LBZ: 1200* steady flat ground towing

[rennat_2006]

Same deal on the way home. 70mph in 5th gear im at 2000rpm's running like 8psi of boost.

4th gear pulling hill i flooree it to see what it would do. 1400-1450 at 75mph at like 26psi of boost when i let off due to speed.

Something is definetely up with the truck. Ive towed the same hill with my rockcrawler on my car trailer(close to 8k) in the summer in mid to high 90* heat and ran it in 4th for egt control at like 3000rpm like it was today and only got it up to 230* once. Today it hit 230* and fan must have engaged and brought it back down to needle laying just before 210 then climbed back up to 230* ish again and repeated the process. Also got the transmission up to like 220* which is the highest ive ever seen it go, trans is a hurting unit though(got a limitless diesel/mike l goodies kit in the shop waiting for some down time).

Air filter is dirty but not horrible. Im going to clean it this week and pressure check the turbo cold side system.

 

[THEFERMANATOR]

Have you checked in between the intercooler and radiator to see if they are plugged up? Low airflow through the cooling stack would cause the engine to run hot, boost to not always come up, and high EGT's.

 

[ironmax]

Check your rail pressure. I had similar problems with mine. Ended up being a bad cp3. I got 330k out of it though. There is also the possibility of a clogged strainer in fuel tank pick up tube.

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[Josh154]

I just towed a 7x16 today about 5-6k total weight. Doing 80 in 6th at 1900 rpm I was about 900rpm on flat ground and maxed at 1050 pulling some grades. This was also running a 60hp tow tune, not stock.

 

[rennat_2006]

Its been 50k since ive pulled the cooling stack apart and cleaned it out. I will take a good look at it again.

Havent checked rail pressure but i will do that. Im sure if that was the case i would have gotten a check engine light on the way home due to how hard it was working.

 

[clrussell]

1200 flat ground running 65ish. Like 1200* the full time im in tow then on hills it goes up from there. On hills i limit myself to 1350 sustained.

I would love to hook a egt gauge to a totally bone stock lbz and see what it does

I've been in a bone stick lbz with a pryo.. Honestly the numbers were very close to yours.

 

[motoking_1990]

FWIW my probe came loose once and I had all kinds of weird readings. I sure hope 1200 is not accurate that seems really high for a steady cruising speed.

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[rennat_2006]

Thats good to know about a stock lbz but at the same time concerning. I would think i should have a noticeable drop vs a stock lbz with my exhaust, downpipe, and intake.

Keeps making me wonder how stock trucks arent melting down, i have to watch mine to keep the egts safe but yet you see stock lbz trucks with way bigger, taller, and heavier fifth wheels with grandpa driving them with the cruise just set at 65mph and he just lets the truck do what it wants.

 

[malibu795]

Thats good to know about a stock lbz but at the same time concerning. I would think i should have a noticeable drop vs a stock lbz with my exhaust, downpipe, and intake.

Keeps making me wonder how stock trucks arent melting down, i have to watch mine to keep the egts safe but yet you see stock lbz trucks with way bigger, taller, and heavier fifth wheels with grandpa driving them with the cruise just set at 65mph and he just lets the truck do what it wants.

Stock truck are rated for 1350 sustained... You are well within the limits

 

[WVRigrat05]

Just do like I do, don't run gauges and you won't have to worry about it, when it's getting warm the throttle will let you know.

 

[S Phinney]

Stock truck are rated for 1350 sustained... You are well within the limits

You do not really beleive that do you? There us a problem with that as a normal temp for him. Parts will fail with extreme heat cycles.

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[malibu795]

You do not really beleive that do you? There us a problem with that as a normal temp for him. Parts will fail with extreme heat cycles.

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He is draging a 8' wide ~12' tall box parachute that is a ~7400lbs travel trailer... On avg they are not designed to be aerodynamic. Weight is nothing! Parachute windrag works the crap out of the engine!! I might know a thing or two about that..

With stock tunning.. My LBZ/LMM both had less then 6° max timing in stock form. Cruise was 3-5°
I run 9-15° cruise pending load and wind drag..

Me personally my egts(4088) cruise @65mph 550-600° just the truck, empty trailer (7-8000lbs) 650-700° loaded low wind drag 750-800 high wind drag 900° I max out at 1150° im already at 400rwhp and limits of the transmission.. I'm sure it will get warmer when I have a transmission to handler more fuel.

VVT/GT4088R egts are 50-75° (4088 is cooler)of each other with exception to max.. They are the same. Same exhaust, OEM down pipe and 4" straight pipe. At least on my truck. Saw no EGT change with gear swap from 3.73 to 4.56.

1200° isn't "extreme" 1400° isn't either... If he said 1500-1600+ I'd be looking for something wrong..

250°ECT is max OEM limit above that ecm derates
Engine fan could be replaced with a Hayden fan clutch clean cooling stack..

Who knows what his engine oil temp is...(the more import temp, IMO) its Probably low due to low timing sending the heat out the exhaust vs through the pistons, resulting relatively warm but not dangerous EGTs..

Should see the egts needed to light off regen!

 

[Dozerboy]

And the "probem" could just and bad egt probe/gauge.

This is the OPs second thread on "high egts" and been given good advice in both. He hasn't give us much feed back.


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[rennat_2006]

Havent had a chance to dig into it yet

 

[Dozerboy]

I didn't mean that quite the way it sounded. Just some members seem to be doing quit a bit of assuming when we don't have a whole lot to go on yet.

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[rennat_2006]

No issue i didnt take it in a bad way. Just trying to finish up this ls swap 66 chevelle so i can get it out and my truck in.

 

[rennat_2006]

Pulled air filter out yesterday, ive got it soaking in dish soap and water right now for cleaning. It was pretty dirty but i dont think it was "plugged" by any means.

Cooling stack is clean between the ac condenser and intercooler, hard to see between intercooler and radiator but what i can see looks good. Im going to try and loosen up the bolts holding the 2 together and see if i can lean them apart a little better. Everything was taken out and throughly steam cleaned at like 118k but im at 156k now.

Going to try and find a 2" plug that i can rig up for a air fitting to pressure test from the turbo outlet on this weekend..

 

[nskyline34]

Resurrecting this from the dead - I'm having the exact same issues and I'm driving the same damn roads even. Did you ever find the problem???