Knocking After warming Up

[Mrcln1]

Remanufactured Engine with only 4k miles. When first started it's as quiet as a church mouse. After warming up or revving it has a bottom end knock. No oil consumption. Started hearing what sounded like a loose heat sheild about a thousand miles ago on decel and light pedal pressure. Now once warm or revving it sounds like knocking from the bottom front. Since theres no knock at initial startup can I save this engine?

Thanks Alot,

Mrcln1

[navistar]

It wouldn't still be under some kind of warranty from the remanufacturer, would it? Or a warranty from the installer? Might not be a bad idea to let the installer hear the sound just because it's not a bad idea.

[Mrcln1]

A friend of mine installed it. I don't think he ever wants to see it again. It gave him a hell of a time.lol From my experiences working on it I don't blame him one bit. It has a 100,000 mile warranty. I'm gonna take it to either a local import mechanic or the dealer in a town about 50 miles away to have it looked at. I can't believe this would happen 4k in and right after my original motor went at 117k. I thought maybe since it has to warm up first I'd be able to salvage it. I honestly just want to get rid of it now. I had a hard time trusting it before but now it's definitely gone once it's running ok again. I'm just trying to get an idea what I'm up against. I'm all ready in the hole from giving it second chance at life. The warranty pays around $50 dollars an hour labor. I'm sure the dealer or any other good shop will charge more than that so I'll be out even more. Still open to suggestions though.

Thanks,

Mrcln1

[navistar]

I think it's important to have it looked at by a CERTIFIED mechanic, ASAP. It might not be death throes. Based on that, you could look at the terms of the warranty assuming you still have the warranty paperwork and contact the remanufacturer. Ask the mechanic how to proceed. I had multiple knocks and noise in the engine of a Rodeo and my mechanic said there was a key or something at the front of the crankshaft somewhere and he fixed it. Said the crank was out of position. I don't remember exactly. Any way, he could have hit me up for a new engine for thousands but the fix was just a couple or three hundred dollars. I sold it to my sister and it's still running years later. Got almost 200,000 miles on it.

Of course, the alternative is to do nothing and see if it gets worse.

[Tobert]

My wife's Subaru had a similar problem. The front pulley bolt had come loose or something then it beat the key out until there was a really wide keyway in the pulley. I got a new pulley from the junk yard and it's all good again now. Loctite is your friend

If you're running 5w30 or 10w30, it should have oil pressure almost immediately upon starting and not drop unless the engine is in really, really bad condition. Your oil light would be coming on in that case. The best way to tell bottom end knock that I learned as a kid is to rev the engine a little and listen for hammering as the rpm's come back down. The theory is that if a rod journal is hammering, it'll hammer more when rpm's are normalizing than when under load.

Other things to check are torque converter bolts, flexplate bolts, and fan clutch. I just noticed last week that the service manual says never to reuse the torque converter bolts. I'm not sure why that is, as it's always worked for me in the past. I'm ordering new ones when my engine goes in, though.

I know that feeling of frustration.

[WILLY]

Check that egr valve nut under the egr,when loose or not put back in they tend to make a noise similar to an engine knock,mine did.

[Mrcln1]

Started it again today to keep the battery from dying and it's completely silent until you rev it a little. Weird.

[Ldub]

Check that egr valve nut under the egr,when loose or not put back in they tend to make a noise similar to an engine knock,mine did.

Did you check this? It would be very easy to overlook upon installation, & it's not uncommon for the EGR nut to vibrate loose.
Many here won't leave home without a 22mm "stubby" wrench in the glove box.

[Mrcln1]

I'm gonna go out and check the egr nut in a little while. I know the dealer said it was cross threaded when they worked on the intake gaskets. I was so happy to have it running that I forgot to ask what they did about it. I'd like to take the whole tube off and check it that way. How hard is that to do? I still can't imagine how that could cause the sound I'm hearing. It definitely sounds like its coming from the bottom of the engine. I really hope thats it cause it'll cost me at least $200.00 to get it to the nearest dealer. I'll update after I check it. Almost forgot that I had a check engine light come on awhile back that ended up being knock sensor low input or output or something. Probably should have mentioned that earlier. I had asked on here what it might mean but no one seemed to know. From the sound of the name I thought it could have been the sensor going bad. Ran fine and the light would come in go with and didn't correspond with the sound. I'll update after I check the egr nut.

Thanks Guys,

Mrcln1

[Ldub]

The other end of the EGR tube is welded to the exhaust system IIRC.

[Tobert]

The other end of the EGR tube is welded to the exhaust system IIRC.

Nah, it's held on by two stainless bolts. Spray 'em with a little penetrating lube and they'll come right off. Be sure to do it with the exhaust cold.

[Ldub]

Nah, it's held on by two stainless bolts. Spray 'em with a little penetrating lube and they'll come right off. Be sure to do it with the exhaust cold.

My mistake, I should have gone out & looked...

[Mrcln1]

Went out and looked at the egr not and it's cross threaded. It's going on at a pretty good angle. I guess the dealer didn't bother to fix it or couldn't. I don't have the tools I need with me right now to get at it. I'd like to take the whole tube off to make sure I get it on right and look at the damage but it looks like it's damn near impossible to get to the bolts behind the motor. I started it and it ran perfectly for 10 minutes. I revved it slowly and the knock comes in around 2000 rpms. I still can't imagine that the egr not could cause this noise. It definitely sounds like knock from the front bottom of the motor. I hope the nut fixes it. I'll keep ya posted.

Thanks Guys,

Mrcln1

[WILLY]

when i found my egr nut was the problem i was in the engine compartment with it running and i was manually reving it with the throttle mechanism right on top of the motor,it was very difficult to diagnose cause i too swore it was the engin nocking and it would only do it when reving and not at idle so when i reached under the egr i felt the suction and wrapped my hand around the tube to block it and there it was,that was the prob,and my nut was just hanging on the tube not even threaded in at all thanks to a someone not putting it back in after replacing my intake gaskets.

[Mrcln1]

I'm not sure now what the deal is cause the hose is at an angle coming off so it may just be my eyes playing tricks on me. The nut is soo tight that I can't get it loose with my shortie wrench. I don't feel any kind of leak and after it warms up and the the knocking makes a klackityklack noise when you rev the engine. I can't ven imagine how it's possible to get to the back egr connection. My buddies 2002 rodeo doesn't have all the crap on the left side of the engine bay in the way and we barely got to it. It's going on a rollback to the dealer tomorrow probably.

Thanks Guys,

Mrcln1