CRD boost diagnostic

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Btownpreacher

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That's a shame, looks like time to pull the cam carrier off.
I reeeally want to. But if I do that then I have to pull the head, get the valves checked, stud it with a new head gasket, machine the manifold, and probably get new injectors. All because while you’re in there you do it all.
 

turblediesel

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New idea. Go ahead and roast me now, because I don’t know the correct terminology for this valve train. The rockers have some kind of hydraulic component to them. I’ve heard different words used to reference them so whatever they are called. I’ve heard some say that they aren’t fluid filled but rely on the engine oil. Regardless, if the hydraulic ram on the rocker collapses couldn’t that cause a metallic chatter from the rocker? The noise goes away with load, about 1000rpm, or after the engine has run and warmed up fully. This would allow the engine to still run but could explain the metallic sound.
The hydraulic component is a tiny lifter attached to one end of the rocker. The other end of the rocker is on a valve with a roller in the middle that contacts the cam lobe. It could make noise if collapsed but it can also jump out of position since the hydraulic pressure from the lifter is all that holds it in place besides the cam. The rollers and pins they spin on wear a lot on the KJ CRDs limiting valve opening so you might want to replace them all while you're in there. The crud from the EGR system causes a lot of wear.

My parts jeep came with a popped turbo hose and non-running engine. I get a little extra click from the exhaust side of cylinder 4 every two hand turns of the crank so my guess is I'll find a broken rocker someday when I tear it down. Nice that it spins anyway.
 

Btownpreacher

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Is the hydraulic pressure internal to the lifters or is it supplied by the engine oil?
 

turblediesel

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Engine oil.

Check out CaptainDean's clinking and clanking thread on LOSTJEEPS. He came up with a nifty way to check his lifters.

As to pulling the camifold and reinstalling it get some 1/2" or 5/8" grey plastic conduit and cut 6-8 2-3" pieces to put between the camifold and head and you can manage it better so the rockers don't get knocked around. Mirrors, flashlights, and cameras can peek the length of the gap to make sure the rocker-lifters haven't moved before the conduit pieces come out.

A couple of long bolts with the heads cut off threaded into the front injector clamp holes to help guide the camifold back into place.
 

Btownpreacher

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"Horrendous metallic rattle"... Did you add a new water pump with the belt change? Could be a rocker-lifter jumped off and maybe fell deep into the counterbalancers down low in the engine. With four valves per cylinder you can lose one rocker and the cylinder can still work at reduced capacity. Exhaust valves sometimes break. Valve seats sometimes drop. The tips on the oem ceramic glowplugs break off and cause damage as they dance with the piston and valves.

Otherwise check the bottom of the hose going from the airbox to the turbo. They tend to rot a hole there with a loss of power. There's a turbo actuator controller that controls the variable vanes in the turbo (US model) that goes bad or doesn't get enough vaccuum due to a cracked line. You can barely reach the vane actuator lever and see if it moves freely. If it doesn't, it won't get full boost.
How much should the vane actuator move? I’m pretty sure mine is seized
 

Btownpreacher

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"Horrendous metallic rattle"... Did you add a new water pump with the belt change? Could be a rocker-lifter jumped off and maybe fell deep into the counterbalancers down low in the engine. With four valves per cylinder you can lose one rocker and the cylinder can still work at reduced capacity. Exhaust valves sometimes break. Valve seats sometimes drop. The tips on the oem ceramic glowplugs break off and cause damage as they dance with the piston and valves.

Otherwise check the bottom of the hose going from the airbox to the turbo. They tend to rot a hole there with a loss of power. There's a turbo actuator controller that controls the variable vanes in the turbo (US model) that goes bad or doesn't get enough vaccuum due to a cracked line. You can barely reach the vane actuator lever and see if it moves freely. If it doesn't, it won't get full boost.
I replaced my turbo a few weeks ago with the Sasquatch parts replacement turbo. It was a very simple installation, although reinstalling the oil lines was a bit of a pain. I've noticed a few new things since the install. First, my red silicone Mishimoto CAC hoses expand a massive amount, maybe 1" in diameter, when they're under boost; this seems off, because if they flex under pressure then they are robbing the boost from the engine by allowing it to expand in the CAC hose. Second, the intake hose going into the front of the turbo is completely rotted; there's no room for a hose clamp anymore. How would this affect performance? turblediesel indicated that it might be related somehow. Third, when I removed the old turbo, the vanes on it were completely seized; obviously the new turbo vanes are intact, but I believe they aren't actually working. My boost threshold is around 2000RPM and it is smoking terribly in first gear below 2000 RPM; second isn't as bad because there's some residual boost from accelerating in first. But when I accelerate, whenever it shifts gears and the rpm drops, it immediately loses boost and takes a couple of seconds to spool again. This makes it very difficult to drive unless you just floor it all of the time. I believe that this indicates a boost actuator problem; is there a way to test this, or does anyone else have a good explanation?
 

seafish

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First, my red silicone Mishimoto CAC hoses expand a massive amount, maybe 1" in diameter, when they're under boost; this seems off, because if they flex under pressure then they are robbing the boost from the engine by allowing it to expand in the CAC hose.
This is not true...while I have no idea exactly why the new hose is blowing up a bit like a ballon, it is not "robbing " you of boost pressure by doing so....well, unless it splits open while under pressure.

That said, blowing up like a ballon IS possibly an indicator of some sort of restriction downstream of the new hose....maybe the intercooler needs a good cleaning, maybe the intake elbow full of soot from the EGR mixing valve. EITHER way, the new Mishimoto hose is NOT the problem.

Second, the intake hose going into the front of the turbo is completely rotted; there's no room for a hose clamp anymore.

The intake hose rotting at the turbo is a common failure point and is most likely the source of your engine/drivability issues and also very possibly the source of your old turbo failure!!!

ANY air that enters through ANY hole in the intake hose, let alone a fully rotted connection right at the turbo, is bypassing the MAS at the airbox... this will NOT allow the ECU to properly control fueling and boost for your CRD.

Also importantly, ANY air that enters the turbo through that hole in the intake is bypassing the air FILTER, which means any and all sorts of particulates dusting and eventually destroying your turbo and engine, particularly if you are driving in off road or in otherwise dusty or polluted conditions.

TLTR-- Stop driving the car and het yourself a replacement intake hose ASAP !!!
...the silicone one form Sasquatch is very high quality and being made from silicone will NOT rot out again. Then, while your installing the new intake hose, ALSO spend time finding the source of the restriction between the IC and the intake manifold. Once all these steps are completed, both your CRD and yourself should be MUCH happier when driving!!!

Just my .02
 
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seafish

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Of course, if you haven't yet, you should ALSO check the vacuum line to the turbo actuator like others have previously suggested!!!
 

Btownpreacher

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This is not true...while I have no idea exactly why the new hose is blowing up a bit like a ballon, it is not "robbing " you of boost pressure by doing so....well, unless it splits open while under pressure.

That said, blowing up like a ballon IS possibly an indicator of some sort of restriction downstream of the new hose....maybe the intercooler needs a good cleaning, maybe the intake elbow full of soot from the EGR mixing valve. EITHER way, the new Mishimoto hose is NOT the problem.



The intake hose rotting at the turbo is a common failure point and is most likely the source of your engine/drivability issues and also very possibly the source of your old turbo failure!!!

ANY air that enters through ANY hole in the intake hose, let alone a fully rotted connection right at the turbo, is bypassing the MAS at the airbox... this will NOT allow the ECU to properly control fueling and boost for your CRD.

Also importantly, ANY air that enters the turbo through that hole in the intake is bypassing the air FILTER, which means any and all sorts of particulates dusting and eventually destroying your turbo and engine, particularly if you are driving in off road or in otherwise dusty or polluted conditions.

TLTR-- Stop driving the car and het yourself a replacement intake hose ASAP !!!
...the silicone one form Sasquatch is very high quality and being made from silicone will NOT rot out again. Then, while your installing the new intake hose, ALSO spend time finding the source of the restriction between the IC and the intake manifold. Once all these steps are completed, both your CRD and yourself should be MUCH happier when driving!!!

Just my .02
Thanks bro. it makes sense now. unfortunately I'm out of work and dead broke right now so it'll take me a few weeks before i can potentially buy anything. I cleaned the MAP, MAF, and cam sensors this afternoon and it drives slightly differently but not necessarily any better.
 

Btownpreacher

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Of course, if you haven't yet, you should ALSO check the vacuum line to the turbo actuator like others have previously suggested!!!
Anything in particular to look for on the vacuum lines? They seem intact and I believe they are holding some vacuum pressure, perhaps not the full amount tho
 

seafish

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unfortunately I'm out of work and dead broke right now so it'll take me a few weeks before i can potentially buy anything. I cleaned the MAP, MAF, and cam sensors this afternoon and it drives slightly differently but not necessarily any better.
Ya cleaning the sensors wont do anything at all if there's still a hole in the bucket...er I mean intake.

I recently switched to the Sasquatch intake hose when I did his turbo. It was just as preventatove maintenance at 200k. In for a penny, in for THOUSANDS, as they say in the KJ CRD world. :rolleyes:

But my old intake was actually still in decent condition and Im more then willing to send it to you if you pay the shipping. Where are you located??
 

seafish

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Looks like I can ship it UPS ground to you for $27.50...make it $30 paypal just in case and its yours. Its in good working condition and will attach a pic later, but just finished errands and gotta rest for a bit.
 

seafish

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K following are the pix...
Obviously the hose needs a light cleaning but is not rotten anywhere.
On close inspection there IS a superficial crack on the smaller turbo side of the hose.
This crack is about 3/4" long but does NOT go all the way through AFAICT.
You can easily see it in the last picture.

I'll bet cleaning in and around the crack with acetone and follow that with some black RTV in and around the crack and this thing would be good for a long time.
Certainly its in MUCH better condition then an intake hose that cant even be clamped to the turbo anymore.

Speaking of clamps, I'll leave both of them on it if you want it and they are also in good woring condition.

All that said, I totally understand if you wanna save your money for the Sasquatch intake hose.
Just lemme know either way.

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KJowner

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Sounds like you are overboosting, as you say possible an actuator problem or an issue with the new turbo or MAP.
Have you cleaned the MAP sensor?
 

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