I just replaced my valley hose. I disconnected the fuel line and removed/replugged many cables.
When starting my engine, I hear a very loud knocking noise, similar to an old tractor.

I rechecked everything, but found nothing wrong.
Any idea, what i should look at ?

 

I repeated all steps (except changing the hose) again.
Ich looked at the valves, which all looked the same.
The knocking is still present. It seems to originate somewhere under the intake manifold.
The car shows no lights or errors.
The sound becomes less loud, if the car runs warm. But as soon I get beyond 600rpm, it's unacceptable.

What could have happened ?

Find attached the sounds.

 

something fell in the combustion chamber or straight up rod knock

 

My car drove very silent, without any knock to my house, where I replaced the valley hose.
So to me, a rod knock seems to be very unlikely. (My jag has about 130000 km)
My car was pretty clean, so some little dust might have fallen into the combustion chamber. Altough I have no experience with objects in combustion chamber, I would expect some larger object.

Is it possible for a damaged gasket to produce such noise ?
Is there a way to locate the cylinder producing this sound ?

 

When you arrived home was the engine still leaking coolant ?

I am in the middle of a valley hose repair.
Could you please tell me how you accessed the brake
vacuum hose and sensor connection after installing the manifold or was it connected
before final installation?

Also did you use RTV sealant on the engine gasket
Thanks
Bob

 

Before I started my valley repairs, the car was without issues. Only a slight coolant leak, which seemed to be caused by valley hose.
I didn't disconnect the brake.I just opened the two screws at the cables. So I could move the manifold about 15cm, which allowed it to raise.
I used new gaskets, but on one side, I squitched one little bracket on tightening. I fixed this, but the noise didn't disappear.
I didn't use any sealant on the gaskets. Do you ?

 

I am not confident that the manifold will be 100%gas tight with just
the new gaskets and will consult a professinal about use of sealant or not
I have just discovered the joint in the vacuum line to the booster which makes things easier

 

On the NA engine, those connections can't be removed until you loosen the manifold and pull it forward as far as the attached wires allow, and the connections must be in place before setting the manifold onto the engine. They are absolutely unreachable unless you actually remove the engine from the car. I know nothing about those connections on a supercharged car. As for the brake hose, I didn't remove it from the manifold, as there was a junction between the manifold and the brake booster which I disconnected. But you can't reach the MAP sensor on the back of the manifold until the manifold is loose, and you can touch, but not disconnect, the plug on the end of the fuel rail until you move the manifold.

As to the RTV question, you don't need it, unless you got the cheap paper gaskets which you can't possibly hold in place during installation of the manifold, so a little RTV as an adhesive to hold them might be useful. The correct gaskets are the metal ones that have the tabs that bend up to hold the gasket at the ports. When I was getting mine, the images showed the correct gasket but I received the flat cardboard gaskets, and returned them. From TWO vendors!

 

Getting that manifold out completely, would help me diagnose my problems.
So if I disconnect the brake junction, is it possible to disconnect the MAP to get the manifold out ?

For my knocking sound, I did some research again:
The front 4 cyclinders were inspected through spark holes, no damage found.
If the car runs for about 10min, the knocking goes down to a volume, comparable to the surrounding engine noise. But raising RPM bringts it up loud.
The location of the knocking seems to be in/below the manifold.
It will take some time, but I'll inspect the last 4 cyclinders and try to get the manifold out completely to inspect valves.

I have no idea, what my problem might be.
Just changing the valley hose shouldn't affect internal rods and bearings.
In case, something fell into the engine, I don't understand why the sound changes its volume.
Any ideas ?

 

Metal gaskets came with the car, & need NO sealant, use those.
Could be slight a vacuume leak, but that would give you a lean code

 

"So if I disconnect the brake junction, is it possible to disconnect the MAP to get the manifold out ?"

Yes

Your noisy engine could be due to oil draining out of one hydaulic lifter
but that is more of a tap than a knock?
Come to think of it I am surprised at the amount of oilwhich has come out
of the manifold when turning it upside down to clean the mating surfaces

 

A lean code is what worried me but it appears that just the new gaskets
should do the job which makes installation a bit easier
Thanks for all replies

 

Hi Nebelfuerst,

What is the engine oil level?

Per xalty's idea, are you missing any sockets?

Cheers,

Don

 

I don't know that it is rod knock, always hard to tell from audio clips over the internet, but just doesn't sound it to me. I listened several times and, though I don't know anything about this model or this job, it almost sounds like a heat shield or some other piece of sheet metal getting hit or vice versa. Sort of reminds me of the cadence and sound like like a playing card in bicycle tire spokes? May be a shot in the dark, but thought I'd throw something out there not yet thought of. Reminds me of a "knock" I had one time on my MINI. I was SURE it was rod knock. 99% sure. Couldn't get in to look at it for a few days, so spent those days thinking I had to rebuild or replace a motor. Once I finally got to it, I discovered that part of the grooving just came off of belt and the blank space left behind was making the tensioner bounce and make this noise. Not helpful in this situation, but just an anecdote that often things that sound like something sure are sometimes totally not what you expected! I agree that it doesn't make sense anything internal would get severely messed up by this job.

 

Oil level is fine. Opening any of the connector immediately gives me a warning light about restricted performance.
( So my guess is, that I didn't forget any.) I think, the wiring is that "fool proove", so it's close to impossible to connect something in the wrong place.

As I cannot work at my jag for the next days, I ordered new gaskets and a dual endoscope.
Then I'll inspect the last 4 chambers and try to get the manifold completely out, to inspect this piece of hell

 

Not until you unbolt the manifold and move it forward so you can reach the back. This will flex the valley hose which runs from the top of the engine to the throttle body (at least on the NA,) and my valley hose actually broke, dumping coolant into the valley for a little bit of cleaning up. With the hose deteriorated badly enough to break from that flexing, I'm glad I made the decision to replace it when I did.

 

Hi Nebelfurest
I see that you have an early Jag so do you fit
gasket AJ85392 to the inlet manifold?
My Jag is also early (Nov 2003) but I got caught out
by the later Vin change and bought the wrong one!
It's a minefield!
Good luck with your noise problem

 

Yes, I used AJ85392.

 

Any problem using AJ 85392 ?

Have you noticed the centre hole shown in my photo?

It does not lie flat and the original gasket does not have that protusion

Was it gas tight?

I hope you get the noise sorted
Bob

Did you flatten this before fitting?

 

Your part looks different. The holes are completely flat in my case. ( Checked the removed gaskets and my set of new gaskets.)
My parts are genuine jaguar. The look idential to those i removed.
The side clip shows a triangle in your case. I just have a flat metal with a little dot.