Hello with another ridiculous problem... While checking something unrelated on the car today I noticed that some of the fuses are obviously getting so hot they left their mark on the battery cover.
I suppose that this is not a normal occurrence? The fuses in question are those on the right side of the picture

The items you've circled red are relays.

The marks on your battery cover are where parts of the cover have been plastic welded together. All Stilo battery covers are like this.
.

That would be great (and embarassing ) if it is true but to me it really seems like it has been damaged... Here is a bigger picture, I hope it shows better:

Above there are two conflicting views, one says they are all like this, the other says no. So a bit of diagnosis is needed.
First identify what each relay is for so you know when it operates.
With the cover off and the engine running, feel to see if any are hot to touch.
Operate each circuit as identified above, for long enough to notice if they get hot or not.
Now you'll know if you have a problem or not.

With several one apparently getting hot, my guess would be the supply connectors are making poor contact, so running hot. Common denominator. Remove each relay, in turn so as not to mix them up, and check their connectors.

Surely if they were getting hot enough to do that sort of damage to the cover, the relays themselves would show evidence if excessive heating too?!

As above if in doubt check how warm your relays are

However if your battery cover was being heated up to the extent that it melted the cover , then your relays or which ever point you thought was causing the melted point of the cover would be in a well melted gooey state i.e you would not be able to read the details on top of the relays which you can from the pic you posted and the plastic cover of the relays would be in a similar state also with that amount of heat generated it would have no trouble burning through the thin coil wire inside the relay or suspect fuse and so certain functions of the car would not operate..and the melted marks on cover would have to align with the suspected heating up part which they do not

By all means check for potential fire risk although I feel you will not be calling out the fire chappies this time

portland_bill said:

So a bit of diagnosis is needed.

Click to expand...

No diagnosis is needed. :bang: It's very obvious that they are melding marks.

If it had been caused by relays overheating, it would be a very strange coincidence that they only overheated where 2 sections of the plastic battery cover had been joined together. (as can be clearly seen in the picture)

Also, as mentioned above, if overheating relays had caused it, those relays would also be burnt.

Why make it more complicated than it is.
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Davren said:

No diagnosis is needed. :bang: It's very obvious that they are melding marks.

If it had been caused by relays overheating, it would be a very strange coincidence that they only overheated where 2 sections of the plastic battery cover had been joined together. (as can be clearly seen in the picture)

Also, as mentioned above, if overheating relays had caused it, those relays would also be burnt.

Why make it more complicated than it is.
.

Click to expand...

Indeed, they are quite obviously welding marks, joining the two parts of the plastic cover.

Listen to the Master, young Padawan, for lie to you he would not.

Thank you all for your replies!

There would also be black plastic transferred onto the hot items. This has been known in other situations before, but in the meantime, is not happening here (as Davren has said).

Hot/clicking relays in the locations circled here are possible if the grey fusebox/relay holder has water inside. For anyone finding this thread when searching for a similar problem, see my guide about taking apart and drying it out.

Otherwise, if everything working normally, then no worries.

-Alex