Aloha! I just acquired my 04 VandenPlas. Beautiful, but the PO had a neighbor work on it (she didn't have a clue).The guy removed part of the intake. He sealed the hole with red goop. From parts photos, it's a box of some kind. I can't quite tell what its purpose was, or why he removed it?
As best as I can tell, the car has old old gas and a clogged fuel filter. Guess he forgot to check that?
Good to meet you all! Marc

 

Resonator on intake. Mine broke when I was changing the auxiliary water pump. I did a neater job of sealing.

 

Yep, its just to help keep the intake quiet when the engine revs.
Make sure that intake pipe at the throttle body end is secured properly - they have been known to come loose and cause issues.


Does the XJ run?

 

BTW There is no Cats solenoid in the top of the strut and is there an air line

connected?

 

They should have used black silicon sealant for a cleaner looking solution. If the car does not care, as far as lighting up the dash with the check engine light, & throwing a code, forget about it, leave it alone. Maybe get out your black marker, and color it A lot easier to miss seeing it that way.

 

Marc, the part that was attached was a resonation chamber, which is designed to smooth intake pulses under load when entering the throttle body. Can this part be omitted? Well, yes the vehicle will still run with it removed. You certainly don't want leaks there though, as it will introduce unmetered air after the MAF. Would I personally look for a replacement intake hose? For me, the answer would be yes, but that's just me.

https://itstillruns.com/air-intake-r...#ixzz2ZhcM3BGS

 

The '06 and up models didn't come with that resonator, so if you don't care about the red goop it won't affect running.

 

Actually, when the 06' X356 was released, and later, the X358 (revised electronics and calibrations) there were both non-resonator and resonator intake tubes used. I would suppose due to engine calibration and SHED.

 

Most informative, thanks! And impressive to have such quick response from knowledgeable sources. I'm going to enjoy this forum and by extension, my ownership experience!
The car does run, albeit not well. I had it towed home and have just begun deciphering the mystery--only had a few minutes so far. Enough to find a low coolant level (alarm bells about head gaskets?), slow starting, and ancient gas. I drained what was left, added fresh fuel and a healthy dose of Seafoam to get things rolling. The weekend can't come soon enough.
Marc

 

@ Meirion - This XJ has probably been converted to a coil over suspension, previous owner probably didn't want to deal with air suspension issues.

 

Thanks-- you are correct. It has been converted to Arnott coilovers, which begs the question: why do that in a car with fewer than 40k miles?
The other discovery is that the performance problem I mentioned is tied to the catalytic convertors, which look good but are apparently plugged (see photo). I disconnected them and suddenly the car runs well. Well, loudly!
HI does not have emissions testing, so I'm now looking at options that don't involve replacing the cats with OEM. Perhaps cheap aftermarket until I can get any performance issues sorted. Regardless, much lies ahead.