A new noise coming from engine compartment

[Eva463]

Nice sharing.

[serge_saati]

Oscar, you should update your threat.

So, Oscar has changed his timing chain and chain tensionner but the noise is still there.

We finally conclude that it could be the camshaft the problem.
The lobes can be damaged an affect the lifters too.

But he doesn't want to spend more money and times for this van, he already spend too much.
I agree with his decision.

[12Ounce]

BTW, since lasting posting .. I have "dropped" and pushed over the sub-frame for better access to the front cover. It all went pretty well as planned. I would add "loosening" the steering shaft-to-steering rack clamp as part of recommended procedure.
.
The reason I was doing the work ... was to eliminate a oil-to-coolant crossover that was putting oil into the coolant; and most likely, putting coolant into the oil. The lower intake manifold and front cover gaskets were replaced. All seems good.

[olopezm]

Hello guys, I'm sorry that I'm bringing this thread back form the death, but I think it's the best way since I'm the OP and I feel like linking to it from a new thread could be unnecessary...

It's been a long journey and lots of work on this matter; I thought I would post an update on this, I made a major discovery.

In november last year I replaced the timing chain as suggested in the replies, like Serge said, the noise went down but it didn't fully disappear; I decided to live with it, for some time, then I took it to another mechanic and he also advised to replace the camshaft synchronizer, I was just thinking "I've replaced all those parts, why not just replace this one?" (I hate being a parts changer, but what else?). It made no change...

It was until a couple of weeks ago that I installed new spark plugs and decided to try something new, something unusual; I opened the upper intake and removed the middle baffle (I had glued it with RTV to the upper cover) just for shits and giggles, well, guess what? THE KNOCKING NOISE WENT AWAY. Check the videos below.

Cold start - Here I only installed the upper cover without the baffle, there's another noise present, I probed around but can't pinpoint it, I remember my neighbor's truck having an exhaust leak and sounding just like that. Your thoughts? It doesn't sound bad to me, but again, I'm no expert...

https://www.youtube.com/watch?v=2bYsNUAHbdE

Hot idle in neutral - Here you can see it sounds pretty much normal, I reinstalled the baffle but used LOTS of RTV to glue it to both (upper and lower) parts. There's still some noise during cold starts, but nothing compared to what it was before, hot idle sounds perfect to me...

https://www.youtube.com/watch?v=oy7yC-GUU9Y

Tapping noise at idle IN GEAR - This noise persits, again, I think it must be from an exhaust leak that "opens" as the engine moves back and forth from being in gear. If I put it in neutral it goes away, today I noticed it also seems to tap for a second as the cooling fans come on. It's definitely related to engine load, but I can't relate it to an actual component.

https://www.youtube.com/watch?v=4T8jBt_7o74

**************************************

My suspicious about an exhaust leak also come from the loud clanking noise I hear after turning off the engine, I haven't been able to catch that in video. It can happen from a few seconds to several minutes after turning off the engine and it happens several times until everything finally cools down. I'll have that checked at an exhaust shop, I don't have enough room at home to deal with it...

I do plan to get an upgraded manifold cover, gluing it was just a "diagnosing method" which has proven to work, however, the vibrations are taking it's toll and the noise seems to be getting louder again.

Oscar.

[scubacat]

Check the rubber exhaust mounts and the flexible exhaust shield first. Also, when cold, just shake all the components back and forth a little. You may find it's something really silly. One of the exhaust hangars on ours was barely hanging by a thread and was almost completely separated.

Are your engine mounts original?

[olopezm]

Thanks scubacat, I'll do that. The engine mounts are original and I was just thinking that one might be bad as the engine moves a little too much in my opinion, you can see it on the last video.

Oscar.

[scubacat]

Only use OEM for the front one. The two hydraulic side ones can be aftermarket. The engine movement in the one video that works appears normal, but it's hard to say for sure without looking more thoroughly. The sound seems rotational though. Bad hydraulic mounts cause severe vibration. (the subframe recall being done wiped out mine..)

[scubacat]

I almost forgot.. Do you have one of these? If not I HIGHLY recommend picking one up. It may solve this mystery for you.

http://www.harborfreight.com/mechani...ope-69913.html

[serge_saati]

I'm glad you fix it. It's funny that the problem was so simple to fix compared to all the heavy work you make on it like replacing timing chain and lifter.
And the noise was close to the intake.
But it was hard to find it, even if I thought about that, because it sounded like a metallic rattle noise, and furthermore you already repaired the intake middle baffle, you glued one time because you already had this problem. So I thought this problem was fixed and it's a new problem, but no it's the same problem. Maybe not glued properly last time.

Anyway, glad that you fix it.
Good that you didn't replaced the long camshaft of the engine block (not the synchronizer I'm talking) for nothing.

3 years later, problem solved. Anyway, it was not a major issue.
You take care a lot of your van. More than people does with their Ferrari haha

[scubacat]

One other thought - have you run the engine (only for a minute at most) without the belt on? Does the noise persist or stop without the belt?

[olopezm]

Originally Posted by scubacat

Only use OEM for the front one. The two hydraulic side ones can be aftermarket. The engine movement in the one video that works appears normal, but it's hard to say for sure without looking more thoroughly. The sound seems rotational though. Bad hydraulic mounts cause severe vibration. (the subframe recall being done wiped out mine..)

Yes, it kinda sounds rotational. I checked the crankshaft for throwout (is that the correct term?) and it all seems OK, there's no in and out play on it.

Originally Posted by scubacat

I almost forgot.. Do you have one of these? If not I HIGHLY recommend picking one up. It may solve this mystery for you.

http://www.harborfreight.com/mechani...ope-69913.html

I have one, but I still have to acquire more experience using it, I mean, it still sounds to me like the noise is coming from everywhere, but I've noticed the ticking noise being the loudest at the actual fuel filter. It's weird because the oil pump, oil bypass valve and camshaft synchronizer and sprocket are new, so there should be no play there...

Originally Posted by serge_saati

I'm glad you fix it. It's funny that the problem was so simple to fix compared to all the heavy work you make on it like replacing timing chain and lifter.
And the noise was close to the intake.
But it was hard to find it, even if I thought about that, because it sounded like a metallic rattle noise, and furthermore you already repaired the intake middle baffle, you glued one time because you already had this problem. So I thought this problem was fixed and it's a new problem, but no it's the same problem. Maybe not glued properly last time.

Anyway, glad that you fix it.
Good that you didn't replaced the long camshaft of the engine block (not the synchronizer I'm talking) for nothing.

3 years later, problem solved. Anyway, it was not a major issue.
You take care a lot of your van. More than people does with their Ferrari haha

It is indeed Serge! I really appreciate all the help I received from you and the other members. I don't regret doing all that, I learned new stuff and got some peace of mind from the parts being in good condition (they are new now lol). As you said, I had glued it before but only to the top part, I guess the RTV was still allowing to baffle to swing inside causing it to hit the lower part.

Such an easy fix causing such a major headache!!!

Do you have any input on that other noise in that last video?

PS. I'm very sure a Ferrari doesn't cause this much troubles LOL

Originally Posted by scubacat

One other thought - have you run the engine (only for a minute at most) without the belt on? Does the noise persist or stop without the belt?

Yes, I've tried that in the past, either hot and cold, and the noise is there only at hot idle in gear, nothing else. I've fixed the broken links...


Oscar.

[12Ounce]

I took a different approach to that internal (infernal!) manifold-baffle: I glued it with RTV to the LOWER. This was done eons ago. Has worked pretty well for me.

[olopezm]

Originally Posted by 12Ounce

I took a different approach to that internal (infernal!) manifold-baffle: I glued it with RTV to the LOWER. This was done eons ago. Has worked pretty well for me.

Thanks, buddy! I glued it to both parts and it improved, however the noise is starting to come back; the vibrations are between the upper and lower parts must be the cause, I suppose.

So you glued it to the lower part, did you break the tabs on the upper cover? Mine still has them intact, I could take it apart, cut them and try your approach, I take it you put the Rtv all around the actual runners, between them and their openings on the lower part? I'm all in when it comes saving money, and this definitely is a good candidate!

[serge_saati]

Well I compared you noise with the older one in 2012, and it's a different noise.
It now sounds like a tapping noise. And it's less loudly. But the noise is at the same frequency.

It seems that you have a noise that came from the harmonic balancer or crankshaft pulley bearing. But that seems to be a different noise, the other one is quieter.
But it doesn't sound like loose flexplate.

It's true that in gear, there's a lot more of engine load because of the torque converter load increase. The double actually. Also it increases when you turn on the A/C, turn the steering wheel, turn on rear defogger and even increase the rpm because more inertia. So there's more air flow that enter in the intake, and yeah more exhaust gazes flow that exit from the intake. Load affects a little bit the pulleys, because the maximum instant angular acceleration of the crankshaft and linear acceleration of the piston increase even if it's the same rpm since the acceleration is not constant and even if it happens each 120° of rotation.

But it doesn't seem like an exhaust noise.

[serge_saati]

I mean a higher exhaust gases flow that exit to the exhaust pipe and muffler, cat...