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I didn't notice till I got out of my neighborhood this morning, but the engine went into limp mode. Meaning, rev's were limited to under about 2,500 and there was a noticeable lack of power - sort of like pushing the throttle pedal past about 1/3 made no difference. But there was no "check engine light" on the dash?
If it matters... it was 12*F this morning. But I did let the engine run for about 7 or 8 minutes in the driveway before taking off.
I have a warranty through the Indy that I bought the truck at and they're very good. But the "no code" thing has me perplexed and was just curious?
Last edited by DennisG01; Jul 2, 2022 at 10:12 PM.
Thanks, Plutoe. That helps to know that it's at least not some crazy, never-heard-of, thing. The Indy does have the proper diagnostic equipment. If for some reason they can't figure it out, I can take it to the local dealer. The warranty, being third party though, doesn't pay full labor rate at a dealer. I would just have to pay the difference, that's all. Not the end of the world.
Did you start the vehicle after you drove it this morning? CEL might show up next time you start it. When was the last time your fuel filter was changed?
While the issue was happening, I did stop, turn it off, then restart. Nothing changed in terms of drivability and a CEL did not come on.
It's definitely not "starving" for fuel because of a blockage, but I understand why you asked that. The engine runs perfectly fine (sound and "seat of the pants", anyways), other than an obviously "computer limited" lack of power. I'm positive it's in a "limp/safe" mode type thing.
Thanks, ALX. I'll get the car in to the Indy soon.
Sometimes simply losing the pipe connection from the turbo to the intercooler/intake manifold will result in loss of power and no code. The bolt holding the pipe from the turbo output to the front of the engine on mine broke off (dealer service error) and the pipe shifted forward and lost its connection to the turbo - no turbo, no power! Also no code! Required replacement of the intake manifold because the broken bolt piece couldn't be removed. Completely wrecked a long vacation!
Sometimes simply losing the pipe connection from the turbo to the intercooler/intake manifold will result in loss of power and no code. The bolt holding the pipe from the turbo output to the front of the engine on mine broke off (dealer service error) and the pipe shifted forward and lost its connection to the turbo - no turbo, no power! Also no code! Required replacement of the intake manifold because the broken bolt piece couldn't be removed. Completely wrecked a long vacation!
Damaging the seal between the turbo and the metal pipe leading to the intercoler will result in underboost condition and corresponding codes logged in the engine mgmt log. No boost will not result in more emissions hence no check engine light.
It'll be a day or so till I'm back at the vehicle...
Wondering outloud... If something was wrong with the pipe between the turbo and IC (or a seal at either end)... wouldn't I hear different sounds coming from the engine/turbo? Meaning, wouldn't I hear a whooshing sound as the air escaped? On my diesel Suburban, the engine was built up and I put a much larger turbo on it (along with adding an IC, which it never had from factory!). Problem was that the clamps (until I got better ones) weren't up to the task of keeping the silicone hoses on the pipes and if they popped up the noise was very noticeable.
Couldn't find anything misaligned or popped off with the hose/pipe from turbo to IC or back. I'll take into the Indy tomorrow for them to look at sometime.
When I started it this morning, there was a CEL lit up. I didn't write it down right away, and forgot by the time I got a piece of paper! But I believe it was a P1240... maybe P1214. I cleared it, but the actual CEL light didn't go away and no more codes showed up on my code reader, but it's likely something more advanced that my code reader can't see.
However, the engine hunted for RPM's (about a 200RPM swing, around the 1,000RPM mark) while it warmed up. And then, on the way to work, I had full power and it ran normally. I'm still dropping it off later today at the Indy, though.
Me, too! Regardless if it's covered under warranty, or not.
I dropped it off last night and they did a quick scan. No idea what the P1240 or P1214 is/was - couldn't find that anywhere. I'm positive about the P12 part, but only about 90% sure on the last two numbers. But here's what their scanner showed. I typically try and avoid short runs with the vehicle - most of my trips are at least 20 minutes long. Maybe something is clogged up? Maybe just a faulty sensor? In my '98 Suburban (diesel), I eliminated the cat/soot trap all together.........
Question... Does my engine ever perform a "regen cycle"? I do NOT have the AdBlue/BlueTec setup, if that matters? I've tried googling, but it seems confusing.
Yes, dpf regen does get executed as needed.Don't worry.
Thank you. Am I understanding correctly that when it happens, it happens in the "background" without me knowing about it? Meaning, there would be no indication on the dash display?
Got it. Thank you... again!!! So, in my truck it uses extra fuel for a regen, whereas the newer ones use urea?
Just out of curiosity, have you seen any type of trend (miles) as to when the DPF starts to get clogged (beyond what a regen can handle)? Or does the regen process work pretty well? Have you heard of people sending them out to be "baked"?
Last edited by DennisG01; Dec 22, 2016 at 11:20 AM.
Reason: more info/clarification
Besides my recently new to me 08 GL320 I own a 2008 Jeep Grand Cherokee with the OM642 and I put on 485000KM ( 302000miles) on it. Just recently I got a CEL error code that the dpf is plugged. Diesel Particulate filter ash accumulation. Based on that, I'm thinking the regen can not clear out the filter any more. It does run lazier and with less power. I don't know how many miles you have on yours but the dpf on my jeep was ok till now. After the holidays I will bring it to my mechanic who has a Liqui Moly DPF cleaning kit that he says will take care of it. I'll let you know how well it does.
Thanks, Homer. It will be interesting to hear how that works out! I have barely a fourth of your mileage!
I'd be tempted to just knock out the "filter material" inside the DPF the way I did with my Suburban (although it was all relatively clear with no regen program/sensor and about 100,000 miles on it at the time). But I don't know how (or if) the DPF sensor can be tricked... or even if it needs to be. And I don't want to be a guinea pig when it comes to programming the DPF out of the mix.
Last edited by DennisG01; Dec 22, 2016 at 11:53 AM.
Got the truck back today and so far, so good. The original Pressure Differential reading was 19HPA and the last time an automatic regen was commanded by the computer was about 17,000 miles ago. They did a force regen and the reading went down to 2HPA. They believe the sensor is OK since the values it measures changed, and didn't want to replace a likely "good" part for no reason. But they did say that there's still a possibility that it's flaky and showed me where it was where I can get an inexpensive replacement to do it myself (or bring it back and they would put a new one in with no charge for labor). They didn't charge anything for the time it was there this time, either.
This picture of their scantool screen was taken while I was there, picking up the vehicle after it was fixed as the tech wanted to show the process they went through.
It was cold again this morning (car stays outside) at 18*F. I experienced the same Limp mode as before. I kept driving it and after about 20 minutes I stopped and shut the engine off/on three times within about a minute. Made no difference.
I then drove another 10 minutes and turned the engine off long enough to go into Dunkin Donuts to get a coffee and back out. I started the engine back up and checked for codes (through OBDII with my little scanner) and got a "pending" code of P1402. I did NOT clear it. I then started driving and everything was back to normal.
P1402 (according to Google, anyways) comes back as an EGR issue (most likely this was the code I reference above, but did not remember it correctly). However, this is not through STAR and I also know that experience often trumps what a code/scanner may say.
But...
-- Could the cold weather be affecting the EGR and once the engine warms up everything returns to normal? Can the EGR be cleaned?
-- Or, is the most likely culprit still the DPF sensor?
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So, in my truck it uses extra fuel for a regen, whereas the newer ones use urea?
