Side engine bay vent grilles

[Apselise]

Hi,

I'm new to forum, and hopefully in the right area.

I managed to somehow suffer damage to my O/S rear engine bay vent grille that sits behind the driver's door.

I have removed the damaged unit, but not for want of trying can't get the replacement in.

Has anyone been able to manipulate this part into place; am Dreading that I may need to somehow split the rear clamshell from the door sill section to gain the necessary access which I feel will be a whole heap of pain!

Any / all advice greatly appreciated.

Thx

[Jonathan E]

I had to replace one on a S2 some years ago but not done an S3, iirc it inserted via the rear wheel arch? ie wheel off, liner out, remove anything that’s in the way etc. I see from your pic you have removed the liner so apologies if you have already tried the above.

[Apselise]

Thanks,

I think the S2 ones are slightly different. A friend has a K series powered early S2 and it comes with what appears to be a separate cover trim.

I can't see how I can fit this from

the rear as the grill

needs to slide back over the flange on the clam.

The inner lug sops the grille sliding forward then back and prevents ot being inserted from

the front. And the outer lug prevents the grill from

beong presented into the opening from outside.

the rear clam bolt access is hidden by the  grille once fitted so cannot see how removing the claM would help

[Jonathan E]

Hmm, never easy to see from pics and doesn’t help that it was a long time ago that I removed one, albeit on a S2. I sometimes wonder what the hell Lotus are playing at with some of the ideas they have. All front lower grills on S3’s are screwed to the front clam from the inside meaning the front clam has to be removed  just to replace the horn which is bonkers🤷🏽‍♂️ it looks like they’ve done the same with the rear grills and clams. I’d be tempted to carefully remove the lugs and just bond the piece in, it seems overkill to have it mounted the way it is and it’s not like the grills are under any sort of stress from the rear. That, or it looks like the clam has to come off?

[Apselise]

Thanks for coming back to me - we had resolved to get in touch with PJS Lotus in the morning as have pushed, pulled and twisted, probably for 3 - 4 hours with several 'sleep-on-it' spells in between, all without any sense of progress.

... had also started to think about lug removal and bonding in place; especially given the strength and quality of some of the modern adhesives.

[Jonathan E]

I wanted to replace the noddy horn on my Cup and finally managed to remove the grill without without having to remove the front clam, I bonded the front grill back on with https://www.halfords.com/motoring/paints-and-body-repair/adhesives/granville-black-silicone-sealant-40g-173867.html has been there for over 10k miles without any issues. Its not a massive job to remove the clam but for something so simple its mad, so if PJS say clam off I'd certainly be looking at bonding it on. Be sure to post back your findings👍

[Lithopsian]

The service manual implies that the bolts can be accessed from inside the wheel arch, and then the grille pulled out to the outside.

[Jonathan E]

9 hours ago, Lithopsian said:

The service manual implies that the bolts can be accessed from inside the wheel arch, and then the grille pulled out to the outside.

That’s certainly the case with the slatted version on S2’s but doesn’t seem like it works that way with the S3 grille version, from what the o/p describes?

Lotus parts diagram isn’t the best but looking at the part in question you would think it fits from the inside of the wheel arch m. Part in the pic above doesn’t appear to match that of the o/p no sign of that large bolt flange?

Edited August 20, 2025 by Jonathan E
Pic

[Apselise]

Hi All,

Many thanks to all those who contributed to this thread and to PJS Sports Cars who provided some vital advice and concerning reality.

Nick at PJS was extremely helpful in advising that the lotus manual for these latest grilles have done a u-turn and they need to be fitted from the front and not the rear as with all previous variants.

He also pointed out that lotus designers, engineers and fitters don't communicate and that is why things can be unnecessarily complicated, bordering on the impossible.

Not being experienced in working with fibreglass and brittle plastics, I openly admit to being out of my comfort zone.

PJS advised from looking at the pictures of the part there should / could be enough flex to bend and twist the grill into place  (encouraging) but be mindful to protect all areas of vulnerable paintwork (increased the anxiety).... still couldn't get it in.

Tried varying amounts of heat, however any benefit was limited due to the stiffness of the mesh and not knowing whether the mesh was held in place with a thermal adhesive... still no joy.

With the the two bolts connecting the clam to the sill section removed (1 necessary for the grille anyway) it is possible to flex the fibreglass out as far as you are comfortable with... almost there but not quite.

Finally resorted to a systematic and gradual reduction of the offending clips and lugs using a fine dremmal cutter, particularly the one perpendicular to the bodywork as this would not pass the painted recessed panel. This one was trimmed down about 7mm in total, 1.5mm into the bolt hole.

Apologies for not taking step by step photos, but was all trial and error, then it just clicked into place, and once in, I wasn't going to risk a re-run.

Now all reassembled and ready to get back out on the road again.

If anyone needs any help with one of these in the future get in touch and will try and guide you through step by step.

Thanks again!

 

 

[Jonathan E]

Well done 👍 hope I never have to do one of mine😂