Fix or Sell?

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SimulatedZero
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Fix or Sell?

Postby SimulatedZero » Mon Dec 04, 2017 2:21 pm

A while back, one of my front catalytic converters completely clogged up and started to crumble. When it gave out, the back pressure blew oil out of the head gaskets all over the engine bay. Since then, I haven't had the money to do many of the repairs or get a new vehicle. I drilled out all four converters, replaced the sparks plugs, replaced one coil pack and went from there.

I have had issues with running lean and issues with bank number 2 a lot since then. Looking in through the intake after removing the manifold I could see some oil scaring on the wall in cylinder 6 (the same cylinder that blew the coil pack). I was never able to track down the running lean issue. I couldn't find a vacuum leak, fuel pressure was fine, o2 senors in the exhaust manifolds were replaced, MAF sensor checked out fine. This left me thinking the fuel injectors got a little bit damaged along with everything else when the converters plugged up.

That's where I left it about 8 months ago. I had to move for my job and have been paying for two places and living between them ever since. No time or spare cash to keep trying things.

That left me with not being able to maintain oil levels, some issues overheating periodically, and the long term fuel trim trying to dump as fuel as possible into the cylinders.

Today, it finally had enough. I had some issues with hard starts yesterday and knew it was time to clear the fuel trims so it didn't flood the engine. On the way home today, it started up, would rev to 1500 rpm and start cutting out like it hit a rev limiter. I managed to limp home, hooked an OBD2 scanner, and suddenly I could't read or clear codes. The little bit I could see was a p0021 for the cam shaft solenoid, a few other issues with the cam shaft performance on both banks, and an ETC sensor giving too high of a voltage.

Now I have a no start condition, no tools with me, and I can't read the codes. Sometimes the engine will almost catch, but mostly just turns over. I know the solenoids have been abused with the bad oil leak, the head gaskets are blown, there is probably some damage to the number 6 cylinder, and probably some damage to the fuel injector system. ( I was never able to a compression test on the engine or a spray test on the injectors)

Does anybody have any additional thoughts or things I can try? I should be able to get my hands on some basic tools this evening or so. Part of me thinks it's time to put this thing out of its misery, but part of me is too stubborn.


element808
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Postby element808 » Tue Dec 05, 2017 11:55 pm

P0021 can be triggered by a few things. A low oil pressure/level will cause this code to trigger. Without the proper oil pressure, there will be no change in Intake Valve Timing when the ecm actuates the solenoid. When the ecm sees no change for that bank, the dtc is triggered. There is also the possibility that it has a faulty ivt solenoid where the ecm attempts to actuate it, but no change in duty cycle observed. You can also have a stuck VTC sprocket (intake cam gear). This is not common, but I have seen a few in the past. If you have a bi-directional scanner, you could data monitor these sensors/signals to see what exactly the ECM is detecting when cranking the engine.
Regarding the cats blowing out....If you notice your engine consuming more than normal amounts of oil, you may have damaged that cylinder(s) when the cat blew. Not only does the main catalyst clog your front tube, there is a high chance that the cat material ended up being sucked back into the cylinder when the engine entered a vacuum state under deceleration.

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SimulatedZero
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Postby SimulatedZero » Wed Dec 06, 2017 8:16 am

I can monitor most of the sensors still (primarily o2, fuel trims, etc...) Not sure if I would be able to see that particulat data. I know oil pressure is the issue for sure. You can watch oil seap from the head gasket onto the exhaust manifold anytime I fill it.

First step at this point is to start pulling the covers and replacing the gaskets. I will probably order in everything to reseal everything else while I'm in there. Get oil pressure back and see if fresh oil and good pressure will clear up the solenoid issues.

If the cat material sucked back into the piston, how bad do you think the damage would be?

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Postby eieio » Wed Dec 06, 2017 11:29 am

SimulatedZero wrote:

If the cat material sucked back into the piston, how bad do you think the damage would be?
..............a compression & leakdown test would answer that.
That would be my recommendation for the next step.
How much would a comparable replacement used R51 be in your region?
How much would a used engine be?

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smj999smj
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Postby smj999smj » Wed Dec 06, 2017 2:37 pm

Obviously, you have some major mechanical issues, but one thing to add: if you gut out the converters on these engines, you will get a lean running condition unless you have the ECM programming re-mapped. So, if you do decide to replace the engine or repair it, you will need to at least replace the upstream catalytic converters OR get a custom ECM tune, i.e. UpRev.

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SimulatedZero
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Postby SimulatedZero » Wed Dec 06, 2017 7:14 pm

For the love of god, this. You have no idea how long I have been trying to figure out why it's running lean.

I do need to run a compression test for sure. As far as tuning it, is uprev the only option? There aren't any shops around me that can tune a car like that.

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smj999smj
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Postby smj999smj » Wed Dec 06, 2017 10:16 pm

UpRev is the most popular option, but I can't say for sure if it's the "only" one. The ECM fuel management program needs to be remapped to compensate for the modification (or "elimination?") of the converters.

element808
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Postby element808 » Wed Dec 06, 2017 11:04 pm

smj999smj wrote:UpRev is the most popular option, but I can't say for sure if it's the "only" one. The ECM fuel management program needs to be remapped to compensate for the modification (or "elimination?") of the converters.
Or you can try and fake out the system by either getting an rear O2 sensor simulator or to try and space out the rear O2 sensor from the direct stream flow of the front exhaust tube.

element808
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Postby element808 » Wed Dec 06, 2017 11:09 pm

SimulatedZero wrote:I can monitor most of the sensors still (primarily o2, fuel trims, etc...) Not sure if I would be able to see that particulat data. I know oil pressure is the issue for sure. You can watch oil seap from the head gasket onto the exhaust manifold anytime I fill it.

First step at this point is to start pulling the covers and replacing the gaskets. I will probably order in everything to reseal everything else while I'm in there. Get oil pressure back and see if fresh oil and good pressure will clear up the solenoid issues.

If the cat material sucked back into the piston, how bad do you think the damage would be?
One more thing regarding the P0021, you can remove the ivt solenoid from the cylinder head and check for any clogs. Remove the 10mm bolt and slide the solenoid out the the housing. You can try and and see if there is anything stuck in it. You can also apply 12v and ground to it and check to see if the solenoids move up and down. If the solenoids don't operate by energizing it, you may just have a faulty solenoid! Good luck!

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SimulatedZero
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Postby SimulatedZero » Thu Dec 07, 2017 3:13 pm

Quick question to add to my options here. Some guys on the Frontier forums did a bunch of digging around about doing a VK55 swap. Do you guys think the 08 Pathfinder VK, wiring harness, and transmission would relatively smooth to drop into an 05? Fairly similar in cost as doing a VQ40 replacement.

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eieio
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Postby eieio » Thu Dec 07, 2017 5:35 pm

SimulatedZero wrote:Quick question to add to my options here. Some guys on the Frontier forums did a bunch of digging around about doing a VK55 swap. Do you guys think the 08 Pathfinder VK, wiring harness, and transmission would relatively smooth to drop into an 05? Fairly similar in cost as doing a VQ40 replacement.
I don't think so.
Seems to me that the engine compartment had to be lengthened in 2008 to accommodate both engine options.

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smj999smj
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Postby smj999smj » Fri Dec 08, 2017 12:18 am

element808 wrote:
smj999smj wrote:UpRev is the most popular option, but I can't say for sure if it's the "only" one. The ECM fuel management program needs to be remapped to compensate for the modification (or "elimination?") of the converters.
Or you can try and fake out the system by either getting an rear O2 sensor simulator or to try and space out the rear O2 sensor from the direct stream flow of the front exhaust tube.
That might prevent a P0420/P0430 code from triggering, but it's not going to do anything for the lean running condition. Rear O2 sensors are only monitoring sensors for the ECM to check the efficiency of the catalytic converters and have no affect on fuel management. Replacing the front converters or getting a custom tune for the ECM is the only thing that is going to fix the lean condition caused by gutting or removing the front converters. It's a fairly common issue discovered by those who swapped the factory exhaust manifolds with long-tube headers, which eliminate the upstream converters.

element808
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Postby element808 » Fri Dec 08, 2017 1:25 am

smj999smj wrote:
element808 wrote:
smj999smj wrote:UpRev is the most popular option, but I can't say for sure if it's the "only" one. The ECM fuel management program needs to be remapped to compensate for the modification (or "elimination?") of the converters.
Or you can try and fake out the system by either getting an rear O2 sensor simulator or to try and space out the rear O2 sensor from the direct stream flow of the front exhaust tube.
That might prevent a P0420/P0430 code from triggering, but it's not going to do anything for the lean running condition. Rear O2 sensors are only monitoring sensors for the ECM to check the efficiency of the catalytic converters and have no affect on fuel management. Replacing the front converters or getting a custom tune for the ECM is the only thing that is going to fix the lean condition caused by gutting or removing the front converters. It's a fairly common issue discovered by those who swapped the factory exhaust manifolds with long-tube headers, which eliminate the upstream converters.
Missed the lean condition part...you are totally correct!

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SimulatedZero
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Postby SimulatedZero » Sun Dec 10, 2017 3:14 pm

Got a litttle time with the engine today. Solenoids weren't clogged and actuate fine. Pulled a spark plug and got a bit of an oil smell as much as a gas smell. Priced out new valve covers and a complete engine gasket kit for around 220 total. I need to get a gauge to do a compression test.

I didn't find any cracks in the block giving it a once over. The timing chain tensioner and water pump access covers have leaking too. I just need to pull the front off the car, pull both valve covers reseal everything and inspect for damage as I go. If thats all that's wrong with it then I can get that done and reflash the ECU at a shop in Orlando.

Battery needs 6o be charged up to do a compression test. Im hoping there isnt too much damage to the cylinder walls.


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