Author Topic: rusty engine bay, fender mounts bonnet hinge drain hole etc  (Read 369 times)

w116john

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hi all

i have some rust in the engine bay, both fender mounts and the base of one of the hinges, i had been putting it on the long finger but when i had the rear brakes done recently the bonnet hinge gave way and it has forced me to deal with it.

i found a guy local to me and i am delighted with the progress, i went to see the car last week and the 2 front fenders were off
and a series of issues discovered. what was surprising was that they were areas that had been repaired before

the fender mount on one side had been repaired in the past and importantly the area of greatest concern the drivers side LHD drain hole near the fuse box, which has been causing me grief for years had been bodged at least once and there was evidence of repairs to the floor and the firewall.

the water ingress in the drivers floor was not coming in by the drain hole itself but lower down in the firewall, there was a bad repair which had rusted again allowing water to seep in.

all the rusted areas were cut out and metal welded in, there is one other area by the rear driver side floor to be done.
i am going to leave the drain hole in the engine bay as it is, just a larger than original hole with no tube.

i think that my car has had a few modifications over the years, for example it has headlight wipers but no extra pump or tubing from the reservoir, it has heated seats(not working) but no extra fuses beside the fuse box? I am thinking of removing the headlight motors as well as the cruise control and that would give me 2 less things to fix, leaving just the A/C and i might investigate the heated seats??

i will post a few photos when i get them

all the best





Justin280s

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Re: rusty engine bay, fender mounts bonnet hinge drain hole etc
« Reply #1 on: 07 December 2018, 04:56 PM »
I have seen it over and over again in the auto body repair trade.  A rust repair can start to rust around a previous repair.  I believe this is caused from the new weld. Failure to clean and seal  the weld from the inside.  Though this can be a hard if not impossible in a box section.. I once had a customer  who owned a truck and insisted rust to be repaired  with fiberglass rather than weld sections for the same reason..

w116john

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Re: rusty engine bay, fender mounts bonnet hinge drain hole etc
« Reply #2 on: 08 December 2018, 01:35 AM »
hi Justin

yeah its very annoying there was a mix of metal and fibreglass in the foot well,  but at least i know where to look next time. hopefully getting the car back next week and i am looking forward to having a dry car?  including the boot as i am having the rear light seals replaced as well.

progress

kind regards

john






w116john

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Re: rusty engine bay, fender mounts bonnet hinge drain hole etc
« Reply #3 on: 22 December 2018, 01:07 PM »
 
quick up date picked up the car a few days ago, happy with the work done and for the first time in some time the interior is dry.

i had had the rear light seals replaced as well, i was surprised at the condition of the old ones expecting them to be in bits, they were near perfect so i will hold on to them.

sadly the trunk/boot is not so dry so i think it must be the rear screen i might change that in the new year, in the quest to have a dry 116.

all the best

ptashek

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Re: rusty engine bay, fender mounts bonnet hinge drain hole etc
« Reply #4 on: 22 December 2018, 03:40 PM »
The trunk may be getting flooded through the gasket if not properly seated and glued in. It would happen only if you drive in rain, not when parked, as the wind pressure pushes water underneath the seal.
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w116john

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Re: rusty engine bay, fender mounts bonnet hinge drain hole etc
« Reply #5 on: 22 December 2018, 11:54 PM »
hi Lukas

i have been driving it in the rain and was pretty bad over here recently. i will investigate it further to see if it happens when parked.

all the best for Christmas and new year

john

UTn_boy

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Re: rusty engine bay, fender mounts bonnet hinge drain hole etc
« Reply #6 on: 28 December 2018, 04:49 PM »
On the chrome trim that sits atop the tail lights on each side there are rubber seals that go between the chrome trim and the car.  These are notorious for letting water in through the tail lights.....making one think that the tail light seals are bad.  Unfortunately, these seals are no longer available.  The seal that goes between the center chrome piece (that houses that trunk release button) is also bad about letting water in.  The seal for this center piece is still available, but it's around $250-$300.  :/ 

The trunk seal can let water in, but usually happens only when the trough the seal sits in is rusted badly.  The same applies for the rear glass seal in that when it leaks it'll usually only soak the parcel shelf and distort it.  Though, water can get into the trunk if enough water leaks in through the glass seal and finds its way through the holes for the speakers or first aid box, and also if the trough the glass seal sits in is rusted away underneath.  I've seen many W116 cars have horrible rust under the rear glass seal.....so much so in some cases that when the rear glass seal was removed a large portion of the car came with it. :/   The problem is that you can't see it until you remove the rear glass and it's seal. 

Glass seals, door seals, tail light seals, etc, are all service items, and have to be renewed on a regular basis.  When I say "regular basis", this could be every ten years, or every 15 years, or maybe less than every ten years.  It depends on the climate where the car is, if it's daily driven or not, and even depends on if the seals were installed correctly with the correct sealant.  Think of them like belts on the engine, or tires.  Even if they're hardly used they age and merit replacement based upon principle.  :)
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w116john

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Re: rusty engine bay, fender mounts bonnet hinge drain hole etc
« Reply #7 on: 28 December 2018, 11:13 PM »

hi

thanks for that advice, i have replaced all the door and sunroof seals and i plan on having both screens done in January, i have had leaks in both, in to the footwell and parcelshelf but i managed to stop them temporarily with some screen sealant.

the boot / trunk is more persistant the trunk seal and both light seals have been replaced. I have been suspicious of that chrome trim and i will investigate it further after the screens are done.

all the best
john


UTn_boy

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Re: rusty engine bay, fender mounts bonnet hinge drain hole etc
« Reply #8 on: 31 December 2018, 06:11 PM »
Just another little note....the glass sealant that is used for the front and rear glass seal, Mercedes part number 001-989-31-20, must be applied between the chassis and the seal, and then between the glass and the seal after the glass has been installed.  It also makes an excellent sealant for the tail lights and trim above the tail lights. 
1966 250se coupe`, black/dark green leather
1970 600 midnight blue/parchment leather
1971 300sel 6.3, papyrus white/dark red leather
1973 300sel 4.5, silver blue metallic/blue leather
1976 280s astral silver/blue MB Tex
1978 450sel 6.9 Euro, Anthr/velour

w116john

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Re: rusty engine bay, fender mounts bonnet hinge drain hole etc
« Reply #9 on: 31 December 2018, 11:29 PM »
hi

thanks for that i will tell the guys doing the screen.

i had a good look at it the other day and i could see water coming in past the light seals, so when i get the screen done i will ask the guys to do the light seals as well.

kind regards and happy new year