TDI engine cover removal

Hello everyone,

With only 67,000 km on the odometer, my CR-TDI (CFHF in the Octavia) rattles more than my old VE-TDI (ASV) did in the Ibiza after 217,000 km. The cause was quickly identified: it's due to the engine cover. If you press it lightly, it immediately becomes quiet.

I disassembled the thing and examined it. Problem number one was quickly apparent: The part sits on four metal balls (mounted on the motor) that fit into corresponding rubber bushings. These bushings, in turn, are loosely inserted into plastic – presumably not from the beginning, but have become looser over time due to vibrations. A small piece of rubber placed in the right spot inside the plastic housing quickly and hopefully temporarily solved this problem.

Unfortunately, it didn't completely solve the problem. The plastic cover has a type of rigid foam insulation on the underside. This seems to have been attached with a combination of clips and some kind of cutting or adhesive mechanisms. However, it's no longer covering the entire area, so the insulation piece is now rubbing against the plastic cover. With the engine running, it almost drowns out the not-so-quiet idling noise of the 16V-CR-TDI.

Back in the old days, things were better... there was this foam material that, unlike this stuff, didn't rattle.

The solution is probably adhesive in the right place, but before I start making wild attempts to see if the insulation material is damaged or if it can even withstand heat, I'm asking for advice: Does anyone have any experience or ideas on how to properly and permanently reattach it?

The aesthetics don't really matter to me - I'm also fine with drilling a hole and using a screw and washers. However, I'm worried that over time, the vibrations from the motor might cause the screw to work its way through the plastic, either loosening or falling out.

I also don't think a new lid is a good solution - something like that should last longer than 67,000 km.

Best regards,

Jan.

P.S.: The current solution is: The entire lid is in the trunk . However, I don't want to make this a permanent solution because of dirt (the area under the cover is much cleaner than the rest) and pedestrian safety (we discussed this years ago).

Hi Jan,

The engine cover vibrated on the BRE, and also on the CFFB, although on the BRE, after many kilometers, the insulation material sometimes detached from the plastic. The material was too soft to withstand the pressure, so it was reattached using Pattex adhesive.

How are causes checked or verified? Annoying and not exactly easy to find.
Okay, I'm ready. Please provide the German text you want me to translate.

Best regards, Rainer.

Hi,

The rattling stops when you press on the cover. Without the cover, there is no rattling. If you hold the cover in one hand and tap it with the other, it rattles. The damping material hits the plastic cover over a fairly large area and is nowhere near as soft as, for example... Foam.

This makes it more likely that other causes can be ruled out.

Maybe I'll just stick some strips of heating insulation tape between the plastic and the insulation material...

Best regards,

Jan.

Hi,

It's really the cover. I just drove to work without them - the car is much quieter now, and it doesn't rattle anymore when you drive at a low, fuel-efficient speed.

So, to make a TDI engine with only 67,000 km (approximately 41,600 miles) quieter, you remove the sound insulation. Actually, it's sad.

In this case, a bit of foam is probably the best solution.

Best regards,

Jan.

I would secure the rubber grommet for the ball head in the cover using silicone. It would have the advantage of keeping the connection flexible.

Hi,

I've already done that using rubberized tape (which is actually intended for insulating heating pipes). It makes it a bit stiffer than before, but it's still flexible. This part doesn't rattle anymore either.

The problem now is with the insulation part against the plastic part.

Best regards,

Jan.

Jan6K wrote:

The problem now is with the insulation part against the plastic part.

That's where I would insert the silicone. Perhaps it wasn't clear enough from my explanation.

Hi,

Okay, I thought you meant the equally shaky recordings.

I'm just not sure if silicone will really hold up there, especially if it gets really hot.

Best regards,

Jan.

This can be achieved with a silicone of the appropriate specification.

Do you have a silicone compound that can withstand high temperatures?
hg
herbert

Hi,

Problem solved for now: The cause was slightly different than I thought. The lid (which I hadn't noticed yesterday) is made of two plastic parts that clip together. These clips are a little loose, and that was the primary reason for the rattling, not the foam piece (which is indeed too soft). So, I unclipped them, added a little bit of the rubberized tape in between at the appropriate spots, and reattached them. It fits snugly now and doesn't rattle anymore. Let's see how long this lasts.

This tape is for insulating heating pipes... After all, heating pipes get very hot. I don't think these plastic parts get hotter than 100 degrees Celsius, because you can normally touch the lid without burning yourself.

Best regards,

Jan.

Quote:

Heating pipes also get quite hot.

Approximately 60°C from the inside, which is the supply temperature.

Herbert.

Hi,

Since there's no warning label, this product is likely safe to use with older systems that have a supply temperature of 75 degrees Celsius, and not just with modern heat pump systems (ours will have a supply temperature of 29 degrees Celsius). I'll see what happens and how long it lasts.

Best regards,

Jan.

Herbert wrote:

Do you have a silicone compound that can withstand high temperatures? hg herbert

PETEC's body adhesive and sealant is temperature resistant up to +90°C. That should be enough.

Petec is silicone-free and polyurethane-based. And 90°C would be a typical temperature for that area, in my opinion.
hg
Herbert.

Edit: A more suitable adhesive would be IsoproQ. That was the only adhesive with a temperature range up to 120°C (and compatible with foam) that I could find for gluing my headliner.
When it comes to hot metal surfaces (like in the sun!) or the engine compartment, I would avoid using products like Pattex & Co., as they only work up to 90°C.

Hello,

Let's see if gluing is even necessary. The clamping solution installed under the snapped part passed its first road test today. If that's not permanent, then I'll glue everything together with one of the adhesives mentioned.

Best regards,

Jan.