Throwing Overboost P0234 code as accelerate through about 60

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

VERY short drive with suggested vacuum hose disconnected... I'd call it a dog... certainly far less pep than my 200 Honda CRV 4 cylinder. Oh, and a whiner too.

Goglio704 · **Posted:** Fri Oct 12, 2012 9:21 pm

Did the noise change? Pop any new codes?

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

So if the vanes are blocked, how do you clear them... and don't suggest Italian Tune Up... been there, tried that... not going there with this whine.

Goglio704 · **Posted:** Fri Oct 12, 2012 9:37 pm

Have you tried helping the linkage by hand? If it is just a carbon build up I would think you could work it loose. Somebody actually had one of the vanes controlled by the actuator get flipped around backwards. Don't remember who that was or what they did for it, but I do remember seeing pictures.

As for earlier questions about leak testing, I would think a clean shop vac with the hose in the blow socket would pressurize the system well enough to blow bubbles for a soapy water test. You may have popped something with overboost. A large leak could explain the noise.

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

Just to reset a bit... I'm trying to identify and solve the newly-acquired (post-Italian-Tune-Up) very loud 'whine' issue now, not specifically the overboost code. GreenDieselEngineering and Goglio704, are you suggesting troubleshooting steps for the whine or are you trying to address the overboost... or do you think the two are linked?

racertracer · **Posted:** Sat Oct 13, 2012 3:33 am

The vanes are stuck. That arm needs to move upward approx. 1 1/4" to 1 1/2". The noise is not a good sign and you should be checking for shaft play.

If you identified the noise as deriving from the turbo and the turbo has considerable shaft play, then it's a done deal and you should be considering replacing it because it will fail and if it fails you know the consequences.

If shaft play is minimal and you want to clean the turbo without performing the Italian tune up, then do what some people have done using oven cleaner.

They cleaned the stuck vanes using spray on oven cleaner sprayed in the exhaust side of the turbo where the vanes are and have gotten good results.

You don't need to remove the turbo to get at it, just detach the downpipe and spray inside (the back part of the turbo). Do it several times and let it sit over night.

After you put it all back together, drive it for an extended long drive to blow the crud out. Don't be afraid to drive it hard if shaft play is minimal.

Oven cleaner does a really good job on dissolving carbon build-up.

Good luck.

jlgail4309 · **Posted:** Sat Oct 13, 2012 8:26 am

I just order this part last night. The hose is from the air box to the turbo. I don't know if mine bad yet. I can tell the oil has got to it and looks old. I read post were its cause problems. U might look at it. I would think if that hose was broke it would be loud turbo noise. U might ask around on this one. We are going to take a long trip. So I'm replacing anything that might cause problems. I also believe u can check for turbo shaft play when u replace that hose. Hope this helps.

Mopar Part 53013104AE CLEAN AIR HOSE

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

I'll check for play again, but I did check that when I originally pulled the bad intake hose... very little lateral play, and about 1/16 to 1/8" in and out play, felt from the intake side. Can stuck vanes or carbon lodged in the vanes / wheel alone cause the whine / whistle? The noise was not there before the repeated Italian Tune Up attempts to clear the overboost issue.

jlgail4309 · **Posted:** Sat Oct 13, 2012 9:59 am

pappyrsg wrote:

I'll check for play again, but I did check that when I originally pulled the bad intake hose... very little lateral play, and about 1/16 to 1/8" in and out play, felt from the intake side. Can stuck vanes or carbon lodged in the vanes / wheel alone cause the whine / whistle? The noise was not there before the repeated Italian Tune Up attempts to clear the overboost issue.

Is that whine or whistle like real load bad or just a sound that is new. Now that I've got mine fixed. I can hear the turbo and I couldn't hear it before. I wouldn't think that stuck vanes would allow it to whistle. I would pm papaindigo .

Goglio704 · **Posted:** Sat Oct 13, 2012 10:52 am

pappyrsg wrote:

Just to reset a bit... I'm trying to identify and solve the newly-acquired (post-Italian-Tune-Up) very loud 'whine' issue now, not specifically the overboost code. GreenDieselEngineering and Goglio704, are you suggesting troubleshooting steps for the whine or are you trying to address the overboost... or do you think the two are linked?

I do think they are related, but troubleshooting based on noise is always chaotic. One man's whine is another man's whistle... Does the whine sound like a louder version of normal turbo noise? If so, I suspect you have a boost leak caused or made worse by the overboost condition. People that have blown hoses have been astonished at the noise the turbo makes. I can't think of anybody reporting more than a minor leak in the intercooler, but it is possible to split a tank or separate a tank from the core.

Might the noise be something else? A bearing in the alternator, idler pulley, or whatever?

For your own peace of mind, I think you should try to find the noise first.

As for the overboost, I don't think the actuator has proper travel. I think the variable portion of the turbo is stuck in the high boost end of the range.

As for the Italian tune up, it is more of a preventative than anything and more applicable to sluggishness than overboost. I think you are wise to avoid it until you are sure your overboost is resolved. It is, however, good preventative medicine.

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

The noise is clearly discernible as coming from within the turbo housing, at least as far as I can tell by applying my stethoscope there. Of course that could mean a whistle being generated by one or more clogged vanes now acting as a musical instrument... with just two tones. One can only hope...

papaindigo · **Posted:** Sat Oct 13, 2012 12:57 pm

You might want to check out this overboost thread viewtopic.php?f=5&t=70679&p=751066&hilit=turbo+vane#p751066

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

Very interesting thread suggested by papaindigo... and a great UTube video link within... big help in understanding the turbo operation. Also noticed a post in that thread by GreenDieselEngineering that stated the vane actuator control rod should move up and down just over 1/2", vs the 1 1/4 to 1 1/2" racertracer suggested. What's up with that?

My actuator rod did seem to move a half inch or so during one portion of my vacuum pump test... although more like 1/4" the last time I tried it. I'll be talking to GDE Monday, but anyone else care to comment on that stroke length given your actual experience?

Tomorrow (Sunday) I'll be opening up the intake (again) and exhaust ports to at least see what I can see from those vantage points. Hopefully I won't see the kind of destruction the Canadian in the one video did within his turbo. Film at 11... or at least a pic or two.

Goglio704 · **Posted:** Sat Oct 13, 2012 10:24 pm

1/2 sounds about right from what I remember. I might get time to measure it tomorrow.

racertracer · **Posted:** Sun Oct 14, 2012 11:01 am

I apologize for the confusion, but my memory failed me; those lengths were from a larger turbo we worked on some time ago. Thank you for the correction.

Racer

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

Well, I pulled turbo intake (again) and exhaust ports... same 'play' results on both ends (to be expected)... maybe 1/32nd in and out, no more than 1/64th lateral... bearings seem good. Both ends look a bit dirty (sorry, I can't figure out how to include pics), but nothing beyond expected for this design, given inadequate blowout frequency (ITU once a week or so might have kept things cleaner). I unbolted the boost control actuator to manipulate that function manually... the variable vanes are definitely impeded inside the turbo... I could work the rod up and down the full expected 1/2" +, but there's no way a vacuum-driven actuator is going to overcome the friction... probably 5lbs resistance. Worked the rod up and down a hundred times or so with no significant change in resistance. Did the oven cleaner thing, will see where we are tomorrow afternoon... also plan to discuss with GDE. Wondering... any opinions on blowing out the oven cleaner dried foam tomorrow with compressed air, anmd then repeating the oven cleaner as necessary, rather than doing a full re-assemble just to let the engine exhaust blow it out? Could the dried foam residue being pushed up into the exhaust manifold, or through a valve into a cylinder, cause any harm? With the coolant reservoir involved, Jeep has made cycling through disassemble, reassemble, and startup for blowout, a real PITA. On that subject, has anyone else noticed how completely the design engineers ignored allowing for any reasonable access to simple maintenance functions... like the radiator petcock. Don't you want to find those weasels and take them out back for a good old-fashioned bitch-slap? This kind of sloppy design gives a bad name to all the other good American engineers who took the trouble to design things right.

Goglio704 · **Posted:** Sun Oct 14, 2012 9:36 pm

I think compressed air could well blow crud back into a cylinder. Rather than reassemble, you might break the egr pipe loose at the back of the manifold. This would provide an inlet for air so you could attach a shop vac and suck the crud out of the turbo. I believe I would hold the impeller on the fresh air side so as not to spin the bearing at speed without oil pressure. I would let it turn some, but I wouldn't let it build much speed.

papaindigo · **Posted:** Mon Oct 15, 2012 9:20 am

FYI there is one fairly obvious hose on the coolant tank that if rerouted allows the tank to be unbolted, slid forward off the metal bracket underneath the tank, and then tilted and moved toward the passenger side hood support out of the way of access to the turbo. It also helps to prop the hood up and simply pop the passenger side hood support off.

As to the radiator petcock see viewtopic.php?f=98&t=56398 for a nice simple tool that makes opening a breeze especially with a racheting wrench.

racertracer · **Posted:** Mon Oct 15, 2012 10:04 am

I found a simple way to get at the radiator drain (petcock).

I removed the air filter box for easy access from the top.

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

Oven cleaner doesn't seem to be doing much... actuator rod still hard to move through its 1/2" stroke. Will likely pull the turbo, split and clean manually. After speaking with Keith at GDE, I'm thinking even that won't remedy my issue... the repeated ITU runs probably fried the bearings as the turbo ran into repeated over-speed trying to handle things with vanes that would not move through their full motion. Not to jump the gun just yet, but assuming I need a replacement turbo, GDE indicates it will be a while before I could get one of theirs. After a quick web search for other sources, found turbochargerpros.com with a very attractive price for their version ($795 new) and even lower for a 'Remanufactured' one ($645)... too good to be true... thoughts?

Throwing Overboost P0234 code as accelerate through about 60

Who is online