Possible Rod Knock?

[jsprewell]

On Monday this week while driving to school a strange "knocking" noise started occurring and the Check Engine Light came on. Then when I came to a stop at the light, my oil pressure went down and the light came on. (the light and pressure went back up once I started moving) At this point I became very worried. Instead of attempting the 1hr drive to class (and on interstate), I turn around and hurry home. So the Envoy has been sitting at home since then. A couple of days ago I came upon this thread by Hatchet and started to think his issue was mine also. Today I had a friend come over who is a mechanic and he forgot his code reader. He said that it sounds like it could be rod knock but didn't want to confirm without the code reader.

Not looking too good but I'm trying to find some options. This is not good considering I just dumped $3,000+ on new tires, suspension parts, and other random stuff.


Anyway, here's a video I made a few days ago.

[video=youtube;9EoIH01odNw]http://www.youtube.com/watch?v=9EoIH01odNw&feature=share&list=UUMRzdsunIWSJqw1uay2Evtg[/video]

 

[Boricua SS]

Wow.. pretty good sounding knock... given my experience and 4 different motors within the past year, sounds like a rod to me... does it increase in noise as rpm's rise?

Hope you're not about to join the ranks of Joe and myself with an engine swap or rebuild

 

[jsprewell]

It seems to increase, or at least I think it does. For some reason it almost seemed to increase and then go away above 2,500 rpm, but now I'm just thinking it increases.

I hope I don't have to go through a swap or rebuild, but with the amount of money I've put into it and parts replaced by me or the body shop (over several minor wrecks), I don't want to just get rid of it.

If it comes to a swap or rebuild, I'm going to have to find someone to do it, I don't have the time to do a project like this. (besides the fact that I have zero knowledge about it and would have to learn)

 

[gmcman]

Disconnect the serpentine belt then try it again, you will be amazed at what a bad water pump sounds like on this motor. Sounds like a rod, but if it doesn't change with the belt off then you have further narrowed it down.

The fact your oil pressure dropped points to a bearing.

 

[jsprewell]

Well, I'm getting a new engine. I was going to see about just getting a used engine but they don't have warranties.

 

[lmcree]

Disconnect the serpentine belt then try it again

Have you tried this?

 

[Hatchet]

Yea does sound like rod knock. I know my oil pressure dropped when I would stop at a light. The bearing shaving collect on the oil pick up. I'm gunna guess you got code P1345?

 

[CaptainXL]

Well, I'm getting a new engine. I was going to see about just getting a used engine but they don't have warranties.

Just what makes you think you need a new engine? What proof do you have? Are you just going by someones word? You said the check engine light came on but gave us no code and had no diagnostic work done? Doesnt make sense. Many times what appears/sounds like rod knock is nothing more than a bad water pump as GMCman stated. The code could be for an overheat condition. Start simple and then work your way up if needed.

Also, GM has a bulletin on engine noise exactly like this. Basically if the wrong oil filter is used. They are emphatic that you use the PF-61e filter. It solves the problem a lot. What I would do is change the oil and filter and go from there. Codes can be read at any chain auto parts store. No need for a mechanic at this stage.

 

[jsprewell]

Yep.

Next step I have to do is ask our mechanic if he would do it, or if he knows someone trustworthy to do it. Then I have to locate an engine. I don't want just a used one. It has to have low miles and a good warranty. (which is why I'm looking at new also)

 

[CaptainXL]

?? It seems like you arent reading any of our advice. Please confirm you have had a proper diagnostic performed. And let us know what the results are. Dont be jumping to any conclusions just yet. Dont even think about planning to replace your engine. Its very expensive and would cost more than the vehicle is worth. A new engine is gonna run upwards of $3000 or more installed. Just get a diagnostic right now before worrying about a replacement.

 

[jsprewell]

?? It seems like you arent reading any of our advice. Please confirm you have had a proper diagnostic performed. And let us know what the results are. Dont be jumping to any conclusions just yet. Dont even think about planning to replace your engine. Its very expensive and would cost more than the vehicle is worth. A new engine is gonna run upwards of $3000 or more installed. Just get a diagnostic right now before worrying about a replacement.

I'm sorry, I didn't see your post above mine. I was responding to Hatchet.

When I first had the problem, I came on here and started searching. The belt was one of the first things I removed.

Also, my friend (or rather he's actually my brother-in-law) has looked at it but has kept forgetting the scanner. So, I went out and bought one myself (today actually). I figured the amount of times I needed one, I should just buy one.

Anyway, I'm getting P1345 and P0014 error codes. The reader says the P1345 is a "Crankshaft Position / Camshaft Position Sensor Correlation" and the P0014 code is an "Exhaust (B) Camshaft Position Timing - Over-Advanced (Bank 1)

I'm going to go speak with the family mechanic (old family friend) to see what my options are.

And again, I'm sorry about the mishap about my prior post. I was not trying to sound negative or un-wanting of help.

I want to feel like I know what's going on and what the worse case scenario is so I'm not surprised.

 

[Sparky]

?? It seems like you arent reading any of our advice. Please confirm you have had a proper diagnostic performed. And let us know what the results are. Dont be jumping to any conclusions just yet. Dont even think about planning to replace your engine. Its very expensive and would cost more than the vehicle is worth. A new engine is gonna run upwards of $3000 or more installed. Just get a diagnostic right now before worrying about a replacement.

Where are you getting that number? Maybe if he goes with a brand new engine, but not a used one. Not saying an engine replacement is cheap either, but still. Also, your comment "don't even think about replacing the engine" - are you suggesting that if the engine is bad that he just junk it? Because that doesn't really make sense if the rest of the truck is in good shape (and sounds like it is). And being 2WD is going to make it far easier to replace than a 4WD, probably wouldn't be that bad of a job over all relatively speaking.

Maybe it isn't that. Those codes are complaining about something else, but there is no code that is labeled "rod knock" either. (FWIW my old car when it spun a rod bearing the SES light never came on at all, and aside from lower oil PSI and the tapping noise it acted normal otherwise, drove fine and all.)

 

[Hatchet]

I'm sorry, I didn't see your post above mine. I was responding to Hatchet.

When I first had the problem, I came on here and started searching. The belt was one of the first things I removed.

Also, my friend (or rather he's actually my brother-in-law) has looked at it but has kept forgetting the scanner. So, I went out and bought one myself (today actually). I figured the amount of times I needed one, I should just buy one.

Anyway, I'm getting P1345 and P0014 error codes. The reader says the P1345 is a "Crankshaft Position / Camshaft Position Sensor Correlation" and the P0014 code is an "Exhaust (B) Camshaft Position Timing - Over-Advanced (Bank 1)

I'm going to go speak with the family mechanic (old family friend) to see what my options are.

And again, I'm sorry about the mishap about my prior post. I was not trying to sound negative or un-wanting of help.

I want to feel like I know what's going on and what the worse case scenario is so I'm not surprised.

Those are the same 2 codes mine was throwing. If you want to verify for sure, here is what you can do.

Take off the coil packs and spark plugs. Take a long screw driver and tape a piece of rubber to the tip (tape it good, don't want it falling off) and in each spark plug hole give a little push down on the piston. We did that to mine and the piston dropped about 1/4" or so. If none do it, I would rotate the engine manually (rotate the crank clockwise) and try again, It might have been on an upstroke at the first try. If any of the pistons move at all, then you have your answer its a blown bearing.

Where are you getting that number? Maybe if he goes with a brand new engine, but not a used one. Not saying an engine replacement is cheap either, but still. Also, your comment "don't even think about replacing the engine" - are you suggesting that if the engine is bad that he just junk it? Because that doesn't really make sense if the rest of the truck is in good shape (and sounds like it is). And being 2WD is going to make it far easier to replace than a 4WD, probably wouldn't be that bad of a job over all relatively speaking.

Maybe it isn't that. Those codes are complaining about something else, but there is no code that is labeled "rod knock" either. (FWIW my old car when it spun a rod bearing the SES light never came on at all, and aside from lower oil PSI and the tapping noise it acted normal otherwise, drove fine and all.)

If you have a shop do it. It would cost about 3k, that is what I was quoted. The mechanics manual says its about 16 hours worth of labor so it adds up. It was 1500 for labor and about 1200 for a used engine. But you can find cheaper used engines around, but the ones that come with a warranty are rebuilt ones and cost a lot.

 

[jsprewell]

Talked to our mechanic and he basically confirmed the possible bad bearing. Problem I'm facing now is finding a reputable place to do it. The guy our mechanic used to recommend is retired.

 

[jsprewell]

I finally found a place to look at the envoy's engine. It's going on Monday. He's going to see how much of it is salvageable and see about doing a rebuild first.

 

[CaptainXL]

I finally found a place to look at the envoy's engine. It's going on Monday. He's going to see how much of it is salvageable and see about doing a rebuild first.

Have you even been given a proper diagnosis and mode of failure (reason)? Surely any type of engine damage can be zeroed in on before any major work can begin. To do this would be prudent so you don't get taken for a ride. Anyone who is anyone can tell you your engine is shot. If all else go with a trusted shop that has been in business for a long time. This should in theory relieve at least some uncertainty.

 

[jsprewell]

Have you even been given a proper diagnosis and mode of failure (reason)? Surely any type of engine damage can be zeroed in on before any major work can begin. To do this would be prudent so you don't get taken for a ride. Anyone who is anyone can tell you your engine is shot. If all else go with a trusted shop that has been in business for a long time. This should in theory relieve at least some uncertainty.

He was recommended by someone in the family. Also, after talking with the mechanic, we've come up with several options about what it could be. What he's going to do now is start testing these options, up to the broken bearing option. Anyway, once he finds the problem, I'm going to have a look with him (with our family mechanic) and go from there.

Is there anything else you would recommend in this process?

 

[jsprewell]

***UPDATE***

The mechanic has finally been able to look at it and the problem is with the #1 cylinder. He said it is probably a bent/broken rod. He didn't say anything about the bearing, but he said he didn't check that specifically. Also, there are now metal flakes in the oil, so at this point it's cheaper to just replace the engine. They searched for used engines and rebuilt engines. After looking at all the options, I wasn't satisfied with the used engines because of the high miles and no/short warranty. So I'm going with the rebuilt engine that comes with a 3-year warranty. It's going to cost $5,200 parts + labor.

 

[CaptainXL]

If you can take the engine out I would hand it over to a machine shop. They can give you a warranty. I hope you meant $5200 total? Reason being is that rebuilt 4.2 GM Goodwrench engines are about $3500.

 

[jsprewell]

If you can take the engine out I would hand it over to a machine shop. They can give you a warranty. I hope you meant $5200 total? Reason being is that rebuilt 4.2 GM Goodwrench engines are about $3500.

Yes, that's the total cost.

The biggest problem is that this is my only vehicle. If it were a second vehicle, I would even look into doing it myself. So the longer it takes, the more money it's costing me in rental fees.

 

[Sparky]

Yes, that's the total cost.

The biggest problem is that this is my only vehicle. If it were a second vehicle, I would even look into doing it myself. So the longer it takes, the more money it's costing me in rental fees.

I feel you. Been there done that with my old car (rod knock/blown engine and only car), except I was bumming rides and borrowing cars from friends.

I don't miss the one car life. Although winter becomes effectively one car as my second is NOT suited for winter at all.

 

[strat81]

It's going to cost $5,200 parts + labor.

NADA lists clean retail price of a 2WD SLT w/ 160,000 miles as $6,000.

$5,200 is a nice down payment on something else. Hit the used car lot today, and sell or part-out the Envoy over the coming weeks. Ask the mechanic who is doing the engine swap if he's interested in buying it from you for $2,000 or whatever you think is appropriate.

Sorry about the bad news.

 

[gmcman]

That stinks.....but also something to consider, if you swap it yourself or get some help, you have a motor with 0 miles....much better than 160K. I know what you're saying about value but if you like the vehicle then what does it take to kep you in it with a fresh motor? Good luck with what ever you decide. I know I love mine, hard to find something built like it these days at a decent cost.

 

[strat81]

Find out how complete that new engine is. Does it include intake and exhaust manifolds, throttle body, alternator, water pump, etc.?

If it doesn't include those items, will you install new ones or swap the ones off your old engine?

Any transmission repairs ever done? With the engine removed, it might be worth it to consider a trans rebuild, u-joints, etc. If the transmission has never been serviced aside from fluid and filters, do you want to put an old transmission behind a brand new engine with the possibility of a dead transmission in the near future?

 

[jsprewell]

I went to talk to our mechanic about how the Envoy engine swap was going. When I drove up, the front was assembled and it looked like it was almost finished, so it looked good... at first. Due to a screwup from the company that we got the new engine from, they sent a 2005 I6 engine instead of a 2002 I6. This was not discovered until after the mechanic had the engine installed. So after a few phone calls, they will be getting new parts to fit the 05 engine. The company supplying the engine will pay for these parts so the cost to me is still the same. They said it should be finished by the end of the week, but that depends on how quickly the parts arrive.

The mechanic told me a few things that needed changed out and what parts were ordered, but as far as PCM reprogramming or any other issues, I am completely in the dark.

EDIT: BTW, this is a refurbished 05 I6.