I'm hoping someone's been down this road before and knows the solution.

Simple- I can hear a metal clattering sound from somewhere in the front when under moderate load, most audible in 3rd gear (automatic).

Also, a recent occurrence is a metal dragging rattle sound when the air outside is cold and the car was just started. This sounds like a heat shield issue, but I'm not certain it's related, because the other sound is a metallic clattering.

Anyone resolve a situation like this?

I haven't fully tested the scenario because if it's serious, I don't want to blow up something before I fixed it.

 

If any of you have ever had a metallic "clattering" sound from somewhere in the front on acceleration, I'd love to hear what it was if you're so inclined, then I can pool the results and troubleshoot. A quick "I had it and it was caused by ____________" would be insanely helpful, again, if you feel inclined. Thanks!

 

Lub: When the heat shield loosened on my firewall catalytic converter, it vibrated a 'buzz' sound until I secured it.

Heat shields are very thin, light aluminum. Does the 'clattering' sound you hear seem like a light, thin heat shield, or from something thicker and heavier?

 

I agree. That said, my sound isn't a clank, but a rattly metallic clatter. I'll carefully drive it tomorrow and hopefully gather better info.

 

This morning I kept my ears open and noticed a slight rattle at idle. I put the car in reverse and I could hear a slight "buzz".

As I drove to work with all windows down and attempted to replicate the clattering sound it was pretty much silent. So the metal clattering is intermittent.

 

I've confirmed that once the car is warmed up a bit, I can duplicate the sound with 50 to 60% throttle in any gear, so it really wasn't doing it more in third as I'd previously thought.

The engine emits a light, random, short "tink" (VERY light) while idling after warmed up. It's so light and random that isolation would have required more run-time than I wanted the engine to sustain in this unknown condition.

Also, light oil leakage is occurring at the vacuum fitting on the intake, as seen in the picture I posted. I'm wondering if it's related? And what would cause oil leakage there? The connection seems to be good. I'm wondering if my vacuum system's working properly. On that note, I have replaced all the usual suspects except the break booster line, including the PCV Valve.

Here's a picture of the oil leakage, and a video of general engine noise (complete with crickets)

 

Oil in that area of manifold is not uncommon. But that tube does look odd near the connection. For the noise you need a pedal operator and a broom handle to push/pry on suspect rattlers, just watch the belts and the handle do not do the nasty.

 

Lub: +1 to innzane's comment that a little oil from the intake manifold is typical. High mileage cars can even have oil leaking down the intake manifold under the IMT valves. If you remove the intake and tip it, expect a little oil to dribble out. Oil gets sucked thru the PCV valve and PCV breather hose into the intake. Replace the PCV valve when it gets old for this reason.

Also +1 to using a broom stick or PVC pipe as a probe. Start with the aluminum heat shields around the catalytic converters, both radiator and firewall sides. As I mentioned above, the shield on my firewall converter was loose and vibrated until I re-secured it. This post has pictures of them: https://www.jaguarforums.com/forum/x...4/#post1084601

 

Thanks for the replies. I will definitely start there (haven't had time to dive in yet) after tossing in a bottle of Lucas octane booster due to my newfound utter terror of detonation. No codes stored or engine light, but apparently detonation doesn't necessarily trigger a code. If it is indeed detonation, I don't want to take any chances...

I'll keep you guys posted, hopefully getting to the bottom of this soon....

 

One last question before I run away and dive into this.

Can NOT bleeding the cooling system in this car cause pinging/knocking/detonation due to hot spots?

I just replaced my radiator, water pump, hoses, etc. but did NOT bleed the cooling system when done, as I was under the impression that it's not important with this engine. I just ran it, topped it off, ran it, topped it off, etc.

 

Lub: Thermo used to advise we 'burp our kitties', but recently said it's not necessary: https://www.jaguarforums.com/forum/x...5/#post1297913