a dance balancing the coolant temp and EGT readings to get up the hills when hot.

I am not sure if I got mine tamed down or not yet.

I changed out the fan clutch today, will be working on a radiator flush next if that don't fix it.

 

[KLockliear]

Given that his sig says the 62/12 is on the 97, I'll go with that.



According to your sig, you have gov springs, #10 plate and that turbo? What injectors? Have you dyno'd the truck - if so, what kind of power does it make?



Have you pressure washed the IC, A/C Condensor and rad? That was 15*F drop for me. Also, how about the 180*F Cummins t-stat?



Also, remember that it will be easier to maintain EGT's in the next lower gear. If it takes 300rwhp to maintain a given speed up a hill, better to do it at 2500rpm than 1800rpm. You're putting the same amount of fuel in at either RPM, but moving more air at the higher RPM which means lower EGT at that power level.

 

[BHuebner]

I have the same problem with egt's. im runnin the 62/14. haulin my 5th wheel (12. 5-13K)on flat ground out of o/d im runnin between 8-900* but once the hills hit 5% or greater the temps climb quick. i can easily hit 1400*. i try and keep a speed of 50-55mph to keep it locked up in 3rd not lugging and get over the hill asap. ive been thinkin of installing a new I. C. but not sure if drop in egt's is worth the $800 or swap the passenger side battery with the intake box to get better/cooler air into the turbo. (curious if anyone has done this?)

 

[JBeasley]

It is on the 97, sorry for not specifing that. The injectors are stock. The only fueling upgrade I've done is the #10 plate, which is set at half way (not all the way forward). I've also got the timing set at 16. 5. I have pressure washed everything in the front when the radiator was out. I forgot to mention I also replaced the fan clutch. I bought the new thermostat from cummins but I don't know which one I got, didn't know there were different ones. I give them my serial number and told them to send me one. I think I've still got the box with the old one in it, so I'll try to get a part #. The truck dynoed 368hp & 853 tq on the stock turbo. Haven't had a chance to dyno with the new one. I thought about putting a set of electric fans on it like the flex-lites or maybe a bigger intercooler, but that's alot to spend if it doesn't help. I'm pretty sure the intercooler wouldn't help but maybe the electric fans?

 

[DPellegrin]

JBeasley- Let's see- your cooling system was designed for and engine that had about 215 fhp (which is about 185-190 rhp), what I'm reading is that you have approximately doubled the horsepower and therefore the amout of BTUs rejected to the cooling system, now you are wondering why there is an over-heating problem at max power??!!



I think you are getting maximum heat transfer capability of that cooling system!!

 

[BDaugherty]

I don't have a lot of experience in your exact shoes... but, it seems to me that cooler air in is cooler air out. Therefore you'll want a true cold air intake such as the one made by PSM (not the only option, but it's what I'm running). Also, the intercooler would help a lot under max power conditions. I really don't see electric fans helping that much. When you're talking about highway speeds, I don't think that the fans will move much more air than what is already being pushed through by your speed? Also, what about louvers in the hood like the Jeep guys install for desert use or in the fenders like the new Super Dutys? Giving the air somewhere to go would reduce restriction and allow more air to travel through your coolers. What about an additional engine oil cooler? My guess is that a lot of your cooling issues comes from the factory cooling system trying to keep your engine oil cool with the amount of fuel you're burning. Have you inspected your water pump? As for keeping the big turbo lit, I seem to read over and over that bigger injectors REALLY help driveability with a bigger turbo. Lastly, you need to look at what RPM you're trying to pull. Lugging the engine is a sure way to run it hot. Get the RPM's up and you'll keep the turbo, water pump, and fan wound up.

 

[Shadrach]

I would go for a bigger intercooler before I would go for electric fans, as Flex-a-lite # 262 is only rated for 18k lbs max, thats truck, trailer and cargo. The Cummins stat will be 180* as thats all they make for that year. Shadrach

 

[hsmith]

I'm looking at the PSM for lower EGT's as I don't have a problem with engine temp's. Anyone with their system want to comment on the noise from the cowl inlet addition? I tow pretty heavy and now can stay below 1200 without a lot of effort. When I get home, I am going back with the stock air box and do some comparisons to the current AFE.

 

[KLockliear]

Something else is done to the truck, and you need to find out what before you can "fix" the problems. NO WAY that a truck with JUST a #10 plate should make 368hp. What kind of dyno were you on? Did you buy the truck new? I bet it has injectors in it already.

 

[JBeasley]

Well I've spent half the day on the phone and I've decided I'm going to order HTT's 13cm stainless exhaust housing. I was told it spools like a 12 but flows like a 14. They said driveability will be the same but with going to a bigger housing will lower my egt's where I won't have to back out of it while towing which will keep the turbo lit, and they said running cooler egt's will help my water temp. problem alot. I was also told going to electric fans will actually be worse while towing, so that won't be an option. Those exhaust housings are expensive,but still half the price of an intercooler, so far I haven't talked to anyone that said it would make a big enough difference to justify the expense. The injectors are stock. I bought the truck with 25k on it from a guy I knew. I run 370's in it for a while but that's way to much fuel for a stock charger trying to tow, so I put the stockers back in. I may put them back in after I get the bigger housing. I'll post the results.

 

[KLockliear]

368hp with stock injectors or with the 370's? That makes more sense if it had the 370's in for that. They are ~105hp more than stock. I'd expect a truck with just a #10 to make in the 250-270rwhp range. Again, what kind of dyno?

 

[DPellegrin]

JBeasely- What makes you think that changing the turbine housing is going to do anything for your max-power overheating problem? At best you may get a slight reduction in EGTs; but, the heat release in this thermodynamic heat machine called a diesel engine is still the same. The fact is, you are just putting about double the BTU's into your cooling system than it was designed to handle!!

 

[KLockliear]

The stock cooling system, when up to par, with a 180* stat will support right about 400rwhp if EGT's can be held in check.



On level 1, my ETH makes ~415rwhp and I can tow my 9k boat/trailer with the Edge doing the limiting at 1250*F up any grade in 110* Vegas/desert temps without getting over 210*F.

 

[DPellegrin]

KLockliear-I'm having a little problem with post #15. You are saying that the radiator in the Cummins Dodge pick-up can do the same job at heat rejection as the radiator in a class 8 Peterbilt or Kenworth? 400hp is 400hp whether is in a Dodge or Kenworth or whether the vehicle combination weight is 20K pounds or 80K pounds. The radiator in a ISM model Cummins powered Peterbilt or Kenworth is twice the size of a Dodge radiator. In other words you are saying that Chrysler has put a radiator that is double the size it needs to be in the Cummins powered pick-up?

Humm?



Regards,

 

[KLockliear]

Sort of. First, you have to realize that even though my truck will make ~415rwhp at the peak, on the floor in level 1 - while I'm maintaining 67mph towing up the hill with EGT being my limiting factor, it's not putting down 415rwhp at the time. EGT is usually the limiting factor. My truck will make just over 500rwhp when turned up on level 6, but when turned down will still tow nicely. It doesn't take 400+hp to tow my rig up those grades.



If my truck had smaller injectors and a less aggressive box - say a set of Stage 2's with an EZ and this turbo, I'd probably be able to flat foot it up the hills towing my rig, but I'd be going 80+mph... not what I want to achieve.

 

[JGK]

Towing twins.



-Jay