I’m new here and I have some questions.

[Waterloo]

(01-16-2020 )cowboycurtis Wrote:  

(01-16-2020 )Lonestar10 Wrote:  EGR tubes are the 2 hose looking things coming from the EGR Delta sensor.

But the EGR has been removed so they wouldn’t be there now, right?

I called Peterbilt in Des Moines and got prices on CAC. OEM is $1500 and aftermarket is $667. I think my plan will be to wait for my Inline 6 reader, which will be here on Monday, and have the ECM program looked at before I throw money at the CAC. Is it possible the ECM is causing the low boost?

That’s my plan, let me know if I should be doing something different?

Has nothing to do with the EGR, these tubes are to a sensor, located up on the intake. They are there.

[Waterloo]

That CAC, buy the OEM, do not be a victim. Been there with a radiator, the aftermarket CAC will cause fuel loss and possible turbo failure. Some parts you can go the chinesium route, the CAC is not one of those items.

[tree98]

Don't even think about putting an aftermarket CAC on your truck. OEM only! The aftermarket ones are made with smaller passages and are restrictive as hell, costing you fuel mileage and other problems.

[cowboycurtis]

I got a hold of the previous owner this afternoon. Really nice guy and very helpful. Said he’s driven 3.5 million miles and the Peterbilt, that I now own, was his last truck and by far his best truck. There was a 2nd owner of the truck prior to my purchase. He owned it for a very short time, and sold it to a dealer, that’s why I never had an opportunity to meet the original owner.

So here’s some important information that I got from him. Hopefully it helps in getting this truck to running the way it should. He said he had the EGR removed around 600,000 miles. They did not change anything with the ECM.

The CAC is original. He said this truck has never had much boost, even when brand new. 32 max is what he saw. I don’t think I’ve ever seen over 25 and it stays at 22 when max power is needed.

The crank balancer is also original. His mechanic told him that when he had the front of the engine apart, the balancer was good so he put it back on.

This is the main info I got. He told me to call back if I had any questions. Great guy!

[Rawze]

(01-16-2020 )cowboycurtis Wrote:  ...
I don’t think I’ve ever seen over 25 and it stays at 22 when max power is needed.

because he drove it around in a derate because he unhooked the egr, did not have it re-programmed for such a thing. It is in a power derate and that boost level is too low. when you drive them around like that they spike about 32 or so then fall back on their face again, exhaust runs hot and its real hard on the turbo if engine is driven hard like that.

the last owner, obviously did not know any better.

[cowboycurtis]

(01-16-2020 )Rawze Wrote:  

(01-16-2020 )cowboycurtis Wrote:  ...
I don’t think I’ve ever seen over 25 and it stays at 22 when max power is needed.

because he drove it around in a derate because he unhooked the egr, did not have it re-programmed for such a thing. It is in a power derate and that boost level is too low.

Ok. I’ll be in touch when my Inline 6 gets here on Monday.

[Chamberpains]

(01-16-2020 )Rawze Wrote:  they spike about 32 or so then fall back on their face again, exhaust runs hot and its real hard on the turbo if engine is driven hard like that.

Mine has done this ever since Mommaburt tuned it a couple years back. I told him about it and we monitored a few things with CT but nothing stood out. It'll spike at 32 and fall back to 28-26ish depending on how heavy and how much of a grade I'm on. I've never seen it drop below 26 on full throttle. It still gains speed and seems to pull just fine for 450 hp. But I rarely ever push boost above 20 so I dont know if this would be a problem for me. I've pressurized the whole engine with no leaks. I always figured its was just what they did. I don't run a pyro so I cant tell what the exhaust temps are. Anything else I should be looking at?

[tree98]

Seems like the boost on an 870 is really hard to get right. Maybe it's a variance in the 870 turbos themselves ? Other guys on this forum including myself have mentioned in the past that our demandated 870's will spike to 40 lbs. For a second and flash a cel for turbo overspeed.

[Rawze]

(01-16-2020 )Chamberpains Wrote:  

(01-16-2020 )Rawze Wrote:  they spike about 32 or so then fall back on their face again, exhaust runs hot and its real hard on the turbo if engine is driven hard like that.

Mine has done this ever since Mommaburt tuned it a couple years back. I told him about it and we monitored a few things with CT but nothing stood out. It'll spike at 32 and fall back to 28-26ish depending on how heavy and how much of a grade I'm on. I've never seen it drop below 26 on full throttle. It still gains speed and seems to pull just fine for 450 hp. But I rarely ever push boost above 20 so I dont know if this would be a problem for me. I've pressurized the whole engine with no leaks. I always figured its was just what they did. I don't run a pyro so I cant tell what the exhaust temps are. Anything else I should be looking at?

it needs to be fixed... no, it is not normal. It has been mentioned many many times on here... this is just one of those times, from back in 2016...

Quote:People think that it does no harm to unplug the EGR on a CM870 without having the ECM re-programmed,.. but it is in fact harmful. The turbo suffers the most.

Unplugging EGR = air-flow derates and lower then normal boost. It derates and drops it to 28-32 PSI max instead of the required 36+ PSI the engine actually needs for proper power. Because of this, EGT's will run a bit higher, and turbo is always running hotter, though there is no sensor or codes for it. A Pyro gauge on the outside of the exhaust manifold like in my gauge instillation videos will typically reveal that it is very easy to get it to 900+ degrees (red-line temp) when pulling hills and that will shorten its lifepan.

ref: http://rawze.com/forums/showthread.php?t...78#pid2278

... there are likely 2 dozen more references to this in the past, if someone looked hard enough.